ROBOTICS AND ITS APPLICATIONS

OTHER ROBOTIC SEMINAR REPORTS

Robots have always had a fascination in our mind. With their various applications in various fields, they have become a common part in our daily life. They are meant to ease our work and increase our comfort of living. The term ‘robot’ got prominence way back in the 1950s when Karl Capek in his play Rossum’s Universal Robots denoted the birth of a superior race that had intelligence similar to that of humans. As Robots come in various forms and have application in various fields defining a Robot becomes that much difficult. There are various definitions for the term Robot. Some of them are:

“Force through intelligence”.

“An automatic device that performs functions normally ascribed to humans or a machine in the form of a human”.

The most accepted definition of a Robot provided by the Robotics Institute of America in 1979 is that:

“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”.

Robotics is that branch which involves with the study and applications of Robots. The goal of Robotics is to mimic natural world as closely as possible. Robotics is a relatively new field of engineering (about approximately 50 years old) and is finding many applications in different areas.

With growing developments in the field of mechatronics and mathematic modeling, Robotics has come a long way. From an iron piece that could move only a few inches, there are now machines capable of jumping from high rise buildings, detecting landmines, performing complicated operations, and troubleshooting.

HISTORY OF ROBOTICS

Robotics compared to other branches is a relatively new field of engineering. It is a multi disciplinary field. The various branches involved in the development of Robotics are:

ü Mechanical Engineering: Deals with the mechanisms of Robots and their structure.

ü Electrical Engineering: Deals with the sensing and controlling of Robots.

ü Computer Engineering: Deals with the motion planning and perception of Robots.

Though the branch of Robotics is new the development of Robots started in the year 1250 when the first Robot was developed. In the period from 1250 to 1950 the Robots were developed for fun rather than for applications.

Brief developments of Robots from the year 1250:

In the year 1250 a Robot was developed that could serve the guests with food. In the year 1738 a Robotic duck was developed which had 4000 parts. It could, quack, bathe, drink water, eat grain, digest it and void it.

In the year 1738 a Robotic duck was developed which had 4000 parts. It could, quack, bathe, drink water, eat grain, digest it and void it.

From the year 1950, due to the development of computers and semiconductor technology Robots found their applications in Industries. This was called the golden era of Robots.

In 1960’s electrical Robots were developed that could walk. This was done by the General Motors.

After 1970 there were some trends that were observed in Robotics. During those periods the robots which were produced where classified into:

ü Model Based Robots: These are Robots that use exact models for the work they are entitled to do. They are not provided with any sensors. Hence they are not required to act on external stimuli.

E.g.: A Robot which used for lifting heavy loads are model based as there will always be a maximum load specified and the robot need not sense the load also there is no other course of action.

ü Sensor Based Robots: These are Robots that are provided with sensors that have to change the course of action based on the stimuli it receives. These Robots are generally used for lower level works.

E.g.: A Robot which is used for maintenance of a furnace depending upon its temperature. In the above case there are various courses of action for the Robot and the Robot has to choose a course of action depending upon the input stimuli received.

CLASSIFICATIONS OF ROBOTS

Robots are classified depending upon the circuitry of the Robots and the ranges of application. The classifications of Robots are into three types:

Simple level Robots
Middle level Robots
Complex level Robots

Simple Level Robots:

They are automatic machines that extend human potential. They cannot be programmed and does not contain a complex circuitry.

E.g.: The best example of a simple level Robot is a semi automatic washing machine.

Middle Level Robots:

They are those Robots which can be programmed but cannot be reprogrammed. They are multi purpose devices. They have sensor based circuitry and can do work which humans do.

E.g.: The best example of a middle level Robot is the fully automatic washing machine.

Complex Level Robots:

They are those Robots which can be programmed and also reprogrammed. They are reprogrammable, multifunctional, manipulators. They contain a model based circuitry and are very complex.

E.g.: The best example of a complex level Robot is the personal computer.

ANATOMY OF A ROBOT

The basic components of a robot system are:

The mechanical linkage
Actuators and transmissions
Sensors
Controllers
User interface
Power conversion unit

The mechanical linkage

The manipulator consists of a set of rigid links connected by joints. The joints are typically rotary or sliding. The last link or the most distal link is called the end effectors because it is this link to which a gripper or a tool is attached. Sometimes one distinguishes between this last link and the end effectors that are mounted to this link at the tool mounting plate or the tool flange.

The manipulator can generally be divided into a regional structure and an orientation structure. The regional structure generally consists of the joints (and the links between them) whose main function is the positioning of the manipulator end effectors. These are generally the proximal joints. The remaining distal joints are mainly responsible for orienting the end effectors.

The different ways a manipulator linkage can move is called its degrees of freedom.

