ATO braking fault detection and processing method

Abstract

The invention discloses an ATO braking fault detecting and processing method. The method comprises the steps that S1, a VOBC monitors the acceleration of a train; s2, the VOBC monitors an ATO control instruction and checks whether a potential fault occurs in an ATO train control channel or not; s3, after the VOBC judges that the potential ATO braking fault exists, the VOBC switches an ATO train control channel; s4, after the VOBC judges that the potential ATO brake fault exists, whether the VOBC needs to apply emergency brake stopping or not is judged; s5, the VOBC monitors the acceleration of the train during emergency braking; s6, the VOBC judges whether an ATO braking fault occurs or not during emergency braking; and S7, when the VOBC judges that the ATO braking non-response fault occurs, the VOBC judges the number of times of detecting the ATO braking fault, and the train is returned to the warehouse for maintenance. The problem of train overshoot caused by the braking response problem is solved.

Description

Technical Field

[0001] The invention relates to a method for detecting and processing an ATO brake fault. Background Art

[0002] With the rapid development of urban rail transit, urban rail transit provides people with fast and convenient travel options and has become the main mode of transportation for people. Especially in first-tier cities, due to the dense population and large passenger flow of rail transit, its importance has become increasingly prominent, and it has also brought huge challenges to the operation of urban rail transit. The automatic train operation (ATO) function plays a vital role in the operation of urban rail transit, especially for rail transit lines operated with fully automatic unmanned driving technology. The ATO function is realized by the collaboration of the on-board controller (VOBC) of the signal system and the train control system (TCMS). VOBC sends ATO train control instructions to TCMS, and TCMS operates the train's traction and braking systems according to these instructions to realize the automatic operation of the train.

[0003] In actual operation, the ATO system may encounter faults due to various reasons when controlling the train, especially ATO brake failure, which causes the train to be unable to respond to the brake command sent by VOBC, and the train cannot slow down, resulting in problems such as train overspeed and overshooting into the station. If the train overshoots on the platform, the train door cannot be opened, and passengers cannot get on and off normally, and the train needs to perform a rollback and benchmarking operation. If the train overshoots too far on the platform and exceeds the train rollback protection distance, the train cannot perform the rollback and benchmarking operation normally, and the signal control system needs to be cut off for manual disposal, which will take a long time and have a greater impact on operations, such as Figure 1 The figure shows a typical fault scenario caused by a train failing to respond to the VOBC braking command. When the train was entering the station for alignment, VOBC issued the ATO maximum braking force command (100% braking force), but the train did not slow down until VOBC issued an emergency braking command because the train ran through the red light before leaving the station. This fault caused the train to overshoot more than 8m on the platform, resulting in a train delay of more than 5 minutes, which had a significant impact on operations.

[0004] The ATO braking function is crucial to ATO train control. It is necessary to detect ATO braking faults in time and handle the faults. Existing technical solutions provide some methods for detecting train braking faults and controlling the train after the faults are detected. For example, Patent No. CN112193230A proposes a train control strategy based on carriage braking fault information; Patent No. CN104875735B introduces a fault detection method based on the difference between the input and output signals of the braking system; Patent No. CN111002970B provides a method for diagnosing vehicle braking faults by monitoring the pressure state of key brake lines; Patent No. CN114323706B identifies ATO train control faults and issues early warnings by calculating the virtual resistance of the train; Patent No. CN108163013B describes a train control method when an ATO on-board device fails.

[0005] The prior art detects train brake faults by constructing models (such as CN104875735B, CN114323706B) or increasing brake equipment monitoring (such as CN112193230, CN111002970B). However, these methods do not take into account the actual operating conditions of the train, and do not consider whether the detected faults have an impact on operations based on the actual results of train control.

[0006] In actual operation, it is found that the main problem of ATO braking is that the train does not respond to the braking command issued by the signal system or responds in time. The problem of braking command response may be caused by various reasons such as command transmission loss or electrical and mechanical characteristics of the braking equipment. These problems are not caused by real ATO-related hardware equipment failures or hardware equipment failures that can be automatically recovered. This kind of failure is basically an occasional short-term failure, but it has a great impact on operations. The existing technical solutions cannot handle this type of braking failure well, and cannot solve problems such as train overshoot caused by braking response problems.

[0007] Therefore, a method for detecting and processing an ATO brake fault is provided. Summary of the invention

[0008] The purpose of the present invention is to overcome the existing defects and provide a method for detecting and processing ATO brake faults to solve the problem of train overshoot caused by brake response problems.

[0009] The technical solution to achieve the above purpose is:

[0010] A method for detecting and processing an ATO brake fault, comprising:

[0011] Step S1, VOBC monitors train acceleration;

[0012] Step S2, VOBC monitors ATO control instructions and checks whether there is a potential fault in the ATO train control channel;

[0013] Step S3, after VOBC determines that there is a potential ATO brake fault, VOBC switches the ATO train control channel;

[0014] Step S4, after VOBC determines that there is a potential ATO brake fault, it determines whether VOBC needs to apply emergency braking to stop the vehicle;

[0015] Step S5, VOBC monitors the train acceleration during emergency braking;

[0016] Step S6, VOBC determines whether an ATO brake failure occurs during emergency braking;

[0017] Step S7, when VOBC determines that the ATO brake no response fault occurs, VOBC determines the number of times the ATO brake fault is detected and returns the train to the depot for maintenance.

[0018] Preferably, in step S1, after the VOBC system is started, in each execution cycle of the VOBC, the VOBC obtains the acceleration value a of the train by collecting the accelerometer installed on the train. raw , and do the following:

[0019] a i =a raw -a grade ;

[0020] In the formula, a grade is the acceleration component caused by the track slope, which can be obtained from the on-board electronic map according to the train position information. i represents the acceleration value of the train without the influence of the slope corresponding to the i-th execution cycle;

[0021] In order to avoid the influence of data noise, the exponential moving average method is used to calculate the train acceleration a i The calculation formula for data smoothing is as follows:

[0022] a' i =α1×a i +(1-α1)×a' i-1 ,i=1,2,3,…;

[0023] Where α1 is the data smoothing parameter, which is the VOBC system parameter, a'0=0, a' i It represents the train acceleration after data smoothing in the i-th execution cycle. The train response to the ATO control command is judged by using the smoothed train acceleration.

[0024] According to the current train acceleration information, the Holt linear trend method is used to calculate the predicted value of the train acceleration after N_BRAKE_DELAY cycles. The calculation formula is as follows:

[0025] initialization:

[0026] L0=0,T0=0;

[0027] In each execution cycle of VOBC, the following are calculated in sequence:

[0028] L i =α2×a′ i +(1-α2)×(L i-1 +T i-1 ),i=1,2,3,…;

[0029] T i =β×(L i -L i-1 )+(1-β)×T i-1 ,i=1,2,3,…;

[0030] predict_a i =L i +N_BRAKE_DELAY×T i ,i=1,2,3,…;

[0031] Where α2 and β are VOBC system parameters, L i is the estimated value of VOBC level in the ith execution cycle, T i is the trend estimate of VOBC in the i-th execution cycle, predict_a i is based on the current acceleration value a' i The predicted acceleration value of the train after N_BRAKE_DELAY cycles. The value of N_BRAKE_DELAY is as follows:

[0032]

[0033] Where, T AtoBrakeDelay T is the delayed response time of the train to the ATO braking command, vobcCycleTime It is the execution time of each execution cycle of VOBC. Both parameters are VOBC system parameters.

