Saturday, November 19, 2016

Senmer News Wire: Application of ARM System on Module in Traffic Signal Machine

There is a concept called “time perception” in psychology, refers to people’s time perception is concerned with activity content, emotion, motivation, and attitude. The most direct example: eager to wait for a result of the time, always felt the time off slowly.

Last week to work late and wait for a red light, I feel red light waiting time is far more than usual! And when I talked it with colleagues, directly to a “time perception” concept to smash me ignorant! In order to explore whether the time perception reasons, after get off work please degree of the mother did a bit of brain up, the final conclusion: red light time longer than usual, really long!

Under the understanding of the traffic light control.

Traffic signal control machine by changing the intersection of traffic signal light color, making the time and space in conflict with the vehicles and pedestrians safely and efficiently through the intersection, the realization of the traffic on the traffic signal to control the intersection of traffic lights, The rational control of the flow, to divert, to improve the purpose of the traffic flow. Control methods include:

1,Induction Control

According to the detected traffic flow data in real time to change the signal green time. Phase at least run the minimum green, if the car through, then extend the extension of a green time, to extend the green time to continue to have a car to reach the green light time, until the maximum green. Through the induction can achieve phase-resident, pedestrians, and other special functions across the street.

2, Adaptive Induction Control

According to the status of traffic flow, real-time automatic adjustment of signal control parameters to adapt to changes in traffic flow control.

3, Fixed-Cycle Control

And the phase signal is output according to the preset control scheme. During the operation of the program cycle length, green letter ratio, phase sequence does not change with the road conditions change.

4, Multi-Time control

At different times, the intersection of traffic conditions are not the same, in order to achieve better control results, should be set to different control programs. Signals can be 24 hours a day divided into several periods, each period of the corresponding cycle, the green letter than the program.

5, Different times,

The red light time is different; even the same time, traffic, traffic flow different red light time also different. Every day quietly stands at the junction of the traffic signal control cabinet, as shown.

Traffic signal machine installed in the traffic signal control cabinet, it is an important component of modern urban transport system, and one for urban road traffic signal control and management.

Traffic signal consists of the liquid crystal display, control panel, light group drive board, button board, power and other components. Control Board Design Block Diagram:

M3352 system on module based on Cortex-A8 processor, up to 800MHz, system on module manufacturers embedded Linux operating system (to support a rich protocol stack and database) on it, to support the user through the QT human-computer interface design to facilitate post-maintenance personnel through the interface to quickly locate Signal lamp failure;

In understanding the signal machine several basic concepts:

1, what is the phase? Phase file is what?

Phase refers to a signal cycle, the release of traffic lights at the same time the collection.

For example, things straight for the direction of traffic lights for 40 seconds for a phase, straight north-south direction of traffic lights for 30 seconds for 1 phase.
Application of ARM System on Module in Traffic Signal Machine
When the above phase is input to the signal controller, the signal will convert the phase into the control function to identify the data, each phase corresponds to a set of data, a number of phase corresponds to a number of groups of data. Save these phase data into a file, called the phase file.

2, what is the time?

In different times of day, traffic flow is different, if all the days of the phase release time is set to a fixed time, then the entire road utilization is very low. Therefore, this introduces a period (also called the time table) to control the phase release time.

For example, in the peak hours of traffic flow such as work and get off work, traffic volume is relatively large, you can set the phase time to a relatively long time.

3, green letter ratio and the maximum green time, what is the difference between the smallest green time?

Green letter ratio is a signal cycle, the phase time and cycle time ratio;

Maximum green time, and the minimum green time, generally used in the intersection of vehicle traffic control above. In the intelligent intersection, the phase release time is based on road traffic automatically set, that is, there may be changes every time; in order to avoid automatically set the phase release time is a very large value or very small Value, the set value must be limited to a range; the maximum green time and the minimum green time are used for this purpose.

4, what is green conflict and green wave with a relationship?

Two release the direction of the conflict in the same time the green light, called green conflict.

Green-band and green-collision are two completely different definitions. The principle of the “Green Wave Band” is to set the time difference of the signal lamp according to the speed of the road vehicles and the distance between the intersections, so as to ensure that the vehicle starts from the first green light and follow the prescribed speed. The semaphores will be green.

Media Contact
Company Name: Shenzhen Graperain Technology Co., Ltd.
Contact Person: Cherry Wang
Phone: +86-755-2302 5312
City: Shenzhen
Country: China

Source: Application of ARM System on Module in Traffic Signal Machine

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