Rail train speed sensor single-end head-tail redundancy design method

Abstract

The invention relates to a rail train speed sensor single-end head-tail redundancy design method, and belongs to the technical field of rail transit. Two speed sensor units, one radar and one set of vehicle-mounted ATP are arranged at the head end and the tail end of a vehicle respectively, the head vehicle-mounted ATP and the tail vehicle-mounted ATP communicate through dual-network redundancy, and therefore dual-network redundancy communication of single-end speed sensor equipment redundancy and superposition of speed sensor information at the head end and the tail end is achieved. The dual redundancy function of the vehicle-mounted ATP single-end and head-tail speed and distance measurement function can be designed and achieved. Single-end speed sensor equipment redundancy is achieved, the reliability of the single-end speed measurement and distance measurement function is improved, meanwhile, the head-tail vehicle-mounted ATP communicates through dual-network redundancy, the head-tail redundancy function of speed measurement and distance measurement information of the head end and the tail end is achieved, and the usability of vehicle-mounted signal equipment is improved.

Description

Technical Field

[0001] This invention belongs to the field of rail transit technology, specifically relating to a design method for single-end and end-to-end redundancy of a rail train speed sensor. Background Technology

[0002] The onboard ATP (Automatic Train Protection) subsystem is a core component of urban rail transit signaling systems. Through interfaces with CI, ATS, ZC, and ATO (Automatic Train Operation) devices, it uses ground and locomotive information to implement an automatic control system that prevents train overspeeding and ensures safe train operation. The speed and distance measurement units used in the onboard ATP are typically wheel-axle photoelectric sensors. The principle of a wheel-axle photoelectric sensor is that it outputs a pulse for every certain angle the wheel rotates; combined with the wheel diameter value, the cumulative distance traveled by the wheel can be obtained by accumulating pulse counts. Simultaneously, by measuring the distance traveled per unit time, the average speed over a period of time can be obtained. Typically, a speed sensor is installed at one end of the wheel, and the onboard ATP completes the speed and displacement calculations by acquiring data from this sensor.

[0003] In existing rail transit signaling systems, a speed sensor device is installed at one end of each vehicle. The onboard ATP (Automatic Train Protection) system at this end can only collect data from its own speed sensor, and there is no exchange of speed sensor displacement information between the onboard ATP systems at the beginning and end. If the speed sensor at this end malfunctions, it cannot calculate speed and displacement related information, rendering the onboard ATP system unusable and severely reducing its availability.

[0004] The single-end redundancy design proposed in this invention solves this problem. When a single speed sensor device at one end fails, the speed and distance measurement functions can continue to operate through the redundancy of dual speed sensors at the other end. When both speed sensors at one end fail, the tail-end speed sensor device continues to provide measurement data for the speed and distance measurement functions through the tail-end redundancy design. In other words, if one of the four speed sensors at both ends fails, the onboard ATP can operate normally. This invention can meet the industry's development trends in FAO and TACS systems, as well as the high availability requirements stipulated by industry standards. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] The technical problem to be solved by this invention is how to provide a design method for single-end and end-to-end redundancy of a train speed sensor, so as to solve the problem that the on-board ATP system cannot be used after the speed sensor ranging device fails in the existing rail transit signaling system.

[0007] (II) Technical Solution

[0008] To solve the above-mentioned technical problems, this invention proposes a design method for single-end and tail-end redundancy of rail train speed sensors. The method includes: setting two speed sensor units, one radar and one on-board ATP at the front and rear ends of the vehicle respectively. The front and rear on-board ATP communicate through dual-network redundancy to realize single-end speed sensor equipment redundancy and superimpose the dual-network redundancy communication of speed sensor information at the front and rear ends.

[0009] The overall process of onboard ATP with redundancy at both ends includes:

[0010] S1, data acquired by speed sensor and radar;

[0011] S2, a single-ended dual-system functional board, processes speed sensor data and radar data.

[0012] S3. Perform a validity check on the single-ended radar data;

[0013] S4. Process the data from the single-ended single-speed sensor;

[0014] S5. Inspect the single-ended dual-speed sensor;

[0015] S6, transmits speed sensor data at both ends;

[0016] S7. After synchronizing the data from the other end, perform dual-end speed sensor redundancy processing, including: speed sensor information redundancy processing, actual train displacement calculation, and displacement delay compensation.

