Multirate digital control system design

A computation effective fixed order multirate digital control system is presented. Introducing a periodically time varying gain, a multirate digital controller is designed, that works without using inter-sample states and delivers a stable closed loop with predictable behavior at every control update instant. The multirate controller outputs control at each control update instant, while the multirate control scheme is evenly computed every measurement sampling period thereby eliminating the need for very powerful processors for implementation. An illustrative example is provided to demonstrate the usefulness of the proposed multirate digital control scheme.