Railway vehicle braking system packet loss rate detection method and system

Abstract

The invention relates to a method and system for detecting the packet loss rate of a railway vehicle braking system, and the method comprises the following steps: distributing the IDs of all data frames in a bus, and enabling the ID of each data frame to be unique and recognizable; determining a scheduling cycle period; in each cycle period, the scheduling card sends scheduling frames to the scheduled card at preset time intervals, and data frames in different communication periods are scheduled in sequence; in the scheduling process, the scheduling card counts data frames returned in the bus, and each scheduled card counts scheduling frames needing to be received and actually received scheduling frames in the cycle period; and calculating the packet loss rate based on the counting information of the scheduling card and each scheduled card. The CAN bus packet loss rate detection method is suitable for CAN bus packet loss rate detection in a master-slave scheduling mode, CAN bus packet loss detection of a single frame, a single board card, an EBCU complete machine and a whole-train braking system can be achieved, and a basis is provided for CAN communication load rate and reliability evaluation of a train braking system.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail vehicles, and particularly relates to a method and system for detecting the packet loss rate of a rail vehicle braking system. Background Art

[0002] The electronic brake control unit (EBCU) is a core component in the rail vehicle braking system, which is used to receive braking commands, apply release commands, and control the train braking. The stability and reliability of its performance are directly related to the braking effect and operation safety of the train.

[0003] Currently, the EBCU usually adopts a microcomputer-controlled electronic module integrated architecture design, and the interconnection method between each module in the EBCU is backplane CAN bus interconnection. Detecting the packet loss rate of the CAN bus in the EBCU can master the communication situation of the CAN bus load in the EBCU, reduce the faults caused by CAN communication after installation, and is of great significance for improving the communication reliability of the EBCU and the braking system.

[0004] The scheduling method of the CAN bus in the EBCU is a master-slave scheduling method. Most of the existing packet loss rate monitoring technologies are for Ethernet devices or links, and their detection methods are mainly limited to the communication environment between point-to-point or two-end devices, and cannot be applied to the multi-node communication architecture based on the CAN bus in the EBCU;

[0005] In addition, when the existing methods detect the packet loss rate, they can only count the proportion of data packet loss, cannot specifically confirm the content of the lost data packets, and cannot accurately locate to a specific CAN node module or a specific scheduling period. In the detection scenarios of the EBCU whole machine or the full train braking system with multiple CAN node modules and each module having multiple scheduling periods, this limitation has caused a great obstacle to optimizing the EBCU software and hardware design and improving the communication reliability of the whole machine. Summary of the Invention

[0006] The purpose of the present invention is to solve one of the above technical problems, and provide a method and system for detecting the packet loss rate of a rail vehicle braking system, which realizes the CAN bus packet loss detection of the master-slave scheduling CAN bus structure in the braking system for a single frame, a single board card, the EBCU whole machine, and the full train braking system, and provides a basis for evaluating the CAN communication load rate and reliability of the train braking system.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A method for detecting the packet loss rate of a rail vehicle braking system, wherein the braking system includes at least one electronic brake control unit EBCU, each EBCU includes a scheduling card and at least one scheduled card, and the scheduling card and the scheduled card are connected by a bus. The packet loss rate detection method includes the following steps:

[0009] Allocate IDs for all data frames in the bus so that the ID of each data frame in the bus is unique and recognizable; the data frames include scheduling frames; at least the EBCU number, the scheduled card number, and the frame number are included in the ID of the data frame;

[0010] Obtain the communication cycles of all data frames in the bus, and use the maximum communication cycle among them as the scheduling cycle;

[0011] Within each cycle, the scheduling card sends scheduling frames to the scheduled cards connected thereto at a predetermined time interval, and schedules the data frames in different communication cycles in sequence according to the order of the communication cycles;

[0012] During the scheduling process, the scheduling card counts the returned data frames in the bus, and each scheduled card counts the number of scheduling frames to be received and the number of actually received scheduling frames in this cycle;

[0013] Calculate the packet loss rate based on the counting information of the scheduling card and each scheduled card.

[0014] In some embodiments of the present invention, during the scheduling process, for the data frames with the same communication cycle in different scheduled cards within the same EBCU, scheduling is performed in sequence based on the order of the frame numbers of each data frame.

