31 Temmuz 2007 Salı
CNC MACHİNES
The abbreviation CNC stands for computer numerical control, and refers specifically to a computer "controller" that reads G-code instructions and drives the machine tool, a powered mechanical device typically used to fabricate metal components by the selective removal of metal. CNC does numerically directed interpolation of a cutting tool in the work envelope of a machine. CNC was developed in the late 1940s and early 1950s by John T. Parsons in collaboration with the MIT Servomechanisms Laboratory. CNC was preceded by NC (Numerically Controlled) machines, which were hard wired to produce one specific part. The first CNC systems used NC style hardware, and the computer was used for the tool compensation calculations and sometimes for editing. Punched tape continued to be used as a medium for transferring G-codes into the controller for many decades after 1950, until it was eventually superseded by RS232 cables, floppy disks, and finally standard computer network cables. The files containing the G-codes to be interpreted by the controller are usually saved under the .NC extension. Most shops have their own saving format that matches their ISO certification requirements. The introduction of CNC machines radically changed the manufacturing industry. Curves are as easy to cut as straight lines, complex 3-D structures are relatively easy to produce, and the number of machining steps that required human action have been dramatically reduced. With the increased automation of manufacturing processes with CNC machining, considerable improvements in consistency and quality have been achieved. CNC automation reduced the frequency of errors and provided CNC operators with time to perform additional tasks. CNC automation also allows for more flexibility in the way parts are held in the manufacturing process and the time required to change the machine to produce different components. In a production environment, a series of CNC machines may be combined into one station, commonly called a "cell", to progressively machine a part requiring several operations. CNC machines today are controlled directly from files created by CAM software packages, so that a part or assembly can go directly from design to manufacturing without the need of producing a drafted paper drawing of the manufactured component. In a sense, the CNC machines represent a special segment of industrial robot systems, as they are programmable to perform many kinds of machining operations (within their designed physical limits, like other robotic systems). CNC machines can run over night and over weekends without operator intervention. Error detection features have been developed, giving CNC machines the ability to call the operator's mobile phone if it detects that a tool has broken. While the machine is awaiting replacement on the tool, it would run other parts it is already loaded with up to that tool and wait for the operator. The ever changing intelligence of CNC controllers has dramatically increased job shop cell production. Some machines might even make 1000 parts on a weekend with no operator, checking each part with lasers and sensors
28 Temmuz 2007 Cumartesi
How to Pick the Right Motor for Your Robot
Motors are like muscles — connect a motor with wheels to a battery and your robot scoots across the floor. Or attach a motor to a lever, and you’ve made a shoulder joint. Or attach a motor to a turntable, and your robot’s head can scan back and forth. Motors are the primary means of articulating a robot. In this month’s Robotics Resources, we’ll examine some of the more common types of motors and how they are used.
Motors for AC or DC
If you’re a scrounger, you probably have a couple of motors laying around you’d like to use in your robot. But some of these motors may be wholly unsuit¬able. Most ‘bots are powered by batter-ies, which means direct current (unless you use a power inverter, but we won’t get into that as it’s not as efficient). Direct current (DC) from batteries and power supplies dominates robotics, so these are the kinds of motors you need to look for. Shelve the alternating current (AC) motor you pulled from that old fan for another project.
DC motors may be the motors of choice. But that doesn’t mean just any DC motor should or can be used in your robot designs. When looking for suitable motors, be sure the ones you use are reversible. Few robotic applications call for just unidirectional (one direction) motors. You must be able to operate the motor in one direction, stop it, and change its direction. Most DC motors are bi-directional, but some design imitations may prevent reversibility.
How can you tell if a motor is reversible? If it doesn’t say, the best and easiest test is to try the motor with a suitable battery or DC power supply. Apply the power leads from the motor to the terminals of the battery or supply. Note the direction of rotation of the motor shaft. Now, reverse the power leads from the motor. The motor shaft should now go the other way.
Continuous Rotation, Stepper, and Brushless Motors
Among the variety of DC motors is a dizzying array of sub-types. Motors that run when you simply apply a DC voltage are continuous rotation and have the most value to robot builders. Internally, most motors of this ilk have a permanent magnet in the casing, and use a meta core that is connected to the motor’s shaft. Around this core are several sets of wires wound in a tight loop. These lead to two brushes — they can also be simple bares wires — that connect to the power source. The motor rotates when the wires (also called coils or windings) are energized. Continuous rotation is made possible due to the geometry of the windings around the core.
Variations on this theme may place the magnet in the core and the wind¬ings around the casing. There are many other designs, and the Internet — as well as any good book on motor design — is full of pictorial discussions of how DC motors operate. There’s no need for me to cover the other approaches here.
Stepper motors are similar to stan-dard DC motors except they are con-structed in such a way that they turn only a degree or so when DC power is applied to a winding. To make the motor turn more, you need to manual¬ly energize the windings in a specific sequence. To enable this, stepper motors have more than two wires; most steppers have between four and eight wires. The number of wires indicates the type of stepper (bipolar or unipolar) and the way the windings are connected internally within the motor.
At one time this was done using mechanical relays, but these days it all happens using electronics. You can build a stepper motor controller circuit out of discrete logic parts, buy a spe-cialized stepper motor chip such as the L297, or program a microcontroller to apply the right pulses to the windings.
Stepper motors are handy when you want to control the angle of move-ment and amount of rotation. You can use stepper motors (like those pulled from old disk drives) in lieu of a stan-dard DC motor, but a more common use is for things like rotating sensor turrets, grippers, or arm mechanisms.
Yet another type of DC motor is the brushless motor. These most often use optics, hall effect sensors, or other technology to switch power to the windings inside the motor. Brushless motors are common when speed control is required, such as the spindle motor of a CD player. They require a controller circuit that senses the precise position of the core at any given time so that the correct windings may be energized. For the most part, brushless DC motors aren’t as useful in amateur robotics, due in part to their complexi¬ty, and also they don’t tend to be as powerful as their continuous rotation and stepper cousins.
R/C Servo Motors
When a motor is connected to a feedback circuit, it’s called a servo motor. The feedback tells the motor how far it’s gone and in what direction. This feedback can be accomplished using a simple potentiometer, a tachometer, an optical encoder, or some other means.
The most common — and inexpen¬sive — servo motor is the R/C servo; R/C stands for radio control, which is the original application of these motors. They are used in model and hobby radio-controlled cars and planes.
R/C servos are in plentiful supply, and cost is reasonable (about $10-$12 for basic units). Though R/C servos are continuous DC motors at heart, they aren’t controlled in the same way. In addition to power leads, you need to provide a control signal to an R/C servo. This signal — varying from one to two milliseconds — controls the direction and angle of the motor. Most robots based on R/C servos use a microcon¬troller to provide this signal. Most any microcontroller is capable of creating the signal and the programming code is simple. Use of R/C servos in robots is so common now that the programming anguage for some microcontrollers ncorporate commands specific to operating the motor. This is the case of the OOPic controller, for example.
There are other forms of servo motors and these are different from the R/C type. If you’re browsing sur¬plus catalogs, you may encounter some large and unreasonably expensive servo motors. They’re a distinct breed from the less expensive R/C type, and are intended for process control, such as factory automation. The typical industrial servo motor is not a complete unit — you cannot simply wire it to a battery and make it work. At a minimum, it needs a control circuit, if not additional components.
While the R/C servo is intended to precisely control angular movement, it’s also possible to retrofit them for continuous rotation. In fact, this is one of the most popular methods of motor-izing a robot. The modification involves partial disassembly of the motor so that the mechanical stops — the things that prevent the motor from turning a full 360 degrees — are removed. In addition, the feedback potentiometer is disengaged and set to its center. In this way, the control signal operates the direction and to some degree the speed of the motor.
Motor Specifications
Motors carry with them numerous specifications. The meaning and purpose of some of the specifications are obvious; others aren’t. Here is a broad and brief overview of some of the more common specifications:
• Operating Voltage All motors are rated by their operating voltage. With small DC hobby motors, the rating is actually a range, usually 1.5 to 12 volts. DC motors for automation usually require 24 to 48 volts. The kinds of motors of most interest to robot builders are the low-voltage variety — those that operate at 1.5 to 12 volts. Most motors can be operated satisfactorily at voltages somewhat higher or lower than that specified. For continuous DC motors, changing the voltage alters the rotation speed.
• Current Draw. This specifies the current, in milliamps or amps, that the motor pulls from the power supply at a given voltage and a given load (motors are designed to perform some work; this is their “load”). Be sure to compare apples to apples. The current draw of a free-running (no load) motor can be quite low, but under load the motor may draw five, 10, even 50 times the current.
• Speed. The rotational speed of a motor is usually given in revolutions per minute (RPM), with most continuous DC motors rotating at between 4,000 to 12,000 RPM. Stepper motors are rated by their maximum steps per second which, when combined with their step angle, can be used to determine revolu¬tions per second or minute. R/C servo motors are rated by their transit time, usually in fractions of a second to cover a 60 degree arc. Except for stepper motors, speed is influenced by voltage.