[0034] Preferably, the step S2 includes: determining whether a potential ATO brake fault occurs and determining whether a potential ATO brake fault is recovered;

[0035] Determine whether a potential ATO brake fault has occurred, namely:

[0036] When the train moves in the ATO operation mode, the VOBC monitors the ATO train control instructions in each execution cycle;

[0037] When VOBC issues the ATO maximum braking force command, VOBC records the train acceleration when it starts issuing the ATO maximum braking force command:

[0038] a brakeInitial =a′ k ;

[0039] Where k is the execution cycle when VOBC issues the ATO maximum braking force command;

[0040] At the same time, VOBC starts to calculate the maximum acceleration change of the train during the period when the ATO maximum braking force is issued:

[0041] a maxATOBrake =MAX(|a' i -a brakeInitial |), i=k, k+1, ...;

[0042] If VOBC continuously sends the ATO maximum braking force command to the train in N_BRAKE_DELAY VOBC execution cycles, that is, the ATO maximum braking force command is sent for more than the braking delay response time T AtoBrakeDelay ;

[0043] Then, in each execution cycle of sending the ATO maximum braking force command, VOBC will calculate the difference between the train acceleration, the predicted train acceleration and the train acceleration when the ATO maximum braking force is issued, that is, calculate:

[0044] diff_a j =a′ k+N_BRAKE_DELAY+j -a brakeInitial ;

[0045] diff_predict_a j =predict_a k+N_BRAKE_DELAY+j -a brakeInitial ;

[0046] In the formula, diff_a j is the difference between the train acceleration and the train acceleration when the ATO maximum braking force is issued, diff_predict_a j is the difference between the predicted train acceleration and the train acceleration when the ATO maximum braking force is issued, j = 1, 2, ..., N_BRAKE_DELAY, N_BRAKE_DELAY+1, ..., 2 × N_BRAKE_DELAY;

[0047] Then, determine the change value of train acceleration diff_a j、diff_predict_a j The minimum acceleration threshold value a of ATO braking response atoBrakeResponseMinLimit The relationship between atoBrakeResponseMinLimit It is the minimum train acceleration threshold when the train responds to the ATO maximum braking force command, which is related to vehicle performance and is a VOBC system parameter;

[0048] In N_BRAKE_DELAY consecutive execution cycles, statistics:

[0049] Satisfies condition (1): |diff_a j |>a atoBrakeResponseMinLimit The number of is N1,

[0050] Satisfies condition (2): |diff_predict_a j |>a atoBrakeResponseMinLimit The number of is N2,

[0051] If diff_a j If condition (1) is met, the value of N1 is accumulated by 1 and N1 is initially 0. If diff_predict_a j If condition (2) is met, the value of N2 is accumulated by 1, and N2 is initially 0;

[0052] If for all diff_a j and diff_predict_a j All have been judged complete;

[0053] Then determine whether there are more than P diff_a j Satisfy condition (1), that is, determine whether P≤N1 holds;

[0054] If P≤N1 holds, it is judged that the train has responded normally to the ATO braking command, and the current braking fault judgment logic ends, waiting for the next VOBC to re-issue the braking command and then perform related judgments;

[0055] If P≤N1 is not true, then determine whether there are more than P diff_predict_a j Satisfy condition (2), that is, determine whether P≤N2 holds;

[0056] If P≤N2 is not true, it is judged that the train does not respond to the ATO braking command in time and there is a potential ATO braking fault;

[0057] If P≤N2 holds, VOBC continues to perform the following processing in the subsequent N_BRAKE_DELAY execution cycles:

[0058] If |diff_a j |>a atoBrakeResponseMinLimitEstablished, N1 is accumulated by 1;

[0059] If for all diff_a j All have been judged complete;

[0060] Then determine whether P≤N1 holds;

[0061] If P≤N1 holds, it is judged that the train has responded normally to the ATO braking command, and the current braking fault judgment logic ends, waiting for the next VOBC to re-issue the braking command and then perform related judgments;

[0062] If P≤N1 is not true, it is judged that the train does not respond to the ATO braking command in time and there is a potential ATO braking fault;

[0063] Wherein, P is a VOBC system parameter and satisfies P≤N_BRAKE_DELAY;

[0064] Potential ATO brake fault recovery determination:

[0065] When the train is moving in the ATO operation mode and when the VOBC changes from issuing an ATO braking command to issuing a non-ATO braking command or no longer issues an ATO maximum braking force command for more than N_BRAKE_DELAY VOBC execution cycles;

[0066] It is judged that the train has responded to the previously issued ATO braking command;

[0067] If a potential ATO brake fault has been determined before, the potential ATO fault information is cleared, the current brake fault judgment logic ends, and the relevant judgment is performed again when the next VOBC re-issues the brake command and the ATO maximum braking force command.

[0068] Preferably, in step S3,

[0069] If VOBC determines that there is a potential ATO brake fault, VOBC sets the ATO control channel status to an unavailable state;

[0070] If the state of another ATO train control channel is available at this time, VOBC switches the ATO train control channel to another ATO train control channel and restarts the ATO brake fault monitoring process;

[0071] If VOBC determines that the potential ATO brake fault is recovered and the ATO train control channel does not detect a corresponding hardware fault, the ATO train control channel status is set to an available status.

[0072] Preferably, in step S4, if VOBC determines that there is a potential ATO brake fault and VOBC continues to send the ATO maximum braking force command, VOBC will apply emergency braking to replace ATO braking when any of the following emergency braking stop conditions are met, that is, when VOBC determines that the train is overspeeding, VCU applies emergency braking:

[0073] When the train speed is less than v stopLimt hour,

[0074] When the train is judged to be in the platform parking area and receives the platform stop signal or the distance from the train to the stop point is less than the stop window d spWindow When sp ≤d spWindow Established, VCU applies emergency brake;

[0075] Among them, v stopLimt is the train stop speed threshold, is the VOBC system parameter, and d sp is the distance from the current train to the stop, d spWindow is the distance threshold from the train to the stop point, which is a VOBC system parameter;

[0076] When the train speed is greater than v stopLimt hour,

[0077] VOBC calculates the estimated distance that the train will travel after emergency braking at its current speed in each execution cycle. The calculation formula is as follows:

[0078]

[0079] v1=v0+a raw ×t0;

[0080]

[0081] Where d1 is the distance traveled by the train within the braking command response time, v1 is the speed of the train after the braking command response time, d2 is the distance traveled by the train from the time the train responds to the emergency braking command to the time the train stops, v0 is the current speed of the train, t0 is the train emergency braking command response time, is the VOBC system parameter, and a raw is the current acceleration of the train, a eb is the acceleration of the train after emergency braking, is the VOBC system parameter, a grade It is the acceleration component caused by the track slope, which can be obtained from the on-board electronic map based on the train position information;

[0082] If d1+d2>d sp If it is established, the VCU applies emergency braking.

[0083] Preferably, in step S5, when VOBC applies emergency braking, VOBC calculates the change value of the train acceleration from the start of applying the emergency braking to the time when the train stops, and then obtains the maximum value of the change value of the train acceleration during the emergency braking, the method is as follows:

[0084] VOBC records the train acceleration when the train emergency brake is applied:

[0085] a ebInitial =a′ m ;

[0086] Where m represents the execution period when VOBC applies train emergency braking;

[0087] VOBC starts to calculate the maximum acceleration change of the train during emergency braking, that is:

[0088] a maxEB =MAX(|a' i -a ebInitial |), i=m, m+1,….

[0089] Preferably, in step S6, when the train stops under emergency braking, VOBC is adjusted according to the maximum acceleration change value a of the train during the period when the ATO maximum braking force instruction is issued. maxATOBrake and the maximum acceleration change a of the train during emergency braking maxEB To determine whether the ATO brake is faulty, the judgment method is as follows:

[0090] If |a maxEB -a maxATOBrake |>a ebBrakeLimit If the ATO brake failure is established, it is determined that the ATO brake failure has occurred, and the number of times the ATO brake failure is detected is N atoBrakeFailure Accumulate 1, where a ebBrakeLimit is the VOBC system parameter, N atoBrakeFailure Initially set to 0 when VOBC starts.

[0091] Preferably, in step S7, after VOBC determines that the ATO brake no response fault occurs, VOBC determines the number of times N that the ATO brake fault is detected. atoBrakeFailure Is it greater than the predefined ATO brake failure number threshold value N? atoBrakeFailureLimt , that is, judge N atoBrakeFailure >N atoBrakeFailureLimt Is it true, where N atoBrakeFailureLimt It is the VOBC system parameter;

[0092] If N atoBrakeFailure >N atoBrakeFailureLimt Established, VOBC will execute the following process:

[0093] VOBC sends an alarm to TOD and ATS, indicating that a train brake failure has been detected;

[0094] If the train stops at the platform, the ATO operation mode set by VOBC is unavailable, and VOBC sends an alarm message to TOD and ATS, prompting the driver to manually drive the train back to the depot for maintenance;

[0095] If the train does not stop at the platform:

[0096] For manned trains, the VOBC sets the ATO operation mode to be unavailable, and an alarm message is given to the TOD to prompt the driver to manually drive the train back to the depot for maintenance;

[0097] For unmanned trains, it is necessary to drive the train to the platform as quickly as possible. After detecting the train brake failure, the ATO control process is as follows:

[0098] Set the train speed limit curve. In the on-board electronic map, the train running speed and track speed limit of all tracks are included. VOBC selects the speed with the smallest value from the speed of all tracks from the current train position to the stop point, and then subtracts the train speeding tolerance value as the target speed of the train.

[0099] VOBC automatically relieves the train from emergency braking. VOBC performs train control in three stages;

[0100] First, VOBC issues a traction command to control the train to accelerate to the target speed;

[0101] Then VOBC controls the train speed to maintain the target speed through coasting command and small-stage traction command;

[0102] The final stage is the emergency braking stage. VOBC calculates the estimated distance that the train will travel after emergency braking at its current speed in each execution cycle. The calculation formula is as follows:

[0103]

[0104] v1=v0+a raw ×t0;

[0105]

[0106] If d1+d2>d sp If established, VOBC applies emergency brake to stop the train. When the train stops at the platform, VOBC sets the ATO operation mode to be unavailable. VOBC sends an alarm message to TOD and ATS, prompting the driver to manually drive the train back to the depot for maintenance.