[0015] In some embodiments of the present invention, the braking system includes one carriage, and each carriage includes at least one EBCU; the carriage number is further included in the ID of the data frame;

[0016] During the scheduling process, for the data frames with the same communication cycle in the bus, the data frames of the EBCUs of each carriage are scheduled in sequence based on the order of the carriage numbers in the ID of the data frame.

[0017] In some embodiments of the present invention, the steps of calculating the packet loss rate include:

[0018] Calculate the single-frame transmission packet loss rate A1xyz:

[0019] A1xyz = (Buffer1xy - Buffer2xy) / Buffer1xy * 100%;

[0020] Calculate the single-frame reception packet loss rate A2xyz:

[0021] A2xyz = (Buffer2xy - Buffer3xy) / Buffer2xy * 100%.

[0022] Among them, buffer1xy is the number of scheduling frames that each scheduled card needs to receive in each cycle; buffer2xy is the number of scheduling frames actually received by each scheduled card; buffer3xy is the number of data frames returned by the bus received by the scheduling card; x is the frame number, and y is the scheduled card number.

[0023] In some embodiments of the present invention, the steps of calculating the packet loss rate further include:

[0024] Calculate the packet loss rate A3xyz for a single frame process;

[0025] A3xyz = (Buffer1xy - Buffer3xy) / Buffer1xy * 100%;

[0026] Calculate the board card packet loss rate A4yz:

[0027]

[0028] Calculate the overall packet loss rate A5z of the EBCU;

[0029]

[0030] Calculate the packet loss rate A6 of the whole train braking system:

[0031]

[0032] Among them, buffer1xy is the number of scheduling frames that each scheduled card needs to receive in each cycle; buffer3xy is the number of data frames returned by the bus received by the scheduling card; x is the frame number, y is the scheduled card number, and z is the EBCU number.

[0033] In some embodiments of the present invention, the predetermined time is less than the ratio of the communication cycle corresponding to the data frame with the shortest communication cycle in the bus to the number of data frames with the shortest communication cycle.

[0034] Some embodiments of the present invention further provide a packet loss rate detection system for a railway vehicle braking system, which is used to implement the above-mentioned packet loss rate detection method for a railway vehicle braking system, including: an electronic brake control unit and a packet loss monitoring device;

[0035] The electronic brake control unit is communicatively connected to the packet loss monitoring device;

[0036] The electronic brake control unit includes a main control card, an interface card, and a conversion card connected through an internal bus;

[0037] Among them, the main control card serves as a scheduling card, and sends scheduling frames to each interface card at intervals of a predetermined time in each scheduling cycle, and counts the number of data frames returned by each interface card;

[0038] The interface card, as the card to be scheduled, counts the number of scheduling frames it needs to receive and the number of actually received scheduling frames based on the scheduling frames sent by the master card;

[0039] The conversion card is used to forward the bus data inside the electronic brake control unit to the packet loss monitoring device. The bus data inside the electronic brake control unit includes the counting information of the master card and each interface card;

[0040] The packet loss monitoring device is used to receive the bus data and calculate the packet loss rate of the electronic brake control unit based on the received bus data.

[0041] In some embodiments of the present invention, there are multiple electronic brake control units, and the multiple electronic brake control units are connected through an external bus;

[0042] The packet loss monitoring device is communicatively connected to each electronic brake control unit through the external bus;

[0043] The conversion card of each electronic brake control unit forwards the internal bus data to the packet loss monitoring device through the external bus.

[0044] In some embodiments of the present invention, the packet loss monitoring device includes a data recording module and a scheduling module;

[0045] The data recording module is used to listen to, parse, record the bus data and forward the parsed bus data to the scheduling module;

[0046] The scheduling module is used to control the scheduling of each board card in each electronic brake control unit and calculate the packet loss rate based on the bus data forwarded by the data recording module.

[0047] In some embodiments of the present invention, each interface card counts the number of scheduling frames it needs to receive based on the scheduling frames sent by the master card, denoted as buffer1xy, and counts the number of actually received scheduling frames of this board card, denoted as buffer2xy; after each interface card receives the scheduling frame, it returns buffer1xy and buffer2xy as part of the data frame data to the master card;

[0048] The master card counts the number of each data frame returned in the internal bus, denoted as buffer3xy, and sends buffer3xy as part of the scheduling frame data during scheduling.

