CN205050347U - Intelligence time delay traffic signal lamp system based on PLC control - Google Patents

Abstract

The utility model relates to an intelligent time-delay traffic signal light system based on PLC control, which belongs to the field of traffic control and communication. Including traffic flow detection circuit, PLC controller, signal light display circuit. The control system is divided into daytime control mode and night control mode. The daytime control mode is divided into normal mode and strong pass mode. In normal mode, the built-in counter of PLC is used to count the number of vehicles and calculate the stranded vehicles in the lanes in each direction to judge whether a green light delay is required, and at the same time detect whether a forced pass is required. When there is an urgent vehicle, turn on the corresponding strong pass switch to let the urgent vehicle pass first. All lane signal lights in night control mode turn yellow. The utility model uses real-time detection and judgment delay to avoid the red light when there are many vehicles in a certain direction when the traffic is busy in one direction, but the green light is still green when there are no vehicles in other directions, which reduces the pressure of the traffic rush hour and the main road. The congestion at the intersection will maximize the effective utilization of the traffic intelligent system.

Description

An intelligent delay traffic signal light system based on PLC control

Technical field:

The utility model relates to an intelligent time-delay traffic signal light system based on PLC control, which belongs to the field of traffic control and communication. .

Background technique:

With the rapid development of my country's economy, people's living standards are generally improving, and the number of people who own private cars is gradually increasing, which makes the problem of urban traffic congestion increasingly prominent. Therefore, in order to ensure the orderly, safe and fast urban traffic, improve the traffic capacity of the urban road network, and realize the scientific management of traffic is imminent. The usual way of traditional traffic control lights at crossroads is: through the investigation of vehicle flow in advance, the time delay of traffic lights in two directions is pre-set by using statistical methods. However, in fact, the traffic flow is a variable, and its determination is uncertain. There are great differences in traffic flow at different intersections at different times. . Even after a long period of test operation, such a phenomenon may still occur: there are almost no vehicles passing by in the direction of the green light, while vehicles in the direction of the red light are waiting in a long queue. This situation will inevitably affect the driver's mood, more or less make passengers complain, and it is also a waste of manpower and material resources.

In order to solve the above problems, it is very realistic and necessary to adopt a scheme that can automatically adjust and control according to the change of traffic flow. The utility model is a traffic light signal system at a crossroad controlled by PLC. This intelligent traffic signal control system uses real-time detection and judgment delay to avoid the red light when there are many vehicles in one direction when the traffic is busy in one direction, but the green light is still on when there are no vehicles or fewer vehicles in other directions. , Alleviate the pressure of the traffic peak period and the congestion at the intersection of the main arterial roads, and maximize the effective utilization rate of the traffic intelligent system. It can effectively improve the traffic efficiency at the intersection and relieve traffic congestion.

Utility model content:

In view of the above situation, in order to solve the defects of the prior art, the purpose of this utility model is to provide a kind of intelligent delay traffic signal light system based on PLC control, including traffic flow detection circuit, PLC controller, signal light display circuit, it is characterized in that, Said traffic flow detection circuit is arranged beside the intersection, said signal light display circuit and PLC controller are arranged on the signal light frame of the intersection, wherein said traffic signal light used to control the operation of traffic flow is connected to control traffic light indication switching module and the crossroad signal control machine of the mode switching module, it is characterized in that: the described crossroad signal control machine is connected with the piezoelectric sensor that is located at each crossroad exit, and the described piezoelectric sensor is buried in the intersection exit road The edge is at a distance of 160m underground.

Preferably, the intelligent time-delayed traffic signal light system based on PLC control is characterized in that the PLC controller is S7-200PLC, the CPU of S7-200PLC is CPU226, and the expansion module is EM223.

Preferably, the PLC-based intelligent time-delay traffic signal system is characterized in that the mode switching module is divided into day mode control and night mode control, and the day mode control is divided into normal mode control with strong pass mode control.

The beneficial effects of the utility model are:

The intelligent traffic signal control system of the utility model uses real-time detection and judgment delay to avoid red lights when there are many vehicles in a certain direction when the traffic is busy in one direction, but there are no vehicles or few passing vehicles in other directions and the lights are still on. The green light reduces the pressure of traffic rush hour and the congestion at the intersection of main arterial roads, and the control system is divided into two stages of control: daytime control mode and nighttime control mode. The daytime control mode also has a forced pass mode. Express vehicles have priority. In the night control mode, the lane signal lights all turn into yellow lights, reminding drivers to drive carefully at night. At the same time, the night mode disconnects the switch of the vehicle detection count, saving electricity. Maximize the effective utilization of traffic intelligence systems. It can effectively improve the traffic efficiency at the intersection and relieve traffic congestion.

Description of drawings:

For ease of illustration, the utility model is described in detail by the following specific implementation and accompanying drawings.

Accompanying drawing 1 is the utility model PLC external wiring diagram

Accompanying drawing 2 is a schematic diagram of the layout of the intersection device of the present invention

detailed description:

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is described below through specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and not intended to limit the scope of the present invention. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessarily confusing the concept of the present invention.

