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.