Components of Robotics

The book describes a robotic system as being built mainly from sensors, power supplies, control systems, manipulators, and the necessary software that coordinates all of them. At the highest level, most robots are said to be composed of three main parts. First, the controller, also known as the 'brain', which is run by a computer program and issues the commands the moving parts follow to perform the job. Second, the mechanical parts -- motors, pistons, grippers, wheels and gears -- that let the robot physically move, grab, turn and lift. Third, sensors, which tell the robot about its surroundings: the sizes and shapes of nearby objects, the distances between objects, and directions. A more detailed eight-item component list follows. (1) Power conversion unit: robots are powered by batteries, solar power, or hydraulics. (2) Actuators: they convert energy into movement, and most actuators produce either rotational or linear motion. (3) Electric motors: used to actuate parts such as wheels, arms, fingers, legs, sensors, cameras and even weapon systems; the most common types are the AC motor, brushed DC motor, brushless DC motor and geared DC motor. (4) Pneumatic air muscles: devices that contract and expand when air is pumped inside them, replicating the function of a human muscle -- they contract by almost 40% when the air is sucked out of them. (5) Muscle wires: thin strands of wire made from shape-memory alloys, which contract by about 5% when an electric current is passed through them. (6) Piezo motors and ultrasonic motors: used mainly in industrial robots. (7) Sensors: generally used in task environments because they supply real-time knowledge of the surroundings. (8) Robot locomotion: the type of movement given to a robot, of which there are four kinds -- legged, wheeled, a combination of legged and wheeled locomotion, and tracked slip/skid locomotion. Separately, the book highlights a category it labels 'Human Robot': robots de …