[0107] If N atoBrakeFailure ≤N atoBrakeFailureLimtEstablished, VOBC will perform the ATO control channel self-check process:

[0108] VOBC checks the related output functions of the relay and ATO interface board hardware by outputting ATO control commands and then detecting the command return value;

[0109] For trains that support brake self-test, VOBC will issue a brake self-test command to the train, instructing the train to perform brake self-test;

[0110] If the self-check passes, the VOBC sets the ATO train control channel status to available, automatically relieves the train emergency brake, and controls the train in the normal ATO operation mode;

[0111] If the self-test fails, atoBrakeFailure >N atoBrakeFailureLimt The processing flow is consistent.

[0112] The beneficial effects of the present invention are:

[0113] 1) The present invention determines whether an ATO brake failure occurs from the perspective of signal system train control and the actual results of train control. Starting from the train control logic that VOBC sends the ATO maximum braking force, the change in train acceleration during the ATO maximum braking process is used to determine the train's response to the ATO brake control. There is no need to establish a train-related control model hypothesis, and the actual state of the train can be truly reflected.

[0114] 2) Only ATO brake failures that affect operations are detected and processed, that is, during the ATO braking process, VOBC determines whether an ATO brake failure has occurred only when the train is subjected to emergency braking, thereby avoiding the impact of short-term brake failures that have no impact on operations on the system and ensuring the availability of ATO function operations to the greatest extent;

[0115] 3) Determine whether an ATO brake failure occurs based on the train acceleration change value during the period when VOBC issues the ATO maximum braking force and the train acceleration change value when the train emergency brake is applied. The method is simple and easy to implement, involving only the VOBC system, and does not require the cooperation of other systems such as the vehicle;

[0116] 4) The present invention also provides a method for handling ATO brake failures. After detecting a fault, VOBC can handle the fault by switching the ATO control channel, applying emergency brakes to stop the vehicle, initiating ATO brake self-test, etc., thereby reducing the impact of the fault on operations. Compared with the existing technology that only reports an alarm when a fault is detected, the present invention can make train control adjustments when a fault is detected, thereby achieving instant fault response processing;

[0117] 5) The present invention will not cause additional impact on operations and systems. When ATO braking has no effect, VOBC will eventually apply emergency braking. When detecting that ATO braking is unresponsive, the present invention evaluates whether emergency braking is needed and applies emergency braking in advance, thereby reducing the impact of ATO braking unresponsiveness failure on operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0118] Figure 1 This is a typical diagram of a fault scenario caused by a train failing to respond to a VOBC braking command;

[0119] Figure 2 It is a complete ATO control process, showing the relationship between ATO control instructions and train speed and acceleration.

[0120] Figure 3 It is a flow chart of a method for detecting and processing ATO brake faults of the present invention;

[0121] Figure 4 It is a schematic diagram of the interface between each VOBC and the train for ATO train control in this embodiment;

[0122] Figure 5 is a diagram showing the relationship between the actual acceleration of the train and the predicted acceleration after smoothing calculated in this embodiment;

[0123] Figure 6 It is a diagram showing the relationship between the target speed, speed and the ATO control instruction issued by VOBC during the train control process when the train ATO brake fails in this embodiment. DETAILED DESCRIPTION

[0124] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0125] The present invention will be further described below in conjunction with the accompanying drawings.

[0126] During the ATO train control process, VOBC is responsible for determining the corresponding train control instructions based on information such as the train's position, line speed limit curve, and distance to the stop point. These train control instructions include traction, coasting and braking commands, as well as the level information corresponding to these commands. Usually, traction, coasting and braking commands are sent to the vehicle through the relay interface on the train line, and the level information is converted by the ATO interface board into current values ​​and sent to the vehicle. After the vehicle receives the train control instructions issued by VOBC, it controls the acceleration, coasting and deceleration of the vehicle according to these instructions. The amplitude of acceleration and deceleration is determined by the level information. There are two completely independent ATO train control channels between VOBC and the vehicle, which are used to send train control instructions to the vehicle to achieve redundancy of vehicle control. During the ATO train control process, VOBC only uses one of the channels to send instructions to the vehicle. However, once a fault is detected in the current channel, VOBC will automatically switch to another channel and continue to send train control instructions to the vehicle. After receiving the train control instructions from VOBC, the train needs to experience a certain response delay before it can respond accordingly. VOBC can monitor the train's response to train control commands by collecting train speed and acceleration data. Figure 2 As shown in the figure, a complete ATO control process is shown, showing the relationship between the ATO control command and the train speed and acceleration. The train acceleration will change accordingly with the change of the ATO train control command, and its change trend follows the train control level information. By monitoring the train acceleration value, the vehicle's response to the train control command can be reflected.

[0127] When VOBC determines that the train needs to slow down, it will issue an ATO braking command. Unless in special circumstances (such as when the train stops), VOBC usually does not directly issue the maximum braking force (100% braking force). However, if the train does not respond to the braking command, VOBC will gradually increase the braking force until it reaches the maximum braking force. Based on this control characteristic, if the VOBC issues the maximum braking force during the movement of the train, this can be regarded as a signal of a potential ATO brake failure.

[0128] Therefore, in order to solve the above practical application problems, based on the above characteristics of ATO train control, a method for detecting and processing ATO brake faults is proposed.

[0129] like Figure 3 As shown, a method for detecting and processing an ATO brake fault includes:

[0130] Step S1, VOBC monitors the train acceleration.

[0131] In the embodiment, after the VOBC system is started, in each execution cycle of the VOBC, the VOBC obtains the acceleration value a of the train by collecting the accelerometer installed on the train. raw , and do the following:

[0132] a i =a raw -a grade ;

[0133] In the formula, a grade is the acceleration component caused by the track slope, which can be obtained from the on-board electronic map according to the train position information. i represents the acceleration value of the train without the influence of the slope corresponding to the i-th execution cycle;

[0134] In order to avoid the influence of data noise, the exponential moving average method is used to calculate the train acceleration a i The calculation formula for data smoothing is as follows:

[0135] a' i =α1×a i +(1-α1)×a' i-1 ,i=1,2,3,…;

[0136] Where α1 is the data smoothing parameter, which is the VOBC system parameter, a'0=0, a' i It represents the train acceleration after data smoothing in the i-th execution cycle. The train response to the ATO control command is judged by using the smoothed train acceleration.

[0137] According to the current train acceleration information, the Holt linear trend method is used to calculate the predicted value of the train acceleration after N_BRAKE_DELAY cycles. The calculation formula is as follows:

[0138] initialization:

[0139] L0=0,T0=0;

[0140] In each execution cycle of VOBC, the following are calculated in sequence:

[0141] L i =α2×a′ i +(1-α2)×(L i-1 +T i-1 ),i=1,2,3,…;

[0142] T i =β×(L i -L i-1 )+(1-β)×T i-1 ,i=1,2,3,…;

[0143] predict_a i =L i +N_BRAKE_DELAY×T i ,i=1,2,3,…;

[0144] Where α2 and β are VOBC system parameters, L i is the estimated value of VOBC level in the ith execution cycle, T i is the trend estimate of VOBC in the i-th execution cycle, predict_a i is based on the current acceleration value a' i The predicted acceleration value of the train after N_BRAKE_DELAY cycles. The value of N_BRAKE_DELAY is as follows:

[0145]

[0146] Where, T AtoBrakeDelay T is the delayed response time of the train to the ATO braking command, vobcCycleTime It is the execution time of each execution cycle of VOBC. Both parameters are VOBC system parameters.

[0147] Step S2, VOBC monitors ATO control instructions and checks whether there is a potential fault in the ATO train control channel.

