ABSTRACT
This chapter focuses on sampled-data control systems using multi-rate filters realized with multi-rate holds and interpolators so that the frequency responses of the multi-rate system can be defined. The wide availability of inexpensive microprocessors has made sampled-data control systems very popular for positioning control in mechatronic products. The sampled-data control system is a hybrid system which includes continuous-time and discrete-time signals, implying that the controlled variable is measured only at specific instants. In a positioning control system, the performance of the control system can be evaluated by the maximum displacement of the control variable. The performance of a positioning control system can be evaluated by looking at the maximum displacement of the controlled variable. In general, a positioning control system must estimate the maximum displacement of the control variable from a finite number of samples of the position signal. In some positioning control systems, changing the sampling frequency may be easier than changing the mechanical resonant frequency.
