Speed control of a DC motor using binary rate modulation of the input power

The paper describes the optimal pulse positioning property of binary rate modulation for a DC motor, modelled as a first order system. The paper compares the speed output performance against that for pulse width modulation. It is shown that binary rate modulation has a better disturbance rejection for the same system performance in speed. Also, the method of producing binary rate modulation waveforms is shown to be simple and comparable with that for pulse width modulation in any computer system. The closed loop digital control system is analysed using an adaptation of the circle criterion for the highly nonlinear method of power dispatch. Results from a practical motor test are included