A method for detecting abnormal state of traffic signal lights

Abstract

The present invention discloses a method for detecting abnormal state of traffic lights, which relates to the field of traffic equipment state detection. The method comprises: for each intersection, obtaining the effective voltage value and effective current value of each signal light in real time; performing red-green simultaneous light detection according to the effective voltage values ​​corresponding to the red light and the green light of the same light group; performing green conflict detection according to the effective voltage values ​​corresponding to the green lights in the preset release conflict direction; performing signal light damage detection according to the effective current values ​​corresponding to each signal light. The method can timely detect abnormal conditions of intersection signal lights: red-green simultaneous light, green conflict and light damage by analyzing and judging the effective values ​​of current and voltage respectively using a preset abnormal detection algorithm, so that the intersection control equipment can timely call the emergency measures plan and automatically report and notify the relevant departments for maintenance.

Description

Technical Field

[0001] The invention relates to the field of traffic equipment state detection, and in particular to a method for detecting abnormal state of a traffic signal lamp. Background Art

[0002] With the rapid development of urbanization in my country, the number of motor vehicles has increased year by year, and urban traffic problems have become increasingly prominent. Many cities use signal control at intersections, and many intersections are equipped with double 8-type countdown devices. Since intersection equipment such as signal lights and countdowns are exposed to the external environment for a long time, or because the equipment is seriously aged due to long installation time, the signal lights and countdowns are damaged, the lines are broken and short-circuited, and the equipment is flooded in rainy and snowy weather, resulting in abnormal intersection signal lights.

[0003] Abnormal equipment conditions include red and green lights, green conflicts, and light damage. There are many factors that lead to red and green lights and green conflicts, such as line overlap due to aging of the line or rainy and snowy weather, or errors in the signal parameters themselves; light damage is generally caused by equipment damage or line disconnection. Whether it is red and green lights, green conflicts or light damage, they are accompanied by huge traffic safety hazards, ranging from traffic congestion and paralysis to traffic accidents. Therefore, how to detect abnormal conditions of traffic lights in a timely manner is a difficulty that needs to be broken through in this field. Summary of the invention

[0004] In view of the above problems and technical requirements, the inventors have proposed a method for detecting abnormal state of traffic lights. The technical solution of the present invention is as follows:

[0005] A method for detecting abnormal state of a traffic light comprises the following steps:

[0006] For each intersection,

[0007] Obtain the effective voltage and current values ​​of each signal light in real time;

[0008] According to the effective voltage values ​​corresponding to the red and green lights of the same light group, red and green simultaneous brightness detection is performed;

[0009] Green conflict detection is performed according to the effective voltage values ​​corresponding to the green lights in the preset release conflict movements;

[0010] According to the effective current value corresponding to each signal lamp, the signal lamp damage detection is carried out.

[0011] A further technical solution is to obtain the effective voltage value of each signal light in real time, including:

[0012] The voltage detection circuit samples each signal light port in real time and outputs a level signal;

[0013] determining an initial voltage value of each signal lamp based on the level signal;

[0014] For each signal light, the detected initial voltage value is smoothed and then compared with a preset voltage threshold, and a voltage greater than the preset voltage threshold is regarded as a valid voltage value.

[0015] Its further technical solution is that the voltage detection circuit includes: first and second diodes, first to fifth resistors, first and second capacitors, and a photoelectric coupler;

[0016] The anode of the first diode is connected to the first end of the first capacitor and is connected to a signal light port, the cathode of the first diode is connected to the anode of the light-emitting side of the photoelectric coupler through the first resistor, the second end of the first capacitor is connected to the cathode of the light-emitting side of the photoelectric coupler through the second resistor, the first end of the third resistor is connected between the first resistor and the anode of the light-emitting side of the photoelectric coupler, the second end of the third resistor is connected between the second resistor and the cathode of the light-emitting side of the photoelectric coupler, the anode of the second diode is connected between the third resistor and the cathode of the light-emitting side of the photoelectric coupler, and the cathode of the second diode is connected between the third resistor and the anode of the light-emitting side of the photoelectric coupler; the collector of the light-receiving side of the photoelectric coupler is connected to the fourth resistor, the fifth resistor and the first end of the second capacitor, the second end of the fourth resistor is connected to the power supply, the second end of the second capacitor and the emitter of the light-receiving side of the photoelectric coupler are grounded, and the second end of the fifth resistor is used as an output end to output a level signal.

