Train safety zero speed detection method, device and medium

Abstract

The present application relates to a kind of train safety zero speed detection method, equipment and medium, the method includes: when satisfying the preset zero speed activation condition, activate zero speed detection flow;Vehicle-mounted equipment VOBC injects test signal D i (k) to encoding odometer, and acquires sensor feedback signal C i (k);Based on the logical combination of D i (k) and C i (k), each sensor state A i (k) is judged;According to the periodic correlation of multiple sensors A i (k), the state of encoding odometer is judged, and the state includes stationary state, moving state and inconsistent state;If continuous multiple period encoding odometer is stationary state, then judge zero speed;If output other state, then terminate zero speed detection flow.Compared with prior art, the present application can accurately detect zero speed state, improve the reliability and safety of vehicle-mounted equipment, and provide solid protection for train controller to realize safety monitoring and efficient driving.

Description

Technical Field

[0001] This invention belongs to the field of rail transit train safety control, and in particular relates to a method, equipment and medium for detecting zero speed of train safety. Background Technology

[0002] In the rail transit field, zero-speed detection of trains is a core component of the safety control system, directly affecting critical functions such as train stopping accuracy, door opening and closing safety, and anti-runaway control. Currently, photoelectric coded odometers are widely used as the core device for train positioning and speed measurement, achieving displacement sensing through coaxially mounted dual-track code disks. Specifically, the outer code disk has evenly spaced light-transmitting holes, scanned by multiple phase-staggered photoelectric sensors, outputting phase difference square wave signals. The system calculates displacement based on pulse count and phase relationship. The inner code disk generates a sequence of coded holes based on a linear feedback shift register, and the accuracy of data acquisition is ensured through consistency verification between the inner and outer code disks.

[0003] However, existing technologies face the following technical bottlenecks in practical applications:

[0004] Insufficient zero-speed detection accuracy: Traditional solutions rely on changes in the number of teeth to determine zero speed. When the train displacement is less than the distance between a single tooth hole, the sensor cannot trigger a pulse change, resulting in a high probability of misjudging zero speed when the train is in low-speed conditions such as creeping or reversing. This makes it difficult to meet the requirements of high-precision positioning and has poor adaptability to complex environments.

[0005] Risk of slippage and misjudgment: Encoded odometers are typically installed on the drive or brake axle. When the train accelerates or decelerates, or encounters severe weather, slippage and wheel spin can easily occur between the wheel and rail, causing a deviation between the wheel speed and the actual displacement. Traditional methods may refuse to determine zero speed due to detecting changes in the number of teeth, threatening train safety.

[0006] System expansion is difficult: If it is necessary to integrate data from multiple sensors for zero-speed verification, the hardware interface and the data protocol need to be significantly modified, which results in high modification costs, poor compatibility, and weak scalability.

[0007] A search of Chinese Patent Publication No. CN114347798A reveals a method, device, and system for determining zero-speed stabilization of maglev trains. This method involves placing a fiber optic grating device within the train station to assist the onboard speed measuring device in determining zero-speed stabilization of the maglev train, without requiring adjustments to the existing train control system. Furthermore, the fiber optic grating device provides real-time, accurate absolute position information of the maglev train, enabling a comprehensive judgment on whether the train has reached a zero-speed stabilization state based on the detection data from the onboard speed measuring equipment. This existing patent utilizes a fiber optic grating device to address the issue of insufficient speed measurement accuracy of onboard speed measuring devices during low-speed train operation. However, due to the use of an external fiber optic grating device, it suffers from high implementation costs and susceptibility to external environmental interference.

[0008] Therefore, how to solve the problem of zero-speed detection of train safety under complex working conditions such as low-speed misjudgment and wheel-rail slippage, so as to achieve accurate identification of zero-speed state and improve the safety and reliability of rail transit operation, has become a technical problem that needs to be solved. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art by providing a method, equipment, and medium for zero-speed detection of train safety, thereby improving the accuracy and reliability of zero-speed detection and ensuring the safe and precise control of trains.

[0010] The objective of this invention can be achieved through the following technical solutions:

[0011] According to a first aspect of the present invention, a method for detecting train safety at zero speed is provided, the method comprising:

[0012] When the preset zero-speed activation conditions are met, the zero-speed detection process is activated.

