Railway head platform range finder

Abstract

The application discloses a railway top platform range finder and relates to the field of railway safety monitoring. The platform range finder is configured as a railway station field propulsion operation safety monitoring component integrating laser ranging and photoelectric sensing. The railway station field propulsion operation safety monitoring component comprises at least two groups of sensor units, a wireless transmission subsystem and an upper computer. Two groups of sensor units are respectively arranged on A and B two operation tracks in the station field. Each group of sensor units comprises a group of laser ranging sensors and four groups of photoelectric sensors. The laser ranging sensors are installed at the track ends and are used for detecting the distance between the vehicle and the track end in real time and outputting the distance value. The railway top platform range finder realizes high-reliability real-time distance monitoring and hierarchical voice alarm of the propulsion operation in a complex environment through laser ranging and photoelectric sensing double-redundancy fusion detection, wireless transmission and multi-station automatic switching.

Description

Technical Field

[0001] This invention relates to railway safety monitoring technology, specifically to a railway top platform rangefinder. Background Technology

[0002] As a crucial component of the national comprehensive transportation system, railway freight transport undertakes the core task of long-distance transportation of bulk commodities and containerized goods. With the continuous development of the national economy and the rapid growth of logistics demand, railway freight volume has shown a year-on-year upward trend, and the frequency and density of shunting operations within railway yards have also increased significantly. In railway yard shunting operations, train propulsion is an extremely common and indispensable operational step. Its main operation involves the locomotive (cab) pushing the vehicles to be assembled or unloaded from one end of the track to the end line to achieve the positioning and parking of the vehicles or their assembly with other vehicles.

[0003] However, the pushing operation is also widely recognized as one of the riskiest aspects of shunting operations. During the pushing process, the rolling car is positioned in front of the locomotive, and the driver's view is obstructed, making it impossible to directly observe the distance between the front of the car and the end line of the track. If the pushing speed is not properly controlled or the distance judgment is inaccurate, the car can easily run off the end line of the track, causing serious safety accidents such as derailment, overturning, or collision with station facilities. These accidents can range from minor damage to the cars and track equipment to serious disruptions to rail transport, cargo damage, and even injuries or fatalities to personnel, posing a significant threat to the continuity and safety of railway logistics.

[0004] Currently, safety monitoring of railway station operations mainly relies on the following methods:

[0005] The first method is the traditional manual lookout. This involves workers standing at the front of the vehicle or beside the track, visually observing and relaying distance information to the driver via hand gestures or walkie-talkies. This method relies entirely on the worker's experience, eyesight, and attention. In low-visibility environments such as nighttime, heavy fog, heavy rain, or sandstorms, the lookout's field of vision is significantly reduced, making it difficult to guarantee accurate judgment and timely response. Furthermore, worker fatigue caused by prolonged, high-intensity work is a significant safety hazard.

[0006] Secondly, some stations employ single-sensor ranging methods. These include laser ranging, ultrasonic ranging, or radar ranging, where distance to vehicles is detected in real-time by ranging devices installed at the ends of the tracks. While this approach improves automation and reduces manual intervention, single sensors have inherent limitations. For example, laser ranging relies on the emission and reflection of a laser beam. In adverse weather conditions such as rain, fog, or sandstorms, the laser beam undergoes severe scattering and attenuation during atmospheric transmission, leading to a sharp decrease in reflected signal strength or even complete loss of reception. This significantly reduces ranging accuracy, resulting in problems such as fluctuating measurement values, signal loss, or false alarms. Furthermore, if a single sensor malfunctions, the system completely loses its monitoring capabilities.

[0007] Thirdly, there are wired transmission safety monitoring solutions. Some existing solutions use wired cables to transmit signals from trackside sensors to the control room or vehicle cab. While this solution provides stable signal transmission, it requires laying long-distance cables, resulting in high construction costs, difficult maintenance, and the large movement range of track-operating vehicles, making wired connections unsuitable for the flexible operation needs of vehicles across regions and stations.

[0008] In addition, most existing safety monitoring solutions are deployed at fixed single sites. When track work vehicles need to work continuously across sites, it is usually necessary to manually reconfigure or switch communication parameters. The operation process is cumbersome, which not only reduces work efficiency, but also makes it easy for human negligence to cause parameter setting errors and create monitoring blind spots.