• Torque. The torque of a motor is the force it exerts upon its load. The higher the torque, the larger the load can be, and the faster the motor will spin under that load. Reduce the torque and the motor slows down, straining under the workload. Torque specifications vary wildly; some are given in old Imperial units of ounce-inches or foot-pounds, while others are force newton-meters or some other standards. When comparing torque specifications that don’t use the same units of measure, you can use an online conversion page, such as at
www.convert-me.com
Motors With and Without Gears
R/C servo motors already incorporate their own internal gearing. The gears reduce the speed of the motor used inside the servo from its usual 7,000 to 10,000 revolutions per minute to roughly 60 RPM. In reducing the speed, the torque of the motor is proportionally increased.
For most robots, the raw speed of a DC motor is far too high, so you usually want some kind of gear reduction. You can create your own gearbox using gears from various sources (bought new or surplus, or pulled out of toys and discarded appliances). But tolerances are tight with gears. Too loose and the gears don’t mesh properly; too tight and the gears bind up, adding a lot of friction.
While you can sometimes add a gearbox to an existing motor, it’s usual-ly easier to simply get a motor with a gearbox already attached. You can find plenty of gear motors on the surplus market of various sizes and styles. Another good source is the Tamiya gear motor kits, available through several online resources such as Pololu (or Tower Hobbies (You build the motor from parts, and most let you select the gear ratio you want.
Adapting a Motor for Your Robot
Simply having a motor and a robot doesn’t mean the two will be happy together. Some types of motors defy being attached to a robot — there are no mounting flanges or screw holes anywhere. The more adaptable motors have at least two holes for securing the thing to a robot.
Sometimes these holes are in the face of the motor (the part where the shaft sticks out). These require screws of a particular length. Some motors use metric threads (example: M3) and others use Imperial threads (example: 4-40). Be sure to use the right type of screws or you’ll mess up the threads in the motor.
Yet other motors have flanges that make mounting easier. This is the case with many stepper motors, which often have a flanged mounting plate with two or four holes. It’s also the case with R/C servos, which are flanged and have two or four eyelets for screws. With some ingenuity and commercially sold brackets (such as those from my small online company, Budget Robotics at you can fit an R/C servo motor just about anywhere. As a last resort, you can always use double-sided foam tape, Velcro, or 3M Dual Lock to secure the motor to your robot.
Next comes attaching a wheel, lever, or other mechanism to the motor shaft, and this is where things often get tricky. I like using R/C motors specifical¬ly because they make it very easy to attach just about anything, including wheels. R/C motors come with an assortment of “horns” — or extras are available for it — in a variety of shapes and sizes. You can drill into the horn so you can adapt it to your particular needs. The horn then securely screws into the output shaft of the motor.
For continuous DC and stepper motors, you need a way to mount something to the shaft. Motor shafts comes in all sizes, lengths, and dimen-sions. Most are made of a hardened metal, so drilling into them is a tough proposition. The most effective designs use setscrews. An example is a setscrew that is part of the hub of a gear. You tighten the setscrew to secure the gear to the shaft.
The diameter of the shaft matters. The hole that fits around it — be it the bore of a wheel or the hub of a gear or sprocket — should be about the same size. If the hole is a little too small, you can usually make things work by drilling it out a little.
Motors for AC or DC
If you’re a scrounger, you probably have a couple of motors laying around you’d like to use in your robot. But some of these motors may be wholly unsuit¬able. Most ‘bots are powered by batter-ies, which means direct current (unless you use a power inverter, but we won’t get into that as it’s not as efficient). Direct current (DC) from batteries and power supplies dominates robotics, so these are the kinds of motors you need to look for. Shelve the alternating current (AC) motor you pulled from that old fan for another project.
DC motors may be the motors of choice. But that doesn’t mean just any DC motor should or can be used in your robot designs. When looking for suitable motors, be sure the ones you use are reversible. Few robotic applications call for just unidirectional (one direction) motors. You must be able to operate the motor in one direction, stop it, and change its direction. Most DC motors are bi-directional, but some design imitations may prevent reversibility.
How can you tell if a motor is reversible? If it doesn’t say, the best and easiest test is to try the motor with a suitable battery or DC power supply. Apply the power leads from the motor to the terminals of the battery or supply. Note the direction of rotation of the motor shaft. Now, reverse the power leads from the motor. The motor shaft should now go the other way.
Continuous Rotation, Stepper, and Brushless Motors
Among the variety of DC motors is a dizzying array of sub-types. Motors that run when you simply apply a DC voltage are continuous rotation and have the most value to robot builders. Internally, most motors of this ilk have a permanent magnet in the casing, and use a meta core that is connected to the motor’s shaft. Around this core are several sets of wires wound in a tight loop. These lead to two brushes — they can also be simple bares wires — that connect to the power source. The motor rotates when the wires (also called coils or windings) are energized. Continuous rotation is made possible due to the geometry of the windings around the core.
Variations on this theme may place the magnet in the core and the wind¬ings around the casing. There are many other designs, and the Internet — as well as any good book on motor design — is full of pictorial discussions of how DC motors operate. There’s no need for me to cover the other approaches here.
Stepper motors are similar to stan-dard DC motors except they are con-structed in such a way that they turn only a degree or so when DC power is applied to a winding. To make the motor turn more, you need to manual¬ly energize the windings in a specific sequence. To enable this, stepper motors have more than two wires; most steppers have between four and eight wires. The number of wires indicates the type of stepper (bipolar or unipolar) and the way the windings are connected internally within the motor.
At one time this was done using mechanical relays, but these days it all happens using electronics. You can build a stepper motor controller circuit out of discrete logic parts, buy a spe-cialized stepper motor chip such as the L297, or program a microcontroller to apply the right pulses to the windings.
Stepper motors are handy when you want to control the angle of move-ment and amount of rotation. You can use stepper motors (like those pulled from old disk drives) in lieu of a stan-dard DC motor, but a more common use is for things like rotating sensor turrets, grippers, or arm mechanisms.
Yet another type of DC motor is the brushless motor. These most often use optics, hall effect sensors, or other technology to switch power to the windings inside the motor. Brushless motors are common when speed control is required, such as the spindle motor of a CD player. They require a controller circuit that senses the precise position of the core at any given time so that the correct windings may be energized. For the most part, brushless DC motors aren’t as useful in amateur robotics, due in part to their complexi¬ty, and also they don’t tend to be as powerful as their continuous rotation and stepper cousins.
R/C Servo Motors
When a motor is connected to a feedback circuit, it’s called a servo motor. The feedback tells the motor how far it’s gone and in what direction. This feedback can be accomplished using a simple potentiometer, a tachometer, an optical encoder, or some other means.
The most common — and inexpen¬sive — servo motor is the R/C servo; R/C stands for radio control, which is the original application of these motors. They are used in model and hobby radio-controlled cars and planes.
R/C servos are in plentiful supply, and cost is reasonable (about $10-$12 for basic units). Though R/C servos are continuous DC motors at heart, they aren’t controlled in the same way. In addition to power leads, you need to provide a control signal to an R/C servo. This signal — varying from one to two milliseconds — controls the direction and angle of the motor. Most robots based on R/C servos use a microcon¬troller to provide this signal. Most any microcontroller is capable of creating the signal and the programming code is simple. Use of R/C servos in robots is so common now that the programming anguage for some microcontrollers ncorporate commands specific to operating the motor. This is the case of the OOPic controller, for example.
There are other forms of servo motors and these are different from the R/C type. If you’re browsing sur¬plus catalogs, you may encounter some large and unreasonably expensive servo motors. They’re a distinct breed from the less expensive R/C type, and are intended for process control, such as factory automation. The typical industrial servo motor is not a complete unit — you cannot simply wire it to a battery and make it work. At a minimum, it needs a control circuit, if not additional components.
While the R/C servo is intended to precisely control angular movement, it’s also possible to retrofit them for continuous rotation. In fact, this is one of the most popular methods of motor-izing a robot. The modification involves partial disassembly of the motor so that the mechanical stops — the things that prevent the motor from turning a full 360 degrees — are removed. In addition, the feedback potentiometer is disengaged and set to its center. In this way, the control signal operates the direction and to some degree the speed of the motor.
Motor Specifications
Motors carry with them numerous specifications. The meaning and purpose of some of the specifications are obvious; others aren’t. Here is a broad and brief overview of some of the more common specifications:
• Operating Voltage All motors are rated by their operating voltage. With small DC hobby motors, the rating is actually a range, usually 1.5 to 12 volts. DC motors for automation usually require 24 to 48 volts. The kinds of motors of most interest to robot builders are the low-voltage variety — those that operate at 1.5 to 12 volts. Most motors can be operated satisfactorily at voltages somewhat higher or lower than that specified. For continuous DC motors, changing the voltage alters the rotation speed.
• Current Draw. This specifies the current, in milliamps or amps, that the motor pulls from the power supply at a given voltage and a given load (motors are designed to perform some work; this is their “load”). Be sure to compare apples to apples. The current draw of a free-running (no load) motor can be quite low, but under load the motor may draw five, 10, even 50 times the current.
• Speed. The rotational speed of a motor is usually given in revolutions per minute (RPM), with most continuous DC motors rotating at between 4,000 to 12,000 RPM. Stepper motors are rated by their maximum steps per second which, when combined with their step angle, can be used to determine revolu¬tions per second or minute. R/C servo motors are rated by their transit time, usually in fractions of a second to cover a 60 degree arc. Except for stepper motors, speed is influenced by voltage.
