Peng hui introduces the application of ARM core board in the traffic signal

Traffic lights manufacturer great introduction psychology has a concept called "time consciousness", refers to people's time consciousness and activity content, emotion, motivation, attitude. The most direct example: eager to await the outcome of a certain time, always feel time is too slow.

 

Crossing through the traffic signal control, traffic signal control machine by changing the color of the intersection traffic signal, make in time and space conflict of vehicles and pedestrians are safe and efficient through the intersection, realize the reasonable control of the traffic flow, and achieve the goal of channel, the improvement of traffic flow. Control methods include:

 

1, induction control

 

According to the real-time change of traffic flow data signal detected green light time. Phase running at least minimum green, if the car through, is to extend the time of an extension of the green, in the extension of the green time continued to have a car to continued to extend the green time, until run to the largest green. Through induction can realize phase resides a special functions such as crossing the street, pedestrians.

 

2, adaptive control

 

According to the condition of the traffic flow, real-time automatic adjustment of the signal control parameters to adapt to the change of traffic flow control method.

 

3, fixed cycle control

 

According to the preset control scheme for phase signal output. During the project operation cycle is long, green, phase sequence changes over the state of the roads.

 

4, more time control

 

In different period of time, intersection traffic condition is also different, in order to achieve good control effect, should be set different control scheme. Signal can be 24 hours a day is divided into several times, each time to run the corresponding cycle, green letter than the solution.

 

5,...

 

Or how to say "have something to ask baidu", see this, saw the traffic lights on and off between and so exquisite! Different period of time, the red light time is different; Even the same time, traffic flow, traffic was red light time is also different. Every day, quietly standing in the intersection traffic signal control cabinet. In traffic signal controller installed on the traffic signal control cabinet, is one of the important composition of modern urban traffic system, used in urban road traffic signal control and management.

 

In the know about the signal several basic concepts:

 

1, what is called phase? What is phase file?

 

Phase is to point to in a signal cycle, at the same time release the set of traffic lights. Things went straight direction traffic lights, for example, 40 seconds for a phase, north and south direction straight down traffic lights 30 seconds to 1 in each phase. Above the phase of the input to the signal control machine, opportunity to convert the phase signal control function identification data, corresponding to each phase 1 set of data, several phase corresponding to several sets of data. Keep the phase data into a file, is called phase file.

 

2, what is time?

 

Vehicle volume in different period, every day is different, if the phase of the release time throughout the day are set to a fixed time, the whole road utilization rate is very low. So, it is introduced a period of time (also called schedule) this means to control the phase release time. At work and after work, for instance, the traffic vehicles such as peak period traffic is bigger, you can set the phase for a long time.

 

3, green ratio and minimum green time, maximum green time what are the differences?

 

Green letter than it is to point to a signal cycle, the ratio of phase time and cycle time; Maximum green time, and minimum green time, generally used in the automatic control of traffic intersection. In the intersection of intelligent, phase release time is set automatically according to the road traffic, also is likely to change every time; In order to avoid the automatic setting of phase release of the value of time is a very large or very small value, must be within the scope of the set value is limited to a; Maximum and minimum green time time is used for the purposes of green.

 

4, what is the green conflict and green waves with a relationship?

 

Given two conflict in the direction of the green light at the same time, is called the green conflict. Green wave band and the green conflict are two completely different definitions. The principle of "green zone" is, according to the road, the distance between the speed of the vehicle and road, set up the lights light up time, to ensure the vehicle starting hit the first green light, as long as the speed according to the regulation, all the lights will be encountered after is a green light.