[0049] The beneficial effects of the present invention are as follows:

[0050] 1. The present invention can be applied to the CAN bus packet loss rate detection of an EBCU adopting a one-master-many-slaves architecture and a master-slave scheduling method. By assigning a unique and identifiable ID to each CAN data frame and performing data scheduling based on the ID, the controllability of data frame management and transmission is improved. Through this method, not only can the packet loss rate between two node modules be detected, but also the CAN bus packet loss detection of single frames, single boards, the entire EBCU, and the full train braking system can be realized, providing a basis for the CAN communication load rate, reliability evaluation, and CAN bus scheduling inside the EBCU and the braking system;

[0051] 2. The present invention provides a hierarchical packet loss rate calculation system, covering all-round evaluations from single frames, boards, the whole machine to the entire system, facilitating accurate positioning of communication anomalies. The formula is simple and easy to use, can be quickly calculated, and is suitable for real-time monitoring and large-scale deployment;

[0052] 3. The detection method provided by the present invention does not require adding additional detection data packets to the bus. The detection can be achieved by counting and statistics on some data bits in the real vehicle network protocol, and the detection accuracy is closer to the real vehicle operation condition;

[0053] 4. The CAN bus data recorder provided by the present invention has real-time monitoring and storage recording functions. Cooperating with the monitoring terminal can realize data recording and playback, and thus can accurately obtain the board where the positioning data packet is lost during the test, providing quantitative data support for the software and hardware optimization of the EBCU and improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will describe the specific embodiments of the present invention in detail with reference to the drawings. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0055] Figure 1 It is a flowchart of a method for detecting the packet loss rate of a railway vehicle braking system;

[0056] Figure 2 It is a CAN bus network architecture diagram of a train braking system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] In order to make the purpose, technical solutions, and advantages of the present application clearer, the following will describe and explain the present application with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0058] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0059] In the case of no conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0060] The technical solutions of the present invention will be described in detail below in conjunction with specific embodiments and the accompanying drawings of the specification.

[0061] As shown in the attached Figure 1 - attached Figure 2 As shown, in a schematic embodiment of a method for detecting packet loss rate of a braking system of a rail vehicle in the present invention, the braking system includes at least one electronic brake control unit EBCU. Each EBCU includes a scheduling card and at least one scheduled card, and the scheduling card and the scheduled card are connected through an internal bus, and different electronic brake control units are connected through an external bus. Among them, the internal bus connection is a backplane CAN bus, and the external bus is a train CAN bus.

[0062] The method for detecting the packet loss rate includes the following steps.

[0063] S1: Allocate the 11-bit ID of all data frames in the bus. Among them, the buses are all CAN buses, and the CAN buses specifically include an internal bus and an external bus. The data frame is a CAN data frame.

[0064] When performing packet loss rate detection on the CAN bus of the entire EBCU or the entire train braking system, in order to accurately locate the CAN node module where packet loss occurs in the EBCU and the type of data frame where packet loss occurs, each data frame in the bus needs to have a unique and identifiable ID during allocation; that is, the ID of the data frame includes at least the EBCU number, the scheduled card number, and the frame number, and each number is set in the corresponding identification bit in the ID to determine the EBCU number, the scheduled card number, and the frame number of the data frame.

[0065] The data frame includes a scheduling frame and a common frame.

[0066] In some embodiments of the present invention, the scheduling frame can be identified by setting a scheduling frame identification bit in the ID of the data frame, that is, the ID of the data frame further includes a scheduling frame identification bit. For example, a data frame with a scheduling frame identification bit of 1 in the ID is determined as the scheduling frame.

[0067] In some embodiments of the present invention, the braking system includes multiple carriages, and each carriage includes at least one EBCU. To facilitate the detection of the packet loss rate of the EBCUs in different carriages, the CAN data frames of different carriages can be identified by setting a scheduling frame identification bit in the ID of the data frame, that is, the ID of the data frame further includes a carriage number;

[0068] In this embodiment, in the 11-bit ID of the data frame, the highest 11 bits are set as the scheduling frame identification bit, the 8-10 bits are set as the interface card identification bit, the 5-7 bits are set as the frame sequence number identification bit, and the 1-4 bits are set as the carriage number identification bit. It should be noted that the bit widths of the respective identification bits can be adjusted according to the actual scheduling situation, and the present invention does not make further limitations in this regard.