[0017] A further technical solution is to determine the initial voltage value of each signal lamp based on the level signal, including:

[0018] The number of times a valid level occurs in the level signal during a predetermined period of time is collected every predetermined period of time, and the valid level is a specified high level or low level;

[0019] The corresponding effective level times under each amplitude voltage affecting the signal light are obtained through experiments, and the corresponding relationship between each amplitude voltage and the effective level times is generated;

[0020] The number of times a valid level occurs in the level signal is compared with the corresponding relationship, and the corresponding voltage is found as the initial voltage value of the signal light.

[0021] A further technical solution is to perform red and green simultaneous brightness detection according to the effective voltage values ​​corresponding to the red light and the green light of the same light group, including:

[0022] If the effective voltage value corresponding to the red light and the effective voltage value corresponding to the green light under the same light group are detected at the same time, and the cumulative number of consecutive detections exceeds the preset red-green conflict threshold, the intersection is determined to be in an abnormal state of red and green at the same time, and emergency response plans are taken.

[0023] A further technical solution is to perform green conflict detection according to the effective voltage values ​​corresponding to the green lights in the preset release conflict direction, including:

[0024] If the effective voltage value corresponding to the green light in the preset release conflict direction is detected at the same time, and the cumulative number of consecutive detections exceeds the preset green conflict threshold, the intersection is determined to be in a green conflict abnormal state and emergency response measures are taken.

[0025] A further technical solution is to obtain the effective current value of each signal lamp in real time, including:

[0026] At each sampling moment, the current value of each signal light port is collected multiple times by the current detection circuit, and the collected values ​​are averaged as the initial current value of each signal light at each sampling moment;

[0027] For each signal lamp, the initial current value is smoothed to obtain the effective current value according to different lamp damage detection conditions.

[0028] Its further technical solution is that the current detection circuit includes: a photoelectric isolation amplifier, a differential amplifier, a sixth and a seventh resistor, a third capacitor, and a third diode;

[0029] The positive input end of the photoelectric isolation amplifier is connected to a signal light port through the sixth resistor, and the output end of the photoelectric isolation amplifier outputs a differential voltage, which is amplified by the differential amplifier and input to the first end of the seventh resistor. The second end of the seventh resistor is respectively connected to the first end of the third capacitor and the anode of the third diode, the second end of the third capacitor is grounded, the cathode of the third diode is connected to the power supply, and the common end of the seventh resistor, the third capacitor and the third diode is used as the output end to output ADC data.

[0030] A further technical solution is to perform signal lamp damage detection according to the effective current values ​​corresponding to each signal lamp, including:

[0031] When testing the current of each signal lamp,

[0032] The initial current value at each sampling moment is directly smoothed to obtain the effective current value;

[0033] If the effective current value is greater than the preset maximum current threshold, and the cumulative number of consecutive detections exceeds the preset excessive current threshold, the signal light head is determined to be in an abnormal current state, and emergency response measures are taken.

[0034] A further technical solution is to detect the damage of the signal lamps according to the effective current values ​​corresponding to the respective signal lamps, and further includes:

[0035] When testing the lighting of each signal light,

[0036] After the intersection lights are on for a certain period of time, the initial current value is smoothed to obtain the effective current value;

[0037] If the effective current value is less than the preset minimum lighting current threshold, and the cumulative number of consecutive detections exceeds the preset lighting threshold, it is determined that the signal light is off when it needs to be on and is in a damaged state, and emergency response measures are taken;

[0038] When testing the off state of each signal light,

[0039] After the lights at the intersection are turned off for a certain period of time, the initial current value is smoothed to obtain the effective current value;

[0040] If the effective current value is greater than the preset minimum lighting current threshold, and the cumulative number of consecutive detections exceeds the preset lighting threshold, it is determined that the signal light is on when it needs to be turned off and is in a damaged state, and emergency response measures are taken.