[0148] In an embodiment, it includes: determining whether a potential ATO brake fault occurs and determining a potential ATO brake fault recovery;

[0149] Determine whether a potential ATO brake fault has occurred, namely:

[0150] When the train moves in the ATO operation mode, the VOBC monitors the ATO train control instructions in each execution cycle;

[0151] When VOBC issues the ATO maximum braking force command, VOBC records the train acceleration when it starts issuing the ATO maximum braking force command:

[0152] a brakeInitial =a′ k ;

[0153] Where k is the execution cycle when VOBC issues the ATO maximum braking force command;

[0154] At the same time, VOBC starts to calculate the maximum acceleration change of the train during the period when the ATO maximum braking force is issued:

[0155] a maxATOBrake =MAX(|a' i -a brakeInitial|), i=k, k+1, ...;

[0156] If VOBC continuously sends the ATO maximum braking force command to the train in N_BRAKE_DELAY VOBC execution cycles, that is, the ATO maximum braking force command is sent for more than the braking delay response time T AtoBrakeDelay ;

[0157] Then, in each execution cycle of sending the ATO maximum braking force command, VOBC will calculate the difference between the train acceleration, the predicted train acceleration and the train acceleration when the ATO maximum braking force is issued, that is, calculate:

[0158] diff_a j =a′ k+N_BRAKE_DELAY+j -a brakeInitial ;

[0159] diff_predict_a j =predict_a k+N_BRAKE_DELAY+j -a brakeInitial ;

[0160] In the formula, diff_a j is the difference between the train acceleration and the train acceleration when the ATO maximum braking force is issued, diff_predict_a j is the difference between the predicted train acceleration and the train acceleration when the ATO maximum braking force is issued, j = 1, 2, ..., N_BRAKE_DELAY, N_BRAKE_DELAY+1, ..., 2 × N_BRAKE_DELAY;

[0161] Then, determine the change value of train acceleration diff_a j 、diff_predict_a j The minimum acceleration threshold value a of ATO braking response atoBrakeResponseMinLimit The relationship between atoBrakeResponseMinLimit It is the minimum train acceleration threshold when the train responds to the ATO maximum braking force command, which is related to vehicle performance and is a VOBC system parameter;

[0162] In N_BRAKE_DELAY consecutive execution cycles, statistics:

[0163] Satisfies condition (1): |diff_a j |>a atoBrakeResponseMinLimit The number of is N1,

[0164] Satisfies condition (2): |diff_predict_a j |>a atoBrakeResponseMinLimit The number of is N2,

[0165] If diff_a j If condition (1) is met, the value of N1 is accumulated by 1 and N1 is initially 0. If diff_predict_a j If condition (2) is met, the value of N2 is accumulated by 1, and N2 is initially 0;

[0166] If for all diff_a j and diff_predict_a j All have been judged complete;

[0167] Then determine whether there are more than P diff_a j Satisfy condition (1), that is, determine whether P≤N1 holds;

[0168] If P≤N1 holds, it is judged that the train has responded normally to the ATO braking command, and the current braking fault judgment logic ends, waiting for the next VOBC to re-issue the braking command and then perform related judgments;

[0169] If P≤N1 is not true, then determine whether there are more than P diff_predict_a j Satisfy condition (2), that is, determine whether P≤N2 holds;

[0170] If P≤N2 is not true, it is judged that the train does not respond to the ATO braking command in time and there is a potential ATO braking fault;

[0171] If P≤N2 holds, VOBC continues to perform the following processing in the subsequent N_BRAKE_DELAY execution cycles:

[0172] If |diff_a j |>a atoBrakeResponseMinLimit Established, N1 is accumulated by 1;

[0173] If for all diff_a j All have been judged complete;

[0174] Then determine whether P≤N1 holds;

[0175] If P≤N1 holds, it is judged that the train has responded normally to the ATO braking command, and the current braking fault judgment logic ends, waiting for the next VOBC to re-issue the braking command and then perform related judgments;

[0176] If P≤N1 is not true, it is judged that the train does not respond to the ATO braking command in time and there is a potential ATO braking fault;

[0177] Wherein, P is a VOBC system parameter and satisfies P≤N_BRAKE_DELAY;

[0178] Potential ATO brake fault recovery determination:

[0179] When the train is moving in the ATO operation mode and when the VOBC changes from issuing an ATO braking command to issuing a non-ATO braking command or no longer issues an ATO maximum braking force command for more than N_BRAKE_DELAY VOBC execution cycles;

[0180] It is judged that the train has responded to the previously issued ATO braking command;

[0181] If a potential ATO brake fault has been determined before, the potential ATO fault information is cleared, the current brake fault judgment logic ends, and the relevant judgment is performed again when the next VOBC re-issues the brake command and the ATO maximum braking force command.

[0182] Step S3: After VOBC determines that there is a potential ATO brake fault, VOBC switches the ATO train control channel.

[0183] In the embodiment, if the VOBC determines that there is a potential ATO brake fault, the VOBC sets the ATO control channel state to an unavailable state;

[0184] If the state of another ATO train control channel is available at this time, VOBC switches the ATO train control channel to another ATO train control channel and restarts the ATO brake fault monitoring process;

[0185] If VOBC determines that the potential ATO brake fault is recovered and the ATO train control channel does not detect a corresponding hardware fault, the ATO train control channel status is set to an available status.

[0186] Step S4: After VOBC determines that there is a potential ATO brake fault, it determines whether VOBC needs to apply emergency braking to stop the vehicle.

[0187] In the embodiment, if VOBC determines that there is a potential ATO brake fault and VOBC continues to send the ATO maximum braking force command, VOBC will apply emergency braking to replace ATO braking when any of the following emergency braking stop conditions are met, that is, when VOBC determines that the train is overspeeding, VCU applies emergency braking:

[0188] When the train speed is less than v stopLimt hour,

[0189] When the train is judged to be in the platform parking area and receives the platform stop signal or the distance from the train to the stop point is less than the stop window d spWindow When sp ≤d spWindow Established, VCU applies emergency brake;

[0190] Among them, v stopLimt is the train stop speed threshold, is the VOBC system parameter, and d sp is the distance from the current train to the stop, d spWindow is the distance threshold from the train to the stop point, which is a VOBC system parameter;

[0191] When the train speed is greater than v stopLimt hour,

[0192] VOBC calculates the estimated distance that the train will travel after emergency braking at its current speed in each execution cycle. The calculation formula is as follows:

[0193]

[0194] v1=v0+a raw ×t0;

[0195]

[0196] Where d1 is the distance traveled by the train within the braking command response time, v1 is the speed of the train after the braking command response time, d2 is the distance traveled by the train from the time the train responds to the emergency braking command to the time the train stops, v0 is the current speed of the train, t0 is the train emergency braking command response time, is the VOBC system parameter, and a raw is the current acceleration of the train, a eb is the acceleration of the train after emergency braking, is the VOBC system parameter, a grade It is the acceleration component caused by the track slope, which can be obtained from the on-board electronic map based on the train position information;

[0197] If d1+d2>d sp If it is established, the VCU applies emergency braking.

[0198] Step S5, VOBC monitors the train acceleration during emergency braking.

[0199] In the embodiment, when VOBC applies emergency braking, VOBC calculates the change value of the train acceleration from the start of applying the emergency braking to the time when the train stops, and then obtains the maximum value of the change value of the train acceleration during the emergency braking, as follows:

[0200] VOBC records the train acceleration when the train emergency brake is applied:

[0201] a ebInitial =a′ m ;

[0202] Where m represents the execution period when VOBC applies train emergency braking;

[0203] VOBC starts to calculate the maximum acceleration change of the train during emergency braking, that is:

[0204] a maxEB =MAX(|a' i -a ebInitial |), i=m, m+1,….

[0205] Step S6, VOBC determines whether ATO brake failure occurs during emergency braking.

[0206] In the embodiment, when the train stops under emergency braking, VOBC is based on the maximum acceleration change value a of the train during the period when the ATO maximum braking force instruction is issued. maxATOBrake and the maximum acceleration change a of the train during emergency braking maxEB To determine whether the ATO brake is faulty, the judgment method is as follows:

[0207] If |a maxEB -a maxATOBrake |>a ebBrakeLimit If the ATO brake failure is established, it is determined that the ATO brake failure has occurred, and the number of times the ATO brake failure is detected is N atoBrakeFailure Accumulate 1, where a ebBrakeLimit is the VOBC system parameter, N atoBrakeFailure Initially set to 0 when VOBC starts.

[0208] Step S7, when VOBC determines that the ATO brake no response fault occurs, VOBC determines the number of times the ATO brake fault is detected and returns the train to the depot for maintenance.

[0209] In the embodiment, after VOBC determines that the ATO brake no response fault occurs, VOBC determines the number of times N that the ATO brake fault is detected. atoBrakeFailure Is it greater than the predefined ATO brake failure number threshold value N? atoBrakeFailureLimt , that is, judge N atoBrakeFailure >N atoBrakeFailureLimt Is it true, where N atoBrakeFailureLimt It is the VOBC system parameter;

[0210] If N atoBrakeFailure >N atoBrakeFailureLimt Established, VOBC will execute the following process:

[0211] VOBC sends an alarm to TOD and ATS, indicating that a train brake failure has been detected;

[0212] If the train stops at the platform, the ATO operation mode set by VOBC is unavailable, and VOBC sends an alarm message to TOD and ATS, prompting the driver to manually drive the train back to the depot for maintenance;

[0213] If the train does not stop at the platform:

[0214] For manned trains, the VOBC sets the ATO operation mode to be unavailable, and an alarm message is given to the TOD to prompt the driver to manually drive the train back to the depot for maintenance;

[0215] For unmanned trains, it is necessary to drive the train to the platform as quickly as possible. After detecting the train brake failure, the ATO control process is as follows:

[0216] Set the train speed limit curve. In the on-board electronic map, the train running speed and track speed limit of all tracks are included. VOBC selects the speed with the smallest value from the speed of all tracks from the current train position to the stop point, and then subtracts the train speeding tolerance value as the target speed of the train.

