DC Servo Drive Control Algorithm
Original Publication Date: 1981-Apr-01
Included in the Prior Art Database: 2005-Feb-11
A control algorithm is known to obtain the duty cycle needed by a pulse-width modulated control signal to drive a DC servo motor for printer carrier operation. The algorithm measures the elapsed time between emitter wheel slots on the motor shaft and subtracts a constant from the elapsed time. This remainder is used to determine the duty cycle required by the pulsewidth modulator to maintain a constant velocity. Variations in load, motor tolerances and changes in temperature will cause the actual velocity of the motor to be altered accordingly until a new equilibrium point of pulse duty cycle and steady-state velocity are reached. This causes wide variations in the actual velocity of operation, both from machine to machine and on a given machine.