[0009] In summary, existing railway station advance operation safety monitoring technologies still have significant shortcomings in terms of adaptability to complex environments, sensor redundancy, automatic switching between multiple stations, and multi-source data fusion processing. Therefore, there is an urgent need to develop a ranging and alarm scheme that can maintain high reliability and real-time performance in harsh environments such as rain, fog, and sandstorms. Summary of the Invention

[0010] The purpose of this invention is to provide a railway top platform distance measuring instrument to solve the problems of limited safety monitoring methods for railway station advancement operations and poor distance measuring reliability in harsh environments in the existing technology.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a railway top platform distance measuring instrument, wherein the platform distance measuring instrument is configured as a railway station advancing operation safety monitoring component integrating laser ranging and photoelectric sensing, and the railway station advancing operation safety monitoring component includes:

[0012] At least two sets of sensor units are deployed on the A and B working tracks within the station. Each set of sensor units includes one set of laser rangefinders and four sets of photoelectric sensors. The laser rangefinders are installed at the end of the track to detect the distance between the vehicle and the end of the track in real time and output the distance value. The four sets of photoelectric sensors are marked at four key distance points of 100m, 50m, 20m and 10m on both sides of the track to trigger and output switch alarm signals when the vehicle enters the corresponding distance point.

[0013] A wireless transmission subsystem includes wireless transmitters connected to a laser rangefinder and a photoelectric sensor respectively, and a wireless receiver installed in the cab of a rail vehicle, for wirelessly transmitting sensor signals to a host computer.

[0014] A host computer, installed in the driver's cab of a rail-operated vehicle, includes:

[0015] The host computer control unit is used to determine the work track and work status based on the received sensor signals, and to control the alarm output;

[0016] A digital display screen is used to display the distance values ​​measured by the laser rangefinder in real time;

[0017] The voice alarm is used to broadcast voice alarms in segments corresponding to the distance based on the trigger signal from the photoelectric sensor.

[0018] Furthermore, the operating status determination logic of the host computer control unit is as follows:

[0019] When the first group of photoelectric sensors corresponding to track A triggers an alarm, and the second to fourth groups of photoelectric sensors do not trigger an alarm, or when the laser ranging sensor of track A shows a distance ≤150m and continues to decrease, it is determined that track A is in the process of propulsion.

[0020] When the first set of photoelectric sensors corresponding to track B triggers an alarm, and the second to fourth sets of photoelectric sensors do not trigger an alarm, or when the laser ranging sensor of track B shows a distance ≤150m and continues to decrease, it is determined that track B is in the process of propulsion.

[0021] Furthermore, the voice alarm system employs an active coverage broadcasting mechanism: when the vehicle sequentially enters key distance points of 100m, 50m, 20m, and 10m, and the corresponding photoelectric sensors are triggered in sequence, the voice alarm system broadcasts the corresponding distance's voice prompts in sequence; when a new photoelectric sensor is triggered, even if the previous voice message has not been completed, the system immediately interrupts the current broadcast and switches to broadcasting the voice content of the latest triggered distance point.

[0022] Furthermore, the voice alarm device repeats the voice content for each trigger distance point. The duration of the repetition is configurable, with a default setting of 10 seconds.

[0023] Furthermore, the host computer control unit is also configured to: after determining the current working track, only process the data of the sensor unit corresponding to the working track, and shield the data of the sensor unit of the non-working track; when the train is in the state of traction and carriage operation, the voice alarm logic is not triggered.

[0024] Furthermore, the wireless transmitter and wireless receiver operate at a frequency of 433MHz, with a transmission distance of ≥800m, and the wireless receiver supports point-to-multipoint communication mode.

[0025] Furthermore, the wireless receiver is equipped with a site identification module. This site identification module is used to automatically establish communication binding between the wireless receiver and all wireless transmitters of the current site when the wireless receiver enters the wireless coverage range of the current site transmitter, and start data collection; after the wireless receiver leaves the wireless coverage range of the current site transmitter, it automatically unbinds from all wireless transmitters of the current site; and when the wireless receiver enters the wireless coverage range of another site transmitter, it automatically establishes communication binding with all wireless transmitters of that other site.

