Real-time speed calculation method for motor train unit without pure towing axle

Abstract

According to the real-time speed calculation method for the motor train unit without the pure towing axle, a speed signal line is connected to an EBCU of each train through a shielding cable, and the single-train single-axle initial speed calculated by the EBCU of each train is transmitted to a TCMS through a network cable; the TCMS performs validity judgment according to the obtained data, obtains the speed of a single vehicle through comparison and calculation, and obtains the real-time speed of each traction unit through comparison and calculation; and when the real-time speed of the first traction unit is valid, the motor train unit preferentially selects the real-time speed of the first traction unit as the real-time speed of the motor train unit, and if the real-time speed of the first traction unit is invalid, the real-time speeds of the second, third and fourth traction units are sequentially selected as the real-time speed of the motor train unit. According to the method, the real-time speed of the motor train unit can be rapidly and accurately determined, the real-time speed deviation caused by the special state of the axle in the running process of the motor train unit can be effectively avoided, the method is more suitable for intelligent control of the motor train unit, and the safety and reliability of the motor train unit are improved.

Description

Technical Field

[0001] The invention belongs to the field of intelligent control of train network control systems, and in particular relates to a real-time speed calculation method for rail vehicles. Background Art

[0002] When EMUs are running at high speed, it is very important to monitor and accurately judge the real-time speed of the train. It is not only an important part of the train's intelligent control, but also the key to safe railway operations.

[0003] In the existing EMU real-time speed calculation method, the speed source is mainly the axle speed collected by the speed sensor installed on the pure towing axle of the trailer, and then the real-time speed of the EMU is obtained through a series of complex calculations, conversions and calibrations. The pure towing axle of the EMU refers to a reference axle that is specially set in the trailer and does not apply normal braking. However, under special conditions such as emergency braking axle locking and idling sliding, the axle speed collected by the speed sensor of the reference axle will still produce inevitable errors, and the single traction unit of the whole vehicle is only equipped with one reference axle, and the data source is single. In summary, the existing EMU real-time speed calculation method has a large room for improvement in actual use.

[0004] Therefore, how to simplify the existing EMU real-time speed calculation scheme and make it more stable and reliable through a series of operations is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0005] In order to solve the above problems, it is considered to cancel the pure drag axle and adopt a real-time speed calculation method with more diverse parameter sources, more stable and reliable under different operating conditions. This can not only reduce the special pure drag axle of the whole vehicle, make the application and distribution of braking force more balanced and simple, but also make the real-time speed of the EMU more accurate and the intelligent vehicle control more accurate and safer.

[0006] In order to achieve the above-mentioned invention object, the present invention provides a method for calculating the real-time speed of an EMU without pure drag axles, characterized in that: the source of the real-time speed of the EMU is a speed sensor installed at each axle end of the braking system, and the speed signal line is connected to each vehicle brake control unit (EBCU) through a shielded cable, and the initial speed of a single vehicle and axle calculated by each vehicle EBCU is then transmitted to the train network control system (TCMS) through a network cable; TCMS performs a series of validity judgments, comparative calculations, etc. based on the obtained data to obtain the single vehicle speed, and then obtains the real-time speed of each traction unit through comparative calculation; when the real-time speed of the first traction unit is valid, the EMU gives priority to using the real-time speed of the first traction unit as the real-time speed of the EMU, and if it is invalid, the real-time speeds of the second, third, and fourth traction units (8-car marshaling cars include two traction units, and 16-car marshaling cars include four traction units) are selected in turn as the real-time speed of the EMU.

[0007] Taking each traction unit calculating its own real-time speed as an example, the method includes the following execution steps:

[0008] Step 1: Obtain the real-time speed data and real-time speed validity of each axle of each EBCU of each vehicle in the braking system of the traction unit on the target EMU;

[0009] Step 2: Determine the validity of the real-time speed of each vehicle in the traction unit. The basis for determination is whether the sum of the number of real-time speed validity of each axle sent by each EBCU of the single vehicle in step 1 meets the required number for calculating the real-time speed of the single vehicle. If so, the real-time speed of the vehicle is considered valid. Otherwise, the real-time speed of the vehicle is considered invalid.