• Torque. The torque of a motor is the force it exerts upon its load. The higher the torque, the larger the load can be, and the faster the motor will spin under that load. Reduce the torque and the motor slows down, straining under the workload. Torque specifications vary wildly; some are given in old Imperial units of ounce-inches or foot-pounds, while others are force newton-meters or some other standards. When comparing torque specifications that don’t use the same units of measure, you can use an online conversion page, such as at
www.convert-me.com
Motors With and Without Gears
R/C servo motors already incorporate their own internal gearing. The gears reduce the speed of the motor used inside the servo from its usual 7,000 to 10,000 revolutions per minute to roughly 60 RPM. In reducing the speed, the torque of the motor is proportionally increased.
For most robots, the raw speed of a DC motor is far too high, so you usually want some kind of gear reduction. You can create your own gearbox using gears from various sources (bought new or surplus, or pulled out of toys and discarded appliances). But tolerances are tight with gears. Too loose and the gears don’t mesh properly; too tight and the gears bind up, adding a lot of friction.
While you can sometimes add a gearbox to an existing motor, it’s usual-ly easier to simply get a motor with a gearbox already attached. You can find plenty of gear motors on the surplus market of various sizes and styles. Another good source is the Tamiya gear motor kits, available through several online resources such as Pololu (or Tower Hobbies (You build the motor from parts, and most let you select the gear ratio you want.
Adapting a Motor for Your Robot
Simply having a motor and a robot doesn’t mean the two will be happy together. Some types of motors defy being attached to a robot — there are no mounting flanges or screw holes anywhere. The more adaptable motors have at least two holes for securing the thing to a robot.
Sometimes these holes are in the face of the motor (the part where the shaft sticks out). These require screws of a particular length. Some motors use metric threads (example: M3) and others use Imperial threads (example: 4-40). Be sure to use the right type of screws or you’ll mess up the threads in the motor.
Yet other motors have flanges that make mounting easier. This is the case with many stepper motors, which often have a flanged mounting plate with two or four holes. It’s also the case with R/C servos, which are flanged and have two or four eyelets for screws. With some ingenuity and commercially sold brackets (such as those from my small online company, Budget Robotics at you can fit an R/C servo motor just about anywhere. As a last resort, you can always use double-sided foam tape, Velcro, or 3M Dual Lock to secure the motor to your robot.
Next comes attaching a wheel, lever, or other mechanism to the motor shaft, and this is where things often get tricky. I like using R/C motors specifical¬ly because they make it very easy to attach just about anything, including wheels. R/C motors come with an assortment of “horns” — or extras are available for it — in a variety of shapes and sizes. You can drill into the horn so you can adapt it to your particular needs. The horn then securely screws into the output shaft of the motor.
For continuous DC and stepper motors, you need a way to mount something to the shaft. Motor shafts comes in all sizes, lengths, and dimen-sions. Most are made of a hardened metal, so drilling into them is a tough proposition. The most effective designs use setscrews. An example is a setscrew that is part of the hub of a gear. You tighten the setscrew to secure the gear to the shaft.
The diameter of the shaft matters. The hole that fits around it — be it the bore of a wheel or the hub of a gear or sprocket — should be about the same size. If the hole is a little too small, you can usually make things work by drilling it out a little.
27 Temmuz 2007 Cuma
ROBYTES
Digging in the dirt may not be a particularly piquant robotic function, but it helps when you’re doing it on Mars. At present, NASA’s Phoenix Mars Lander is scheduled to head that direction — weather permitting — on August 3rd. Phoenix is the first mission of NASA’s Mars Scout Program
competitively proposed, relatively cheap missions to the red planet.
Selected in 2003, Phoenix saves money by using a lander structure and other components originally built for a cancelled 2001 mission. The robotic arm will scrape into the icy soil on a Martian arctic plain next spring, collecting samples and bringing them back onto the Phoenix’s science deck where it will be analyzed in terms of aquatic history and possible complex organic materials.
Artificial Snot Enhances Sensors
Leave it to the people who invented black pudding, the Bowler hat, and imperial measurements to keep coming up with strange concepts. One of the latest is “artificial snot,” which researchers at the University of Warwick and the University of Leicester have devised to enhance the performance of electronic noses, which are commonly used in robotics and other applications ranging from food quality control to toxic substance sensing.
It seems that the human nose incorporates more than 100 million receptors that work togeth¬er in very complex ways to identify the molecules they encounter. However, electronic noses often have fewer than 50 sensors, so they discern a much narrower range of smells. One of the ways a
natural nose accomplishes its mission is to dissolve the scents in mucus, allowing them to arrive at receptors at different speeds, and our brain somehow uses this information to sharpen the smelling operation. Mimicking this process, the Warwick and Leicester team placed a 10 micron thick layer of polymer, normally used to separate gases, over the sensors in their electronic nose. Apparently, the device can now make heretofore impossible distinctions, such as between milk and a banana. The improved device, includ¬ng the sensors and mucus, can be produced for less than $10, so keep it in mind for your next project. Details are available in the Proceedings of the Roya Society)
High-Torque, Thin-Package Motor
Also on the component level is an improved planetary gear train pancake motor from Haydon Switch & Instrument (www.hsi-inc.com). By using a gear train located inside the motor, Haydon has devised a product with a package that is only 18.5 mm thick and 80 mm in diameter. Nevertheless, it provides up to 120 oz-in (85 N-cm) of torque and is available with a 3.75° step angle and a the hospital rather than the clink, having developed hypothermia from the 1°C (34°F) temperature. When asked why he took off his clothes, the suspect reportedly just said, “Leave me alone. I’m not feeling well.”enough for nearly anyone to build from off-the-shelf parts and (b) sophisticated enough to perform useful operations under wireless Internet control. The dea has manifested itself in the form of the Telepresence Robot Kit (TeRK), which is actually a set of “recipes” that one can follow to create a wide range of customized bots. They can take many forms, from a mobile model equipped with a digital camera to a flower loaded with infrared sensors (see photo). All TeRKs are based on the same controller, called Qwerk, which combines a com¬puter with the various software and hardware components of the assembly. Although the TeRK goal is to make available highly capable robots that are affordable for students and anyone else nterested in robotics, the website says that a robotic flower will cost you about $750 to build, which is more than I paid for my last car, so be advised that “afford¬able” is a somewhat subjective concept. Recipes, software, technical support, and other information are available free at the TeRK website The Qwerk controller is available for sale from Charmed Labs . SV
26 Temmuz 2007 Perşembe
robot
What is robot?
Human shape dolls have been found in classical clock in Europe and Karakuri in Japan. We found such dolls in the story of Pinocchio. The word ``Robot” came from Czech‘ｓ1920 Play ``Rossum’s Universal Robot” by Karl Capeck, where robotas, robot in Czech, meaning mechanical slaves developed by Rossum revolved against humans.
The stories about robots are found in Issac Asimov science fiction to Osamu Tezuka’s long story manga ``Astro-Boy”. They are mechanical men look like and work for humans. Especially in the science fiction of Issac Asimov(1920-92) ``I, Robot” three Laws of Robotics impressed the audience. The three laws are
A robot may not injure a human being, or through inaction, allow a human being to come to harm
A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.
In spite the fact that the science fictions and animated comics have given vivid image of the robots and cyborgs, the robots found in the real life are placed in the factories and they are just arms with end effecter doing repeated simple tasks of moving, assembling, palletizing, painting, cutting and welding. Such robots are said industrial robots. In 1996, Honda Motor Co. announced the first humanoid robot P2 which could autonomously walk with biped, which bought the shock to scientists and engineers who had done researches on walking robot, since Honda had kept the project secret since 1986 from its start. In 1997 the more advanced P3 appeared and in November 2000, the popular Asimo appeared and humanoid researches have been progressed in Japan. Nearly the same time, Sony Co. announced its small autonomous biped robot SDR-3X which uses the similar software architecture with entertaining robot dog AIBO, which is a new robot product to entertain human. When AIBO was sold firstly through the network, it was said that 3,000 units were sold in twenty minutes.
Robot
What is robot?
Human shape dolls have been found in classical clock in Europe and Karakuri in Japan. We found such dolls in the story of Pinocchio. The word ``Robot” came from Czech‘ｓ1920 Play ``Rossum’s Universal Robot” by Karl Capeck, where robotas, robot in Czech, meaning mechanical slaves developed by Rossum revolved against humans.
The stories about robots are found in Issac Asimov science fiction to Osamu Tezuka’s long story manga ``Astro-Boy”. They are mechanical men look like and work for humans. Especially in the science fiction of Issac Asimov(1920-92) ``I, Robot” three Laws of Robotics impressed the audience. The three laws are
A robot may not injure a human being, or through inaction, allow a human being to come to harm
A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.
In spite the fact that the science fictions and animated comics have given vivid image of the robots and cyborgs, the robots found in the real life are placed in the factories and they are just arms with end effecter doing repeated simple tasks of moving, assembling, palletizing, painting, cutting and welding. Such robots are said industrial robots. In 1996, Honda Motor Co. announced the first humanoid robot P2 which could autonomously walk with biped, which bought the shock to scientists and engineers who had done researches on walking robot, since Honda had kept the project secret since 1986 from its start. In 1997 the more advanced P3 appeared and in November 2000, the popular Asimo appeared and humanoid researches have been progressed in Japan. Nearly the same time, Sony Co. announced its small autonomous biped robot SDR-3X which uses the similar software architecture with entertaining robot dog AIBO, which is a new robot product to entertain human. When AIBO was sold firstly through the network, it was said that 3,000 units were sold in twenty minutes.
