A subway track bed foreign matter real-time detection alarm system and method

Abstract

The application relates to a subway track bed foreign matter real-time detection alarm system and method, belongs to the railway track bed inspection technical field, and solves the problems of high inspection cost, large data processing amount and poor real-time performance of inspection results of the image processing-based inspection technology; the technical scheme of the application adopts a line-scan laser sensor to inspect the subway track bed, sends the line-scan laser sensor to collect the height data of the subway track bed through an MCU chip, judges whether the track bed has foreign matters by checking whether the height data in the data is greater than the safety height limit value of the track bed, cross-collects the data of the line-scan laser sensor through the reading asynchronous time sequence control line-scan laser sensor, and inversely cross-reads the data collected by the line-scan laser sensor; the scanning height data loss or distortion caused by the scanning light superposition interference between the line-scan laser sensors is avoided, the real-time performance of the collected data is ensured, the application does not need to process complex image data, has high timeliness, the overall structure of the system is simple, and the inspection cost is low.

Description

Technical Field

[0001] This invention belongs to the field of railway track bed inspection technology, and relates to a real-time detection and alarm system and method for foreign objects on subway track beds. Background Technology

[0002] With the advancement of smart town construction in my country, breakthroughs have been achieved in the construction of urban subways in many cities. The increase in subway operating lines has placed higher demands on the daily operation and maintenance of subways. To ensure the safe daily operation of subway lines, subway maintenance requires regular safety inspections of subway tracks. Currently, common inspection technologies are still mainly based on image recognition, using laser scanners and high-precision cameras to collect on-site data, which is then transmitted to the backend for data processing, and inspection results are given based on the processing results. For example, the Chinese invention patent application CN112528861A, published on March 19, 2021, entitled "Method and Device for Foreign Object Detection Applied to Track Bed in Railway Tunnels," monitors the presence of foreign objects in the railway tunnel track bed by acquiring video frame images captured by a pre-set image acquisition device in the railway tunnel.

[0003] Image processing-based inspection technology involves numerous devices with complex integration. Furthermore, the vast amounts of data collected by these devices, especially massive amounts of image data, need to be transmitted to the backend for data synthesis, processing, and analysis before inspection results can be obtained. This results in high inspection costs and poor real-time performance of inspection conclusions. Due to the complexity and high cost of image processing-based systems, they are generally used for automated inspection of subway tunnel walls. Since the railway track bed is located beneath the rails, automated inspection technology based on tunnel walls struggles to obtain effective data about it and cannot detect foreign objects. As the load-bearing foundation for subway operation, the enclosed environment of the track bed means that even small foreign objects pose a safety hazard, while large ones can disrupt subway train operation. If the same inspection methods used for subway tunnel walls were applied to track bed inspection, not only would the redundant system layout lead to even higher inspection costs, but the real-time performance of inspection conclusions would also be poor. Summary of the Invention

[0004] The purpose of this invention is to design a real-time detection and alarm system and method for foreign objects in subway track beds, so as to solve the problems of high inspection cost, large amount of data to be processed, and poor real-time performance of inspection results in image processing-based inspection technology.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0006] A real-time foreign object detection and alarm system for subway track bed includes: a local control unit, a first linear scan laser sensor, and a second linear scan laser sensor; the local control unit includes: an MCU chip, a data acquisition enable modulation circuit, an expansion network port, and a remote communication module; the serial port of the MCU chip is connected to the remote communication module, the I / O port of the MCU chip is connected to the input terminal of the data acquisition enable modulation circuit, the two enable signal output terminals of the data acquisition enable modulation circuit are respectively connected to the first linear scan laser sensor and the second linear scan laser sensor, the network port of the MCU chip is connected to the first linear scan laser sensor, and the SPI port of the MCU chip is connected to the expansion network port. One end of the port is connected, and the other end of the extended network port is connected to the second linear scanning laser sensor; the IO port of the MCU chip outputs two enable signals with the same period and opposite polarity through the output asynchronous timing control acquisition enable modulation circuit, thereby controlling the first and second linear scanning laser sensors to collect track bed cross-sectional height data in an alternating manner; at the same time, the network port and SPI port of the MCU chip read the data collected by the first and second linear scanning laser sensors in an anti-interleaving manner; the serial port of the MCU chip sends out the generated alarm data through the remote communication module.