[0026] Furthermore, the laser rangefinder has a range of 0–200 m and an accuracy of ±0.5 m. It also features a severe weather compensation algorithm, which keeps the ranging error within ±1 m in rain, fog, and dusty environments.

[0027] Furthermore, the photoelectric sensor has a response time of ≤10ms, a trigger accuracy of ≥99.5%, and an IP65 protection rating and resistance to sand and dust adhesion.

[0028] Furthermore, the host computer control unit uses a built-in state machine model to poll the signals of each sensor in real time and combine the distance change trend to determine the operation direction and stage; when the detection information of the laser rangefinder and the photoelectric sensor are inconsistent, the host computer control unit outputs the judgment result according to the preset redundancy judgment rules and generates an abnormal log record.

[0029] Compared with existing technologies, the railway top platform rangefinder provided by this invention overcomes the shortcomings of single sensors in adverse weather conditions such as rain, fog, and sandstorms by using a dual-redundant deployment of a laser ranging sensor and four sets of photoelectric sensors. Simultaneously, it uses the switching trigger signal of the photoelectric sensor as a verification method for laser ranging, effectively improving the system's detection reliability and fault tolerance in complex environments. Furthermore, through a wireless transmission subsystem and automatic multi-site identification and binding function, it achieves wireless uploading of sensor signals and automatic switching across sites, avoiding the construction and maintenance costs of laying long-distance wired cables and meeting the practical needs of flexible and continuous multi-site operation of track maintenance vehicles. Finally, through a multi-sensor weighted fusion ranging algorithm, a real-time propulsion speed estimation algorithm, and a redundancy verification consistency judgment algorithm, the system can adaptively adjust the fusion weights according to environmental visibility, dynamically estimate the remaining vehicle travel time, and provide early warnings. At the same time, based on a graded judgment of sensor deviation, it adopts differentiated output strategies, significantly improving ranging accuracy, timely warning, and fault isolation capabilities. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0031] Figure 1 This is a schematic diagram of the functional module of the railway top platform distance measuring instrument provided in Embodiment 1 of the present invention;

[0032] Figure 2 This is a schematic diagram of railway station deployment provided in Embodiment 1 of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Sensor Unit; 101. Laser Rangefinder; 102. Photoelectric Sensor; 2. Wireless Transmission Subsystem; 201. Wireless Transmitter; 202. Wireless Receiver; 3. Host Computer; 301. Host Computer Control Unit; 302. Voice Alarm Device; 303. Digital Display Screen. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0036] As attached Figure 1 To be continued Figure 2 As shown:

[0037] Example 1:

[0038] The present invention provides a railway top platform rangefinder, which is configured as a railway station advancement operation safety monitoring component integrating laser ranging and photoelectric sensing. The railway station advancement operation safety monitoring component includes at least two sets of sensor units 1, a wireless transmission subsystem 2 and a host computer 3.

[0039] 1. In one embodiment of the present invention, two sets of sensor units 1 are respectively deployed on two working tracks A and B in the station. Each set of sensor units 1 includes a set of laser rangefinders 101 and four sets of photoelectric sensors 102. The laser rangefinders 101 are installed at the end of the track to detect the distance between the vehicle and the end of the track in real time and output the distance value. The four sets of photoelectric sensors 102 are marked at four key distance points of 100m, 50m, 20m and 10m on both sides of the track, respectively, to trigger and output switch alarm signals when the vehicle enters the corresponding distance point.

[0040] 2. In one embodiment of the present invention, the wireless transmission subsystem 2 includes a wireless transmitter 201 that is connected to the laser rangefinder 101 and the photoelectric sensor 102 respectively, and a wireless receiver 202 installed in the cab of the rail vehicle, for wirelessly transmitting sensor signals to the host computer 3.

[0041] 3. In one embodiment of the present invention, the host computer 3 is installed in the driver's cab of the rail work vehicle, and includes:

[0042] The host computer control unit 301 is used to determine the work track and work status based on the received sensor signals, and to control the alarm output;

[0043] Digital display screen 303 is used to display the distance value measured by laser rangefinder 101 in real time;

[0044] The voice alarm 302 is used to broadcast voice alarms corresponding to the distance in segments based on the trigger signal of the photoelectric sensor 102.