[0069] S2: Obtain the communication cycles of all data frames in the bus. For the data frames in the same EBCU, take the maximum communication cycle as the cyclic period scheduled by this EBCU.

[0070] For example, there are three CAN data frames in the internal bus of the same EBCU. Among them, the communication cycle of CAN frame 1 is 1000 ms, the communication cycle of CAN frame 2 is 500 ms, and the communication cycle of CAN frame 3 is 100 ms. Then the maximum cyclic period is determined to be 1000 ms.

[0071] Within each cyclic period, the scheduling card sends a scheduling frame to the scheduled cards connected thereto at a predetermined time interval, and schedules the data frames with different communication cycles in ascending order of the communication cycle.

[0072] In some embodiments of the present invention, when detecting the CAN bus packet loss rate inside the entire EBCU of a single unit, during the scheduling process, for the data frames with the same communication cycle in different scheduled cards within the same EBCU, they are scheduled in descending order or ascending order based on the frame sequence numbers of the respective data frames. Through the sequential scheduling based on the frame sequence number, the transmission order of the data frames within the same EBCU is ensured, thereby avoiding transmission failures or misparsing caused by frame disorder.

[0073] In some embodiments of the present invention, when detecting the packet loss rate of the CAN bus of the full - train braking system, during the scheduling process, for the data frames with the same communication cycle in the internal buses of multiple EBCUs in the full train, the data frames of the EBCUs in each carriage are scheduled in sequence based on the order of the carriage numbers in the ID of the data frame. By adding the carriage number information to the data frame ID, the coordinated scheduling of the multi - carriage system is realized, and the scheduling efficiency is improved.

[0074] In some embodiments of the present invention, the predetermined time is less than the ratio of the communication cycle corresponding to the data frame with the shortest communication cycle in the bus to the number of data frames with the shortest communication cycle.

[0075] For example, there are a total of 4 CAN data frames in the bus. Among them, the communication cycle of CAN frame 1 is 1000ms, the communication cycle of CAN frame 2 is 500ms, and the communication cycles of CAN frame 3 and CAN frame 4 are both 100ms. Then the communication cycle corresponding to the data frame with the shortest communication cycle in the current bus is 100ms, and the number of data frames with the shortest communication cycle is 2. Then the maximum value of the predetermined time is 100ms / 2 = 50ms. That is, during the actual scheduling process, the predetermined interval time for the scheduling card in the EBCU to send scheduling frames must be less than 50ms.

[0076] S3: During the scheduling process, the scheduling card counts the returned data frames in the bus, and each scheduled card counts the number of scheduling frames to be received and the number of actually received scheduling frames in this cycle.

[0077] Specifically, it includes the following steps:

[0078] Each scheduled card in the same EBCU determines the number of scheduling frames to be received by itself based on the scheduling frames sent by the scheduling card, denoted as buffer1xy.

[0079] Each scheduled card in the same EBCU counts the number of actually received scheduling frames on its own board, denoted as buffer2xy.

[0080] After each scheduled card in the same EBCU receives the scheduling frame, it returns buffer1xy and buffer2xy as part of the data frame data to the scheduling card;

[0081] The scheduling card counts the number of each returned data frame in the internal bus, denoted as buffer3xy, and sends buffer3xy as part of the scheduling frame data during scheduling.

[0082] It should be noted that the data scheduling method and the data volume can be set according to the actual vehicle data volume to make the detection accuracy closer to the actual vehicle operation condition.

[0083] S4: Connect a packet loss detection device to the external bus. The packet loss detection device listens to and records all scheduling frames sent by the scheduling card on the bus and the data frames returned by each scheduled card, and analyzes the data of each data packet to obtain the counting information of the scheduling card and each scheduled card, and then calculates the packet loss rate. Among them, the packet loss rate includes single-frame transmission packet loss rate, single-frame reception packet loss rate, single-frame process packet loss rate, board packet loss rate, EBCU whole machine packet loss rate, and full train braking system packet loss rate.

[0084] In some embodiments of the present invention, the steps of calculating the packet loss rate include.

[0085] Calculate the single-frame transmission packet loss rate A1xyz.