The utility model provides an intelligent time-delay traffic signal light system based on PLC control, which includes a traffic flow detection circuit, a PLC controller, and a signal light display circuit, and is characterized in that the control system is divided into two sections: a daytime control mode and a nighttime control mode Control, the night control mode signal light turns yellow, and the daytime control mode is divided into normal mode and strong pass mode; in normal mode, after the signal light runs for half a cycle, the piezoelectric sensor is used to detect the passage of vehicles in the lane, and then the PLC is used to detect the passing of vehicles in the lane. The built-in counter counts the number of vehicles and calculates the amount of vehicles stranded in the lanes in each direction. According to the delay conditions, it is judged whether the delay of the green light is realized, and at the same time, it is detected whether a forced pass is required; when there is an urgent vehicle, turn on the corresponding forced pass switch. Let the emergency vehicles pass first; the night control mode lane signal lights all turn into yellow lights, reminding night drivers to drive carefully, and at the same time, the night mode disconnects the switch of vehicle detection and counting, which saves power consumption; the traffic flow detection circuit is Use piezoelectric sensors to detect traffic in all directions at crossroads; place piezoelectric sensors underground and embed piezoelectric sensors 160 meters away from each crossroad. Assume that the same detector is installed at the exit (stop line) on each roadway and at the entrance at a certain distance from the exit. The distance between the two sensors on the same lane is the normal operation of the lane. The longest parking distance allowed is better.

In this embodiment, the overall control idea of the control system of the utility model is to start the first cycle of the PLC, clear the output and the counter, and set the initial value at the same time. At the same time, read the current time of the PLC, and compare and judge. When the current time of the PLC is greater than or equal to 5 and less than 22, that is, during the period from 5:00 am to 23:00 pm, the daytime control mode is adopted. When the current time of the PLC is greater than 22 or less than 5, that is, from 23:00 to 5:00 the next day, the night control mode is adopted. In the daytime control mode, after executing a cycle, read and compare the current time of the PLC again, if it is still in the daytime period, continue to execute the daytime control mode until after a certain cycle is executed, the current time of the PLC enters the nighttime period , execute night control mode. In the night control mode, read and compare the current time of the PLC from time to time, and if it is not satisfied, it will enter the day control mode.

The described daytime control mode of the utility model is the main part of the control system, and is the main and important operation mode of the control system. The specific process is shown in Figure 2. When the current time of the PLC belongs to the time period of the day mode, the vehicle counting and strong pass detection are started, and the signal lights work at the same time. First, the green light turns on when the thing turns left, and the time is 20s (can be set according to the experience value); after the timer ends, the green light flashes for 2 seconds when the thing turns left, and the traffic of vehicles turning left is prohibited; then the yellow light turns on when the left turns for 3 seconds; When the straight-going green light is on, set a timer for 30s first (set according to experience values). After the timer expires, the delay starts. The delay conditions are: the maximum retention of east-west traffic - the maximum retention of north-south traffic > the fixed value δ and the retention of north-south traffic is less than δ and the delay time does not exceed the maximum delay time; when the delay condition is no longer met, the east-west straight green light flashes for 2s; then the east-west straight yellow light turns on for 3s; so far, the half cycle ends. Next is north-south traffic, which is similar to east-west traffic. First turn left from north to south, the green light turns on for 30 seconds, then flashes for 2 seconds, and then the yellow light turns on; then, the north-south straight line turns green and has a delay. After the delay ends, the green light flashes for 2 seconds, and then the yellow light turns on. . The whole cycle is over.

The night mode of the utility model is very simple. When the current time of the PLC belongs to the time period of the night mode, the lane signal lights all turn into yellow lights to remind drivers to drive carefully at night. At the same time, the night mode disconnects the switch of the vehicle detection count, saving electricity.

The strong pass mode is an important control unit in the daytime control unit. The forced on-off of emergency vehicles is controlled by a forced-on switch. When there is no emergency vehicle, control according to the normal cycle plan. When the emergency vehicle comes, turn on the emergency vehicle forced pass button. Regardless of the previous signal situation, the green light in the direction of the emergency vehicle will be forcibly turned on until the emergency vehicle passes normally. original state. After the emergency vehicle runs normally, the method of returning to the original state can be adopted, or the method of continuing this state and circulating downward can be adopted. Since returning to the original state requires a switching time of 5s (for safety, it is necessary to add the green light flashing for 2s and the yellow light for 3s), and the time for the express vehicle to pass the intersection is not much different from the fixed timing, and it is not necessarily reasonable to return to the original state , so the method of circulating downwards following the strong pass state is adopted.

The basic principles and main features of the present utility model and the advantages of the present utility model have been shown and described above. Those skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model The new model also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection required by the utility model is defined by the appended claims and their equivalents.

Claims (2)

1. An intelligent time-delayed traffic signal light system based on PLC control, comprising traffic flow detection circuit, PLC controller, expansion module EM223, traffic signal light display circuit, traffic light signal light indication switching module, traffic light signal light mode switching module, its characteristics In that: the traffic flow detection circuit is arranged beside the intersection, the signal light display circuit and the PLC controller are arranged on the signal light stand at the intersection, and the PLC controller is connected to a vehicle located at each intersection through the RS485 communication interface. The piezoelectric sensor of the exit road, the piezoelectric sensor is buried at a distance of 160m from the edge of the intersection exit road. 2. A kind of intelligent time-delay traffic signal light system based on PLC control according to claim 1, characterized in that: said PLC controller is S7-200PLC, the CPU of S7-200PLC is CPU226, and the expansion module is EM223.