Actuators and Transmissions:

An Actuator is a device that makes freedom possible. The basic form of actuator is an electric motor. The various electric motors used are:

1. Stepper Motors: They are used to control the arms of robots.

2. Servo Motors: They are used to control the wheels of Robots. They use PWM technique for speed control.

The actuators are typically linear or rotary actuators. Also they may be electric, pneumatic or hydraulic. Typically, electric actuators or motors are better suited to high speed, low load applications while hydraulic actuators do better at low speed and high load applications. Pneumatic actuators are like hydraulic actuators except that they are generally not used for high payload.

Transmissions

Transmissions are elements between the actuators and the joints of the mechanical linkage.

They are generally used for three reasons:

Often the actuator output is not directly suitable for driving the robot linkage. The high speed DC motor (running at say 3000 rpm) may not be suitable for running a robot at lower speeds. However, with appropriate gearing or transmission, the speed may be reduced to 30 rpm (1/2 rotation per second) which is reasonably fast. In addition, the rated torque at 3000 rpm is amplified by a factor of 100 (assuming a highly efficient gearbox).

Two types of gear boxes are generally used in Robotics:

The output of the actuator may be kinematically different from the joint motion. For example, the linear actuator is kinematically different from the elbow joint it drives. Thus the linkage consisting of the three passive joints and the linear actuator may be viewed as a transmission that converts the linear motion of the actuator to the rotary motion of the elbow joint.
The actuators are usually big and heavy and often it is not practical to locate the actuator at the joint. First, big actuators have large inertias and they are harder to move around in space than the links that comprise the mechanical linkage. So it is desirable to locate them at a fixed base. Second, because of their size, they can impede the motion of one or more links of the robot. Thus, it is not uncommon to find linkages or gear trains that transmit the power from the actuator over a large distance to the joint.

Sensors

The control of a manipulator or industrial robot is based on the correct interpretation of sensory information. This information can be obtained either internally to the robot (for example, joint positions and motor torque) or externally using a wide range of sensors.

The different types of sensors used are:

1. Tactile Sensors

2. Time flight sensors

3. Compasses

4. Miscellaneous

Tactile sensors

They tell us if the Robot has hit an object. It deals with collision detection. The switch closes if a hit has occurred and current flows by which we can detect a collision

Various types of Tactile Sensors are:

Magnetic
Optical
Microwave
Ultrasonic

Time of Flight Sensors

They tell us how much a Robot is away from an object. The procedure adopted is quite simple

1. Send a signal and start at timer (t1=0 sec)

2. Wait for echo signal, and stop timer (t2 = 12 sec)

3. Calculate difference (t1 –t2 =12 sec)

4. Use time difference to calculate distance (distance = speed *time)

Compasses

They tell us where the Robot is heading i.e., either

North, South, West, East or by 0*

Miscellaneous:

Gyroscope: Gyroscopes are used in robots that need to maintain balance or are not inherently stable. Gyroscopes are often coupled with powerful robot controllers that have the processing power necessary calculate thousands of physical Gyroscope

Simulations per second. There are also many other sensors used for temperature sensing, pressure sensing, motion detection, smoke detection.

Controllers:

The controller provides the intelligence that is necessary to control the manipulator system. It looks at the sensory information and computes the control commands that must be sent to the actuators to carry out the specified task.

It generally includes

• Memory to store the control program and the state of the robot system obtained from the sensors

• A computational unit (CPU) that computes the control commands

• The appropriate hardware to interface with the external world (sensors and actuators)

• The hardware for a user interface.

The user interface

This interface allows use a human operator to monitor or control the operation of the robot. It must have a display that shows the status of the system. It must also have an input device that allows the human to enter commands to the robot. The user interface may be a personal computer with the appropriate software or a teach pendant.

The power conversion unit

The power conversion unit takes the commands issued by the controller which may be low power and even digital signals and converts them into high power analog signals that can be used to drive the actuators. For example, for an electric actuator, this power conversion unit may consist of a digital to analog converter and an amplifier with a power supply. For a pneumatic actuator, this may consist of a compressor, the appropriate servo valves for regulating the flow of air, an amplifier and a digital to analog converter. For a hydraulic robot, you will have a pump and a cooler instead of a compressor.

ARTIFICIAL INTELLIGENCE

Artificial intelligence (AI) is arguably the most exciting field in robotics. It's certainly the most controversial: Everybody agrees that a robot can work in an assembly line, but there's no consensus on whether a robot can ever be intelligent.

Like the term "robot" itself, artificial intelligence is hard to define. Ultimate AI would be a recreation of the human thought process -- a man-made machine with our intellectual abilities. This would include the ability to learn just about anything, the ability to reason, the ability to use language and the ability to formulate original ideas. Robot cists are nowhere near achieving this level of artificial intelligence, but they have had made a lot of progress with more limited AI. Today's AI machines can replicate some specific elements of intellectual ability.

