The Application Of Fuzzy PID Control In Water Level Control System

Water level control is an important problem in industry control. Aimed at the characteristics of long time lag, nonlinearity and variation with time in the process of level control, a vast range of advanced intelligent controllers are designed to meet the control demand of complex systems,——among which is fuzzy PID controller. Combining the advantages of PID control algorithm and fuzzy control, fuzzy PID control could realize online adjusting of PID parameters, so as to quicken the control system response speed, reduce the overshoot, shorten the transitional period, and decrease the oscillating time. The system has strong robustness and stability, and plays a leading role in fuzzy control.This thesis introduces the application of fuzzy PID control in double-tank water level system. It first builds a mathematical model of the water level control system, illustrating the rationale of PID control, fuzzy control and fuzzy PID. Then it uses a tool of MATLAB to have a simulating experiment of set-point tracking, disturbance rejection, and accommodating to the object's parameter variation. The results show that comparing with the normal PID algorithm, fuzzy PID control algorithm has characteristics such as strong robustness and good dynamic performance. This control method is effective to the double-tank water level system.