High accuracy control system

A high accuracy control system for driving a motor to move a member. The control system includes feedback means for generating a cyclical signal for providing an indication of the actual position of the member. The accuracy of the feedback means is maximized by introducing a gear mechanism between the motor output and the feedback means. Further provided are means for generating command pulses, each of which is indicative of an increment of commanded or desired movement of the member, and means for generating a command signal indicative of the desired commanded movement of the member. In one mode of operation, the incremental command pulses are multiplied by a factor of K to change the command signal by K increments for each incremental command pulse. In another mode of operation, M number of incremental command pulses are converted to a single incremental pulse, and this single incremental pulse is used to change the command signal by one increment of movement for M number of incremental command pulses. Further provided is means responsive to the signal from the feedback means and to the command signal to generate an error signal which is used to drive the member toward the desired commanded position.