Multi-rate adaptive pole-placement control for pneumatic servo system with additive external forces

In the existent pneumatic servo system with additive external forces, the plant is subjected to the constant disturbances caused by additive external forces. In that case, it is difficult to accomplish good control performance by using the conventional design scheme of an adaptive pole-placement control. In this paper, we propose an improved design scheme of the adaptive pole-placement control for the pneumatic servo system with additive external forces. In this design scheme, difference process of the signals in the identification mechanism and the compensator in the controller are introduced to eliminate the influence of the constant disturbances caused by the additive external forces. Furthermore, a multirate type adaptive law is adopted to improve the control performance. The effectiveness of the proposed design scheme is confirmed by experiments using the existent pneumatic servo system.