[0013] The onboard device VOBC injects a test signal D into the coded odometer. i (k), and acquire sensor feedback signal C i (k), where i = 1, 2, ..., n, n is the number of sensor channels used to collect the number of teeth on the outer ring of the coded odometer, and k is the interrupt period;

[0014] Based on D i (k) and C i The logical combination of (k) determines the state A of each sensor. i (k);

[0015] Based on n-channel sensor A i (k) periodic correlation, determine the coded odometer state, the state including static state and inconsistent state;

[0016] If the odometer remains stationary for M consecutive cycles and passes the data consistency check between the two processing units, it is determined to be at zero speed; otherwise, the zero speed detection process is terminated.

[0017] As a preferred technical solution, the zero-speed activation condition is: the number of outer ring teeth of the coded odometer collected during the continuous Q interruption cycle of the on-board device VOBC remains unchanged, and the number of outer ring teeth is consistent with the inner ring coding verification.

[0018] As a preferred technical solution, the vehicle-mounted device VOBC adopts a 2-out-of-2 architecture, including processing unit one and processing unit two, and the test signal D i(k) is generated by processing unit one and written into the coded odometer register, and simultaneously forwarded to processing unit two. After receiving it, processing unit two keeps in sync with processing unit one.

[0019] As a preferred technical solution, the sensor A i (k) The state determination logic is as follows:

[0020] When D i (k) When the output is high, according to C i (k) Actual value record A i ((k);

[0021] When D i (k) Output low level and C i (k) When the feedback is high, the i-th sensor is determined to be faulty;

[0022] When D i (k) Output low level and C i (k) When the feedback is low, mark A. i (k) represents an unknown state, and the state record A from the previous interrupt cycle is used. i (k).

[0023] As a preferred technical solution, the test signal D i (k) can be independently configured to be high or low.

[0024] As a preferred technical solution, the coded odometer status is specifically as follows:

[0025] If all sensor states satisfy A i (k) equals A i ((k-1), then the current coded odometer is determined to be in a stationary state;

[0026] If all sensor states are A i (k) If they are completely identical or the i-th sensor is faulty, then the coded odometer is determined to be in an inconsistent state;

[0027] If A exists i (k)≠A i (k-1) and not all A i If (k) is the same, the coded odometer is determined to be in a moving state.

[0028] As a preferred technical solution, the data consistency verification includes:

[0029] Within M interrupt cycles, the difference in the number of teeth collected by the two processing units is zero;

[0030] The feedback signals from the n sensors are consistent between the two processing units.

[0031] As a preferred technical solution, the other output states include:

[0032] If the output is inconsistent, the zero-speed detection process will be terminated and the coded odometer will be marked as invalid.

[0033] If the output shows a movement status, then only the zero-speed detection process will be terminated.

[0034] According to a second aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described thereon.

[0035] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described thereon.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1. This invention combines optically encoded odometer tooth count information, real-time signals from onboard speed measuring equipment, and active test results to construct a multi-condition logic judgment model. Through mutual verification between two processing units, the accuracy and anti-interference capability of zero-speed detection are improved, effectively reducing the risk of misjudgment due to the failure of a single processing unit, and significantly improving the availability and safety of train operation.

[0038] 2. Based on the operating principle of optical coded odometer, this invention prohibits zero-speed determination when the coding verification fails or the sensor malfunctions, thus ensuring the security of the algorithm itself and avoiding safety hazards caused by train position misjudgment due to algorithm defects, thereby fundamentally ensuring the safety of train operation.

[0039] 3. This invention optimizes the in-vehicle software algorithm without requiring changes to the hardware structure, greatly reducing the cost of technology upgrades and implementation complexity, and possesses good scalability and compatibility. Attached Figure Description

[0040] Figure 1 This is a flowchart of the zero-speed detection process of the present invention;

[0041] Figure 2 This is a flowchart of the coding odometer status determination process of the present invention;

[0042] Figure 3 This is an example diagram of the sensor signal of the present invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0044] This invention is a method for detecting zero speed in train safety. It combines optically encoded odometer tooth count information, real-time signals from onboard speed measuring equipment, and active test results to accurately determine zero speed after continuous periodic verification.

