Design and Simulation on PID Variable Damping Ratio Controller of Second-Order System

Generally,in order to improve dynamic performance,second-order systems generally decrease oscillation and overshoot of output response by increasing equivalent damping ratio with velocity feedback.But output response will be dull and system´s speediness property will be worse because of damping ratio´s increment. Variable damping ratio control by fuzzy adaptive PID may adjust system´s damping ratio in real-time on line on the base of output response´s different phases,so improve system´s dynamic property.It is proposed variable damping though establishing PID´s three parameters´ fuzzy logic control rules based on property of PID control and fuzzy logic control.Simulation results verify that the method is feasible,dynamic property´s improvement is prominent,and disturbance rejection property and robust is excellent.