The PI Control Method in the Input Multi-rate Digital Control System with Low Sample-rate Sensors

The low sample-rate of the sensors limit the control performance of the control system. The traditional control methods such as PI control method can provide little extra effect to improve the system's control property. Thus, the input multi-rate digital control system with PI controller is proposed and analyzed in this paper to improve the system's property, which adopts the low sample-rate sensors. The controlled object is discretized as an input multi-rate digital control system. We propose the design method of the multi-rate PI controller, which can be used in the input multi-rate digital control system. The Lyapunov stability criterion is used to guarantee the stabilization of the closed-loop input multi-rate digital control system. The Schur complement is utilized to solve the Linear Matrix Inequalities and to calculate the parameters of the proposed multi-rate PI controller. In the end, the simulations proved the validity of the proposed PI controller in the input multi-rate digital control system, which can help the system have a faster response speed.