[0041] The beneficial technical effects of the present invention are:

[0042] This method collects the current and voltage of the signal light for multiple times, obtains the effective value of the current and voltage after certain processing, and analyzes and judges the effective value of the current and voltage using a preset anomaly detection algorithm. It can timely detect abnormal conditions of intersection signal lights: red and green are on at the same time, green conflicts, and light damage, so that the intersection control equipment (signal machine) can call emergency measures in time, and automatically report to the relevant departments for maintenance, so as to prevent intersection paralysis and abnormal conflict trends caused by abnormal disorder of signal light equipment, reduce traffic safety hazards, and avoid traffic accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a flow chart of the abnormal state detection method of traffic lights provided in this application.

[0044] Figure 2 This is a voltage detection circuit diagram provided by this application.

[0045] Figure 3 This is a current detection circuit diagram provided by this application. DETAILED DESCRIPTION

[0046] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0047] Please refer to Figure 1As shown, an embodiment of the present application provides a method for detecting abnormal status of traffic lights. The method can detect the status of each signal light at each intersection. Each intersection has many groups of signal lights. Usually, the motor vehicle light group has three lamp heads: green, yellow, and red. The pedestrian light group consists of two lamp heads: green and yellow. The specific contents of the method are described below, including the following contents:

[0048] (1) Obtain the effective voltage value of each signal light in real time.

[0049] First, the voltage detection circuit samples each signal light port in real time and outputs a level signal. In this embodiment, each signal light is equipped with a voltage detection circuit, which includes: a first diode, a second diode, a first to a fifth resistor, a first capacitor, a second capacitor, and a photoelectric coupler, and the connection relationship is as follows: Figure 2 As shown: the anode of the first diode D1 is connected to the first end of the first capacitor C1 and is connected to a signal light port LO1, the cathode of the first diode D1 is connected to the anode of the light-emitting side of the photoelectric coupler U1 through the first resistor R1, the second end of the first capacitor C1 is connected to the cathode of the light-emitting side of the photoelectric coupler U1 through the second resistor R2, the first end of the third resistor R3 is connected between the first resistor R1 and the anode of the light-emitting side of the photoelectric coupler U1, the second end of the third resistor R3 is connected between the second resistor R2 and the cathode of the light-emitting side of the photoelectric coupler U1, the anode of the second diode D2 is connected between the third resistor R3 and the cathode of the light-emitting side of the photoelectric coupler U1, and the cathode of the second diode D2 is connected between the third resistor R3 and the anode of the light-emitting side of the photoelectric coupler U1. The collector of the light-receiving side of the photocoupler U1 is connected to the fourth resistor R4, the fifth resistor R5 and the first end (common end) of the second capacitor C2, the second end of the fourth resistor R4 is connected to the power supply, the second end of the second capacitor C2 and the emitter of the light-receiving side of the photocoupler U1 are grounded, and the second end of the fifth resistor R5 is used as the output end DRV_V_LO1 to output a level signal. The strong electric signal of the signal light is collected from LO1, and the strong electric signal is converted into a level signal that can be recognized by the I / O port of the MCU through a protection circuit composed of a resistor and a diode, and then through a photocoupler, and output to the MCU through DRV_V_LO1, thereby improving the safety and stability of the traffic system.