[0017] (III) Beneficial Effects

[0018] This invention proposes a design method for single-end and tail-end redundancy of a railway train speed sensor. The beneficial effects of this invention are:

[0019] The availability and stability of speed sensor equipment directly affect the safe operation of onboard ATP (Automatic Train Protection). Improving the redundancy management method of speed sensor equipment is of great practical significance for enhancing the reliability of onboard signaling equipment and ensuring the normal operation of trains. The single-end and dual-redundancy design scheme for train speed sensor equipment proposed in this invention has the following advantages:

[0020] 1. It has the function of redundancy of single-end speed sensor equipment. When the speed sensor at the head end fails, it will not affect the normal operation of the speed and distance measurement function, nor will it affect the normal operation of the train.

[0021] 2. It has the function of redundancy of the head and tail speed sensors. When both speed sensors at the head fail, it can switch to the speed sensor at the tail to continue operation.

[0022] 3. Considering that the probability of slippage at the rear end is relatively low when the train at the head end is the only traction / braking source, the redundant design of the head and tail speed sensors means that if slippage occurs at the head end, the speed sensor information at the tail end can be switched, which significantly reduces the probability of triggering the processing of slippage speed sensor information and reduces the processing related to abnormal scenarios.

[0023] 4. It has the advantages of low cost and easy implementation, and effectively improves the availability of the entire system while maintaining the existing vehicle signal equipment structure and installation scheme. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the onboard ATP redundancy system of the present invention;

[0025] Figure 2 A diagram showing the redundancy of the onboard ATP speed and distance measurement software.

[0026] Figure 3 Flowchart for handling redundancy at the beginning and end of the onboard ATP system;

[0027] Figure 4 This is a schematic diagram illustrating the calculation of delay compensation for in-vehicle ATP communication.

[0028] Figure 5 The figure shows the simulation results of the vehicle-mounted ATP positioning error. Detailed Implementation

[0029] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0030] Terminology Explanation

[0031]

[0032] In rail transit signaling systems, speed and distance measurement are fundamental functions of onboard ATP (Automatic Train Protection) systems. These functions provide basic safety data for higher-level operations. Each end of the train is equipped with a speed sensor for measuring and calculating speed and distance. However, the onboard signaling equipment at one end can only collect information from its own speed sensor and cannot exchange speed or distance information with the onboard signaling equipment at the other end. If the speed sensor at one end fails, the onboard signaling equipment cannot be used. This invention proposes a single-end, dual-redundancy design for train speed sensor equipment. Specifically, it sets up two speed sensor devices at each end of the vehicle, achieving redundancy at one end and improving the reliability of single-end speed and distance measurement. Simultaneously, the onboard ATP at both ends communicates through dual-network redundancy, achieving head-to-tail redundancy of speed and distance measurement information at both ends, thereby improving the availability of the onboard signaling equipment.

[0033] 1. Structural Design

[0034] To achieve redundancy at both ends of the speed and distance measurement system, this invention sets up two speed sensor units, one radar, and one onboard ATP system at the front and rear of the vehicle, respectively. The front and rear onboard ATP systems communicate through dual-network redundancy to achieve redundancy of the speed sensor equipment at each end. This dual-network redundancy communication, combining speed sensor information from both ends, enables the design to achieve dual redundancy of speed and distance measurement functions at both ends of the onboard ATP system. The system structure diagram is shown below. Figure 1 As shown.

[0035] The onboard ATP speed and distance measurement system features redundant software processing structure at both ends, as follows: Figure 2 As shown:

[0036] The software structure is divided into a data interface layer, a data processing layer, a redundancy processing layer, and a computing layer from bottom to top.

[0037] The data interface layer receives local speed sensor and radar data and completes redundant processing of local dual-system input data, including: processing of speed sensor data collected by the left and right system input boards of the vehicle safety platform and processing of radar data collected by the left and right system communication boards of the safety platform.

[0038] The data processing layer includes a speed sensor processing module and a radar processing module, which respectively complete the selection and processing of local speed sensor data and radar data processing.

[0039] The redundancy processing layer receives the speed sensor information sent by the other end and completes the redundancy processing of the first and last speed sensors.

[0040] The computing layer calculates the speed and distance measurement results for this cycle based on the redundant data, which is then used by other modules of the onboard ATP system.

