ROBOTS n robotics

Robotics is the science and technology of robots, design manufacture and applications. It requires a working knowledge of electronics, mechanics and software. the word robot was introduced in 1920 by a play writer KAREL CAPEK, which means tedious work in czech. then from 1954 the technology was developed and today it has grown to a level that we have sent robots to other planets to test whether life is possible there or not and the work till now is being suceeded.

Robotics is often viewed from three perspectives: perception (sensing), manipulation (affecting changes in the world), and cognition (intelligence). Robotic systems integrate aspects of all three of these areas. The study of motion can be divided into kinematics and dynamics. Direct kinematics refers to the calculation of end effector position, orientation, velocity and acceleration when the corresponding joint values are known. Inverse kinematics refers to the opposite case in which required joint values are calculated for given end effector values, as done in path planning. Once all relevant positions, velocities and accelerations have been calculated using kinematics, methods from the field of dynamics are used to study the effect of forces upon these movements. Direct dynamics refers to the calculation of accelerations in the robot once the applied forces are known. Direct dynamics is used in computer simulations of the robot. Inverse dynamics refers to the calculation of the actuator forces necessary to create a prescribed end effector acceleration. This information can be used to improve the control algorithms of a robot.

Now coming to the types of motors used in it, it becomes stepper motor, dc motors, piezo motors etc. The actuators are the 'muscles' of a robot; the parts which convert stored energy into movement. By far the most popular actuators are electric motors, but there are many others, some of which are powered by electricity, while others use chemicals, or compressed air. DC motors, which are familiar to many people, spin rapidly when an electric current is passed through them. They will spin backwards if the current is made to flow in the other direction. Stepper motors: As the name suggests, stepper motors do not spin freely like DC motors, they rotate in steps of a few degrees at a time, under the command of a controller. This makes them easier to control, as the controller knows exactly how far they have rotated, without having to use a sensor. Therefore they are used on many robots and CNC machining canters.

Piezo motors: A recent alternative to DC motors are Piezo motors, also known as ultrasonic motors. These work on a fundamentally different principle, whereby tiny piezoceramic elements, vibrating many thousands of times per second, cause linear or rotary motion. There are different mechanisms of operation; one type uses the vibration of the Piezo elements to walk the motor round in a circle or a straight line. Another type uses the Piezo elements to cause a nut to vibrate and drive a screw. The advantages of these motors are incredible nanometer resolution, speed and available force for their size. Air muscles: The air muscle is a simple yet powerful device for providing a pulling force. When inflated with compressed air, it contracts by up to 40% of its original length. The key to its behavior is the braiding visible around the outside, which forces the muscle to be either long and thin, or short and fat. Since it behaves in a very similar way to a biological muscle, it can be used to construct robots with a similar muscle/skeleton system to an animal. Electroactive polymers: Electroactive polymers are a class of plastics which change shape in response to electrical stimulation. They can be designed so that they bend, stretch or contract, but till date this technology has not been robust, it may be developed in the future.

The next concept becomes the movement of the robots. this is known as locomotion of robots. Locomotion is the name given to the ways of movement of the robots. There are several methods of locomotion. Some of them are two wheeler locomotive, four wheelerlocomotive, walking robots, flying robots, etc.Some examples are; Rolling Robots-Segway, it can balance on a ball instead of legs or wheels; Walking Robots-iCub robot, designed by the RobotCub Consortium, etc. Even though walking robots were found it was difficult to make them walk on rocky places and terrains and hence many techniques were found (ZMP technique, Hopping, Dynamic balancing and Passive dynamics). Perhaps the most promising approach utilizes passive dynamics where the momentum of swinging limbs is used for greater efficiency. It has been shown that totally unpowered humanoid mechanisms can walk down a gentle slope, using only gravity to propel themselves. Using this technique, a robot need only supply a small amount of motor power to walk along a flat surface or a little more to walk up a hill.

All robots are controlled from one place called the control room, the control of robots remain with the computers which are controlled by humans. This sort of controlling robots is known as computer interfacing. Many of the huge robots such as those left in the orbits for researching are controlled by the computers in the earth. the advantages that compile with the robots are as follows:

1.Increase Productivity- With robots, throughput speeds increase, which directly impacts production. Because robots have the ability to work at a constant speed without pausing for breaks, sleep, vacations, they have the potential to produce more than a human worker.

2.Safety- Robots increase workplace safety. Workers are moved to supervisory roles, so they no longer have to perform dangerous applications in hazardous settings.

3.Efficiency & consistency of products- We get good range of products manufactured from the robots. Their efficiency is very high because they use very little amount energy for any sort of work and their consistency is also high and hence they can be highly reliable.

4.Quality- Robots have the capacity to dramatically improve product quality. Applications are performed with precision and high repeatability every time. This level of consistency can be hard to achieve any other way.

5.Savings- Greater worker safety leads to financial savings. There are fewer healthcare and insurance concerns for employers. Robots also offer untiring performance which saves valuable time. Their movements are always exact, so less material is wasted.

So to conclude we have now come to known how the computer works and the system of controlling the robots. thus the theory of robotics is studied.