[0007] Further, the acquisition enable modulation circuit includes: resistors R1, R2, R3, and R4; capacitors C1 and C2; and isolation optocouplers Q1 and Q2. One end of resistor R2 and one end of resistor R4 are connected together and then connected to the IO port of the MCU chip. The other end of resistor R2 is connected to pin 3 of isolation optocoupler Q1. Pin 1 of isolation optocoupler Q1 is connected to the power supply, and pin 4 of isolation optocoupler Q1 is grounded. One end of resistor R1 is connected to pin 5 of isolation optocoupler Q1, and the other end of resistor R1 is connected to pin 6 of isolation optocoupler Q1. One end of capacitor C1 is grounded, and the other end of capacitor C1 is connected to the isolation optocoupler Q2. Pin 6 of optocoupler Q1 is connected to a +5V power supply, and pin 5 of optocoupler Q1 is connected to the first linearly scanned laser sensor. The other end of resistor R4 is connected to pin 1 of optocoupler Q2, pin 3 of optocoupler Q2 is grounded, pin 4 of optocoupler Q2 is grounded, one end of resistor R3 is connected to pin 5 of optocoupler Q2, and the other end of resistor R3 is connected to pin 6 of optocoupler Q2. One end of capacitor C2 is grounded, and the other end of capacitor C2 is connected to pin 6 of optocoupler Q2. Pin 6 of optocoupler Q2 is connected to the power supply, and pin 5 of optocoupler Q2 is connected to the second linearly scanned laser sensor.

[0008] Furthermore, the isolation optocoupler Q1 and isolation optocoupler Q2 are of model ACPL-M61.

[0009] Furthermore, the method for generating the asynchronous acquisition and reading timing is as follows:

[0010] The MCU chip generates a square wave with a period of T from the I / O port via a timer interrupt. After being modulated by the acquisition enable modulation circuit, it generates two enable signals with the same period but opposite polarities. The positive level time of the square wave with period T is the data acquisition time of the line-scan laser sensor. At the same time, the data reading time of each line-scan laser sensor is within the period when the acquisition enable signal of that line-scan laser sensor is invalid; the relationship is as follows:

[0011] T 采 =T 右读 =T 左读 =T / 2

[0012] Among them, T 采 T represents the data acquisition time of the line-scan laser sensor. 左读 T is the time it takes to read the data acquired by the first line-scan laser sensor. 右读 The time for reading data collected by the second linear laser sensor.

[0013] A method for applying the aforementioned real-time foreign object detection and alarm system for subway track bed includes the following steps:

[0014] S1. When the system starts working, record the system startup time T. 启动 Subsequently, the MCU chip’s timer interrupt controls the IO port to generate a square wave. The square wave is matched by the acquisition enable modulation circuit to generate enable signals for the first line scan laser sensor and the second line scan laser sensor.

[0015] S2. When the enable signal is high, the first and second line-scan laser sensors start cross-data acquisition. During the cross-data acquisition process, the MCU chip performs anti-cross data reading through the network port and SPI port to achieve real-time reading after data acquisition.

[0016] S3. After reading the data collected by the corresponding line scan laser sensor, obtain the dataset of all collected heights, traverse and compare the datasets, and check whether the height data H(i) in the dataset is greater than the safety height limit H of the track bed. 限 If no data is greater than H after traversing all data, 限 If the data is greater than or equal to H, it is determined that there are no foreign objects in the track bed. 限 If so, it is determined that there is a foreign object in the track bed;

[0017] S4. After determining that there is a foreign object in the track bed, obtain the current alarm time T. 告警 Subtract system startup time T 启动 The system obtains the time ΔT from system startup to the detection of the foreign object in the track bed, and calculates the location where the foreign object was detected using the system's moving speed V.

