Industrial robots are primarily designed for manipulation purposes. The primitive actions imposed at the hand by the manipulator are:
- from point to point
- following a desired trajectory
- following a contoured surface
2. Changing Orientation
Non-servo robots can provide a sequence of point to point (PTP) motions. For each motion, the manipulator members move full tilt until the limits of travel are reached. Thus they are often referred to as "bang-bang", "pick and place" or "limited sequence" robots. "Programming is done by setting up the desired sequence of moves and by adjusting the end stops for each axis" (Tanner, 1979, p. 7). The use of mechanical stops and limit switches yields good positional accuracy, which is typically repeatable to better than + 0.5 mm (Simons, 1980, p. 20)
. Servo-controlled robots can be designed to provide a sequence of PTP motions, with controlled intermediate velocities. They can also be used to follow a pro- grammed trajectory or by using sensors to follow a contoured surface.
If we consider end effectors, the robot can also be made to grasp, push and pull, twist, use tools, perform insertions and assembly, and do other mani- pulations done by humans.
If sensors and appropriate computations are added, the obot can perceive, inspect, recognize, test and do many of the other perceptua. functions now done by humans.
All applications require that the robot interact with environment in the execution of its programmed task. Thus the robot is of , designed to