[0041] 2. Processing flow

[0042] 1) Overall Process

[0043] The overall process of onboard ATP with redundancy at both ends can be divided into:

[0044] S1, data acquired by speed sensor and radar;

[0045] S2, a single-ended dual-system functional board, processes speed sensor data and radar data.

[0046] S3. Perform a validity check on the single-ended radar data;

[0047] S4. Process the data from the single-ended single-speed sensor;

[0048] S5. Inspect the single-ended dual-speed sensor;

[0049] S6, transmits speed sensor data at both ends;

[0050] S7. After synchronizing the data from the other end, perform dual-end speed sensor redundancy processing, including: speed sensor information redundancy processing, actual train displacement calculation, and displacement delay compensation.

[0051] Each process is as follows Figure 3 As shown, this process takes the onboard ATP at the front end as an example, and the ATP at the rear end performs the corresponding mirroring process:

[0052] S1, External Data Acquisition

[0053] During the external data acquisition phase, the speed sensors and radars at the front and rear ends send speed and distance measurement data to the onboard ATP at their respective ends. The onboard ATP application layer obtains this speed and distance measurement information by reading the dual-system function boards (i.e., the left and right system input boards and the left and right system communication boards).

[0054] S2, Single-ended dual-system data processing

[0055] During the single-end dual-system data processing stage, the onboard ATP performs dual-system redundancy processing on both radar and speed sensor I / 2 data. For radar data, since the left and right communication boards collect the same radar data (consistent source data), the onboard ATP uses the data with the latest serial number as the input for the current cycle. For speed sensor I / 2 data, the onboard ATP determines the system selection for the current speed sensor data based on the communication status of the left and right input boards. Under the same conditions, the left system data is preferentially used for speed and distance measurement calculations by default.

[0056] S3, Single-ended radar data processing

[0057] During the single-end radar data processing stage, the front and rear on-board ATP systems need to perform validity checks on their respective radar data. The checks include: working status, signal quality, directional validity, and speed and mileage information conversion.

[0058] If the radar validity determination fails in a given period, the onboard ATP will not use the data.

[0059] S4, Single-ended single-speed sensor data processing

[0060] In this phase, the onboard ATP systems at both the front and rear of the vehicle process the data from their respective speed sensors (half the data), including:

[0061] (1) Check data loss status: If speed sensor information is continuously lost (channel failure or pulse disconnection), the speed sensor information is unavailable in this cycle;

[0062] (2) Consistency check of three-way data: Each speed sensor has 3 pulses. The consistency of the speed of the 3 pulses of the speed sensor is checked, and the consistency of the distance of the 3 pulses of the speed sensor is checked.

[0063] (3) Time domain distance increment jump check: If the distance shrinks, a single jump exceeds the threshold, or the difference between the sampling distance and the predicted distance over several cycles is too large, then the speed sensor is set to an abnormal working state.

[0064] (4) Time-domain idling and slippage status check of the speed sensor itself and the radar: The acceleration / deceleration calculated by the speed sensor is compared with empirical values, and the idling / slippage status is checked by combining the speed sensor speed and the radar speed difference. If the acceleration of the speed sensor exceeds the set threshold for two consecutive samplings, and the latest sampling speed exceeds the maximum predicted speed, then idling is determined to have occurred; if the deceleration exceeds the threshold for two consecutive samplings, and the latest sampling speed is lower than the minimum predicted speed, then slippage is determined to have occurred. When idling and slippage occur, the speed, mileage, and other data of the radar will be switched to achieve the purpose of compensation.

[0065] If the first three checks fail, the speed sensor is marked as not working. The fourth check, idling and slipping status, is used to mark the state of the speed sensor, which serves as the basis for determining whether to use the data transmission data in subsequent calculations.

[0066] S5. Single-ended speed sensor shaft breakage fault inspection

[0067] In this stage, the ATP at both ends checks the axle breakage status based on the data from the dual speed sensors at this end. The axle breakage is determined by checking whether the difference in the measured speeds of the dual speed sensors continuously exceeds a specified threshold within a certain time range.

[0068] Simultaneously, radar data is used to detect speed sensor shaft breakage faults. If the speed sensor measures zero speed, but the radar speed measurement exceeds a certain threshold and continues for a period of time, then the speed sensor is determined to have a shaft breakage fault, and the speed sensor is set to abnormal.

