Traffic signal lamp is a kind of traffic safety products, it is an important tool to strengthen road traffic safety management, reduce or avoid traffic accidents, improve road use efficiency, and improve all aspects of traffic conditions. It is suitable for intersections such as T-shaped and crosses. It is controlled by a road traffic signal controller to guide vehicles and pedestrians to pass safely and in an orderly manner.
Traffic signal lights can be divided into timing control, induction control, and adaptive control.
1, timing control. The traffic signal control machines all operate according to the pre-set timing plan, which is also called fixed-period control. The one that only uses one timing plan is called single-stage timing control; the one that uses several timing plans according to the traffic volume at different times is called multi-stage timing control.
The most basic control method is the timing control of a single intersection. Both line control and area control can also be controlled by timing, which is also called static line control system and static area control system.
2, induction control. Induction control is a control method in which vehicle detectors are installed on the entrances of intersections, and the traffic signal light timing scheme is calculated by a computer or an intelligent signal controller, and can be changed at any time with the traffic information detected by the detector. The basic method of induction control is induction control at a single intersection, referred to as single-point control induction control. Single-point induction control can be divided into semi-induction control and full induction control depending on the detector setting mode.
3, adaptive control. Regarding the traffic system as an uncertain system, it can continuously measure its state, such as traffic flow, number of stops, delay time, queue length, etc., gradually understand and master the objects, compare them with the desired dynamic characteristics, and use the difference to Changing the adjustable parameters of the system or generating a control, so as to ensure that no matter how the environment changes, the control effect can be a control method that achieves better or sub-optimal control.
