The automatic command system of traffic lights is the key to realizing the orderly traffic. Traffic lights are an important part of traffic signals and the basic language of road traffic.
Traffic lights consist of red lights (indicating no traffic), green lights (indicating permitting traffic), and yellow lights (indicating warnings). Divided into: motor vehicle signal light, non-motor vehicle signal light, pedestrian crossing signal light, lane signal light, direction indicator signal light, flashing warning signal light, road and railway level crossing signal light.
Road traffic lights are a category of traffic safety products. They are an important tool to strengthen road traffic management, reduce traffic accidents, improve road use efficiency and improve traffic conditions. It is suitable for intersections such as crosses and T-shaped intersections. It is controlled by the road traffic signal control machine, so that vehicles and pedestrians can pass in a safe and orderly manner.
It can be divided into timing control, induction control and adaptive control.
1. Timing control. The traffic signal controller at the intersection runs according to the pre-set timing scheme, also known as regular cycle control. The one that uses only one timing scheme in a day is called single-stage timing control; the one that adopts several timing schemes according to the traffic volume of different time periods is called multi-stage timing control.
The most basic control method is the timing control of a single intersection. Line control and surface control can also be controlled by timing, also called static line control system and static surface control system.
Second, the induction control. Induction control is a control method in which a vehicle detector is set on the entrance of the intersection, and the traffic signal timing scheme is calculated by a computer or an intelligent signal control computer, which can be changed at any time with the traffic flow information detected by the detector. The basic method of induction control is the induction control of a single intersection, which is referred to as single-point control induction control. Single-point induction control can be divided into half-induction control and full-induction control according to the different setting methods of the detector.
3. Adaptive control. Taking 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 calculate A control method that changes the adjustable parameters of the system or generates a control to ensure that the control effect can reach the optimal or sub-optimal control no matter how the environment changes.
Post time: Jun-08-2022