[0217] VOBC automatically relieves the train from emergency braking. VOBC performs train control in three stages;

[0218] First, VOBC issues a traction command to control the train to accelerate to the target speed;

[0219] Then VOBC controls the train speed to maintain the target speed through coasting command and small-stage traction command;

[0220] The final stage is the emergency braking stage. VOBC calculates the estimated distance that the train will travel after emergency braking at its current speed in each execution cycle. The calculation formula is as follows:

[0221]

[0222] v1=v0+a raw ×t0;

[0223]

[0224] If d1+d2>d sp If established, VOBC applies emergency brake to stop the train. When the train stops at the platform, VOBC sets the ATO operation mode to be unavailable. VOBC sends an alarm message to TOD and ATS, prompting the driver to manually drive the train back to the depot for maintenance.

[0225] If N atoBrakeFailure ≤N atoBrakeFailureLimt Established, VOBC will perform the ATO control channel self-check process:

[0226] VOBC checks the related output functions of the relay and ATO interface board hardware by outputting ATO control commands and then detecting the command return value;

[0227] For trains that support brake self-test, VOBC will issue a brake self-test command to the train, instructing the train to perform brake self-test;

[0228] If the self-check passes, the VOBC sets the ATO train control channel status to available, automatically relieves the train emergency brake, and controls the train in the normal ATO operation mode;

[0229] If the self-test fails, atoBrakeFailure >N atoBrakeFailureLimt The processing flow is consistent.

[0230] This implementation example is based on a 2x2-out-of-2 redundant onboard control system. Using a 2x2-out-of-2 redundant onboard control system, each train is equipped with two independent VOBCs with a 2-out-of-2 redundant structure, and each VOBC has a separate ATO control channel for train control. To facilitate intuitive understanding, Figure 4 This is a schematic diagram of the interface between each VOBC and the train for ATO train control in this embodiment. VOBC mainly includes ATP and ATO functional modules. The ATO functional module sends train control instructions and level information to the train according to the current train operation information to control the train operation.

[0231] The specific steps are as follows:

[0232] Determine ATO brake fault detection and handling parameters:

[0233] α1: exponential moving average formula parameter. This embodiment uses the exponential moving average method to smooth the train acceleration value, which is used to smooth the train acceleration data and reduce the impact of data noise;

[0234] α2, β: Holt linear trend formula parameters, used to predict the trend of train acceleration;

[0235] T AtoBrakeDelay : The maximum braking response delay of the train ATO is related to the braking performance of the train;

[0236] a atoBrakeResponseMinLimit : The minimum acceleration change value threshold of the train ATO braking response;

[0237] P: During the period when VOBC applies the ATO maximum braking force command, the train acceleration change value exceeds the number threshold P value of the ATO braking response minimum acceleration change value. If the number of train acceleration change values ​​exceeding the ATO braking response minimum acceleration change value is less than the P value, it indicates that the train fails to respond to the ATO braking command;

[0238] a eb : The acceleration of the train after emergency braking, which is related to the braking performance of the train;

[0239] a ebBrakeLimit : The difference threshold between the maximum acceleration change value during the emergency braking of the train and the maximum acceleration change value during the application of the ATO maximum braking force command. If the difference between the above two values ​​is greater than the threshold, it indicates that the train fails to respond to the ATO braking command;

[0240] N atoBrakeFailureLimt : The maximum number of ATO brake failures that the system tolerates. If the number of ATO brake failures detected by VOBC exceeds N atoBrakeFailureLimt , the train needs to be repaired and is not allowed to continue operating in ATO mode;

[0241] T vobcCycleTime : In this embodiment, VOBC performs train control according to a fixed cycle. This parameter is the execution time of each VOBC cycle, and the value is 70ms;

[0242] t0: train emergency brake command response time, which is a vehicle system parameter and is 200ms in this embodiment;

[0243] v stopLimt : The speed threshold value for the train to stop at the station, in this embodiment, the value is 3km / h;

[0244] d spWindow : The train stop benchmark window value, in this embodiment, the value is 0.5m.

[0245] In this embodiment, the parameters α1, α2, and β can be obtained by analyzing and fitting the historical data of train operation. Commonly used data analysis and processing techniques can determine these parameters; the values ​​of α2 and β need to ensure that the difference between the predicted acceleration value and the true value is within [-0.05m / s 2 ,0.05m / s 2 ], the values ​​are as follows: α1 = 0.3, α2 = 0.75, β = 0.15; parameter T AtoBrakeDelay 、a atoBrakeResponseMinLimit 、a eb 、a ebBrakeLimit The value is related to the train braking performance and can be obtained by combining the train system parameters and the historical data of train operation. The value is as follows: T AtoBrakeDelay =500ms, a atoBrakeResponseMinLimit =0.1m / s 2 , a eb =0.85m / s 2 , a ebBrakeLimit =0.3m / s 2 ; The value of parameter P is 6, and the value of parameter N atoBrakeFailureLimt The value is 3.

[0246] In order to more accurately judge the ATO braking response, parameter a atoBrakeResponseMinLimit , a ebBrakeLimit Different parameter values ​​can be taken according to the current train speed.

[0247] In this embodiment, when the train speed is less than 5 km / h, a atoBrakeResponseMinLimit =0.1m / s 2 , when the train speed is greater than 5km / h and less than 20km / h, a atoBrakeResponseMinLimit =0.2m / s 2 , when the train speed is greater than 20km / h, a atoBrakeResponseMinLimit =0.4m / s 2 ; When the train speed is less than 15km / h, a ebBrakeLimit =0.3m / s 2 , when the train speed is greater than 15km / h, a ebBrakeLimit =0.5m / s 2 To simplify the description, the two parameters a mentioned below are atoBrakeResponseMinLimit , a ebBrakeLimit They are all different values ​​based on the current speed.

[0248] Step S1, VOBC monitors the train acceleration.

[0249] When the VOBC system is started, in each VOBC execution cycle, VOBC obtains the train acceleration value a by collecting the accelerometer installed on the train. raw , and do the following:

[0250] a i =a raw -a grade ;

[0251] In the formula, a grade is the acceleration component caused by the track slope, which can be obtained from the on-board electronic map according to the train position information. i represents the acceleration value of the train without the influence of the slope corresponding to the i-th execution cycle;

[0252] In order to avoid the influence of data noise, the exponential moving average method is used to calculate the train acceleration a i The calculation formula for data smoothing is as follows:

[0253] a' i =α1×a i +(1-α1)×a' i-1 ,i=1,2,3,…;

[0254] Where α1 is the data smoothing parameter, which is the VOBC system parameter, a'0=0, a' iIt represents the train acceleration after data smoothing in the i-th execution cycle. The train response to the ATO control command is judged by using the smoothed train acceleration.

[0255] According to the current train acceleration information, the Holt linear trend method is used to calculate the predicted value of the train acceleration after N_BRAKE_DELAY cycles. The calculation formula is as follows:

[0256] initialization:

[0257] L0=0,T0=0;

[0258] In each execution cycle of VOBC, the following are calculated in sequence:

[0259] L i =α2×a′ i +(1-α2)×(L i-1 +T i-1 ),i=1,2,3,…;

[0260] T i =β×(L i -L i-1 )+(1-β)×T i-1 ,i=1,2,3,…;

[0261] predict_a i =L i +N_BRAKE_DELAY×T i ,i=1,2,3,…;

[0262] Where α2 and β are VOBC system parameters, L i is the estimated value of VOBC level in the ith execution cycle, T i is the trend estimate of VOBC in the i-th execution cycle, predict_a i is based on the current acceleration value a' i The predicted acceleration value of the train after N_BRAKE_DELAY cycles. The value of N_BRAKE_DELAY is as follows:

[0263]

[0264] Where, T AtoBrakeDelay T is the delayed response time of the train to the ATO braking command, vobcCycleTime is the execution time of each execution cycle of VOBC. Both parameters are VOBC system parameters. In this embodiment, N_BRAKE_DELAY takes a value of 8. Figure 5As shown, the actual acceleration and predicted acceleration of the train after smoothing calculated by this embodiment. Except for the short-term data jump in the final stopping stage, it can be ensured that the difference between the actual acceleration and the predicted acceleration of the train is within the range of ±0.05m / s / s. The time of the final stopping stage is short, the train will stop quickly, and the short-term data jump does not affect this method.