Industrial Robot
The robots found in the factory floors are consisting of arms and the end effecter and doing simple motion like pick and place following the program mainly used for manufacturing are said industrial robots. Industrial robot is more precisely described by the Robot Institute of America as
A robot is a reprogrammable multifunctional manipulator designed to move material, parts, tools, or specialized devices, through variable programmed motions for the performance of a variety of tasks. So the robot is used for a general purpose by changing the program.
The industrial robot of the arm shape is designed to achieve general purpose tasks by using appropriate end effecter which is the mechanical instrument to affect the work such as a gripper, spray, welding device and so on. The first industrial robot was built in 1961 by Unimation, Danbury, Connecticut started by J. Engelberger.
Either industrial robot or humanoid robot, they are constructed by the mechanical link structures and joints controlled using sensors and controllers implemented by computers. Robotics is the discipline of the robot, and autonomous vehicles, tele-manipulating mechanism and many other automated machines working for human are considered robots. Robotics is the interdisciplinary subject consisting of the following sciences and engineering disciplines:
Mechanism; How to design mechanical structures:
Control; Driving actuators to drive joints achieve the tasks following the paths determined based on the sensed information and/or planned motion:
Information processing; Software construction of the procedure based on the artificial intelligence to achieve the given tasks by integrating the processing of the sensed information and adapting to the environmental situation.
Applications; Tasks robotics depend on application fields such as industries, space, medical surgery tele-operation:
Mechanism
The basic robot mechanical structures said arms are links and joints. The rotational type joint is said articulate joint and sliding type joint is said prismatic. The revolved joint is usually driven by the motor. The end of the arm is said the wrist or hand and the hand is equipped to the end effecter.
To move the hand to the appropriate position with appropriate orientation, the arm should be moved by controlling the joints. The position in the open space is specified by the x, y, z coordinates and specified by the three degrees of freedom. The orientation of the hand is specified by the roll, pitch, and yaw. So the robot needs six degrees of freedom to move to the given position and orientation. For the given joint angels the tip position and orientation are uniquely determined which is said the forward kinematics. The motion of the usual industrial robot is commanded by the position and orientation, and all joint angles should be controlled to follow the command which should solve the inverse kinematics problem of determining angles of the joint for the given position and orientation.
To place thing at an arbitrary position with specified orientation in the space, six degrees of freedoms are realized by the six joints. Position in the space is specified by the vector in the three dimensional coordinate space, and the orientation is given by the roll, pitch and yaw. So to place a thing at an arbitrary position, six degrees of freedom are required. One degree of freedom is brought by a joint with a link. There are two kinds of joint. One is revolving and the other is sliding. The number of joints required to place a thing at a given position and orientation in the space is at least six. If the manipulator has more than six joints, there exist several postures of links to place a thing at a given position and attitude in the space. This manipulator is said a redundant manipulator. The joint is driven by a electric motor. All joint angles are specified, the position and orientation of the tip of the manipulator is uniquely specified. When the position and orientation of the manipulator tip is given, the problem of determining joint angles is difficult problem and is said ``inverse kinematics problem”. The problem is known to be treated by Homogenous transformation. The first systematic treatment of the problem is found in the book written by R.P. Paul.
Dynamics and control
The mechanical systems working for the human muscle power was said the Servo-control, which came from the word meaning service.
The fly ball governor installed by James Watt in his steam engine in 1788 for keeping rotational speed of engine constant is said the origin of the control, and the foundation of the control theory was born aiming to solve the stability of this closed loop system by J.C. Maxwell of UK and J.Wischnegradski of Russia. The control has been used in all fields since then such as in ships, airplane and chemical processes. The servo-mechanism had been used in assisting the steering of the ship rudder. Elmer and Lawrence Sperry used the gyroscope to control the attitude of the airplane and demonstrated their autostabiliser in 1914 in Paris. The fire control in the combination of radar had been developed during World War II in Radiation Laboratory. After the war, the project to develop the training simulator for pilots started at MIT under the direction of J. Forrester. The project had brought the digital computer ``Whirlwind”. The digital computer later had brought the digital control.
The problem of the robot control is how to control the joint angles to have the robot move to the given position and orientation. By the inverse kinematics for the desired position and orientation, the angles are determined. To control the joint angles to be desired ones, the motors at the joint should be controlled to generate the necessary torque to drive joints. The dynamics between the input torque and the joint angles are depending on the attitude of the robot, which are described by the nonlinear differential equations. The development of small computers has made possible to integrate the above three technical ingredients into making robot working for human. The robot appeared was doing simple motion like pick and place following the program mainly used for manufacturing. The conventional industrial robot control the input torque based on PID logic of the error between the joint angles and the reference angles. This control law however is not able to apply to the manipulator in the space shuttle since the robot dynamics is heavily nonlinear. When the reference joint angles are given, the necessary input torque can be determined. This procedure is said the inverse dynamics. This is equivalent to the nonlinear feedback compensation to make the closed loop of the robot be linear. Such control law has made possible to develop the advanced robot.
Intelligent Robot
When the computer and sensors are used, the intelligent robot comes to be used. The definition of the intelligence is said the ability to adapt to the varying environment by C. Evans in his book ``Mighty Micros”. To have the ability to adapt to the environment, it is necessary to have the following functions:
1, Information and data acquisition using sensors and through communication
2, Data storage in the data base
3, Logics to structure and use the data
4, Interaction with the environment
The intelligent robot has the function to adapt to the environment by using sensors information, so the robot can pick up the randomly distributed work pieces, which is said bin picking. Under the structure of intelligent control, many kinds of control realizing robot dexterity have been developed such as the force control, coordination control of multi-arms. The sensed data are feed into the computer for storing in the database. The data are structured to form the knowledge and learning ability will be considered.
The techniques of robot control are now to aim to make the robot mimic the animals. One of the famous such robots are snake robot developed by S.Hirose.
Hirose Anaconda
The new Toyota Hybrid automobile has the function to park autonomously in line, which seems to be controlled by robot. Robot arm has equipped actuators at joints, but recently the robot with un-actuated joints called under actuated robot has been developed. One of such robot is the rotating type pendulum called Furuta Pendulum.
Furuta Pendulum
Future
Looking at the history of the robot, as above-mentioned, the robot was first invented as a word used in a play. The robot was described as a machine that will do various tasks in lie of human workers in the factory. In the technology, the robot was also developed as a machine that would do various tasks in lieu of human workers. In 1950s, a robotic system that was called as a manipulator was developed to remotely handle radioactive materials in nuclear power plants. It was a machine that could do a dangerous task in lieu of human workers. It was a machine used to release humans from hazardous and dirty works. Currently, there are many robots that are used in hazardous environment, like for plant maintenance in deep undersea, high voltage power live-line maintenance, exploring space and/or planet as well as nuclear power maintenance.
Fig. 1 shows an example of a live-line maintenance robot developing by YASKAWA Electric Corp. This shows a robot that is renewing a worn insulator on a utility pole, this is a typical task required for the live-line maintenance. In order to maintain continuous energy supply it must be done without the power shutdown. It is very dangerous work for human to do it. Currently, the robot is being verified by skilled human workers to release humans from such dangerous works in the actual work field.
The manufacturing factory is the other typical place where a lot of robots are employed. Many industrial robots are working especially at the manufacturing factories for automobile industry, home electronic product industries and so on. In such a factory, there are many repeated and simple tasks that are tedious if human workers will do it. In order to release humans from such tasks, the robot is efficiently employed as a human substitution machine.
An important robot application in future will be the one for supporting humans in their daily life. In several countries in the world, a problem in the 21st century is the increase of elderly people population and decrease of labor power enough to keep industrial and social activities high quality. For example, in Japan, there is a prediction in which the rate of elderly people (older than 65) population in the total population will reach to 25% in 2020. It means one of 4 persons will be more than 65 years old. In such a society, it will be supposed that the number of people who need some kinds of assistance in several situations of their daily life will increase. Because of those problems in future society, since the beginning of 1990s, the robot which can work together with human and/or support human in human environment has drawn robotics researcher’s attention and several contributions have been made in this research area. Such a new area in robotics is called as “Human Friendly Robotics”.
There are several kinds of human friendly robots which support humans, that is, rehabilitation robots, house care robot, information service robot, entertainment robot, and so on.
Fig. 2 shows a robot that helps quadriplegics when he/she has a meal by himself, “My Spoon” developed by SECOM Co., Ltd. It can bring the foods on the table to his/her mouse using a robotic arm according to the command produced by him/her.
