Feedback components

Abstract

It has been demonstrated that closed-loop control is required if a robot arm is to be accurately positioned in the presence of disturbances such as gravity loads. Since computation is necessary to transform from world coordinates, the required values of machine coordinates originate as digital information from a computer. Figure 6.1 shows four designs of control systems, each of p g which could set the elbow of a robot at an angle θ, the set-point value of θ being digital output of a processor. In all parts of Figure 6.1, a solid line output represents an analogue signal, and a broken a digital signal.