[0045] like Figure 1 As shown, the specific process of this invention includes the following steps:

[0046] Step S1: In the 2-out-of-2 architecture vehicle-mounted device VOBC, the two processing units work together through data synchronization and cross-validation mechanisms, and collect the outer ring tooth count of the coded odometer in real time through n sensors. When the outer ring tooth count of the coded odometer remains unchanged for Q consecutive interrupt cycles and the outer ring tooth count is consistent with the inner ring coding verification, processing unit 1 sends a test pulse to activate the zero-speed detection process and proceeds to step S2; if the above conditions are not met, it directly jumps to step S6 to perform exception handling.

[0047] Step S2: The coded odometer has n test signal interfaces. After the test starts, in each interrupt cycle, only the processing unit generates the test signal sequence D. i (k) Write the sequence into the coded odometer register and forward it synchronously to the second processing unit. After receiving the sequence, the second processing unit keeps in sync with the first processing unit to ensure that the test signals sent by the two processing units are completely consistent.

[0048] Step S3: Within the same interrupt cycle, the on-board unit VOBC determines the status of the coded odometer based on the transmitted test signal and the collected sensor feedback information:

[0049] If the on-board unit VOBC determines that the odometer status is stationary for M consecutive interrupt cycles and passes the security code verification, then it stops the odometer sensor detection and records the tooth value of the current interrupt cycle.

[0050] If an inconsistency occurs during the detection process, immediately terminate the zero-speed detection and jump to step S6 to perform exception handling;

[0051] If a fluttering state is detected, terminate the zero-speed detection process.

[0052] Step S4: During the M interrupt cycles of the entire zero-speed detection, continuously verify the tooth count difference between the two processing units and the consistency of the feedback information from the n sensors. If any data inconsistency occurs, perform exception handling.

[0053] Step S5: The wheels are considered stationary only when the train has completed the entire zero-speed test process described above, and all test conditions are met and the verification results are passed.

[0054] Step S6: During the zero-speed detection process, if any abnormal situation such as sensor failure or data verification failure occurs, the odometer will be deemed invalid, and the zero-speed detection judgment process will be terminated to avoid the risk of misjudgment.

[0055] This invention overcomes the physical limitations of traditional photoelectric encoders that rely on tooth pitch changes by actively injecting test signals. Combined with a dual-processing unit verification mechanism, it can safely and accurately detect zero-speed states, ensuring safe and precise control of trains, improving the reliability and safety of onboard equipment, and providing a solid guarantee for train controllers to achieve safe monitoring and efficient driving.

[0056] like Figure 2 As shown, in step S3, the determination of the coded odometer status specifically involves:

[0057] Step S31: The two processing units of the on-board equipment VOBC send test signal D. i ((k), and within the same interrupt cycle, the feedback signals C from n sensors are acquired. i ((k);

[0058] Step S32: Based on test signal D i (k) and sensor feedback C i (k) logical combinations to realize n-channel sensor A i (k) State determination:

[0059] When the test signal outputs a high level, the sensor is allowed to feedback a low or high level.

[0060] When the test signal outputs a low level, only low-level feedback from the sensor is allowed. If a high-level feedback occurs, the sensor is considered faulty. Low-level feedback is considered an unknown state. (A) i (k) Use the state A from the previous cycle. i ((k-1);

[0061] Step S33: Set the status A of each of the n-channel sensors in the current interrupt cycle of the coded odometer to the current status A. i (k), respectively corresponding to state A of the previous interrupt cycle. i Compare with (k-1):

[0062] If all Ai (k) equals A i (k-1) indicates that the current coded odometer is in a stationary state;

[0063] If the status A of n sensors during this interruption cycle i If ((k) are exactly the same, the coded odometer is determined to be malfunctioning.

[0064] In other cases, it is determined that the coded odometer may have moved relative to the axle.

[0065] This invention dynamically determines the sensor status by combining test signals and feedback logic, and determines the coded odometer status by combining a periodic status comparison mechanism, providing a reliable status basis for zero-speed determination and improving the accuracy and anti-interference capability of train safety control.