Fig. 3 shows a robot that looks after the house in another’s absence, a home security robot, “Banryu” developed by tmsuk Co., Ltd. and SANYO DENKI Co., Ltd. It has a legged mobile robot with obstacle avoidance and a TV camera to monitor the house connected to cellular phone. When the house owner is absent, the robot looks around inside the house and sends the monitored image of the house to the owner. Also, it can provide various security services using several sensory functions installed in the body
In robotics, traditionally the robot “motions” have been used to do some kinds of physical tasks. However, when a robot will exist with human in the same environment and the human can directly see and touch the robot, the human may feel something from the motions of the robot and touching the robot. Using such an emotional effect the human will have from the robot, new several applications of human friendly robot have been proposed for entertainment, mental health care applications and so on. One of the famous examples of such a robot is AIBO developed by Sony Corp.. AIBO is a four-legged robot with vision sensors, auditory sensors and so on. It can do various actions using actuators, responding to the inputs to those sensors. It has also several kinds of intelligence to recognize objects, to understand human voice commands for human-robot communication, and also to express emotion via the behaviors. With those functions, human can play with the robot and feel happiness via communication with it. It is an efficient mental support device for people who are living alone and feel the loneliness hard in their everyday life.
Fig. 4 shows the other example of the mental commit robot, which is called as “PARO” developed by AIST, Japan. It has a seal shape robot with flexible tactile sensors on the surface, auditory sensors in the head that can detect human voice and proximity sensors in the face that can detect an approaching object. Also this robot has an emotional behavior generator that is driven by the inputs to the sensors installed in the robot. With those functions, human can enjoy several behaviors of the robot via physically interacting with the robot. Though it can be used as a robot for entertainment for the people who are living alone like AIBO, currently, it is considered to apply it to mental therapy.
When the robot lives together with human, humanoid, a robot that has a human shape, will be more suitable rather than other shape robot. Since middle of 1990s, humanoid technology has made remarkable advancements. Currently, there are several practical humanoid developed by several universities, institutions and industries.
Fig. 5 is an example of humanoid developed by AIST, Japan and Kawada Industries, Inc.
The “human shape” has a possibility of producing several attractive features in human-robot communication. For example, even when a humanoid will do a simple repetitive task that a conventional industrial robot also can do, people who will see it will have more attractive impression from the humanoid than from the conventional industrial robot. Because of those effects, humanoid can be considered to be an effective human interface device and several application ideas have been investigated, an example of those applications will be an entertainment robot, Qrio Sony Corporation has developed. It is a machine that can communicate with human and shows an attractive behavior to human, like dancing and so on. Even for robot applications to support human physically, because of the emotional function, humanoid technology will also be important.
In future, more number of robots and more kinds of robot will be used in our society and they will play an important role to improve the quality of our life.
Human shape dolls have been found in classical clock in Europe and Karakuri in Japan. We found such dolls in the story of Pinocchio. The word ``Robot” came from Czech‘ｓ1920 Play ``Rossum’s Universal Robot” by Karl Capeck, where robotas, robot in Czech, meaning mechanical slaves developed by Rossum revolved against humans.
The stories about robots are found in Issac Asimov science fiction to Osamu Tezuka’s long story manga ``Astro-Boy”. They are mechanical men look like and work for humans. Especially in the science fiction of Issac Asimov(1920-92) ``I, Robot” three Laws of Robotics impressed the audience. The three laws are
A robot may not injure a human being, or through inaction, allow a human being to come to harm
A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.
In spite the fact that the science fictions and animated comics have given vivid image of the robots and cyborgs, the robots found in the real life are placed in the factories and they are just arms with end effecter doing repeated simple tasks of moving, assembling, palletizing, painting, cutting and welding. Such robots are said industrial robots. In 1996, Honda Motor Co. announced the first humanoid robot P2 which could autonomously walk with biped, which bought the shock to scientists and engineers who had done researches on walking robot, since Honda had kept the project secret since 1986 from its start. In 1997 the more advanced P3 appeared and in November 2000, the popular Asimo appeared and humanoid researches have been progressed in Japan. Nearly the same time, Sony Co. announced its small autonomous biped robot SDR-3X which uses the similar software architecture with entertaining robot dog AIBO, which is a new robot product to entertain human. When AIBO was sold firstly through the network, it was said that 3,000 units were sold in twenty minutes.
Robot
What is robot?
Human shape dolls have been found in classical clock in Europe and Karakuri in Japan. We found such dolls in the story of Pinocchio. The word ``Robot” came from Czech‘ｓ1920 Play ``Rossum’s Universal Robot” by Karl Capeck, where robotas, robot in Czech, meaning mechanical slaves developed by Rossum revolved against humans.
The stories about robots are found in Issac Asimov science fiction to Osamu Tezuka’s long story manga ``Astro-Boy”. They are mechanical men look like and work for humans. Especially in the science fiction of Issac Asimov(1920-92) ``I, Robot” three Laws of Robotics impressed the audience. The three laws are
A robot may not injure a human being, or through inaction, allow a human being to come to harm
A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.
In spite the fact that the science fictions and animated comics have given vivid image of the robots and cyborgs, the robots found in the real life are placed in the factories and they are just arms with end effecter doing repeated simple tasks of moving, assembling, palletizing, painting, cutting and welding. Such robots are said industrial robots. In 1996, Honda Motor Co. announced the first humanoid robot P2 which could autonomously walk with biped, which bought the shock to scientists and engineers who had done researches on walking robot, since Honda had kept the project secret since 1986 from its start. In 1997 the more advanced P3 appeared and in November 2000, the popular Asimo appeared and humanoid researches have been progressed in Japan. Nearly the same time, Sony Co. announced its small autonomous biped robot SDR-3X which uses the similar software architecture with entertaining robot dog AIBO, which is a new robot product to entertain human. When AIBO was sold firstly through the network, it was said that 3,000 units were sold in twenty minutes.
Industrial Robot
The robots found in the factory floors are consisting of arms and the end effecter and doing simple motion like pick and place following the program mainly used for manufacturing are said industrial robots. Industrial robot is more precisely described by the Robot Institute of America as
A robot is a reprogrammable multifunctional manipulator designed to move material, parts, tools, or specialized devices, through variable programmed motions for the performance of a variety of tasks. So the robot is used for a general purpose by changing the program.
The industrial robot of the arm shape is designed to achieve general purpose tasks by using appropriate end effecter which is the mechanical instrument to affect the work such as a gripper, spray, welding device and so on. The first industrial robot was built in 1961 by Unimation, Danbury, Connecticut started by J. Engelberger.
Either industrial robot or humanoid robot, they are constructed by the mechanical link structures and joints controlled using sensors and controllers implemented by computers. Robotics is the discipline of the robot, and autonomous vehicles, tele-manipulating mechanism and many other automated machines working for human are considered robots. Robotics is the interdisciplinary subject consisting of the following sciences and engineering disciplines:
Mechanism; How to design mechanical structures:
Control; Driving actuators to drive joints achieve the tasks following the paths determined based on the sensed information and/or planned motion:
Information processing; Software construction of the procedure based on the artificial intelligence to achieve the given tasks by integrating the processing of the sensed information and adapting to the environmental situation.
Applications; Tasks robotics depend on application fields such as industries, space, medical surgery tele-operation:
Mechanism
The basic robot mechanical structures said arms are links and joints. The rotational type joint is said articulate joint and sliding type joint is said prismatic. The revolved joint is usually driven by the motor. The end of the arm is said the wrist or hand and the hand is equipped to the end effecter.
To move the hand to the appropriate position with appropriate orientation, the arm should be moved by controlling the joints. The position in the open space is specified by the x, y, z coordinates and specified by the three degrees of freedom. The orientation of the hand is specified by the roll, pitch, and yaw. So the robot needs six degrees of freedom to move to the given position and orientation. For the given joint angels the tip position and orientation are uniquely determined which is said the forward kinematics. The motion of the usual industrial robot is commanded by the position and orientation, and all joint angles should be controlled to follow the command which should solve the inverse kinematics problem of determining angles of the joint for the given position and orientation.
To place thing at an arbitrary position with specified orientation in the space, six degrees of freedoms are realized by the six joints. Position in the space is specified by the vector in the three dimensional coordinate space, and the orientation is given by the roll, pitch and yaw. So to place a thing at an arbitrary position, six degrees of freedom are required. One degree of freedom is brought by a joint with a link. There are two kinds of joint. One is revolving and the other is sliding. The number of joints required to place a thing at a given position and orientation in the space is at least six. If the manipulator has more than six joints, there exist several postures of links to place a thing at a given position and attitude in the space. This manipulator is said a redundant manipulator. The joint is driven by a electric motor. All joint angles are specified, the position and orientation of the tip of the manipulator is uniquely specified. When the position and orientation of the manipulator tip is given, the problem of determining joint angles is difficult problem and is said ``inverse kinematics problem”. The problem is known to be treated by Homogenous transformation. The first systematic treatment of the problem is found in the book written by R.P. Paul.
Dynamics and control
The mechanical systems working for the human muscle power was said the Servo-control, which came from the word meaning service.
The fly ball governor installed by James Watt in his steam engine in 1788 for keeping rotational speed of engine constant is said the origin of the control, and the foundation of the control theory was born aiming to solve the stability of this closed loop system by J.C. Maxwell of UK and J.Wischnegradski of Russia. The control has been used in all fields since then such as in ships, airplane and chemical processes. The servo-mechanism had been used in assisting the steering of the ship rudder. Elmer and Lawrence Sperry used the gyroscope to control the attitude of the airplane and demonstrated their autostabiliser in 1914 in Paris. The fire control in the combination of radar had been developed during World War II in Radiation Laboratory. After the war, the project to develop the training simulator for pilots started at MIT under the direction of J. Forrester. The project had brought the digital computer ``Whirlwind”. The digital computer later had brought the digital control.