[0018] S5. After calculating the location of the foreign object in the track bed, the alarm location and discovery time information of the foreign object in the track bed are sent to the remote communication module through the serial port of the MCU chip. The remote communication module then sends the alarm location and discovery time information of the foreign object in the track bed to the metro automated operation and maintenance platform.

[0019] Furthermore, the dataset is: H 采 ={H(1), H(2), H(3), ... H(i)}, where i ranges from 1 to N, N is the total number of height data collected in this reading, and H(i) represents the i-th height data collected in this reading.

[0020] Furthermore, the formula for calculating the location of foreign objects found in the track bed is as follows: L 异物 =ΔT V = (T) 告警 -T 启动 ) V, where L 异物 This represents the distance the system travels from startup until it detects a foreign object in the track bed.

[0021] Furthermore, the remote communication module transmits the location and discovery time information of the foreign object alarm on the track bed to the metro automated operation and maintenance platform via 4G / GPRS wireless means.

[0022] The advantages of this invention are:

[0023] (1) The technical solution of the present invention uses a line-scan laser sensor to inspect the subway track bed. The MCU chip sends asynchronous timing control to the line-scan laser sensor to collect the height data of the subway track bed. The system checks whether the height data in the dataset is greater than the safe height limit of the track bed to determine whether there are foreign objects in the track bed. There is no need to process complex image data, the timeliness is high, the overall system structure is simple, and the inspection cost is low.

[0024] (2) A method was designed to acquire data from asynchronous timing control line scan laser sensors by cross-acquiring data and to read data from line scan laser sensors by reverse cross-acquiring data. Cross-acquiring data avoids the loss or distortion of scanning height data caused by the superposition of scanning light between line scan laser sensors, and reverse cross-acquiring data ensures the real-time performance of the acquired data. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the real-time detection and alarm system for foreign objects in subway track bed according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the acquisition enable modulation circuit of the real-time detection and alarm system for foreign objects in subway track bed according to an embodiment of the present invention.

[0027] Figure 3 This is a waveform diagram showing the timing of data acquisition for the real-time detection and alarm system for foreign objects in subway track bed according to an embodiment of the present invention.

[0028] Figure 4 This is a flowchart illustrating the workflow of the real-time detection and alarm system for foreign objects in subway track bed according to an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0031] Example 1

[0032] like Figure 1 As shown, a real-time foreign object detection and alarm system for subway track bed includes: a local control unit 10, a left-line scan laser sensor 11, and a right-line scan laser sensor 12; the local control unit 10 includes: an MCU chip 101, a data acquisition enable modulation circuit 102, an expansion network port 103, and a remote communication module 104; the serial port of the MCU chip 101 is connected to the remote communication module 104, the I / O port of the MCU chip 101 is connected to the input terminal of the data acquisition enable modulation circuit 102, the two enable signal output terminals of the data acquisition enable modulation circuit 102 are respectively connected to the left-line scan laser sensor 11 and the right-line scan laser sensor 12, the network port of the MCU chip 101 is connected to the left-line scan laser sensor 11, and the MCU chip 101... The SPI port is connected to one end of the expansion network port 103, and the other end of the expansion network port 103 is connected to the right line-scan laser sensor 12. The IO port of the MCU chip 101 outputs left and right enable signals through the acquisition enable modulation circuit 102 to control the left line-scan laser sensor 11 and the right line-scan laser sensor 12 to acquire data, thereby obtaining complete track bed cross-sectional height data. The network port of the MCU chip 101 is used to read the data acquired by the left line-scan laser sensor 11. The SPI port of the MCU chip 101 reads the data acquired by the line-scan laser sensor 11 through the expansion network port 103. The serial port of the MCU chip 101 sends the generated alarm data out through the remote communication module 104.