[0045] 4. In one embodiment of the present invention, the operation status determination logic of the host computer control unit 301 is as follows:

[0046] When the first group of photoelectric sensors 102 corresponding to track A triggers an alarm, and the second to fourth groups of photoelectric sensors 102 do not trigger an alarm, or when the laser ranging sensor 101 of track A displays a distance ≤150m and continues to decrease, it is determined that track A is in the process of propulsion.

[0047] When the first group of photoelectric sensors 102 corresponding to track B triggers an alarm, and the second to fourth groups of photoelectric sensors 102 do not trigger an alarm, or when the laser ranging sensor 101 of track B displays a distance ≤150m and continues to decrease, it is determined that track B is in the process of propulsion.

[0048] 5. In one embodiment of the present invention, the voice alarm device 302 has an active coverage broadcasting mechanism: that is, when the vehicle enters the key distance points of 100m, 50m, 20m and 10m in sequence, and the corresponding photoelectric sensors 102 are triggered in sequence, the voice alarm device 302 broadcasts the voice prompts for the corresponding distances in sequence; when a new photoelectric sensor 102 is triggered, even if the previous voice broadcast has not been completed, the system immediately interrupts the current broadcast and switches to broadcasting the voice content of the latest triggered distance point.

[0049] 6. In one embodiment of the present invention, the voice alarm device 302 repeatedly broadcasts the voice content of each trigger distance point. The duration of repeated broadcast is configurable and is set to 10 seconds by default.

[0050] 7. In one embodiment of the present invention, the host computer control unit 301 is further configured to: after determining the current working track, only process the data of the sensor unit 1 corresponding to the working track, and shield the data of the sensor unit 1 of the non-working track; when the train is in the state of traction carriage operation, the voice alarm logic is not triggered.

[0051] 8. In one embodiment of the present invention, the wireless transmitter 201 and the wireless receiver 202 operate in a frequency band of 433MHz, have a transmission distance of ≥800m, and the wireless receiver 202 supports point-to-multipoint communication mode.

[0052] 9. In one embodiment of the present invention, the wireless receiver 202 is configured with a site identification module. The site identification module is used to automatically establish a communication binding between the wireless receiver 202 and all wireless transmitters 201 of the current site when the wireless receiver 202 enters the wireless coverage range of the current site transmitter, and start data acquisition; after the wireless receiver 202 leaves the wireless coverage range of the current site transmitter, it automatically unbinds the communication binding with all wireless transmitters 201 of the current site; and when the wireless receiver 202 enters the wireless coverage range of another site transmitter, it automatically establishes a communication binding with all wireless transmitters 201 of that other site.

[0053] 10. In one embodiment of the present invention, the laser rangefinder 101 has a range of 0 to 200 m and an accuracy of ±0.5 m. It has a severe weather compensation algorithm and the ranging error is controlled within ±1 m in rain, fog and dust environments.

[0054] 11. In one embodiment of the present invention, the photoelectric sensor 102 has a response time ≤10ms, a trigger accuracy ≥99.5%, and has an IP65 protection rating and the ability to resist sand and dust adhesion.

[0055] 12. In one embodiment of the present invention, the host computer control unit 301 polls the signals of each sensor in real time using a built-in state machine model and determines the operation direction and stage by combining the distance change trend; when the detection information of the laser rangefinder 101 and the photoelectric sensor 102 is inconsistent, the host computer control unit 301 outputs the judgment result according to the preset redundancy judgment rule and generates an abnormal log record.