[0069] S6, Transmitting speed sensor data at both ends

[0070] At this point, the onboard ATP system at both the beginning and end has completed all processing of the speed sensor data at its respective end. The beginning and end maintain time synchronization, with the end sending redundant speed sensor information to the beginning, including: speed sensor number, speed sensor pulse distance, speed sensor status (normal / abnormal / not working), speed sensor error code (specific fault type), sampled acceleration value, sampled velocity value, sampled displacement value, and direction of travel. The speed sensor status and speed sensor error code together serve as the basis for determining the usability of the speed sensor at the end.

[0071] S7, Dual-ended speed sensor redundancy processing

[0072] After receiving the speed sensor redundancy data from the remote vehicle's ATP, the local vehicle-mounted ATP performs dual-end speed sensor redundancy processing. The processing procedure is as follows:

[0073] (1) Redundancy handling

[0074] After receiving the speed sensor information from the other end, this end performs redundancy processing on all four speed sensor units at both ends. The processing method is as follows:

[0075] S71. Check the operating status of all speed sensors: Normal, Abnormal, Unavailable;

[0076] S72. If the working state of the speed sensor is abnormal, detect the error information of the speed sensor: idling, slippage, information loss, channel failure, abnormal distance increment jump, and broken shaft failure.

[0077] S73. When all speed sensors are in the same working state, the transmission priority from high to low is as follows: local speed sensor 1, local speed sensor 2, remote speed sensor 1, and remote speed sensor 2.

[0078] S74. Select the speed sensor that is in normal working condition, has no error code, and has the highest priority as the speed sensor data source for this cycle.

[0079] S75. If the speed sensor is not working and the error message code is not "idle / slippery" (e.g., information loss, channel failure, abnormal distance increment jump, or broken shaft failure), the dual-end redundancy processing module determines that the speed sensor should be "unavailable". Only when all other speed sensors are "unavailable" can the speed sensor data with the error message code "idle / slippery" be used.

[0080] (2) Calculation method

[0081] Considering the frame loss and delay issues in redundant communication between the first and last terminals, the onboard ATP (Automatic Train Protection) system (ATP) struggles to determine the total pulse correspondence between the current primary speed sensor and all redundant speed sensors. Therefore, when using the total pulse calculation method, if a speed sensor unit switch occurs, the local onboard ATP cannot accurately calculate displacement information from the data from the other end, or a position jump may occur. If the speed sensor travel distance difference calculation method is used, since the speed sensor switching scenario also exists, it is necessary to maintain the pulse difference between any two of the four speed sensors at the first and last terminals, making the switching algorithm complex and prone to errors.

[0082] Therefore, in this invention, the peer directly sends the sampling speed and displacement values ​​for the current cycle (100ms) to the first end each cycle. If there is no packet loss, the local end can directly use the incremental algorithm to calculate the travel distance; if packet loss occurs, the corresponding speed sensor does not participate in the redundant calculation for the current cycle. When the local onboard ATP uses the speed and distance measurement data from the peer, communication delay compensation is required. The dual-end onboard ATP should calculate clock deviation and communication delay, such as... Figure 4 As shown:

[0083] Let the clock deviation of the other end relative to this end be . The communication delay between the beginning and end is Then there is

[0084]

[0085] T1 is the time when the head end sends the velocity and displacement values ​​to the tail end; T2 is the time when the tail end receives the data packet; T3 is the time when the tail end sends the velocity and displacement values ​​to the head end; T4 is the time when the head end receives the data packet.

[0086] set up The peer report the sampling displacement value for this period at any time. The application cycle of vehicle-mounted ATP is The total displacement value of this end in the previous cycle is If the displacement is calculated using data from the other end, then the total displacement at this end during this period is:

[0087] +

[0088]

[0089] Onboard ATP calculates the actual displacement of the train at all times. for

[0090]

[0091] in This is for displacement delay compensation. Note that the report from the other end only contains... It is added to the total displacement at this end. Each cycle is recalculated and not accumulated into the total displacement at this end, thus avoiding [the impact on] the total displacement at this end. and This has an impact on calculations. That is, at any given moment, when the onboard ATP uses local data, it only performs... Displacement delay compensation over a period of time.