[0033] The local control unit 10 controls the left and right linear laser sensors 11 and 12 to cross-collect data and read data in reverse cross-collection via asynchronous timing output. Cross-collection avoids data loss or distortion caused by interference from overlapping scanning beams between the laser sensors, while reverse cross-collection ensures real-time data acquisition. After reading the data, the local control unit 10 compares it with the track bed safety height limit in real time. If the height exceeds the limit, the location of the exceedance point is calculated, an alarm is generated, and sent via the remote communication module 104. The system has a simple overall structure, low inspection costs, and requires no complex background image data processing. Data is collected, processed locally, and the results are sent out in real time.

[0034] like Figure 2 As shown, the acquisition enable modulation circuit 102 includes: resistors R1, R2, R3, and R4; capacitors C1 and C2; and isolation optocouplers Q1 and Q2. One end of resistor R2 and one end of resistor R4 are connected together and then connected to the I / O port of the MCU chip 101. The other end of resistor R2 is connected to pin 3 of isolation optocoupler Q1. Pin 1 of isolation optocoupler Q1 is connected to a +3.3V power supply, and pin 4 of isolation optocoupler Q1 is grounded. One end of resistor R1 is connected to pin 5 of isolation optocoupler Q1, and the other end of resistor R1 is connected to pin 6 of isolation optocoupler Q1. One end of capacitor C1 is grounded, and the other end of capacitor C1 is connected to pin 6 of isolation optocoupler Q1. Connect to a +5V power supply. Pin 5 of the isolation optocoupler Q1 is connected to the left linear scan laser sensor 11 to output a left enable signal. The other end of resistor R4 is connected to pin 1 of isolation optocoupler Q2. Pins 3 and 4 of isolation optocoupler Q2 are grounded. One end of resistor R3 is connected to pin 5 of isolation optocoupler Q2, and the other end of resistor R3 is connected to pin 6 of isolation optocoupler Q2. One end of capacitor C2 is grounded, and the other end of capacitor C2 is connected to pin 6 of isolation optocoupler Q2. Pin 6 of isolation optocoupler Q2 is connected to a +5V power supply. Pin 5 of isolation optocoupler Q2 is connected to the right linear scan laser sensor 12 to output a right enable signal. The isolation optocouplers Q1 and Q2 are of model ACPL-M61.

[0035] The system's workflow is as follows:

[0036] 1) When the system starts working, the MCU chip 101 records the system startup time T. 启动Subsequently, a square wave is generated by controlling the IO port through a timer interrupt. The square wave is matched by the acquisition enable modulation circuit 102 to generate the left and right enable signals of the left linear laser sensor 11 and the right linear laser sensor 12. The left and right enable signals have completely opposite level signals, ensuring that when the left enable signal is valid, the right enable signal is invalid. That is, at the same time, only one of the two linear laser sensors is in the acquisition state, thereby avoiding the problem of loss or distortion of scanning height data caused by the superposition interference of scanning light.

[0037] 2) When the left and right linear laser sensors 11 and 12 are at a high level, they initiate cross-data acquisition. During the cross-data acquisition process, the MCU chip 101 performs anti-cross data reading through the network port and SPI port to achieve real-time data reading after acquisition. The specific timing is as follows: Figure 3 As shown, the MCU chip 101 generates a square wave with a period of T from the IO port via a timer interrupt. After being modulated by the acquisition enable modulation circuit 102, it generates two enable signals with the same period but opposite polarities. The positive level time of the square wave is the data acquisition time of the line scan laser sensor. Simultaneously, the data reading time of each line scan sensor is within the period when the sensor's acquisition enable signal is invalid, realizing left acquisition and right reading, and right acquisition and left reading. The timing relationships are as follows:

[0038] T 采 =T 右读 =T 左读 =T / 2

[0039] Among them, T 采 T represents the data acquisition time of the line-scan laser sensor. 右读 To extend the time for the network port to read data acquired by the right-side linear laser sensor 12, T 左读 T represents the time it takes for the network port to read data collected by the left-side linear scanning laser sensor 11, where T is the period of the generated square wave.