[0050] Secondly, the initial voltage value of each signal light is determined based on the level signal. Specifically, the number of times the effective level occurs in the level signal during the predetermined period is collected. The effective level is a specified high level or low level. In this embodiment, the high level is specified as the effective level. Through experiments, the corresponding number of effective levels under each amplitude voltage that affects the signal light is obtained, and the corresponding relationship between each amplitude voltage and the number of effective levels is generated. The number of times the effective level occurs in the level signal is compared with the corresponding relationship, and the corresponding voltage is found as the initial voltage value of the signal light. In this embodiment, an oscilloscope and a voltage generator are used in the laboratory to collect voltages of various amplitudes that affect the signal lights, and the number of high levels of the voltages of the relevant amplitudes is obtained, so as to formulate a corresponding relationship between the number of I / O high levels and the voltage value, which is exemplarily expressed as follows: 0 to 17 times: 0V, 18 to 41 times: 80V, 42 to 54 times: 100V, 45 to 61 times: 120V, 62 to 67 times: 140V, 68 to 71 times: 160V, 72 to 74 times: 180V, 75 to 76 times: 220V, 77 to 80 times: 240V.

[0051] Since the voltage at the intersection is generally 220V 50HZ AC, and its cycle is 20 milliseconds, in this embodiment, the number of high levels of each I / O port of the MCU is collected every 20 milliseconds, and then the initial voltage value of each signal light is found from the corresponding relationship shown above. The collected initial voltage value is transmitted to the signal control machine or the intersection edge calculator for abnormal detection and judgment.

[0052] Finally, for each traffic light, the signal controller or the intersection edge calculator first smoothes the initial voltage value, then compares it with the preset voltage threshold, and regards the voltage greater than the preset voltage threshold as a valid voltage value.

[0053] (2) Perform red-green simultaneous lighting detection based on the effective voltage values ​​corresponding to the red and green lights of the same light group. Since the red and green lights of the same light group cannot be on at the same time, otherwise it will affect the judgment of drivers / pedestrians. Therefore, if the effective voltage value corresponding to the red light and the effective voltage value corresponding to the green light of the same light group are detected at the same time (i.e., they are on at the same time), and the cumulative number of consecutive detections exceeds the red-green conflict threshold preset in the signal machine (for example, 3 times), then the intersection is determined to be in an abnormal red-green simultaneous lighting state, and emergency response plans are taken, such as notifying the intersection control unit (signal control machine) of the abnormal red-green simultaneous lighting information, so as to control the yellow flashing of the light group signal for a period of time and then switch back to the initial timing plan, and then re-sample and detect. If it is still in the abnormal red-green simultaneous lighting state, notify the maintenance personnel to handle it.

[0054] (3) Green conflict detection is performed based on the effective voltage values ​​corresponding to the green lights in the preset release conflict direction. Since there are many conflict points between the various directions at the intersection, vehicles with conflicting directions cannot be released at the same time, otherwise vehicle collision accidents are likely to occur. For example, the east-west straight and north-south straight directions can be set as preset release conflict directions. Therefore, if the effective voltage values ​​corresponding to the green lights in the preset release conflict direction are detected at the same time (i.e., the lights are on at the same time), and the cumulative number of consecutive detections exceeds the preset green conflict threshold value inside the signal machine (for example, 7 times), it is determined that the intersection is in a green conflict abnormal state, and an emergency plan is adopted. The processing method can refer to the emergency plan processing shown in point (2), and will not be repeated later.

[0055] (4) Obtain the effective voltage and current values ​​of each signal light in real time.

[0056] First, at each sampling moment, the current value of each signal light port is collected multiple times (for example, 6 times) by the current detection circuit, and the collected values ​​are averaged as the initial current value of each signal light at each sampling moment, and the collected initial current value is transmitted to the signal control machine or the intersection edge calculator for abnormal detection and judgment. In this embodiment, each signal light is equipped with a current detection circuit, which includes: a photoelectric isolation amplifier dedicated to AC servo motor current sampling, a differential amplifier, a sixth and seventh resistor, a third capacitor, and a third diode, and the connection relationship is as follows: Figure 3 As shown: the positive input end of the photoelectric isolation amplifier U2 is connected to a signal light port DRV_DIT_OUT through the sixth resistor R6 to collect electrical signals, and the output end of the photoelectric isolation amplifier U2 outputs a differential voltage, which is amplified by the differential amplifier U3 and input to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is respectively connected to the first end of the third capacitor C3 and the anode of the third diode D3, the second end of the third capacitor C3 is grounded, and the cathode of the third diode D3 is connected to the power supply, and the common end of the seventh resistor R7, the third capacitor C3 and the third diode D3 is used as the output end AD_DIT_OUT_IN to output ADC data. This circuit can suppress common mode signals, thereby improving the measurement accuracy of the signal.

