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.