The effects of sampling time (Ts) on the control performance
are investigated by incorporating digital samplers in
the simulation program. The characteristics of step speed response
and impact load disturbance under different sampling
periods are illustrated in Fig. 18. With increased sampling
time, the speed ripples also increase, and the transient response
deviates slightly. In spite of these, the system still
exhibits reasonable disturbance rejection and minimal steadystate
error.