Improved direct digital control algorithm for microprocessor implementation

An improved optimal regulator control system synthesis method has been developed in order to obtain good steady-state characteristics for the designed control system in spite of variations of the parameters of the controlled object. This control system includes proportional action, averaged derivative action, and integral action. Several physical constraints, such as input variable constraints, state variable constraints, and input delay times, are treated simultaneously. To reveal the effectiveness of the method, the speed control system of a static Scherbius induction motor system was synthesized by this method and satisfactory experimental results were obtained using microprocessor system as the controller. In this experiment, the processing time in the microprocessor must be considered as an input delay time; and the input variable constraints due to the restricted range of the controlling angle of the cycloconverter must be taken into account.