[0086] A1xyz = (Buffer1xy - Buffer2xy) / Buffer1xy * 100%;

[0087] Calculate the single-frame reception packet loss rate A2xyz.

[0088] A2xyz = (Buffer2xy - Buffer3xy) / Buffer2xy * 100%.

[0089] Wherein, buffer1xy is the number of scheduling frames that each scheduled card needs to receive in this cycle; buffer2xy is the number of scheduling frames actually received by each scheduled card; buffer3xy is the number of data frames returned by the bus received by the scheduling card; x is the frame number, and y is the scheduled card number.

[0090] It should be noted that A1xyz specifically represents the single-frame transmission packet loss rate of the data frame with frame number x, scheduled card number y, and EBCU number z in the CAN ID; A2xyz specifically represents the single-frame reception packet loss rate of the data frame with frame number x, scheduled card number y, and EBCU number z in the CAN ID.

[0091] In some embodiments of the present invention, the steps of calculating the packet loss rate further include.

[0092] Calculate the single-frame process packet loss rate A3xyz;

[0093] A3xyz = (Buffer1 xy - Buffer3xy) / Buffer1 xy * 100%.

[0094] Calculate the board packet loss rate A4yz:

[0095]

[0096] Calculate the EBCU whole machine packet loss rate A5z:

[0097]

[0098] Calculate the packet loss rate A6 of the full - train braking system:

[0099]

[0100] Where buffer1xy is the number of scheduling frames that each scheduled card needs to receive in its current cycle; buffer3xy is the number of data frames returned by the bus received by the scheduling card; x is the frame number, y is the scheduled card number, and z is the EBCU number.

[0101] It should be noted that A3xyz specifically represents the single - frame packet loss rate of the data frame with frame number x, scheduled card number y, and EBCU number z; A4yz specifically represents the packet loss rate of the board with scheduled card number y and EBCU number z; A5z specifically represents the packet loss rate of the entire EBCU with EBCU number z.

[0102] Based on the above - calculated results of packet loss rates at all levels, the following judgments can be made:

[0103] (1) If the packet loss rate of a single CAN data frame on the bus is relatively large, hardware problems can be excluded, and it is necessary to optimize the sending scheduling software and receiving software of this CAN frame specifically.

[0104] (2) If the packet loss rates of all CAN frames of a certain interface card on the bus are significantly greater than those of other interface cards, it is necessary to check the hardware problems of this interface card or optimize the CAN frame transceiver software of this interface card.

[0105] (3) If the packet loss rates of CAN frames of all interface cards on the entire CAN bus are relatively high, it is necessary to check the bus connection or optimize the CAN bus scheduling, reduce the communication rate and load rate to improve the communication quality.

[0106] In the above - mentioned exemplary embodiment, a hierarchical packet loss rate calculation system is provided, which covers a comprehensive evaluation from single - frame, board, whole machine to the whole system, facilitating accurate positioning of communication anomalies. The formula is simple and easy to use, can be calculated quickly, and is suitable for real - time monitoring and large - scale deployment.

[0107] Moreover, in the above - mentioned exemplary embodiment, by assigning a unique and identifiable ID to each CAN data frame and performing data scheduling based on the ID, the controllability of data frame management and transmission is improved. It can not only detect the packet loss rate between two node modules, but also detect the CAN bus packet loss of single - frame, single - board card, EBCU whole machine and full - train braking system, providing a basis for the evaluation of the CAN communication load rate, reliability and CAN bus scheduling inside the EBCU and braking system.

[0108] Some embodiments of the present invention further provide a packet loss rate detection system for a rail vehicle braking system, which is used to implement the above-mentioned packet loss rate detection method for the rail vehicle braking system. The detection system includes: a plurality of electronic brake control units (EBCUs) and a packet loss monitoring device.

[0109] The plurality of electronic brake control units are connected through an external bus, and the packet loss monitoring device is communicatively connected to each electronic brake control unit through the external bus.

[0110] The electronic brake control unit includes a main control card, an interface card, and a CAN bus conversion card connected through an internal bus.

[0111] Among them, the main control card serves as a scheduling card, which is used to schedule the data packets of each interface card, sends a scheduling frame to each interface card at a predetermined time interval within each scheduling cycle, and counts the number of data frames returned by each interface card.

