TOC-PID control for double integrating systems with input saturation

Abstract
This paper introduces a nonlinear composite control, method, i.e., a combination of time optimal control (TOC) and PID control, for double integrating systems with input saturation. The TOC part is designed to enable the time optimization. Unfortunately, it is well known that the classical TOC is not robust with respect to the system uncertainties and measurement noises. Therefore, we proposed the method to solve the drawback of TOC. In the method, when the error is small to a certain level, it will switches to the PID part to overcome the chatter problem caused by the TOC. Finally, the simulation results, approximate time optimization and fair robustness demonstrate the effectiveness and feasibility of the proposed method.