[0092] Assuming the vehicle moves at approximately a constant speed during the delay, the displacement delay compensation calculation method is as follows:

[0093]

[0094] If it is assumed that the vehicle is undergoing approximately uniform acceleration during the delay, then this end needs to record the sampled displacement value reported by the other end in the previous period. The calculation method is as follows:

[0095]

[0096] Obviously if If the value is 0, the formula is transformed into an approximate uniform motion calculation formula. Generally, an approximate uniform motion calculation formula is sufficient to meet positioning accuracy requirements. Furthermore, approximate uniform acceleration significantly increases computational complexity and storage space, and only when there is high acceleration and no slippage will a significant improvement in positioning accuracy be obtained.

[0097] Example 1:

[0098] This invention models and simulates delay calculations. The vehicle model updates its position with a period of 10 ms and converts the travel distance into pulse values; the onboard ATP model updates its position with a period of 100 ms (…). Vehicle positioning is calculated based on pulse values ​​over a period of time; head-to-tail communication is assumed. .

[0099] The vehicle starts at 0 m / s, accelerates at 1 m / s for 0-20 s, maintains a constant speed for 20-400 s, and decelerates at -0.7 m / s for 400-500 s until it comes to a complete stop. The positioning error between the onboard ATP and the vehicle model throughout the entire process is as follows: Figure 5 As shown:

[0100] The onboard ATP (Automatic Positioning Adapter) is defined as the "local" end and the "rear" end as the "reverse" end. It can be observed that the local ATP updates its position with a period of 100ms. Therefore, the positioning error between the local ATP and the vehicle model (updating with a 10ms period) is divided into 10 levels, with an error range of (-1.6, 0.2)m. The minimum positioning error is 0m, occurring during the ATP's position update calculation period. After introducing a communication delay of 120ms at the rear end, the positioning error with the vehicle model expands to (-4, -2.2)m. After delay compensation, the error range is (-1.6, 0.2)m, maintaining consistency with the local positioning error during the constant speed phase.

[0101] Example 2

[0102] To address the issue of the vehicle's ATP system becoming unusable after a speed sensor ranging device malfunctions, a high-precision lidar device can be installed on one end, combined with existing wheel axle photoelectric sensors, to achieve a heterogeneous redundancy design for speed and ranging sensors. However, this approach may be limited by the high cost of lidar equipment, restricted installation locations, and inability to function properly in adverse weather conditions (such as rain and snow). It lacks the advantages of this invention, such as low cost, ease of installation and adaptation, and high reliability.

[0103] Key points of this invention:

[0104] 1. A technical solution for redundant management of information from dual speed sensors in a single-end vehicle-mounted ATP system;

[0105] 2. A solution for ATP to use tail velocity measurement data for positioning when the head velocity sensor fails;

[0106] 3. The time synchronization and related compensation methods used in the process of calculating speed and displacement using the tail end speed and distance measurement data at the head end.

[0107] The beneficial effects of this invention are:

[0108] The availability and stability of speed sensor equipment directly affect the safe operation of onboard ATP (Automatic Train Protection). Improving the redundancy management method of speed sensor equipment is of great practical significance for enhancing the reliability of onboard signaling equipment and ensuring the normal operation of trains. The single-end and dual-redundancy design scheme for train speed sensor equipment proposed in this invention has the following advantages:

[0109] 1. It has the function of redundancy of single-end speed sensor equipment. When the speed sensor at the head end fails, it will not affect the normal operation of the speed and distance measurement function, nor will it affect the normal operation of the train.

[0110] 2. It has the function of redundancy of the head and tail speed sensors. When both speed sensors at the head fail, it can switch to the speed sensor at the tail to continue operation.

[0111] 3. Considering that the probability of slippage at the rear end is relatively low when the train at the head end is the only traction / braking source, the redundant design of the head and tail speed sensors means that if slippage occurs at the head end, the speed sensor information at the tail end can be switched, which significantly reduces the probability of triggering the processing of slippage speed sensor information and reduces the processing related to abnormal scenarios.

[0112] 4. It has the advantages of low cost and easy implementation, and effectively improves the availability of the entire system while maintaining the existing vehicle signal equipment structure and installation scheme.