[0265] Step S2, VOBC monitors ATO control instructions and checks whether ATO train control channel has potential faults. It includes: determining whether potential ATO brake fault has occurred and potential ATO brake fault recovery determination;

[0266] Determine whether a potential ATO brake fault has occurred, namely:

[0267] When the train moves in the ATO operation mode, the VOBC monitors the ATO train control instructions in each execution cycle;

[0268] When VOBC issues the ATO maximum braking force command, VOBC records the train acceleration when it starts issuing the ATO maximum braking force command:

[0269] a brakeInitial =a′ k ;

[0270] Where k is the execution cycle when VOBC issues the ATO maximum braking force command;

[0271] At the same time, VOBC starts to calculate the maximum acceleration change of the train during the period when the ATO maximum braking force is issued:

[0272] a maxATOBrake =MAX(|a' i -a brakeInitial |), i=k, k+1, ...;

[0273] If VOBC continuously sends the ATO maximum braking force command to the train in N_BRAKE_DELAY VOBC execution cycles, that is, the ATO maximum braking force command is sent for more than the braking delay response time T AtoBrakeDelay ;

[0274] Then, in each execution cycle of sending the ATO maximum braking force command, VOBC will calculate the difference between the train acceleration, the predicted train acceleration and the train acceleration when the ATO maximum braking force is issued, that is, calculate:

[0275] diff_a j =a′ k+N_BRAKE_DELAY+j -a brakeInitial ;

[0276] diff_predict_a j=predict_a k+N_BRAKE_DELAY+j -a brakeInitial ;

[0277] In the formula, diff_a j is the difference between the train acceleration and the train acceleration when the ATO maximum braking force is issued, diff_predict_a j is the difference between the predicted train acceleration and the train acceleration when the ATO maximum braking force is issued, j = 1, 2, ..., N_BRAKE_DELAY, N_BRAKE_DELAY+1, ..., 2 × N_BRAKE_DELAY;

[0278] Then, determine the change value of train acceleration diff_a j 、diff_predict_a j The minimum acceleration threshold value a of ATO braking response atoBrakeResponseMinLimit The relationship between atoBrakeResponseMinLimit It is the minimum train acceleration threshold when the train responds to the ATO maximum braking force command, which is related to vehicle performance and is a VOBC system parameter;

[0279] In N_BRAKE_DELAY consecutive execution cycles, statistics:

[0280] Satisfies condition (1): |diff_a j |>a atoBrakeResponseMinLimit The number of is N1,

[0281] Satisfies condition (2): |diff_predict_a j |>a atoBrakeResponseMinLimit The number of is N2,

[0282] If diff_a j If condition (1) is met, the value of N1 is accumulated by 1 and N1 is initially 0. If diff_predict_a j If condition (2) is met, the value of N2 is accumulated by 1, and N2 is initially 0;

[0283] If for all diff_a j and diff_predict_a j All have been judged complete;

[0284] Then determine whether there are more than P diff_a j Satisfy condition (1), that is, determine whether P≤N1 holds;

[0285] If P≤N1 holds, it is judged that the train has responded normally to the ATO braking command, and the current braking fault judgment logic ends, waiting for the next VOBC to re-issue the braking command and then perform related judgments;

[0286] If P≤N1 is not true, then determine whether there are more than P diff_predict_a j Satisfy condition (2), that is, determine whether P≤N2 holds;

[0287] If P≤N2 is not true, it is judged that the train does not respond to the ATO braking command in time and there is a potential ATO braking fault;

[0288] If P≤N2 holds, VOBC continues to perform the following processing in the subsequent N_BRAKE_DELAY execution cycles:

[0289] If |diff_a j |>a atoBrakeResponseMinLimit Established, N1 is accumulated by 1;

[0290] If for all diff_a j All have been judged complete;

[0291] Then determine whether P≤N1 holds;

[0292] If P≤N1 holds, it is judged that the train has responded normally to the ATO braking command, and the current braking fault judgment logic ends, waiting for the next VOBC to re-issue the braking command and then perform related judgments;

[0293] If P≤N1 is not true, it is judged that the train does not respond to the ATO braking command in time and there is a potential ATO braking fault;

[0294] Wherein, P is a VOBC system parameter and satisfies P≤N_BRAKE_DELAY;

[0295] Potential ATO brake fault recovery determination:

[0296] When the train is moving in the ATO operation mode and when the VOBC changes from issuing an ATO braking command to issuing a non-ATO braking command or no longer issues an ATO maximum braking force command for more than N_BRAKE_DELAY VOBC execution cycles;

[0297] It is judged that the train has responded to the previously issued ATO braking command;

[0298] If a potential ATO brake fault has been determined before, the potential ATO fault information is cleared, the current brake fault judgment logic ends, and the relevant judgment is performed again when the next VOBC re-issues the brake command and the ATO maximum braking force command.

[0299] Step S3: After VOBC determines that there is a potential ATO brake fault, VOBC switches the ATO train control channel.

[0300] When VOBC uses two redundant ATO train control channels, VOBC will maintain the availability information of the two channels. When VOBC is started, it will perform the ATO train control channel self-check process. After the self-check passes, VOBC will mark the status of the two ATO train control channels as available. When VOBC detects an ATO control hardware failure, it will set the ATO control channel status to unavailable.

[0301] In the present invention, if VOBC determines that there is a potential ATO brake fault, VOBC also sets the ATO control channel state to an unavailable state. If the state of another ATO train control channel is available at this time, VOBC switches the ATO train control channel to another ATO train control channel and restarts the ATO brake fault monitoring process.

[0302] If VOBC determines that there is a potential ATO brake fault, VOBC sets the ATO control channel status to an unavailable state;

[0303] If the state of another ATO train control channel is available at this time, VOBC switches the ATO train control channel to another ATO train control channel and restarts the ATO brake fault monitoring process;

[0304] If VOBC determines that the potential ATO brake fault is recovered and the ATO train control channel does not detect a corresponding hardware fault, the ATO train control channel status is set to an available status.

[0305] In this embodiment, each VOBC is equipped with an ATO train control channel, and a main VOBC and a backup VOBC together constitute two redundant ATO train control channels. The two VOBCs exchange status information about their respective ATO train control channels through the network. When the main VOBC detects that its ATO train control channel is unavailable, if the ATO train control channel of the backup VOBC is in an available state and meets the conditions for becoming the main VOBC, then the main VOBC will switch to the backup state, and the backup VOBC will switch to the main state. Through the main-backup switching of VOBC, the switching of the ATO train control channel is realized. If the ATO train control channel of the backup VOBC is also in an unavailable state, or does not meet the conditions for becoming the main VOBC, the VOBC will not switch, and the main VOBC will continue to be responsible for train control.

[0306] Step S4: After VOBC determines that there is a potential ATO brake fault, it determines whether VOBC needs to apply emergency braking to stop the vehicle.

[0307] If VOBC determines that there is a potential ATO brake failure and VOBC continues to send the ATO maximum braking force command, VOBC will apply emergency braking to replace ATO braking when any of the following emergency braking stop conditions are met, that is, when VOBC determines that the train is overspeeding, VCU applies emergency braking:

[0308] When the train speed is less than v stopLimt hour,

[0309] When the train is judged to be in the platform parking area and receives the platform stop signal or the distance from the train to the stop point is less than the stop window d spWindow When sp ≤d spWindow Established, VCU applies emergency brake;

[0310] Among them, v stopLimt is the train stop speed threshold, is the VOBC system parameter, and d sp is the distance from the current train to the stop, d spWindow is the distance threshold from the train to the stop point, which is a VOBC system parameter;

[0311] When the train speed is greater than v stopLimt hour,

[0312] VOBC calculates the estimated distance that the train will travel after emergency braking at its current speed in each execution cycle. The calculation formula is as follows:

[0313]

[0314] v1=v0+a raw ×t0;

[0315]

[0316] Where d1 is the distance traveled by the train within the braking command response time, v1 is the speed of the train after the braking command response time, d2 is the distance traveled by the train from the time the train responds to the emergency braking command to the time the train stops, v0 is the current speed of the train, t0 is the train emergency braking command response time, is the VOBC system parameter, and a raw is the current acceleration of the train, a eb is the acceleration of the train after emergency braking, is the VOBC system parameter, a grade It is the acceleration component caused by the track slope, which can be obtained from the on-board electronic map based on the train position information;

[0317] If d1+d2>d sp If it is established, the VCU applies emergency braking.

[0318] Step S5, VOBC monitors the train acceleration during emergency braking.