[0040] 3) MCU chip 101 in T 左读 Or T 右读 After reading the data collected by the corresponding line-scan laser sensor, the entire height dataset for this collection is obtained. The dataset is as follows:

[0041] H 采 ={H(1), H(2), H(3),...H(i)}

[0042] Where i ranges from 1 to N, N is the total number of height data points collected in this reading, and H(i) represents the i-th height data point collected in this reading.

[0043] Then, the MCU chip 101 will iterate through and compare the dataset, checking whether the height data H(i) in the dataset is greater than the safety height limit H of the track bed.限 If no data is greater than H after traversing all data, 限 If the data is greater than or equal to H, it is determined that there are no foreign objects in the track bed during this inspection. 限 If there is a foreign object in the track bed during this inspection, it can be determined that there is a foreign object in the track bed.

[0044] 4) After determining that there is a foreign object in the track bed, the MCU chip 101 obtains the current time T. 告警 Subtract system startup time T 启动 The time ΔT from system startup to detection of the foreign object in the track bed is obtained. Using the system's moving speed V, the position of the foreign object relative to the system startup time is obtained:

[0045] L 异物 =ΔT V = (T) 告警 -T 启动 ) V

[0046] 5) After calculating the location of the foreign object in the track bed, the MCU chip 101 transmits the alarm location and discovery time information of the foreign object in the track bed (L... 异物 T 告警 The information is sent to the remote communication module 104 via the serial port of the MCU chip 101, and the remote communication module 104 sends the information to the metro automated operation and maintenance platform via 4G / GPRS wireless means.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A real-time detection and alarm system for foreign objects in subway track bed, characterized in that, include: Local control unit, first line scan laser sensor, second line scan laser sensor; The local control unit includes: an MCU chip, a data acquisition enable modulation circuit, an extended network port, and a remote communication module. The serial port of the MCU chip is connected to the remote communication module. The IO port of the MCU chip is connected to the input of the data acquisition enable modulation circuit. The two enable signal outputs of the data acquisition enable modulation circuit are connected to the first and second linear scan laser sensors, respectively. The network port of the MCU chip is connected to the first linear scan laser sensor. The SPI port of the MCU chip is connected to one end of the extended network port, and the other end of the extended network port is connected to the second linear scan laser sensor. The IO port of the MCU chip outputs two enable signals with the same period but opposite polarity to the data acquisition enable modulation circuit through asynchronous timing control, thereby controlling the first and second linear scan laser sensors to acquire track bed cross-sectional height data in an alternating manner. Simultaneously, the network port and SPI port of the MCU chip read the data acquired by the first and second linear scan laser sensors in an anti-interleaving manner. The serial port of the MCU chip sends the generated alarm data out through the remote communication module. The method for generating the asynchronous acquisition timing is as follows: The MCU chip generates a square wave with a period of T from the I / O port via a timer interrupt. After being modulated by the acquisition enable modulation circuit, it generates two enable signals with the same period but opposite polarities. The positive level time of the square wave with period T is the data acquisition time of the line-scan laser sensor. At the same time, the data reading time of each line-scan laser sensor is within the period when the acquisition enable signal of that line-scan laser sensor is invalid; the relationship is as follows: T 采 =T 右读 =T 左读 =T / 2 Among them, T 采 T represents the data acquisition time of the line-scan laser sensor. 左读 T is the time it takes to read the data acquired by the first line-scan laser sensor. 右读 The time for reading data collected by the second linear laser sensor.