[0113] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A design method for single-end and tail-end redundancy of a rail train speed sensor, characterized in that, The method includes: setting up two speed sensor units, one radar and one on-board ATP at the front and rear ends of the vehicle respectively. The front and rear on-board ATP communicate through dual-network redundancy to achieve redundancy of the speed sensor equipment at one end and superimpose the speed sensor information at the front and rear ends for dual-network redundancy communication. The overall process of onboard ATP with redundancy at both ends includes: S1, data acquired by speed sensor and radar; S2, a single-ended dual-system functional board, processes speed sensor data and radar data. S3. Perform a validity check on the single-ended radar data; S4. Process the data from the single-ended single-speed sensor; S5. Inspect the single-ended dual-speed sensor; S6, transmits speed sensor data at both ends; S7. After synchronizing the data from the other end, perform dual-end speed sensor redundancy processing, including: speed sensor information redundancy processing, actual train displacement calculation, and displacement delay compensation.

2. The design method for single-end and tail-end redundancy of the rail train speed sensor as described in claim 1, characterized in that, The vehicle-mounted ATP system is equipped with redundancy software for speed and distance measurement, which includes a data interface layer, a data processing layer, a redundancy processing layer, and a calculation layer. The data interface layer receives local speed sensor and radar data and completes redundant processing of local dual-system input data, including: processing of speed sensor data collected by the left and right system input boards of the vehicle safety platform and processing of radar data collected by the left and right system communication boards of the safety platform. The data processing layer includes a speed sensor processing module and a radar processing module, which respectively complete the selection and processing of local speed sensor data and radar data processing; The redundancy processing layer receives the speed sensor information sent by the other end and completes the redundancy processing of the first and last speed sensors. The computing layer calculates the speed and distance measurement results for this cycle based on the redundant data, which is then used by other modules of the onboard ATP system.

3. The design method for single-end and tail-end redundancy of the rail train speed sensor as described in claim 1, characterized in that, S1 includes: the speed sensors at the front and rear ends and the radar respectively send speed and distance measurement data to the vehicle ATP at their respective ends; the vehicle ATP application layer obtains speed and distance measurement information by reading the dual-system function board; the dual-system function board includes: left and right system input board and left and right system communication board.

4. The design method for single-end and tail-end redundancy of the rail train speed sensor as described in claim 3, characterized in that, S2 includes: the vehicle-mounted ATP performs dual-system redundancy processing on radar and speed sensor 1 / 2 data respectively; for radar data, since the left and right communication boards collect the same radar data, which is the same source data, the vehicle-mounted ATP takes the data with the latest serial number as the input for the current cycle; for speed sensor 1 / 2 data, the vehicle-mounted ATP determines the system selection of the current speed sensor data according to the communication status of the left and right input boards. Under the same conditions, the left system data is preferred by default for speed and distance measurement calculation.

5. The design method for single-end and tail-end redundancy of the rail train speed sensor as described in claim 4, characterized in that, S3 includes: the onboard ATP at both ends of the vehicle performs validity checks on the radar data of their respective ends. The detection content includes: working status, signal quality, direction validity, speed and mileage information conversion. If the radar validity determination fails in this cycle, the onboard ATP does not use the data.

6. The design method for single-end and tail-end redundancy of the rail train speed sensor as described in claim 4, characterized in that, S4 includes: the onboard ATP at both ends of the vehicle processes the data from their respective speed sensors 1 / 2, including: (1) Check data loss status: If speed sensor information is continuously lost, then the speed sensor information is unavailable in this period; (2) Consistency check of three-way data: Each speed sensor has 3 pulses. The consistency of the speed of the 3 pulses of the speed sensor is checked, and the consistency of the distance of the 3 pulses of the speed sensor is checked. (3) Time domain distance increment jump check: If the distance shrinks, a single jump exceeds the threshold, or the difference between the sampling distance and the predicted distance over several cycles is too large, then the speed sensor is set to an abnormal working state. (4) Checking the idling and slippage status of the speed sensor itself and the radar in the time domain: The acceleration / deceleration calculated by the speed sensor is compared with the empirical value, and the idling / slippage status is checked by combining the speed sensor speed and the radar speed difference; If the speed sensor continuously samples acceleration exceeding the set threshold for two consecutive times, and the latest sample exceeds the maximum predicted speed, it is determined that idling has occurred; If continuously samples deceleration exceeding the threshold for two consecutive times, and the latest sample is lower than the minimum predicted speed, it is determined that slippage has occurred; When idling and slippage occur, the speed and mileage data of the radar will be switched to achieve the purpose of compensation; If the first three checks fail, the speed sensor is marked as not working. The fourth check, idling and slipping status, is used to mark the state of the speed sensor, which serves as the basis for determining whether to use the data transmission data in subsequent calculations.

