Particle swarm optimization based PI controller for freeway ramp metering

A PI (Proportional-Integral) control method based on particle swarm optimization (PSO) is proposed to regulate the number of vehicles entering a freeway entrance point. First, the objective of ramp metering is determined, and the freeway traffic flow model is built. Then the particle swarm algorithm is formulated. In conjunction with nonlinear feedback theory, PSO based PI controller for on-ramp metering is designed. Finally, the controller is simulated in MATLAB software. The result shows that the controller designed has fast response, and good dynamic and steady-state performance. This method has a good effect on freeway ramp metering.