[0056] Working Principle: In this embodiment, the railway top platform distance measuring instrument uses sensor units 1 deployed on two working tracks, A and B, to collect distance signals from the track ends and vehicle position trigger signals in real time. A laser distance sensor 101, installed at the track end, continuously emits a laser beam towards the advancing vehicle and receives the reflected signal, acquiring the distance between the vehicle and the track end in real time. Four sets of photoelectric sensors 102 are arranged at calibration points of 100m, 50m, 20m, and 10m along both sides of the track. When the vehicle enters the corresponding distance point, the photoelectric sensor 102 triggers and outputs a switch alarm signal. The signals collected by each sensor are wirelessly transmitted via a connected wireless transmitter 201 at a frequency of 433MHz. The wireless receiver (wireless receiver 202) installed in the driver's cab of the track working vehicle receives the signals and transmits them to the host computer control unit 301. The host computer control unit 301 determines the current working track and working status based on the trigger sequence of the photoelectric sensors 102 and the trend of the laser distance measurement values. When the conditions for advancing the vehicle are met, only the sensor data for the corresponding working track is processed. The laser ranging value is displayed in real time on the digital display screen 303. Simultaneously, when the vehicle sequentially triggers the photoelectric sensor 102 at calibration points of 100m, 50m, 20m, and 10m, the voice alarm 302 broadcasts the corresponding distance prompts in an active overlay broadcast mode, repeating the broadcast for 10 seconds at each distance point. A new trigger signal immediately interrupts the previous voice prompt. When the track maintenance vehicle enters another station, the wireless receiver automatically unbinds the transmitter at the original station and establishes a binding with the transmitter at the new station, enabling continuous operation across stations. When the laser ranging and photoelectric sensor information are inconsistent, the system outputs a judgment result based on redundancy judgment rules and generates an anomaly log to ensure operational safety.

[0057] Example 2:

[0058] This embodiment is basically the same as the previous embodiment, except that the host computer control unit 301 is also equipped with a multi-sensor weighted fusion ranging algorithm. When the laser ranging sensor 101 and the photoelectric sensor 102 simultaneously output valid signals, the comprehensive distance value is calculated according to the following formula:

[0059]

[0060] In equation (1), This is the combined distance value after fusion. This represents the current measured distance value of the laser rangefinder 101. This is the calibration distance value corresponding to the most recently triggered photoelectric sensor 102. These are dynamic weighting coefficients;

[0061] Dynamic weighting coefficients Based on current environmental visibility (Unit: meters) Adaptive adjustment, with the following adjustment rules:

[0062]

[0063] In low-visibility environments, the system automatically reduces the weight of laser ranging and increases the weight of the switching signal of photoelectric sensor 102 to ensure ranging reliability.

[0064] 1. In one embodiment of the present invention, the host computer control unit 301 is further configured with a real-time propulsion speed estimation algorithm, which calculates the real-time propulsion speed of the vehicle by continuously sampling the laser ranging value according to the following formula:

[0065]

[0066] In equation (3), for The speed of progress of time, for The laser rangefinder value at time [time]. for Laser ranging values ​​from a previous time period The sampling time interval;

[0067] The host computer control unit 301 further adjusts the current propulsion speed. and fusion distance value Calculate the estimated remaining travel time using the following formula:

[0068]

[0069] when When the value is less than the preset threshold, the host computer control unit 301 triggers a warning signal to remind the driver to pay attention to braking in advance.

[0070] 2. In one embodiment of the present invention, the host computer control unit 301 is further configured with a redundancy check consistency judgment algorithm, which calculates the deviation between laser ranging and photoelectric sensing according to the following formula:

[0071]

[0072] In the formula, The calibration distance value is the closest forward photoelectric sensor 102 that has been triggered to the vehicle's current position.

[0073] when When the data from the two sensors are determined to be consistent, the output is directly determined. As an effective distance value;

[0074] when When a deviation is determined, the following method is adopted. Used as a valid distance value and recorded in the deviation log;

[0075] when When a sensor malfunction or severe interference is detected, a fault alarm is triggered, and the switching signal of photoelectric sensor 102 is used first. At the same time, an abnormal log is generated for maintenance personnel to check.

[0076] Working Principle: Based on Example 1, Example 2 further introduces a multi-sensor weighted fusion ranging algorithm, a real-time propulsion speed estimation algorithm, and a redundancy verification consistency judgment algorithm. When both the laser ranging sensor 101 and the photoelectric sensor 102 output valid signals simultaneously, the host computer control unit 301 dynamically adjusts the weighting coefficients according to the current environmental visibility, performs weighted fusion of the laser ranging value and the photoelectric calibration value, and outputs a comprehensive distance value, improving the robustness of ranging in harsh environments. Simultaneously, the host computer control unit 301 calculates the vehicle's real-time propulsion speed and estimated remaining travel time by continuously sampling the laser ranging value, triggering an early warning when the remaining time is lower than a preset threshold. Furthermore, consistency verification of the two sensor data is performed through deviation calculation, and different distance output strategies are selected based on the degree of deviation to ensure safe operation of the system even under sensor failure or interference conditions.