7. The design method for single-end and tail-end redundancy of the rail train speed sensor as described in claim 6, characterized in that, The S5 includes: the ATP at the beginning and end of the ATP performs a shaft breakage fault status check based on the data from the dual speed sensors at this end, and makes a shaft breakage judgment by checking whether the measured speed difference of the dual speed sensors continuously exceeds a specified threshold within a certain time range. Simultaneously, radar data is used to detect speed sensor shaft breakage faults. If the speed sensor measures zero speed, but the radar speed measurement exceeds a certain threshold and continues for a period of time, then the speed sensor is determined to have a shaft breakage fault, and the speed sensor is set to abnormal.

8. The design method for single-end and tail-end redundancy of the rail train speed sensor as described in claim 7, characterized in that, S6 includes: the onboard ATP at both ends completing all processing of the speed sensor data at their respective ends, maintaining time synchronization between the two ends, and the tail end sending speed sensor redundancy information to the head end, including: speed sensor number, speed sensor pulse distance, speed sensor status, speed sensor error code, sampled acceleration value, sampled velocity value, sampled displacement value, and running direction information; wherein, the speed sensor status and speed sensor error code together serve as the basis for whether the tail end speed sensor is usable.

9. The design method for single-end and tail-end redundancy of a rail train speed sensor as described in claim 8, characterized in that, S7 includes: after receiving the speed sensor information from the other end, the local end performs redundancy processing on all four speed sensor units of both ends. The processing method is as follows: S71. Check the operating status of all speed sensors: Normal, Abnormal, Unavailable; S72. If the working state of the speed sensor is abnormal, detect the error information of the speed sensor: idling, slippage, information loss, channel failure, abnormal distance increment jump, and broken shaft failure. S73. When all speed sensors are in the same working state, the transmission priority from high to low is as follows: local speed sensor 1, local speed sensor 2, remote speed sensor 1, and remote speed sensor 2. S74. Select the speed sensor that is in normal working condition, has no error code, and has the highest priority as the speed sensor data source for this cycle. S75. If the speed sensor is inactive and the error code is not "idle / slippery", the dual-end redundancy processing module determines that the speed sensor is "unavailable". Only when all other speed sensors are "unavailable" can the speed sensor data with the error code "idle / slippery" be used.

10. The design method for single-end and tail-end redundancy of a rail train speed sensor as described in claim 9, characterized in that, In S7, the actual train displacement calculation and displacement delay compensation include: The peer directly sends the sampling speed and displacement values ​​of the current cycle to the first end each cycle; if there is no packet loss, the local end directly uses the incremental algorithm to calculate the travel distance; if packet loss occurs, the corresponding speed sensor does not participate in the redundant calculation of the current cycle; when the local on-board ATP uses the speed and distance measurement data of the peer, communication delay compensation is required. Let the clock deviation of the other end relative to this end be . The communication delay between the beginning and end is Then there is T1 is the time when the head end sends the velocity and displacement values ​​to the tail end; T2 is the time when the tail end receives the data packet; T3 is the time when the tail end sends the velocity and displacement values ​​to the head end; T4 is the time when the head end receives the data packet. set up The peer report the sampling displacement value for this period at any time. The application cycle of vehicle-mounted ATP is The total displacement value of this end in the previous cycle is If the displacement is calculated using data from the other end, then the total displacement at this end during this period is: + Onboard ATP calculates the actual displacement of the train at all times. for in For displacement delay compensation; only the report from the other end is available. It is added to the total displacement at this end. Each cycle is recalculated and not accumulated into the total displacement at this end, thus avoiding [the impact on] the total displacement at this end. and The calculations are affected; that is, at any given moment, when the onboard ATP uses local data, only... Displacement delay compensation over a long period of time; Assuming the vehicle moves at approximately a constant speed during the delay, the displacement delay compensation calculation method is as follows: If it is assumed that the vehicle is undergoing approximately uniform acceleration during the delay, then this end needs to record the sampled displacement value reported by the other end in the previous period. The calculation method is as follows: 。

Images