Development of a nonlinear PID controller with saturated function design

This paper presents a simple nonlinear proportional-integral-derivative (N-PID) controller incorporated with a saturated function design, for performance improvement of conventional linear PID controller. The proposed controller is formulated by using a new class of saturated function derived from quasi-natural potential function to shape the position and velocity. The global asymptotic stability of the controlled system is proven for the setpoint position control. Simulation and experiment are carried out to demonstrate the effectiveness of the proposed approach.