A robot is a mechanical manipulator which can be programmed to perform various physical tasks.
Robots have been demonstrated to play soccer, operate switches, turn doorknobs, and climb stairs, in addition to performing such industrial tasks as assembly of machine parts, welding and spray-painting of automobile bodies, and inspection of products.
A properly designed robot is truly a mechatronic system.
Programmability and the associated flexibility of carrying out tasks are necessary characteristics for a robot, according to this commonly used definition.
Furthermore, a robotic task might be complex to the extent that some degree of intelligence would be required for satisfactory performance of the task.
There is an increasing awareness of this and there have been calls to include intelligence, which would encompass abilities to perceive reason, learn and infer from incomplete information, as a requirement in characterizing a robot.
Productivity and product quality of an automated manufacturing process rely on the accuracy of the individual manufacturing tasks such as parts transfer, assembly, welding, and inspection.
In modern manufacturing work cells many of these tasks are carried out by robotic manipulators.
The performance of a robotic manipulator depends considerably on the way the manipulator is controlled, and this has a direct impact on the overall performance of the manufacturing system.
In this context, a robot can be interpreted as a control system. Its basic functional components are the structural skeleton of the robot; the actuator system which drives the robot; the sensor system which measures signals for performance monitoring, task learning and playback, and for control; the signal modification system for functions such as signal conversion, filtering, amplification, modulation, and demodulation; and the direct digital controller which generates drive signals for the actuator system so as to reduce response error.
Higher level tasks such as path planning, activity coordination and supervisory control have to be treated as well within the overall control system.