Abstract
This paper presents design of H∞-control for plants that have integrators which have been difficult to be handled in the H∞-mixed sensitivity problem.
In output feedback control based on the mixed sensitivity problem, the plant must not have poles at the origin of the complex plane because of the restrictions of the 2-Riccati algorithm. However, there are many plants that have integrators such as motors and vehicles. Some design methods for plants that have integrators have already been proposed, but in the methods the controllers have no integrators. Therefore if the stepwise disturbances are injected at the input or the states of the plant, the error between the output of the plant and the reference will not converge to zero.
The proposed design is based on partial state feedback control which uses some states of the plant. As in the partial feedback control proposed by Zhang and Hosoe, there is no limitation on the pole of the plant at the origin, it can be applied to the plants that have integrators. The proposed control system has the integrators in the controller, so even if the disturbances are injected at the input or the states of the plants the error will converge to zero. Furthermore in the proposed control system, the degree of the controller can be reduced by the number of the measurable states.
This paper shows the difficulties of the output feedback control in the mixed sensitivity problem, the design method based on the partial feedback control and the application to motion control.