[0112] The interface card serves as a scheduled card, and counts the number of scheduling frames that itself needs to receive and the number of actually received scheduling frames based on the scheduling frame sent by the main control card.

[0113] The conversion card is used to forward the internal bus data of the electronic brake control unit to the packet loss monitoring device through the external bus. The internal bus data of the electronic brake control unit at least includes the counting information of the main control card and each interface card.

[0114] Among them, the method for the interface card and the main control card to count is as follows:

[0115] Each interface card counts the number of scheduling frames that itself needs to receive based on the scheduling frame sent by the main control card, denoted as buffer1 xy, and counts the number of actually received scheduling frames of this board card, denoted as buffer2xy; after each interface card receives the scheduling frame, it returns buffer1xy and buffer2xy as part of the data frame data to the main control card.

[0116] The main control card counts the number of each data frame returned in the internal bus, denoted as buffer3xy, and sends buffer3xy as part of the scheduling frame data during scheduling, so as to facilitate the packet loss monitoring device to calculate the packet loss rate.

[0117] The packet loss monitoring device is used to receive the internal bus data of the electronic brake control unit, and calculate the packet loss rate of each electronic brake control unit and the packet loss rate of the entire train braking system based on the received bus data.

[0118] The above-mentioned schematic embodiments provide an efficient and modular packet loss rate detection system architecture, which is easy to expand and maintain. Through the efficient cooperation between modules, the accuracy of data statistics and analysis is improved, and moreover, it supports real-time detection and analysis, meeting the high safety requirements of the rail vehicle braking system.

[0119] In some embodiments of the present invention, the packet loss monitoring device includes a data recording module and a scheduling module.

[0120] Among them, the data recording module is a CAN bus data recorder. The CAN bus data recorder is connected to an external bus and is used to listen to, parse, and record the internal bus data of each electronic brake control unit and forward the parsed bus data to the scheduling module.

[0121] The scheduling module includes a monitoring terminal with a human-machine interface and a software detection algorithm running on the monitoring terminal.

[0122] Among them, the monitoring terminal is communicatively connected to the CAN bus data recorder to receive the bus data forwarded by the CAN bus data recorder. The software detection algorithm is used to control each board in each electronic brake control unit to implement the CAN bus data scheduling of the entire EBCU and each board module, and calculate the packet loss rate based on the bus data forwarded by the data recording module.

[0123] After the monitoring terminal is connected to the CAN bus data recorder, the playback and query of the data recorded by the CAN data recorder can be realized through the human-machine interface of the monitoring terminal.

[0124] In the above-described exemplary embodiments, the modular design of data recording and packet loss rate calculation makes the system structure clearer, more convenient for maintenance and expansion, improves the efficiency of data parsing and scheduling control, and reduces the computational pressure of packet loss rate monitoring.

[0125] Finally, it should be noted that the embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0126] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A method for detecting packet loss rate of a rail vehicle braking system, characterized in that: The braking system includes at least one electronic brake control unit EBCU, each EBCU includes a dispatching card and at least one dispatched card, and the dispatching card and the dispatched card are connected via a bus. The packet loss rate detection method includes the following steps: Allocating IDs of all data frames in the bus so that the ID of each data frame in the bus is unique and identifiable; the data frame includes a scheduling frame; the ID of the data frame includes at least an EBCU number, a scheduled card number, and a frame number; Obtain the communication cycles of all data frames in the bus, and use the maximum communication cycle as the scheduling cycle; In each cycle, the dispatch card sends a dispatch frame to the connected dispatched card at a predetermined interval, and dispatches the data frames of different communication cycles in sequence according to the order of the communication cycle; During the scheduling process, the scheduling card counts the returned data frames in the bus, and each scheduled card counts the number of scheduling frames that need to be received in this cycle and the number of scheduling frames actually received; The packet loss rate is calculated based on the counting information of the scheduling card and each scheduled card.

2. The method for detecting packet loss rate of a rail vehicle braking system according to claim 1, characterized in that: During the scheduling process, data frames with the same communication cycle in different scheduled cards in the same EBCU are scheduled in sequence based on the order of the frame numbers of the data frames.