The problem of the robot control is how to control the joint angles to have the robot move to the given position and orientation. By the inverse kinematics for the desired position and orientation, the angles are determined. To control the joint angles to be desired ones, the motors at the joint should be controlled to generate the necessary torque to drive joints. The dynamics between the input torque and the joint angles are depending on the attitude of the robot, which are described by the nonlinear differential equations. The development of small computers has made possible to integrate the above three technical ingredients into making robot working for human. The robot appeared was doing simple motion like pick and place following the program mainly used for manufacturing. The conventional industrial robot control the input torque based on PID logic of the error between the joint angles and the reference angles. This control law however is not able to apply to the manipulator in the space shuttle since the robot dynamics is heavily nonlinear. When the reference joint angles are given, the necessary input torque can be determined. This procedure is said the inverse dynamics. This is equivalent to the nonlinear feedback compensation to make the closed loop of the robot be linear. Such control law has made possible to develop the advanced robot.
Intelligent Robot
When the computer and sensors are used, the intelligent robot comes to be used. The definition of the intelligence is said the ability to adapt to the varying environment by C. Evans in his book ``Mighty Micros”. To have the ability to adapt to the environment, it is necessary to have the following functions:
1, Information and data acquisition using sensors and through communication
2, Data storage in the data base
3, Logics to structure and use the data
4, Interaction with the environment
The intelligent robot has the function to adapt to the environment by using sensors information, so the robot can pick up the randomly distributed work pieces, which is said bin picking. Under the structure of intelligent control, many kinds of control realizing robot dexterity have been developed such as the force control, coordination control of multi-arms. The sensed data are feed into the computer for storing in the database. The data are structured to form the knowledge and learning ability will be considered.
The techniques of robot control are now to aim to make the robot mimic the animals. One of the famous such robots are snake robot developed by S.Hirose.
Hirose Anaconda
The new Toyota Hybrid automobile has the function to park autonomously in line, which seems to be controlled by robot. Robot arm has equipped actuators at joints, but recently the robot with un-actuated joints called under actuated robot has been developed. One of such robot is the rotating type pendulum called Furuta Pendulum.
Furuta Pendulum
Future
Looking at the history of the robot, as above-mentioned, the robot was first invented as a word used in a play. The robot was described as a machine that will do various tasks in lie of human workers in the factory. In the technology, the robot was also developed as a machine that would do various tasks in lieu of human workers. In 1950s, a robotic system that was called as a manipulator was developed to remotely handle radioactive materials in nuclear power plants. It was a machine that could do a dangerous task in lieu of human workers. It was a machine used to release humans from hazardous and dirty works. Currently, there are many robots that are used in hazardous environment, like for plant maintenance in deep undersea, high voltage power live-line maintenance, exploring space and/or planet as well as nuclear power maintenance.
Fig. 1 shows an example of a live-line maintenance robot developing by YASKAWA Electric Corp. This shows a robot that is renewing a worn insulator on a utility pole, this is a typical task required for the live-line maintenance. In order to maintain continuous energy supply it must be done without the power shutdown. It is very dangerous work for human to do it. Currently, the robot is being verified by skilled human workers to release humans from such dangerous works in the actual work field.
The manufacturing factory is the other typical place where a lot of robots are employed. Many industrial robots are working especially at the manufacturing factories for automobile industry, home electronic product industries and so on. In such a factory, there are many repeated and simple tasks that are tedious if human workers will do it. In order to release humans from such tasks, the robot is efficiently employed as a human substitution machine.
An important robot application in future will be the one for supporting humans in their daily life. In several countries in the world, a problem in the 21st century is the increase of elderly people population and decrease of labor power enough to keep industrial and social activities high quality. For example, in Japan, there is a prediction in which the rate of elderly people (older than 65) population in the total population will reach to 25% in 2020. It means one of 4 persons will be more than 65 years old. In such a society, it will be supposed that the number of people who need some kinds of assistance in several situations of their daily life will increase. Because of those problems in future society, since the beginning of 1990s, the robot which can work together with human and/or support human in human environment has drawn robotics researcher’s attention and several contributions have been made in this research area. Such a new area in robotics is called as “Human Friendly Robotics”.
There are several kinds of human friendly robots which support humans, that is, rehabilitation robots, house care robot, information service robot, entertainment robot, and so on.
Fig. 2 shows a robot that helps quadriplegics when he/she has a meal by himself, “My Spoon” developed by SECOM Co., Ltd. It can bring the foods on the table to his/her mouse using a robotic arm according to the command produced by him/her.
Fig. 3 shows a robot that looks after the house in another’s absence, a home security robot, “Banryu” developed by tmsuk Co., Ltd. and SANYO DENKI Co., Ltd. It has a legged mobile robot with obstacle avoidance and a TV camera to monitor the house connected to cellular phone. When the house owner is absent, the robot looks around inside the house and sends the monitored image of the house to the owner. Also, it can provide various security services using several sensory functions installed in the body
In robotics, traditionally the robot “motions” have been used to do some kinds of physical tasks. However, when a robot will exist with human in the same environment and the human can directly see and touch the robot, the human may feel something from the motions of the robot and touching the robot. Using such an emotional effect the human will have from the robot, new several applications of human friendly robot have been proposed for entertainment, mental health care applications and so on. One of the famous examples of such a robot is AIBO developed by Sony Corp.. AIBO is a four-legged robot with vision sensors, auditory sensors and so on. It can do various actions using actuators, responding to the inputs to those sensors. It has also several kinds of intelligence to recognize objects, to understand human voice commands for human-robot communication, and also to express emotion via the behaviors. With those functions, human can play with the robot and feel happiness via communication with it. It is an efficient mental support device for people who are living alone and feel the loneliness hard in their everyday life.
Fig. 4 shows the other example of the mental commit robot, which is called as “PARO” developed by AIST, Japan. It has a seal shape robot with flexible tactile sensors on the surface, auditory sensors in the head that can detect human voice and proximity sensors in the face that can detect an approaching object. Also this robot has an emotional behavior generator that is driven by the inputs to the sensors installed in the robot. With those functions, human can enjoy several behaviors of the robot via physically interacting with the robot. Though it can be used as a robot for entertainment for the people who are living alone like AIBO, currently, it is considered to apply it to mental therapy.
When the robot lives together with human, humanoid, a robot that has a human shape, will be more suitable rather than other shape robot. Since middle of 1990s, humanoid technology has made remarkable advancements. Currently, there are several practical humanoid developed by several universities, institutions and industries.
Fig. 5 is an example of humanoid developed by AIST, Japan and Kawada Industries, Inc.
The “human shape” has a possibility of producing several attractive features in human-robot communication. For example, even when a humanoid will do a simple repetitive task that a conventional industrial robot also can do, people who will see it will have more attractive impression from the humanoid than from the conventional industrial robot. Because of those effects, humanoid can be considered to be an effective human interface device and several application ideas have been investigated, an example of those applications will be an entertainment robot, Qrio Sony Corporation has developed. It is a machine that can communicate with human and shows an attractive behavior to human, like dancing and so on. Even for robot applications to support human physically, because of the emotional function, humanoid technology will also be important.
In future, more number of robots and more kinds of robot will be used in our society and they will play an important role to improve the quality of our life.
19 Temmuz 2007 Perşembe
plc
Programmable Logic Controller
A Programmable Logic Controller, PLC, or Programmable Controller(PLC) or Programmable Logic Controller is a registered trademark of the Allen-Bradley Company) is an electronic device used for automation of industrial processes, such as control of machinery on factory assembly lines. Unlike general-purpose computers, the PLC is designed for extended temperature ranges, dirty or dusty conditions, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or read-only memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise miscontrol will result. Thus PLC is a collection of digital relays in series. PLC Compared With Other Control SystemsPLCs are well-adapted to a certain range of automation tasks. These are typically industrial processes in manufacturing where the cost of developing and maintaining the automation system is high relative to the total cost of the automation, and where changes to the system would be expected during its operational life. PLCs contain input and output devices compatible with industrial pilot devices and controls; little electrical design is required, and the design problem centers on expressing the desired sequence of operations in ladder logic (or function chart) notation. PLC applications are typically highly customized systems so the cost of a packaged PLC is low compared to the cost of a specific custom-built controller design. On the other hand, in the case of mass-produced goods, customized control systems are economic due to the lower cost of the components, which can be optimally chosen instead of a "generic" solution, and where the non-recurring engineering charges are spread over thousands of sales.Some modern PLCs with full capabilities are available for a few hundred USD. This allows them to be economically applied on very small control problems.For high volume or very simple fixed automation tasks, different techniques are used. For example, a consumer dishwasher would be controlled by an electromechanical cam timer costing only a few dollars in production quantities. A microcontroller-based design would be appropriate where hundreds or thousands of units will be produced and so the development cost (design of power supplies and input/output hardware) can be spread over many sales, and where the end-user would not need to alter the control. Automotive applications are an example; millions of units are built each year, and very few end-users alter the programming of these controllers. (However, some specialty vehicles such as transit busses economically use PLCs instead of custom-designed controls, because the volumes are low and the development cost would be uneconomic.)Very complex process control, such as used in the chemical industry, may require algorithms and performance beyond the capability of even high-performance PLCs. Very high speed controls may also require customised solutions; for example, aircraft flight controls.PLCs may include logic for single-variable feedback analog control loop, a "proportional, integral, derivative" or "PID controller." A PID loop could be used to control the temperature of a manufacturing process, for example. Historically PLCs were usually configured with only a few analog control loops; where processes required hundreds or thousands of loops, a distributed control system (DCS) would instead be used. However, as PLCs have become more powerful, the boundary between DCS and PLC applications has become less clear-cut.
