PID with a Switching Action Controller for Nonlinear Systems of Second-order Controller Canonical Form

The desired performance of nonlinear systems by using only proportional-integral-derivative (PID) controllers is difficult to obtain because of its simple structure. To improve the control performance of nonlinear systems, we proposed a PID with a switching action (PIDSA) controller that only adds the switching action of a sliding mode control (SMC) while maintaining the structure of the PID. The PIDSA controller has the simplicity of PID and the robustness of SMC. In addition, a double integral sliding surface (DISS) was designed to match the characteristics of the PID with the switching action. The stability of the overall system was proved for nonlinear systems by performing the Lyapunov stability analysis. Finally, experiments were conducted on a hydraulic manipulator, which is a highly nonlinear system. The results show that the proposed controller exhibits excellent performance and that DISS enhances the performance compared with using an integral sliding surface.