[0057] Finally, for each signal lamp, the initial current value is smoothed according to different lamp damage detection conditions to obtain the effective current value. The smoothing time of different lamp damage detection conditions will be described in detail in point (5) below.

[0058] (5) Perform signal light damage detection based on the effective current value corresponding to each signal light.

[0059] When testing the current of each signal light, the initial current value at each sampling moment is directly smoothed to obtain the effective current value, which is compared with the maximum current threshold preset inside the signal machine. If the effective current value is greater than the maximum current threshold, and the cumulative number of consecutive detections exceeds the preset current over-threshold (for example, 7 times), it is determined that the current of the signal light head is too large and in an abnormal current state, and emergency response measures are taken.

[0060] When performing the lighting detection of each signal light, in order to more accurately determine the current status of the signal light, the initial current value is smoothed to obtain the effective current value after the intersection light is on for a certain period of time (for example, after 1.4 seconds). If the effective current value is less than the minimum lighting current threshold preset inside the signal machine, and the cumulative number of consecutive detections exceeds the preset light-off threshold (for example, 7 times), it is determined that the signal light is off when it needs to be on and is in a damaged state, and emergency response measures are taken.

[0061] When performing the off detection of each signal light, in order to more accurately determine the current status of the signal light, the initial current value is smoothed to obtain the effective current value after the intersection light is off for a certain period of time (for example, after 2.4 seconds). If the effective current value is greater than the preset minimum on current threshold, and the cumulative number of consecutive detections exceeds the preset on threshold (for example, 7 times), it is determined that the signal light is on when it needs to be off and is in a damaged state, and emergency response measures are taken.

[0062] The above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A method for detecting abnormal state of a traffic light, characterized in that: The method comprises: For each intersection, Obtain the effective voltage and current values ​​of each signal light in real time; According to the effective voltage values ​​corresponding to the red and green lights of the same light group, red and green simultaneous brightness detection is performed; Green conflict detection is performed according to the effective voltage values ​​corresponding to the green lights in the preset release conflict movements; According to the effective current value corresponding to each signal lamp, the signal lamp damage detection is carried out.

2. The method for detecting abnormal state of a traffic light according to claim 1, characterized in that: Get the effective voltage value of each signal light in real time, including: The voltage detection circuit samples each signal light port in real time and outputs a level signal; determining an initial voltage value of each signal lamp based on the level signal; For each signal lamp, the detected initial voltage value is smoothed and then compared with a preset voltage threshold, and a voltage greater than the preset voltage threshold is regarded as a valid voltage value.

3. The method for detecting abnormal state of a traffic light according to claim 2, characterized in that: The voltage detection circuit includes: first and second diodes, first to fifth resistors, first and second capacitors, and a photoelectric coupler; The anode of the first diode is connected to the first end of the first capacitor and is connected to a signal light port, the cathode of the first diode is connected to the anode of the light-emitting side of the photoelectric coupler through the first resistor, the second end of the first capacitor is connected to the cathode of the light-emitting side of the photoelectric coupler through the second resistor, the first end of the third resistor is connected between the first resistor and the anode of the light-emitting side of the photoelectric coupler, the second end of the third resistor is connected between the second resistor and the cathode of the light-emitting side of the photoelectric coupler, the anode of the second diode is connected between the third resistor and the cathode of the light-emitting side of the photoelectric coupler, and the cathode of the second diode is connected between the third resistor and the anode of the light-emitting side of the photoelectric coupler; the collector of the light-receiving side of the photoelectric coupler is connected to the fourth resistor, the fifth resistor and the first end of the second capacitor, the second end of the fourth resistor is connected to the power supply, the second end of the second capacitor and the emitter of the light-receiving side of the photoelectric coupler are grounded, and the second end of the fifth resistor is used as the output end to output the level signal.