[0066] by Figure 3 For example, let's explain the sensor status determination process in detail:

[0067] During the middle of the k-th interrupt, the two processing units of the on-board equipment VOBC send test signal D. i (k) = 0, and the sensor feedback signal C is acquired within the same interrupt cycle. i (k) = 0;

[0068] Because of D i (k)=0, and C i (k) = 0, according to the sensor state determination rule, mark A. i (k) represents an unknown state, so we continue using A. i (k)=A i (k-1).

[0069] The status A of each of the n sensors in the current interrupt cycle of the odometer is set. i (k), respectively corresponding to state A of the previous interrupt cycle. i Compare (k-1): If A i (k)==A i ((k-1), i=1,2,…n, assuming all sensor states in the odometer are completely consistent with the previous interrupt cycle, then return to STOPPING, determining that the current odometer is in a stationary state; if A1(k)==A2(k)==…A i (k)…==…A n (k) If the states of the n sensors are completely identical during the current interruption cycle, return INCONSISTENT to indicate that the odometer is malfunctioning; otherwise, return FLOATING to indicate that the odometer may be moving relative to the axle.

[0070] This invention also provides an electronic device including a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or loaded from a storage unit into a random access memory (RAM). The RAM may also store various programs and data required for device operation. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0071] Multiple components in the device are connected to the I / O interface, including: input units such as keyboards and mice; output units such as various types of displays and speakers; storage units such as disks and optical discs; and communication units such as network interface cards (NICs), modems, and wireless transceivers. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0072] The processing unit executes the various methods and processes described above, such as methods S1 to S6. For example, in some embodiments, methods S1 to S6 may be implemented as computer software programs tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via ROM and / or a communication unit. When the computer program is loaded into RAM and executed by the CPU, one or more steps of methods S1 to S6 described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute methods S1 to S6 by any other suitable means (e.g., by means of firmware).

[0073] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0074] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0075] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0076] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for detecting train safety at zero speed, characterized in that, Includes the following steps: When the preset zero-speed activation conditions are met, the zero-speed detection process is activated. The onboard device VOBC injects a test signal into the coded odometer. And collect sensor feedback signals. ,in n is the number of sensor channels used to collect the number of teeth on the outer ring of the coded odometer, and k is the interrupt cycle; based on and The logical combination determines the status of each sensor. ; Based on n sensors The periodic correlation is used to determine the status of the coded odometer, which includes a static state and an inconsistent state. If the odometer is stationary for M consecutive cycles and passes the data consistency check between the two processing units, it is determined to be at zero speed; if other states are output, the zero speed detection process is terminated. The zero-speed activation condition is as follows: the number of outer ring teeth of the coded odometer collected during the continuous Q interruption cycle of the on-board device VOBC remains unchanged, and the number of outer ring teeth is consistent with the inner ring code verification. The sensor mentioned The state determination logic is as follows: when When the output is high, according to Actual value record ; when Output low level and When the feedback level is high, the i-th sensor is determined to be faulty; when Output low level and When the feedback is low, the flag is displayed. Since the state is unknown, the state record from the previous interrupt cycle will be used. ; The specific status of the coded odometer is as follows: If all sensor states satisfy equal If so, it is determined that the current coded odometer is in a stationary state; If all sensor status If the sensors are completely identical or the i-th sensor is faulty, the coded odometer is determined to be in an inconsistent state. If it exists And not all If they are the same, the coded odometer is determined to be in a moving state.

2. The train safety zero-speed detection method according to claim 1, characterized in that, The vehicle-mounted VOBC device adopts a 2-out-of-2 architecture, including processing unit one and processing unit two, and the test signal... The coded odometer register is generated by processing unit one and written to it, and simultaneously forwarded to processing unit two. After receiving the data, processing unit two operates in sync with processing unit one.

3. The method for detecting zero-speed train safety according to claim 1, characterized in that, The test signal It can be independently configured to be high or low level.

4. The method for detecting zero speed in train safety according to claim 1, characterized in that, The data consistency verification includes: Within M interrupt cycles, the difference in the number of teeth collected by the two processing units is zero; The feedback signals from the n sensors are consistent between the two processing units.

5. The method for detecting zero-speed train safety according to claim 1, characterized in that, Other output states include: If the output is inconsistent, the zero-speed detection process will be terminated and the coded odometer will be marked as invalid. If the output shows a movement status, then only the zero-speed detection process will be terminated.

6. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 5.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 5.

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