An optimal model for tunnel lighting control systems

We present a tunnel lighting optimal control model in considering traffic safety and energy-saving problems. Firstly, the demand brightness function with relation to tunnel exterior brightness, traffic flow and speed is described. Then an actual tunnel brightness curve is derived according to lamp equipment layouts and lamp properties in tunnels. Further, a simple method is used to determine an average brightness indicator in tunnels. We present a nonlinear optimal control tunnel lighting model in meeting the demand brightness, total average brightness and minimum dimming ratio constraints and so on. Finally, the simulation results at the JiangBeiLing tunnel of Wenzhou city in China show the optimal control system can meet the demand brightness and total average brightness constraints, and have a notable energy-saving effect.