Introduction to Robotics
What does one visualize while thinking of a Robot? Does a robot roll as R2D2 (from Star Wars) or walk upright as C3P0? Does it have expressionistic face or a mechanical one? Does it function as vacuum or picks objects for you? As there are many uses of Robotics, it is reasonable to think that there are various designs too. To know how these complex yet intelligent machines move, one needs to look at their engineering, physics closely.
Other than the sci-fi movies, the Robots can be seen around us assembling the cars, in bottling factory etc. The robots have been in the industry for last two decades because of their continuous working ability in an atmosphere, where humans are not even able to stand for minutes, without any supporting equipment, like space.
Since recent years, the researchers are continuously trying to develop more intelligent and self-reliant robots for various applications. The Honda’s ASIMO is the best example of such intelligent robots. The human (Homo sapiens) is the most intelligent creature in the world because he has senses like vision, touch etc. The researchers are trying to emulate human capabilities by creating “Robo sapiens” having all these senses.
Basic structure of robots is very much similar to humans. How do humans sense? For example a human sees something and sends neural signals to the brain via neurons and reacts accordingly. The development of all these senses artificially is achieved through 'Sensors'. Sensors are the transducers which receive the physical changes of the environment and convert them into electrical or electronic signals. These analog signals are converted into digital by using analog-to-digital convertors.Control system functions as a brain in robotic systems.
PID controller is a popular method for controlling robots. Point of the control system is to get robot actuators do what one wishes to. An encoder on actuator, basically a sensor, determines what all is changing. Program that one writes, defines final results and actuators make changes. Other sensor senses environment, providing robot a better sense of working.
Among different components, actuators are the most important for robotic automation. This component helps in conversion of stored energy in movement. Usually, these are the electric motors, although compressed air and chemical actuators are also available for use. Stepper motor rotates in controllable motions and are commanded by controllers. Ultrasonic motor uses fast vibrating piezo-ceramic element for causing motion. With the help of compressed air, air muscles work exactly like human muscles, contracting and expanding.
Robots are made from an assortment of materials and are driven in many ways too. These can be constructed from sturdy, heavy steel or light weighted plastics. Surgical robots and Robotic arms have uncomplicated rotational joints. These are driven by hydraulics and electrical motors along with longitudinal joints that are moved with rotating screws. Some mobile robots have various wheels that can operate on various planes while others can walk on different terrains with multiple legs. You can find robots with sensing mechanisms like cameras operating as eyes and touch sensors for feeling the environment.