Computers can already solve problems in limited realms. The basic idea of AI problem-solving is very simple, though its execution is complicated. First, the AI robot or computer gathers facts about a situation through sensors or human input. The computer compares this information to stored data and decides what the information signifies. The computer runs through various possible actions and predicts which action will be most successful based on the collected information. Of course, the computer can only solve problems it's programmed to solve -- it doesn't have any generalized analytical ability.

Some modern robots also have the ability to learn in a limited capacity. Learning robots recognize if a certain action achieved a desired result. The robot stores this information and attempts the successful action the next time it encounters the same situation. Again, modern computers can only do this in very limited situations. They can't absorb any sort of information like a human can. Some robots can learn by mimicking human actions. In Japan, robot cists have taught a robot to dance by demonstrating the moves themselves.

Some robots can interact socially. Kismet, a robot at M.I.T's Artificial Intelligence Lab, recognizes human body language and voice inflection and responds appropriately. Kismet's creators are interested in how humans and babies interact, based only on tone of speech and visual cue. This low-level interaction could be the foundation of a human-like learning system.

Kismet and other humanoid robots at the M.I.T. AI Lab operate using an unconventional control structure. Instead of directing every action using a central computer, the robots control lower-level actions with lower-level computers. We do most things automatically; we don't decide to do them at the highest level of consciousness.

The real challenge of AI is to understand how natural intelligence works. Developing AI isn't like building an artificial heart -- scientists don't have a simple, concrete model to work from. We do know that the brain contains billions and billions of neurons, and that we think and learn by establishing electrical connections between different neurons. But we don't know exactly how all of these connections add up to higher reasoning, or even low-level operations. The complex circuitry seems incomprehensible.

Because of this, AI research is largely theoretical. Scientists hypothesize on how and why we learn and think, and they experiment with their ideas using robots. It also makes it easier for people to interact with the robots, which potentially makes it easier for the robot to learn.

Just as physical robotic design is a handy tool for understanding animal and human anatomy, AI research is useful for understanding how natural intelligence works. For some robot cists, this insight is the ultimate goal of designing robots. Others envision a world where we live side by side with intelligent machines and use a variety of lesser robots for manual labor, health care and communication. A number of robotics experts predict that robotic evolution will ultimately turn us into cyborgs -- humans integrated with machines. Conceivably, people in the future could load their minds into a sturdy robot and live for thousands of years!

ADVANTAGES OF ROBOTS

• Robotics and automation can, in many situation, increase productivity, safety, efficiency, quality, and consistency of products

• Robots can work in hazardous environments

• Robots need no environmental comfort

• Robots work continuously without any humanity needs and illnesses

• Robots have repeatable precision at all times

• Robots can be much more accurate than humans; they may have mili or micro inch accuracy.

• Robots and their sensors can have capabilities beyond that of humans

• Robots can process multiple stimuli or tasks simultaneously, humans can only one.

• Robots replace human workers who can create economic problems

DISADVANTAGES OF ROBOTS

• Robots lack capability to respond in emergencies, this can cause:

– Inappropriate and wrong responses

– A lack of decision-making power

– A loss of power

– Damage to the robot and other devices

– Human injuries

• Robots may have limited capabilities in

– Degrees of Freedom

– Dexterity

– Sensors

– Vision systems

– Real-time Response

• Robots are costly, due to

– Initial cost of equipment

– Installation Costs

– Need for peripherals

– Need for training

– Need for Programming

APPLICATIONS OF ROBOTS

Ø Automotive industry

Ø Assembly

Ø Medical laboratories

Ø Medicine

Ø Nuclear energy

Ø Agriculture

Ø Spatial exploration s

Ø Underwater inspection

Ø Customer service

Ø Arts and entertainment

FUTURE OF ROBOTICS

The future developments of Robots can be found in various places. The major among them is in the field of:

Medicine: New techniques for Tele surgery will be developed in future for Remote operations and also for complex operations like cardiac surgery.

Spatial Exploration: With the development of computers the power of Robonauts will increase by which spatial exploration can develop. Robots are already sent into space like the Voyager to Mars and Cassini to Saturn.

Development is going in the field of artificial intelligence. This will invoke thinking in Robots which in future will help Man kind in problem solving.

Development is going on in the field of nano system which deals with implanting of small chips into human body for early detection of diseases. This can also help in locating a person by GPS technology.

CONCLUSION

Robots are going to play a very significant part in our daily life. Like computers in the 20 th century Robots are going to be common house hold items in future. With the development of computers, semiconductor technology Robotics will grow in leaps and bounds. They will find applications in almost all areas and become universal. There are expected times when Robots will over power mankind in future. The ethnicity of providing intelligence to robots is questioned but future is the answer to this question. It is for us to wait and see whether the creators or the creation will rule the world.

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