[0319] When VOBC applies emergency braking, VOBC calculates the change in train acceleration from the start of emergency braking to the time when the train stops, and then obtains the maximum value of the change in train acceleration during emergency braking, as follows:

[0320] VOBC records the train acceleration when the train emergency brake is applied:

[0321] a ebInitial =a′ m ;

[0322] Where m represents the execution period when VOBC applies train emergency braking;

[0323] VOBC starts to calculate the maximum acceleration change of the train during emergency braking, that is:

[0324] a maxEB =MAX(|a' i -a ebInitial |), i=m, m+1,….

[0325] Step S6, VOBC determines whether ATO brake failure occurs during emergency braking.

[0326] In the embodiment, when the train stops under emergency braking, VOBC is based on the maximum acceleration change value a of the train during the period when the ATO maximum braking force instruction is issued. maxATOBrake and the maximum acceleration change a of the train during emergency braking maxEB To determine whether the ATO brake is faulty, the judgment method is as follows:

[0327] If |a maxEB -a maxATOBrake |>a ebBrakeLimit If the ATO brake failure is established, it is determined that the ATO brake failure has occurred, and the number of times the ATO brake failure is detected is N atoBrakeFailure Accumulate 1, where a ebBrakeLimit is the VOBC system parameter, N atoBrakeFailure Initially set to 0 when VOBC starts.

[0328] Step S7, when VOBC determines that the ATO brake no response fault occurs, VOBC determines the number of times the ATO brake fault is detected and returns the train to the depot for maintenance.

[0329] When VOBC determines that the ATO brake no response fault occurs, VOBC determines the number of times N that the ATO brake fault is detected. atoBrakeFailure Is it greater than the predefined ATO brake failure number threshold value N? atoBrakeFailureLimt, that is, judge N atoBrakeFailure >N atoBrakeFailureLimt Is it true, where N atoBrakeFailureLimt It is the VOBC system parameter;

[0330] If N atoBrakeFailure >N atoBrakeFailureLimt Established, VOBC will execute the following process:

[0331] VOBC sends an alarm to TOD and ATS, indicating that a train brake failure has been detected;

[0332] If the train stops at the platform, the ATO operation mode set by VOBC is unavailable, and VOBC sends an alarm message to TOD and ATS, prompting the driver to manually drive the train back to the depot for maintenance;

[0333] If the train does not stop at the platform:

[0334] For manned trains, the VOBC sets the ATO operation mode to be unavailable, and an alarm message is given to the TOD to prompt the driver to manually drive the train back to the depot for maintenance;

[0335] For unmanned trains, it is necessary to drive the train to the platform as quickly as possible. After detecting the train brake failure, the ATO control process is as follows:

[0336] Set the train speed limit curve. In the on-board electronic map, the train running speed and track speed limit of all tracks are included. VOBC selects the speed with the smallest value from the speed of all tracks from the current train position to the stop point, and then subtracts the train speeding tolerance value as the target speed of the train.

[0337] VOBC automatically relieves the train from emergency braking. VOBC performs train control in three stages;

[0338] First, VOBC issues a traction command to control the train to accelerate to the target speed;

[0339] Then VOBC controls the train speed to maintain the target speed through coasting command and small-stage traction command;

[0340] The final stage is the emergency braking stage. VOBC calculates the estimated distance that the train will travel after emergency braking at its current speed in each execution cycle. The calculation formula is as follows:

[0341]

[0342] v1=v0+a raw ×t0;

[0343]

[0344] If d1+d2>d sp If the train stops at the platform, VOBC sets the ATO mode to be unavailable, and sends an alarm message to TOD and ATS, prompting the driver to manually drive the train back to the depot for maintenance. Figure 6 As shown, the target speed, speed and ATO control instructions issued by VOBC during the train control process when the train ATO brake fails in this embodiment are displayed.

[0345] If N atoBrakeFailure ≤N atoBrakeFailureLimt Established, VOBC will perform the ATO control channel self-check process:

[0346] VOBC checks the related output functions of the relay and ATO interface board hardware by outputting ATO control commands and then detecting the command return value;

[0347] For trains that support brake self-test, VOBC will issue a brake self-test command to the train, instructing the train to perform brake self-test;

[0348] If the self-check passes, the VOBC sets the ATO train control channel status to available, automatically relieves the train emergency brake, and controls the train in the normal ATO operation mode;

[0349] If the self-test fails, atoBrakeFailure >N atoBrakeFailureLimt The processing flow is consistent.

[0350] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting and processing ATO brake faults, characterized in that: include: Step S1, VOBC monitors train acceleration; Step S2, VOBC monitors ATO control instructions and checks whether there is a potential fault in the ATO train control channel; Step S3, after VOBC determines that there is a potential ATO brake fault, VOBC switches the ATO train control channel; Step S4, after VOBC determines that there is a potential ATO brake fault, it determines whether VOBC needs to apply emergency braking to stop the vehicle; Step S5, VOBC monitors the train acceleration during emergency braking; Step S6, VOBC determines whether an ATO brake failure occurs during emergency braking; Step S7, when VOBC determines that the ATO brake no response fault occurs, VOBC determines the number of times the ATO brake fault is detected and returns the train to the depot for maintenance.

2. The method for detecting and processing ATO brake fault according to claim 1, characterized in that: In step S1, after the VOBC system is started, in each execution cycle of the VOBC, the VOBC obtains the acceleration value a of the train by collecting the accelerometer installed on the train. raw , and do the following: a i =a raw -a grade ; In the formula, a grade is the acceleration component caused by the track slope, which can be obtained from the on-board electronic map according to the train position information. i represents the acceleration value of the train without the influence of the slope corresponding to the i-th execution cycle; In order to avoid the influence of data noise, the exponential moving average method is used to calculate the train acceleration a i The calculation formula for data smoothing is as follows: a′ i =α1×a i +(1-α1)×a′ i-1 ,i=1,2,3,…; Where α1 is the data smoothing parameter, which is the VOBC system parameter, a'0=0, a' i It represents the train acceleration after data smoothing in the i-th execution cycle. The train response to the ATO control command is judged by using the smoothed train acceleration. According to the current train acceleration information, the Holt linear trend method is used to calculate the predicted value of the train acceleration after N_BRAKE_DELAY cycles. The calculation formula is as follows: initialization: L0=0,T0=0; In each execution cycle of VOBC, the following are calculated in sequence: L i =α2×a′ i +(1-α2)×(L i-1 +T i-1 ),i=1,2,3,…; T i =β×(L i -L i-1 )+(1-β)×T i-1 ,i=1,2,3,…; predict_a i =L i +N_BRAKE_DELAY×T i ,i=1,2,3,…; Where α2 and β are VOBC system parameters, L i is the estimated value of VOBC level in the ith execution cycle, T i is the trend estimate of VOBC in the i-th execution cycle, predict_a i is based on the current acceleration value a' i The predicted acceleration value of the train after N_BRAKE_DELAY cycles. The value of N_BRAKE_DELAY is as follows: Where, T AtoBrakeDelay T is the delayed response time of the train to the ATO braking command, vobcCycleTime It is the execution time of each execution cycle of VOBC. Both parameters are VOBC system parameters.