A Programmable Logic Controller, PLC, or Programmable Controller(PLC) or Programmable Logic Controller is a registered trademark of the Allen-Bradley Company) is an electronic device used for automation of industrial processes, such as control of machinery on factory assembly lines. Unlike general-purpose computers, the PLC is designed for extended temperature ranges, dirty or dusty conditions, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or read-only memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise miscontrol will result. Thus PLC is a collection of digital relays in series. PLC Compared With Other Control SystemsPLCs are well-adapted to a certain range of automation tasks. These are typically industrial processes in manufacturing where the cost of developing and maintaining the automation system is high relative to the total cost of the automation, and where changes to the system would be expected during its operational life. PLCs contain input and output devices compatible with industrial pilot devices and controls; little electrical design is required, and the design problem centers on expressing the desired sequence of operations in ladder logic (or function chart) notation. PLC applications are typically highly customized systems so the cost of a packaged PLC is low compared to the cost of a specific custom-built controller design. On the other hand, in the case of mass-produced goods, customized control systems are economic due to the lower cost of the components, which can be optimally chosen instead of a "generic" solution, and where the non-recurring engineering charges are spread over thousands of sales.Some modern PLCs with full capabilities are available for a few hundred USD. This allows them to be economically applied on very small control problems.For high volume or very simple fixed automation tasks, different techniques are used. For example, a consumer dishwasher would be controlled by an electromechanical cam timer costing only a few dollars in production quantities. A microcontroller-based design would be appropriate where hundreds or thousands of units will be produced and so the development cost (design of power supplies and input/output hardware) can be spread over many sales, and where the end-user would not need to alter the control. Automotive applications are an example; millions of units are built each year, and very few end-users alter the programming of these controllers. (However, some specialty vehicles such as transit busses economically use PLCs instead of custom-designed controls, because the volumes are low and the development cost would be uneconomic.)Very complex process control, such as used in the chemical industry, may require algorithms and performance beyond the capability of even high-performance PLCs. Very high speed controls may also require customised solutions; for example, aircraft flight controls.PLCs may include logic for single-variable feedback analog control loop, a "proportional, integral, derivative" or "PID controller." A PID loop could be used to control the temperature of a manufacturing process, for example. Historically PLCs were usually configured with only a few analog control loops; where processes required hundreds or thousands of loops, a distributed control system (DCS) would instead be used. However, as PLCs have become more powerful, the boundary between DCS and PLC applications has become less clear-cut.
15 Temmuz 2007 Pazar
electric electronic industrial
An industrial robot is a manipulator designed to move materials, parts and tools, and perform a variety of programmed tasks in manufacturing and production settings.
Industrial robots are reshaping the manufacturing industry. They are often used to perform duties that are dangerous or unsuitable for human workers. Ideal for situations that require high output and no errors, the industrial robot is becoming a common fixture in factories.
The industrial robot is a good fit for many applications. It is most often used for arc welding, material handling, and assembly applications. They are grouped according to number of axes, structure type, size of work envelope, payload capability, and speed. A robot controller provides the interface for programming and operating the industrial robot. A device called a teach pendant is used to plot the motions needed to perform the application.
Industrial Robot Basics
An industrial robot is a programmable, multi-function manipulator designed to automate tasks such as welding or the movement of materials through variable programmed motions. Robots are capable of performing a wide variety of tasks and are an integral part of automated manufacturing systems.
Industrial robots consist of a number of rigid links connected by joints and controlled by a computer. The link assembly, or robot arm, is connected to a body that is mounted onto a base. A wrist attached to the robot arm uses an end effector to facilitate gripping or handling. The complete motion of the end effector is accomplished through a series of motions and positions of the links, joints, and wrist.
Typical Robot ApplicationsMany factors determine which robot is best suited for a specific application.These include the axes of movement, type of drive, end effector, work envelope, axis speed, load capability (payload), working environment sensitivity, and structural rigidity. Each application demands a performance capability that matches the task. Typical applications include :
*Spot and arc welding
*Pick and place activities
*Clamping for machining
*Transfer and manipulation of parts
RobotWorx is an industrial robot integrator. Robot integrators specialize in customizing robot workcells and programming the robots for specific tasks or applications. Robots can be programmed for a wide variety of applications and can increase productivity, reduce labor costs, and increase quality of output.
Industrial robots are reshaping the manufacturing industry. They are often used to perform duties that are dangerous or unsuitable for human workers. Ideal for situations that require high output and no errors, the industrial robot is becoming a common fixture in factories.
The industrial robot is a good fit for many applications. It is most often used for arc welding, material handling, and assembly applications. They are grouped according to number of axes, structure type, size of work envelope, payload capability, and speed. A robot controller provides the interface for programming and operating the industrial robot. A device called a teach pendant is used to plot the motions needed to perform the application.
Industrial Robot Basics
An industrial robot is a programmable, multi-function manipulator designed to automate tasks such as welding or the movement of materials through variable programmed motions. Robots are capable of performing a wide variety of tasks and are an integral part of automated manufacturing systems.
Industrial robots consist of a number of rigid links connected by joints and controlled by a computer. The link assembly, or robot arm, is connected to a body that is mounted onto a base. A wrist attached to the robot arm uses an end effector to facilitate gripping or handling. The complete motion of the end effector is accomplished through a series of motions and positions of the links, joints, and wrist.
Typical Robot ApplicationsMany factors determine which robot is best suited for a specific application.These include the axes of movement, type of drive, end effector, work envelope, axis speed, load capability (payload), working environment sensitivity, and structural rigidity. Each application demands a performance capability that matches the task. Typical applications include :
*Spot and arc welding
*Pick and place activities
*Clamping for machining
*Transfer and manipulation of parts
RobotWorx is an industrial robot integrator. Robot integrators specialize in customizing robot workcells and programming the robots for specific tasks or applications. Robots can be programmed for a wide variety of applications and can increase productivity, reduce labor costs, and increase quality of output.
8 Temmuz 2007 Pazar
VHDL
VHDL(VHSIC Hardware Description Language)
VHDL is a language for describing digital electronic systems. It arose out of the United States Government’s Very High Speed Integrated Circuits (VHSIC) program, initiated in 1980. In the course of this program, it became clear that there was a need for a standard language for describing the structure and function of integrated circuits (ICs). Hence the VHSIC Hardware Description Language (VHDL) was developed, and subsequently adopted as a standard by the Institute of Electrical and Electronic Engineers (IEEE) in the US. VHDL is designed to fill a number of needs in the design process. Firstly, it allows description of the structure of a design, that is how it is decomposed into sub-designs, and how those sub-designs are interconnected. Secondly, it allows the specification of the function of designs using familiar programming language forms. Thirdly, as a result, it allows a design to be simulated before being manufactured, so that designers can quickly compare alternatives and test for correctness without the delay and expense of hardware prototyping. The purpose of this booklet is to give you a quick introduction to VHDL. This is done by informally describing the facilities provided by the language, and using examples to illustrate them. This booklet does not fully describe every aspect of the language. For such fine details, you should consult the IEEE Standard VHDL Language Reference Manual. However, be warned: the standard is like a legal document, and is very difficult to read unless you are already familiar with the language. This booklet does cover enough of the language for substantial model writing. It assumes you know how to write computer programs using a conventional programming language such as Pascal, C or Ada. The remaining chapters of this booklet describe the various aspects of VHDL in a bottom-up manner. Chapter2 describes the facilities of VHDL which most resemble normal sequential programming languages. These include data types, variables, expressions, sequential statements and subprograms. Chapter3 then examines the facilities for describing the structure of a module and how it it decomposed into sub-modules. Chapter4 covers aspects of VHDL that integrate the programming language features with a discrete event timing model to allow simulation of behaviour. Chapter5 is a key chapter that shows how all these facilities are combined to form a complete model of a system. Then Chapter6 is a potpourri of more advanced features which you may find useful for modeling more complex systems. Throughout this booklet, the syntax of language features is presented in Backus-Naur Form (BNF). The syntax specifications are drawn from the IEEE VHDL Standard. Concrete examples are also given to illustrate the language features. In some cases, some alternatives are omitted from BNF
VHDL is a language for describing digital electronic systems. It arose out of the United States Government’s Very High Speed Integrated Circuits (VHSIC) program, initiated in 1980. In the course of this program, it became clear that there was a need for a standard language for describing the structure and function of integrated circuits (ICs). Hence the VHSIC Hardware Description Language (VHDL) was developed, and subsequently adopted as a standard by the Institute of Electrical and Electronic Engineers (IEEE) in the US. VHDL is designed to fill a number of needs in the design process. Firstly, it allows description of the structure of a design, that is how it is decomposed into sub-designs, and how those sub-designs are interconnected. Secondly, it allows the specification of the function of designs using familiar programming language forms. Thirdly, as a result, it allows a design to be simulated before being manufactured, so that designers can quickly compare alternatives and test for correctness without the delay and expense of hardware prototyping. The purpose of this booklet is to give you a quick introduction to VHDL. This is done by informally describing the facilities provided by the language, and using examples to illustrate them. This booklet does not fully describe every aspect of the language. For such fine details, you should consult the IEEE Standard VHDL Language Reference Manual. However, be warned: the standard is like a legal document, and is very difficult to read unless you are already familiar with the language. This booklet does cover enough of the language for substantial model writing. It assumes you know how to write computer programs using a conventional programming language such as Pascal, C or Ada. The remaining chapters of this booklet describe the various aspects of VHDL in a bottom-up manner. Chapter2 describes the facilities of VHDL which most resemble normal sequential programming languages. These include data types, variables, expressions, sequential statements and subprograms. Chapter3 then examines the facilities for describing the structure of a module and how it it decomposed into sub-modules. Chapter4 covers aspects of VHDL that integrate the programming language features with a discrete event timing model to allow simulation of behaviour. Chapter5 is a key chapter that shows how all these facilities are combined to form a complete model of a system. Then Chapter6 is a potpourri of more advanced features which you may find useful for modeling more complex systems. Throughout this booklet, the syntax of language features is presented in Backus-Naur Form (BNF). The syntax specifications are drawn from the IEEE VHDL Standard. Concrete examples are also given to illustrate the language features. In some cases, some alternatives are omitted from BNF
VHDL
Using Foundation Express with VHDL
Foundation Express translates a VHDL description to an internal
gate-level equivalent format. This format is then optimized for a
given FPGA technology.