[0077] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A railway platform distance measuring instrument, wherein the platform distance measuring instrument is configured as a railway station advancement operation safety monitoring component integrating laser ranging and photoelectric sensing, characterized in that, The safety monitoring components for railway station advance operations include: At least two sets of sensor units (1) are deployed on two working tracks, A and B, within the station. Each set of sensor units (1) includes a set of laser rangefinders (101) and four sets of photoelectric sensors (102). The laser rangefinders (101) are installed at the end of the track to detect the distance between the vehicle and the end of the track in real time and output the distance value. The four sets of photoelectric sensors (102) are marked at four key distance points of 100m, 50m, 20m and 10m on both sides of the track to trigger and output a switch alarm signal when the vehicle enters the corresponding distance point. A wireless transmission subsystem (2) includes a wireless transmitter (201) connected to a laser rangefinder (101) and a photoelectric sensor (102) respectively, and a wireless receiver (202) installed in the cab of a rail vehicle, for wirelessly transmitting sensor signals to a host computer (3). A host computer (3) is installed in the driver's cab of a rail work vehicle, and includes: The host computer control unit (301) is used to determine the work track and work status based on the received sensor signals, and to control the alarm output; A digital display screen (303) is used to display the distance value measured by the laser rangefinder (101) in real time; The voice alarm device (302) is used to broadcast voice alarms corresponding to the distance in segments based on the trigger signal of the photoelectric sensor (102).

2. The railway top platform distance measuring instrument according to claim 1, characterized in that, The operation status determination logic of the host computer control unit (301) is as follows: When the first group of photoelectric sensors (102) corresponding to track A triggers an alarm and the second to fourth groups of photoelectric sensors (102) do not trigger an alarm, or when the laser ranging sensor (101) of track A displays a distance ≤150m and continues to decrease, it is determined that track A is in the process of propulsion operation. When the first group of photoelectric sensors (102) corresponding to track B triggers an alarm and the second to fourth groups of photoelectric sensors (102) do not trigger an alarm, or when the laser ranging sensor (101) of track B displays a distance ≤150m and continues to decrease, it is determined that track B is in the process of propulsion.

3. The railway top platform distance measuring instrument according to claim 1, characterized in that, The voice alarm device (302) is configured with an active coverage broadcast mechanism: when the vehicle enters the key distance points of 100m, 50m, 20m and 10m in sequence, the corresponding photoelectric sensors (102) are triggered in sequence, and the voice alarm device (302) broadcasts the corresponding distance voice prompts in sequence.

4. The railway top platform distance measuring instrument according to claim 1, characterized in that, The host computer control unit (301) is further configured to: after determining the current working track, only process the data of the sensor unit (1) corresponding to the working track.

5. The railway top platform distance measuring instrument according to claim 1, characterized in that, The wireless transmitter (201) and wireless receiver (202) operate at a frequency of 433MHz and have a transmission distance of ≥800m.

6. The railway top platform distance measuring instrument according to claim 1, characterized in that, The wireless receiver (202) is equipped with a site identification module. When the wireless receiver (202) enters the wireless coverage range of the current site transmitter, the site identification module automatically establishes a communication binding between the wireless receiver (202) and all wireless transmitters (201) of the current site, and starts data collection.

7. The railway top platform distance measuring instrument according to claim 1, characterized in that, The host computer control unit (301) uses a built-in state machine model to poll the signals of each sensor in real time and combine the distance change trend to determine the operation direction and stage. When the detection information of the laser rangefinder (101) and the photoelectric sensor (102) is inconsistent, the host computer control unit (301) outputs the judgment result according to the preset redundancy judgment rules and generates an abnormal log record.

8. The railway top platform distance measuring instrument according to claim 1, characterized in that, The laser rangefinder (101) and photoelectric sensor (102) are connected to the power supply via wired power lines, and the wireless transmitter (201) is integrated with its respective sensor.

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