Freeway on-ramp metering using fuzzy immune PID controller

Aiming at the nonlinear and time variable characteristics of freeway traffic system, a fuzzy immune PID controller is designed and applied to freeway ramp metering based on the biological immune feedback regulating law and the adaptive ability of fuzzy inference. The freeway traffic flow model is firstly built. Then the principle of immune controller is formulated. Combined fuzzy inference with nonlinear feedback method, a freeway on-ramp metering is realized. Finally, the control system is simulated. The result shows that the fuzzy immune PID controller has good dynamic and steady-state performance. This method is very effective to the on-ramp metering.