3. The method for detecting and processing ATO brake fault according to claim 2, characterized in that: The step S2 includes: determining whether a potential ATO brake fault occurs and determining whether a potential ATO brake fault is recovered; Determine whether a potential ATO brake fault has occurred, namely: When the train moves in the ATO operation mode, the VOBC monitors the ATO train control instructions in each execution cycle; When VOBC issues the ATO maximum braking force command, VOBC records the train acceleration when it starts issuing the ATO maximum braking force command: a brakeInitial =a′ k ; Where k is the execution cycle when VOBC issues the ATO maximum braking force command; At the same time, VOBC starts to calculate the maximum acceleration change of the train during the period when the ATO maximum braking force is issued: a maxATOBrake =MAX(|a′ i -a brakeInitial |),i=k,k+1,…; If VOBC continuously sends the ATO maximum braking force command to the train in N_BRAKE_DELAY VOBC execution cycles, that is, the ATO maximum braking force command is sent for more than the braking delay response time T AtoBrakeDelay ; Then, in each execution cycle of sending the ATO maximum braking force command, VOBC will calculate the difference between the train acceleration, the predicted train acceleration and the train acceleration when the ATO maximum braking force is issued, that is, calculate: diff_a j =a′ k+N_BRAKE_DELAY+j -a brakeInitial ; diff_predict_a j =predict_a k+N_BRAKE_DELAY+j -a brakeInitial ; In the formula, diff_a j is the difference between the train acceleration and the train acceleration when the ATO maximum braking force is issued, diff_predict_a j is the difference between the predicted train acceleration and the train acceleration when the ATO maximum braking force is issued, j = 1, 2, ..., N_BRAKE_DELAY, N_BRAKE_DELAY+1, ..., 2 × N_BRAKE_DELAY; Then, determine the change value of train acceleration diff_a j 、diff_predict_a j The minimum acceleration threshold value a of ATO braking response atoBrakeResponseMinLimit The relationship between atoBrakeResponseMinLimit It is the minimum train acceleration threshold when the train responds to the ATO maximum braking force command, which is related to vehicle performance and is a VOBC system parameter; In N_BRAKE_DELAY consecutive execution cycles, statistics: Satisfies condition (1): |diff_a j |>a atoBrakeResponseMinLimit The number of is N1, Satisfies condition (2): |diff_predict_a j |>a atoBrakeResponseMinLimit The number of is N2, If diff_a j If condition (1) is met, the value of N1 is accumulated by 1 and N1 is initially 0. If diff_predict_a j If condition (2) is met, the value of N2 is accumulated by 1, and N2 is initially 0; If for all diff_a j and diff_predict_a j All have been judged complete; Then determine whether there are more than P diff_a j Satisfy condition (1), that is, determine whether P≤N1 holds; If P≤N1 holds, it is judged that the train has responded normally to the ATO braking command, and the current braking fault judgment logic ends, waiting for the next VOBC to re-issue the braking command and then perform related judgments; If P≤N1 is not true, then determine whether there are more than P diff_predict_a j Satisfy condition (2), that is, determine whether P≤N2 holds; If P≤N2 is not true, it is judged that the train does not respond to the ATO braking command in time and there is a potential ATO braking fault; If P≤N2 holds, VOBC continues to perform the following processing in the subsequent N_BRAKE_DELAY execution cycles: If |diff_a j |>a atoBrakeResponseMinLimit Established, N1 is accumulated by 1; If for all diff_a j All have been judged complete; Then determine whether P≤N1 holds; If P≤N1 holds, it is judged that the train has responded normally to the ATO braking command, and the braking fault judgment logic ends, waiting for the next VOBC to re-issue the braking command and then perform the relevant judgment; If P≤N1 is not true, it is judged that the train does not respond to the ATO braking command in time and there is a potential ATO braking fault; Wherein, P is a VOBC system parameter and satisfies P≤N_BRAKE_DELAY; Potential ATO brake fault recovery determination: When the train is moving in the ATO operation mode and when the VOBC changes from issuing an ATO braking command to issuing a non-ATO braking command or no longer issues an ATO maximum braking force command for more than N_BRAKE_DELAY VOBC execution cycles; It is judged that the train has responded to the previously issued ATO braking command; If a potential ATO brake fault has been determined before, the potential ATO fault information is cleared, the current brake fault judgment logic ends, and the relevant judgment is performed again when the next VOBC re-issues the brake command and the ATO maximum braking force command.

4. The method for detecting and processing ATO brake fault according to claim 3, characterized in that: In the step S3, If VOBC determines that there is a potential ATO brake fault, VOBC sets the ATO control channel status to an unavailable state; If the state of another ATO train control channel is available at this time, VOBC switches the ATO train control channel to another ATO train control channel and restarts the ATO brake fault monitoring process; If VOBC determines that the potential ATO brake fault is recovered and the ATO train control channel does not detect a corresponding hardware fault, the ATO train control channel status is set to an available status.

5. The method for detecting and processing ATO brake fault according to claim 4, characterized in that: In step S4, if VOBC determines that there is a potential ATO brake fault and VOBC continues to send the ATO maximum braking force command, VOBC will apply emergency braking to replace ATO braking when any of the following emergency braking stop conditions are met, that is, when VOBC determines that the train is overspeeding, VCU applies emergency braking: When the train speed is less than v stopLimt hour, When the train is judged to be in the platform parking area and receives the platform stop signal or the distance from the train to the stop point is less than the stop window d spWindow When sp ≤d spWindow Established, VCU applies emergency brake; Among them, v stopLimt is the train stop speed threshold, is the VOBC system parameter, and d sp is the distance from the current train to the stop, d spWindow is the distance threshold from the train to the stop point, which is a VOBC system parameter; When the train speed is greater than v stopLimt hour, VOBC calculates the estimated distance that the train will travel after emergency braking at its current speed in each execution cycle. The calculation formula is as follows: v1=v0+a raw ×t0; Where d1 is the distance traveled by the train within the braking command response time, v1 is the speed of the train after the braking command response time, d2 is the distance traveled by the train from the time the train responds to the emergency braking command to the time the train stops, v0 is the current speed of the train, t0 is the train emergency braking command response time, is the VOBC system parameter, and a raw is the current acceleration of the train, a eb is the acceleration of the train after emergency braking, is the VOBC system parameter, a grade It is the acceleration component caused by the track slope, which can be obtained from the on-board electronic map based on the train position information; If d1+d2>d sp If it is established, the VCU applies emergency braking.

6. The method for detecting and processing ATO brake fault according to claim 5, characterized in that: In step S5, when VOBC applies emergency braking, VOBC calculates the change in the train acceleration from the start of applying the emergency braking to the train stopping, and then obtains the maximum value of the change in the train acceleration during the emergency braking, as follows: VOBC records the train acceleration when the train emergency brake is applied: a ebInitial =a′ m ; Where m represents the execution period when VOBC applies train emergency braking; VOBC starts to calculate the maximum acceleration change of the train during emergency braking, that is: a maxEB =MAX(|a′ i -a ebInitial |),i=m,m+1,…。 7. The method for detecting and processing ATO brake fault according to claim 6, characterized in that: In step S6, when the train stops under emergency braking, VOBC is set according to the maximum acceleration change value a of the train during the period when the ATO maximum braking force command is issued. maxATOBrake and the maximum acceleration change a of the train during emergency braking maxEB To determine whether the ATO brake is faulty, the judgment method is as follows: If |a maxEB -a maxATOBrake |>a ebBrakeLimit If the ATO brake failure is established, it is determined that the ATO brake failure has occurred, and the number of times the ATO brake failure is detected is N atoBrakeFailure Accumulate 1, where a ebBrakeLimit is the VOBC system parameter, N atoBrakeFailure Initially set to 0 when VOBC starts.

8. The method for detecting and processing ATO brake fault according to claim 7, characterized in that: In step S7, after VOBC determines that the ATO brake no response fault occurs, VOBC determines the number of times N that the ATO brake fault is detected. atoBrakeFailure Is it greater than the predefined ATO brake failure number threshold value N? atoBrakeFailureLimt , that is, judge N atoBrakeFailure >N atoBrakeFailureLimt Is it true, where N atoBrakeFailureLimt It is the VOBC system parameter; If N atoBrakeFailure >N atoBrakeFailureLimt Established, VOBC will execute the following process: VOBC sends an alarm to TOD and ATS, indicating that a train brake failure has been detected; If the train stops at the platform, the ATO operation mode set by VOBC is unavailable, and VOBC sends an alarm message to TOD and ATS, prompting the driver to manually drive the train back to the depot for maintenance; If the train does not stop at the platform: For manned trains, the VOBC sets the ATO operation mode to be unavailable, and an alarm message is given to the TOD to prompt the driver to manually drive the train back to the depot for maintenance; For unmanned trains, it is necessary to drive the train to the platform as quickly as possible. After detecting the train brake failure, the ATO control process is as follows: Set the train speed limit curve. In the on-board electronic map, the train running speed and track speed limit of all tracks are included. VOBC selects the speed with the smallest value from the speed of all tracks from the current train position to the stop point, and then subtracts the train speeding tolerance value as the target speed of the train. VOBC automatically relieves the train from emergency braking. VOBC performs train control in three stages; First, VOBC issues a traction command to control the train to accelerate to the target speed; Then VOBC controls the train speed to maintain the target speed through coasting command and small-stage traction command; The final stage is the emergency braking stage. VOBC calculates the estimated distance that the train will travel after emergency braking at its current speed in each execution cycle. The calculation formula is as follows: v1=v0+a raw ×t0; If d1+d2>d sp If established, VOBC applies emergency brake to stop the train. When the train stops at the platform, VOBC sets the ATO operation mode to be unavailable. VOBC sends an alarm message to TOD and ATS, prompting the driver to manually drive the train back to the depot for maintenance. If N atoBrakeFailure ≤N atoBrakeFailureLimt Established, VOBC will perform the ATO control channel self-check process: VOBC checks the related output functions of the relay and ATO interface board hardware by outputting ATO control commands and then detecting the command return value; For trains that support brake self-test, VOBC will issue a brake self-test command to the train, instructing the train to perform brake self-test; If the self-check passes, the VOBC sets the ATO train control channel status to available, automatically relieves the train emergency brake, and controls the train in the normal ATO operation mode; If the self-test fails, atoBrakeFailure >N atoBrakeFailureLimt The processing flow is consistent.

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