This chapter discusses concepts that you need to work with VHDL.
These concepts are covered in the following sections.
• “Hardware Description Languages”
• “About VHDL”
• “Foundation Express Design Process”
• “Using Foundation Express to Compile a VHDL Design”
• “Design Methodology”
The United States Department of Defense, as part of its Very High
Speed Integrated Circuit (VHSIC) program, developed VHSIC HDL
(VHDL) in 1982. VHDL describes the behavior, function, inputs, and
outputs of a digital circuit design. VHDL is similar in style and
syntax to modern programing languages, but includes many hardware-
specific constructs.
Foundation Express reads and parses the supported VHDL syntax.
The “VHDL Constructs” chapter lists all VHDL constructs and
includes the level of support provided for each construct.
Foundation Express translates a VHDL description to an internal
gate-level equivalent format. This format is then optimized for a
given FPGA technology.
This chapter discusses concepts that you need to work with VHDL.
These concepts are covered in the following sections.
• “Hardware Description Languages”
• “About VHDL”
• “Foundation Express Design Process”
• “Using Foundation Express to Compile a VHDL Design”
• “Design Methodology”
The United States Department of Defense, as part of its Very High
Speed Integrated Circuit (VHSIC) program, developed VHSIC HDL
(VHDL) in 1982. VHDL describes the behavior, function, inputs, and
outputs of a digital circuit design. VHDL is similar in style and
syntax to modern programing languages, but includes many hardware-
specific constructs.
Foundation Express reads and parses the supported VHDL syntax.
The “VHDL Constructs” chapter lists all VHDL constructs and
includes the level of support provided for each construct.
HARDWARE
Hardware Description Languages
Hardware description languages (HDLs) are used to describe the
architecture and behavior of discrete electronic systems.
HDLs were developed to deal with increasingly complex designs. An
analogy is often made to the development of software description
languages; from machine code (transistors and solder) to assembly
language (netlists) to high-level languages (HDLs).
Top-down, HDL-based system design is most useful in large projects,
where several designers or teams of designers are working concurrently.
HDLs provide structured development. After major architectural
decisions have been made and major components and their
connections have been identified, work can proceed independently
on subprojects.
Typical Uses for HDLS
HDLs typically support a mixed-level description, where structural
or netlist constructs can be mixed with behavioral or algorithmic
descriptions. With this mixed-level capability, you can describe
system architectures at a high level of abstraction; then incrementally
refine a design into a particular component-level or gate-level implementation.
Alternatively, you can read an HDL design description
into Foundation Express, then direct the compiler to synthesize a
gate-level implementation automatically.
Hardware description languages (HDLs) are used to describe the
architecture and behavior of discrete electronic systems.
HDLs were developed to deal with increasingly complex designs. An
analogy is often made to the development of software description
languages; from machine code (transistors and solder) to assembly
language (netlists) to high-level languages (HDLs).
Top-down, HDL-based system design is most useful in large projects,
where several designers or teams of designers are working concurrently.
HDLs provide structured development. After major architectural
decisions have been made and major components and their
connections have been identified, work can proceed independently
on subprojects.
Typical Uses for HDLS
HDLs typically support a mixed-level description, where structural
or netlist constructs can be mixed with behavioral or algorithmic
descriptions. With this mixed-level capability, you can describe
system architectures at a high level of abstraction; then incrementally
refine a design into a particular component-level or gate-level implementation.
Alternatively, you can read an HDL design description
into Foundation Express, then direct the compiler to synthesize a
gate-level implementation automatically.
THE CONCEPTUAL DESİGN OF THE PLC
THE CONCEPTUAL DESIGN OF THE PLC
The first programmable controllers were more or less just relay replacers.
Their primary function was to perform the sequential operations that were
previously implemented with relays. These operations included ON/OFF
control of machines and processes that required repetitive operations, such as
transfer lines and grinding and boring machines. However, these
programmable controllers were a vast improvement over relays. They were
easily installed, used considerably less space and energy, had diagnostic
indicators that aided troubleshooting, and unlike relays, were reusable if a
project was scrapped.
Programmable controllers can be considered newcomers when they are
compared to their elder predecessors in traditional control equipment
technology, such as old hardwired relay systems, analog instrumentation,
and other types of early solid-state logic. Although PLC functions, such as
speed of operation, types of interfaces, and data-processing capabilities, have
improved throughout the years, their specifications still hold to the
designers’ original intentions—they are simple to use and maintain.
The first programmable controllers were more or less just relay replacers.
Their primary function was to perform the sequential operations that were
previously implemented with relays. These operations included ON/OFF
control of machines and processes that required repetitive operations, such as
transfer lines and grinding and boring machines. However, these
programmable controllers were a vast improvement over relays. They were
easily installed, used considerably less space and energy, had diagnostic
indicators that aided troubleshooting, and unlike relays, were reusable if a
project was scrapped.
Programmable controllers can be considered newcomers when they are
compared to their elder predecessors in traditional control equipment
technology, such as old hardwired relay systems, analog instrumentation,
and other types of early solid-state logic. Although PLC functions, such as
speed of operation, types of interfaces, and data-processing capabilities, have
improved throughout the years, their specifications still hold to the
designers’ original intentions—they are simple to use and maintain.
PROGRAMMABLE CONTROLLERS AND THE FUTURE
PROGRAMMABLE CONTROLLERS AND THE FUTURE
The future of programmable controllers relies not only on the continuation of
new product developments, but also on the integration of PLCs with other
control and factory management equipment. PLCs are being incorporated,
through networks, into computer-integrated manufacturing (CIM) systems,
combining their power and resources with numerical controls, robots, CAD/
CAM systems, personal computers, management information systems, and
hierarchical computer-based systems. There is no doubt that programmable
controllers will play a substantial role in the factory of the future.
New advances in PLC technology include features such as better operator
interfaces, graphic user interfaces (GUIs), and more human-oriented man/
machine interfaces (such as voice modules). They also include the
development of interfaces that allow communication with equipment,
hardware, and software that supports artificial intelligence, such as fuzzy
logic I/O systems.
Software advances provide better connections between different types of
equipment, using communication standards through widely used networks.
New PLC instructions are developed out of the need to add intelligence to a
controller. Knowledge-based and process learning–type instructions may be
introduced to enhance the capabilities of a system.
The user’s concept of the flexible manufacturing system (FMS) will determine
the control philosophy of the future. The future will almost certainly
continue to cast programmable controllers as an important player in the
factory. Control strategies will be distributed with “intelligence” instead of
being centralized. Super PLCs will be used in applications requiring complex
calculations, network communication, and supervision of smaller PLCs and
machine controllers
The future of programmable controllers relies not only on the continuation of
new product developments, but also on the integration of PLCs with other
control and factory management equipment. PLCs are being incorporated,
through networks, into computer-integrated manufacturing (CIM) systems,
combining their power and resources with numerical controls, robots, CAD/
CAM systems, personal computers, management information systems, and
hierarchical computer-based systems. There is no doubt that programmable
controllers will play a substantial role in the factory of the future.
New advances in PLC technology include features such as better operator
interfaces, graphic user interfaces (GUIs), and more human-oriented man/
machine interfaces (such as voice modules). They also include the
development of interfaces that allow communication with equipment,
hardware, and software that supports artificial intelligence, such as fuzzy
logic I/O systems.
Software advances provide better connections between different types of
equipment, using communication standards through widely used networks.
New PLC instructions are developed out of the need to add intelligence to a
controller. Knowledge-based and process learning–type instructions may be
introduced to enhance the capabilities of a system.
The user’s concept of the flexible manufacturing system (FMS) will determine
the control philosophy of the future. The future will almost certainly
continue to cast programmable controllers as an important player in the
factory. Control strategies will be distributed with “intelligence” instead of
being centralized. Super PLCs will be used in applications requiring complex
calculations, network communication, and supervision of smaller PLCs and
machine controllers
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