4. The method for detecting abnormal state of a traffic light according to claim 2, characterized in that: Determining an initial voltage value of each signal lamp based on the level signal includes: Collecting the number of times a valid level occurs in the level signal during a predetermined period of time, wherein the valid level is a specified high level or low level; The corresponding effective level times under each amplitude voltage affecting the signal light are obtained through experiments, and the corresponding relationship between each amplitude voltage and the effective level times is generated; The number of times the effective level occurs in the level signal is compared with the corresponding relationship, and the corresponding voltage is found as the initial voltage value of the signal light.

5. The method for detecting abnormal state of a traffic light according to claim 1, characterized in that: The red and green simultaneous light detection is performed according to the effective voltage values ​​respectively corresponding to the red light and the green light of the same light group, including: If the effective voltage value corresponding to the red light and the effective voltage value corresponding to the green light under the same light group are detected at the same time, and the cumulative number of consecutive detections exceeds the preset red-green conflict threshold, the intersection is determined to be in an abnormal state of red and green at the same time, and emergency response plans are taken.

6. The method for detecting abnormal state of a traffic light according to claim 1, characterized in that: The green conflict detection is performed according to the effective voltage values ​​respectively corresponding to the green lights in the preset release conflict movement, including: If the effective voltage value corresponding to the green light in the preset release conflict direction is detected at the same time, and the cumulative number of consecutive detections exceeds the preset green conflict threshold, the intersection is determined to be in a green conflict abnormal state and emergency response measures are taken.

7. The method for detecting abnormal state of a traffic light according to claim 1, characterized in that: Get the effective current value of each signal light in real time, including: At each sampling moment, the current value of each signal light port is collected multiple times by the current detection circuit, and the collected values ​​are averaged as the initial current value of each signal light at each sampling moment; For each signal lamp, the initial current value is smoothed to obtain the effective current value according to different lamp damage detection conditions.

8. The method for detecting abnormal state of a traffic light according to claim 7, characterized in that: The current detection circuit includes: a photoelectric isolation amplifier, a differential amplifier, a sixth and a seventh resistor, a third capacitor, and a third diode; The positive input end of the photoelectric isolation amplifier is connected to a signal light port through a sixth resistor, and the output end of the photoelectric isolation amplifier outputs a differential voltage, which is amplified by the differential amplifier and input to the first end of the seventh resistor. The second end of the seventh resistor is respectively connected to the first end of the third capacitor and the anode of the third diode, the second end of the third capacitor is grounded, and the cathode of the third diode is connected to the power supply. The common end of the seventh resistor, the third capacitor and the third diode is used as the output end to output ADC data.

9. The method for detecting abnormal state of a traffic light according to claim 7, characterized in that: The signal lamp damage detection is performed according to the effective current values ​​corresponding to the respective signal lamps, including: When testing the current of each signal lamp, The initial current value at each sampling moment is directly smoothed to obtain the effective current value; If the effective current value is greater than the preset maximum current threshold, and the cumulative number of consecutive detections exceeds the preset excessive current threshold, it is determined that the signal lamp head is in an abnormal current state, and emergency response measures are taken.

10. The method for detecting abnormal state of a traffic light according to claim 7, characterized in that: The signal lamp damage detection is performed according to the effective current values ​​corresponding to the respective signal lamps, and further includes: When testing the lighting of each signal light, After the intersection lights on for a certain period of time, the initial current value is smoothed to obtain an effective current value; If the effective current value is less than the preset minimum lighting current threshold, and the cumulative number of consecutive detections exceeds the preset lighting threshold, it is determined that the signal light is off when it needs to be on and is in a damaged state, and emergency response measures are taken; When testing the off state of each signal light, After the lights at the intersection are turned off for a certain period of time, the initial current value is smoothed to obtain an effective current value; If the effective current value is greater than the preset minimum lighting current threshold, and the cumulative number of consecutive detections exceeds the preset lighting threshold, it is determined that the signal light is on when it needs to be turned off and is in a damaged state, and emergency response measures are taken.

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