A manipulator is hydraulically actuated. Consider movement of one joint in isolation. National Instruments (NI) software on a PC is used to control the robot. The PC transmits information to a NI Compact Fieldpoint Real-Time controller (cFP) linked to the hydraulics. For control design purposes, this is expressed as an input signal in the range -5 to +5 where + and - implies the joint will open or close respectively (zero means stop moving).

A potentiometer feedback sensor measures the joint angle, returning a calibrated signal in the range 10 to 120 degrees. An algorithm on the PC attempts to control this angle, i.e. so that it follows a pre-defined trajectory.

The manipulator is used to first move an empty gripper (the end effector) and subsequently to first grasp and lift a heavy object.

Your task: draw a block diagram of the closed-loop control system for regulating joint angle (consider just one joint), identifying the plant, controller, output, control input, disturbance input and the set point, and noting the practical range of any signals where appropriate.