3. The method for detecting packet loss rate of a rail vehicle braking system according to claim 1, characterized in that: The braking system includes a carriage, each carriage includes at least one EBCU; the ID of the data frame further includes a carriage number; During the scheduling process, for data frames with the same communication cycle in the bus, the data frames of the EBCU of each carriage are scheduled in sequence based on the order of the carriage numbers in the ID of the data frame.

4. The method for detecting packet loss rate of a rail vehicle braking system according to any one of claims 1 to 3, characterized in that: The steps to calculate the packet loss rate include: Calculate the single frame transmission packet loss rate A1xyz: A1xyz=(Buffer1xy-Buffer2xy) / Buffer1xy*100%; Calculate the single frame receiving packet loss rate A2xyz: A2xyz=(Buffer2xy-Buffer3xy) / Buffer2xy*100%. Among them, buffer1xy is the number of scheduling frames that each scheduled card needs to receive in this cycle; buffer2xy is the number of scheduling frames actually received by each scheduled card; buffer3xy is the number of data frames returned by the bus and received by the scheduling card; x is the frame number, y is the scheduled card number, and z is the EBCU number.

5. The method for detecting packet loss rate of a rail vehicle braking system according to any one of claims 1 to 3, characterized in that: The step of calculating the packet loss rate further includes: Calculate the packet loss rate of a single frame process A3xyz; A3xyz=(Buffer1xy-Buffer3xy) / Buffer1xy*100%; Calculate the board packet loss rate A4yz: Calculate the EBCU packet loss rate A5z: Calculate the packet loss rate A6 of the entire train braking system: Among them, buffer1xy is the number of scheduling frames that each scheduled card needs to receive in this cycle; buffer3xy is the number of data frames returned by the bus received by the scheduling card; x is the frame number, y is the scheduled card number, and z is the EBCU number.

6. The method for detecting packet loss rate of a rail vehicle braking system according to claim 1, characterized in that: The predetermined time is smaller than the ratio of the communication cycle corresponding to the data frame with the shortest communication cycle in the bus to the number of the data frames with the shortest communication cycle.

7. A railway vehicle braking system packet loss rate detection system, used to implement the railway vehicle braking system packet loss rate detection method according to any one of claims 1 to 6, characterized in that: include: Electronic brake control unit and packet loss monitoring device; The electronic brake control unit is communicatively connected with the packet loss monitoring device; The electronic brake control unit comprises a main control card, an interface card and a conversion card connected via an internal bus; The main control card acts as a scheduling card, sends scheduling frames to each interface card at predetermined intervals in each scheduling cycle, and counts the number of data frames returned by each interface card; As the scheduled card, the interface card counts the number of scheduling frames it needs to receive and the number of scheduling frames actually received based on the scheduling frames sent by the main control card; The conversion card is used to forward the bus data inside the electronic brake control unit to the packet loss monitoring device, and the bus data inside the electronic brake control unit includes counting information of the main control card and each interface card; The packet loss monitoring device is used to receive bus data and calculate the packet loss rate of the electronic brake control unit based on the received bus data.

8. The railway vehicle braking system packet loss rate detection system according to claim 7, characterized in that: It includes a plurality of electronic brake control units, and the plurality of electronic brake control units are connected via an external bus; The packet loss monitoring device is communicatively connected with each electronic brake control unit via the external bus; The conversion card of each electronic brake control unit forwards the internal bus data to the packet loss monitoring device through the external bus.

9. The railway vehicle braking system packet loss rate detection system according to claim 7 or 8, characterized in that: The packet loss monitoring device includes a data recording module and a scheduling module; The data recording module is used to listen, analyze, and record bus data and forward the analyzed bus data to the scheduling module; The scheduling module is used to control the scheduling of each board in each electronic brake control unit, and calculate the packet loss rate based on the bus data forwarded by the data recording module.

10. The railway vehicle braking system packet loss rate detection system according to claim 7 or 8, characterized in that: Each interface card counts the number of scheduling frames it needs to receive based on the scheduling frames sent by the main control card, which is recorded as buffer1xy, and counts the number of scheduling frames actually received by the board, which is recorded as buffer2xy; after receiving the scheduling frames, each interface card returns buffer1xy and buffer2xy as part of the data frame data to the main control card; The main control card counts the number of each data frame returned in the internal bus, records it as buffer3xy, and sends buffer3xy as a part of the scheduling frame data during scheduling.

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