A multirate sampled-data controller with multiplexed inputs and outputs

Abstract

In this thesis, the multirate sampled-data controller is extended to include multiplexed inputs and outputs. The controller detects the ith plant output ni times respectively during a period To with uniform sampling period T and changes the plant inputs once during To. Two designs to obtain the state transition and the input gains matrices of the controller are presented. It will be shown that if a plant satisfies three conditions of being controllable, observable, and having no zeros at origin, this controller can be made equivalent to the state variable feedback control law and the state transition matrix of the controller itself can be set arbitrarily in order to meet the controller's stability. The effects of disturbances to this controller are discussed and it will be explained how to choose the design parameters to minimize the disturbance effects. Control algorithms for this controller are developed and implemented on an IBM PC/AT microcomputer which has a multiplexed A/D and D/A converter aboard as an interfacing unit. Finally, three application examples are then presented to demonstrate the system performance.