PID Controller Design for a Second-Order Nonlinear Plant

A procedure for designing PID controllers for the class of second-order nonlinear non-stationary plants is proposed. The proportional and differential components of the controller are transferred to the system feedback channel to reduce possible control jumps. It is shown that the presence of a special fast-response differentiating device in the system generates fast processes against the background of slow working processes, which are identified using the motion separation method. The controller designed on this basis ensures invariance of the system under external uncontrolled disturbances as well as under a change in the plant parameters. The results of numerical simulation of the system in MATLAB illustrate the basic properties of the system.