2. The real-time detection and alarm system for foreign objects in subway track bed according to claim 1, characterized in that, The acquisition enable modulation circuit includes: resistors R1, R2, R3, and R4; capacitors C1 and C2; and isolation optocouplers Q1 and Q2. One end of resistor R2 and one end of resistor R4 are connected together and then connected to the I / O port of the MCU chip. The other end of resistor R2 is connected to pin 3 of isolation optocoupler Q1. Pin 1 of isolation optocoupler Q1 is connected to the power supply, and pin 4 of isolation optocoupler Q1 is grounded. One end of resistor R1 is connected to pin 5 of isolation optocoupler Q1, and the other end of resistor R1 is connected to pin 6 of isolation optocoupler Q1. One end of capacitor C1 is grounded, and the other end of capacitor C1 is connected to isolation optocoupler Q2. Pin 6 of Isolation Optocoupler Q1 is connected to a +5V power supply, and pin 5 of Isolation Optocoupler Q1 is connected to the first linearly scanned laser sensor. The other end of resistor R4 is connected to pin 1 of Isolation Optocoupler Q2, pin 3 of Isolation Optocoupler Q2 is grounded, pin 4 of Isolation Optocoupler Q2 is grounded, one end of resistor R3 is connected to pin 5 of Isolation Optocoupler Q2, and the other end of resistor R3 is connected to pin 6 of Isolation Optocoupler Q2. One end of capacitor C2 is grounded, and the other end of capacitor C2 is connected to pin 6 of Isolation Optocoupler Q2. Pin 6 of Isolation Optocoupler Q2 is connected to the power supply, and pin 5 of Isolation Optocoupler Q2 is connected to the second linearly scanned laser sensor.

3. The real-time detection and alarm system for foreign objects in subway track bed according to claim 2, characterized in that, The isolation optocouplers Q1 and Q2 are of model ACPL-M61.

4. A method for applying the real-time detection and alarm system for foreign objects in subway track bed as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1. When the system starts working, record the system startup time T. 启动 Subsequently, the MCU chip’s timer interrupt controls the IO port to generate a square wave. The square wave is matched by the acquisition enable modulation circuit to generate enable signals for the first line scan laser sensor and the second line scan laser sensor. S2. When the enable signal is high, the first and second line-scan laser sensors start cross-data acquisition. During the cross-data acquisition process, the MCU chip performs anti-cross data reading through the network port and SPI port to achieve real-time reading after data acquisition. S3. After reading the data collected by the corresponding line scan laser sensor, obtain the dataset of all collected heights, traverse and compare the datasets, and check whether the height data H(i) in the dataset is greater than the safety height limit H of the track bed. 限 If no data is greater than H after traversing all data, 限 If the data is greater than or equal to H, it is determined that there are no foreign objects in the track bed. 限 If so, it is determined that there is a foreign object in the track bed; S5. After determining that there is a foreign object in the track bed, obtain the current alarm time T. 告警 Subtract system startup time T 启动 The system obtains the time ΔT from system startup to the detection of the foreign object in the track bed, and calculates the location where the foreign object was detected using the system's moving speed V. S6. After calculating the location of the foreign object in the track bed, the alarm location and discovery time information of the foreign object in the track bed are sent to the remote communication module through the serial port of the MCU chip. The remote communication module then sends the alarm location and discovery time information of the foreign object in the track bed to the metro automated operation and maintenance platform.

5. The method according to claim 4, characterized in that, The dataset mentioned is: H 采 ={H(1), H(2), H(3), ... H(i)}, where i ranges from 1 to N, N is the total number of height data collected in this reading, and H(i) represents the i-th height data collected in this reading.

6. The method according to claim 5, characterized in that, The formula for calculating the location of foreign objects found in the track bed is as follows: L 异物 =ΔT V = (T) 告警 -T 启动 ) V, where L 异物 This represents the distance the system travels from startup until it detects a foreign object in the track bed.

7. The method according to claim 6, characterized in that, The remote communication module transmits the location and discovery time of the foreign object alarm on the track bed to the metro automated operation and maintenance platform via 4G / GPRS wireless means.

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