Abstract
Today, microprocessors are easily obtained, and many digital control methods can be considered and realized. In this paper, at first, we propose a new optimal control method using only input/output data. The result coincides with the series compensator which can be constructed by optimal regulator incorporated with minimal order observer. However, in the proposed method, the total optimality of closed loop system is derived directly from modified optimal regulator theory.
However, in the above case, there are some cases where the strong stability are not guaranteed. So, we reformulate the method so that it uses the intersample output data as well, then the strong stability is assured for almost all plants with mild restrictions. Further, the final compensator form is given by an optimal output feedback control.
Especially, in the case where the plant is given by the linearlized mechanical system, the above optimal output feedback is always realizable using only 2 samples output data prior to current sample. Therefore, it is a very attractive method for the control of robots, for example.
