Abstract—Since the liquid level control system of the twocontainer
water tank is characterized by nonlinearity and
timing-varying parameter, the paper, based on analysis of
the limitation of conventional PID controller, adopts fuzzy
logic and applies the control method of setting PID
parameter by fuzzy rule to the two-container water tank
liquid level system control to design a fuzzy PID controller
and carries out online setting on three parameters of PID by
MATLAB software simulation. The simulation test shows
that the fuzzy PID controller is better than conventoinal PID
controller in terms of performance and is able to effectively
improve control effects.