Abstract: A programmable variable degree of tactile feedback for the operation of a manipulator by a pair of motors, one connected to the load and one to the control. Computer controlled four quadrant regulators for each motor are used to drive the load motor shaft to the same position as the control motor shaft and to vary the feedback force on the control motor in proportion to selected forces developed during the manipulation process.

Abstract: A threaded fastener assembly tool is affixed to the output shaft of a DC motor, the torque of which is controlled by the current through the windings. An angular position encoder is attached to the shaft. A microprocessor monitors the angular position of the shaft as a function of time and controls a programmable current source which provides current to the windings of the motor. The processor varies the amount of torque applied to the fastener tool as a function of various parameters to control the installation of the fastener and detect defective fastener units.

Abstract: A microprocessor based electric actuator control system is provided which allows accurate determination of the forces opposing movement of manipulator driveshaft. The control system electronically sets a predetermined current through an actuator to produce an electromagnetic force. A displacement measuring device, in conjunction with a time clock measures velocity and calculates acceleration of the actuator in response to the current. The force on the shaft is computer varied such that the acceleration is determined. For the acceleration to be zero, the electromagnetic force be exactly balanced by forces equal but opposite in magnitude. Since the force value is determined by the computer, the opposing force is also accurately determined with no external sensing device needed.