[0010] Step 3: Determine the validity of the real-time speed of the traction unit. The basis for the determination is that the sum of the number of valid real-time speeds of each vehicle in step 2 is not less than three. If the condition is satisfied, the real-time speed of the traction unit is considered valid and step 4 is executed. Otherwise, the real-time speed of the traction unit is considered invalid and step 9 is executed.

[0011] Step 4: In order to obtain the data source for calculating the real-time speed of each vehicle in this traction unit, the real-time speed data of each axle of each vehicle in this traction unit needs to be screened. The specific method is: for the real-time speed data of each axle sent by each EBCU of a single vehicle in step 1 and its validity, if the real-time speed validity of any axle is invalid, the real-time speed data of the axle is discarded, otherwise, the real-time speed data of the axle is retained for the calculation in step 5;

[0012] Step 5: sort the effective real-time speed data of each axle of the single vehicle obtained in step 4, and record the second largest data in the obtained data list as braking condition data, and the second smallest data as traction condition data, which are used for calculation in step 6;

[0013] Step six: Obtain the driving status of the EMU of this traction unit through TCMS, which is used to calculate the real-time speed data of each vehicle of this traction unit. When it is obtained that the EMU is in a braking condition, in order to avoid the real-time speed data being too small due to special working condition data such as locking of each vehicle and each axle, the braking working condition data in step five is selected as the real-time speed data of each vehicle; when it is obtained that the EMU is in a traction condition, in order to avoid the real-time speed data being too large due to special working condition data such as idling of each vehicle and each axle, the traction working condition data in step five is selected as the real-time speed data of each vehicle; if it is obtained that the EMU is in an idling condition, the real-time speed data used by the EMU in the previous condition is selected as the real-time speed data of each vehicle;

[0014] Step 7: In order to obtain a data source for calculating the real-time speed of the traction unit, the real-time speed data of each vehicle in the traction unit needs to be screened. The specific method is: judging the validity of the real-time speed of each vehicle in the traction unit obtained in step 2. If the real-time speed of the vehicle is invalid, the real-time speed data of the vehicle is discarded. Otherwise, the real-time speed data of the vehicle is retained for calculation in step 8.

[0015] Step 8: Sort the real-time speed data of each vehicle obtained in step 7, remove the minimum value for safety considerations, and calculate the average value of the remaining real-time speed data of each vehicle as the real-time speed of the traction unit;

[0016] Step nine: If the real-time speed of the traction unit is invalid, the real-time speed of the traction unit is 0, and the failure information of the real-time speed of the traction unit is sent to TCMS via a message, prompting maintenance personnel to handle it in the form of a fault.

[0017] The present invention is also characterized in that the characteristic information and methods appearing in the above steps include:

[0018] (1) Regarding the determination of the validity of the speed of each vehicle and each axle from the EBCU in step 1, the present method has the following characteristics: the EBCU diagnoses the working status of the speed sensor of each vehicle and each axle, and the TCMS sets a maximum value limit on the received real-time speed data on the premise that the speed sensor is in normal working status. If the speed exceeds the set maximum value, the speed of the vehicle and the axle is invalid; otherwise, it is valid.

[0019] (2) With regard to the real-time speed data of each axle of each vehicle obtained in step 1, since the real-time speed data sent by the EBCU is calculated based on the wheel diameter value of the benchmark semi-worn EMU, the wheel diameter value of the EMU needs to be calibrated in real time in actual application. Therefore, the wheel diameter calibration interface is set on the human-machine interactive display screen in the driver's cab to calibrate the wheel diameter value in real time, and the set wheel diameter data is stored in the readable storage medium of the TCMS; the calibrated wheel diameter value of each axle of each vehicle is calculated by ratio with the benchmark semi-worn EMU wheel diameter value, and then the ratio is calculated with the real-time speed data of each axle of each vehicle, so as to obtain the calibrated real-time speed data of each axle of each vehicle.

[0020] (3) With respect to the number of valid real-time speeds of each axle of the vehicle required for calculating the real-time speed of the vehicle in step 2 (here, the case of a vehicle with dual-channel EBCU redundancy and four axles is taken as an example), the present method stipulates as follows: When the number of failed real-time speed information of each axle of the vehicle does not exceed 3, or when at least one EBCU communicates normally and the real-time speeds of each axle are all valid, the real-time speed of the vehicle can be obtained and calculated.

[0021] (4) Regarding the number of valid real-time speeds of each vehicle required for calculating the real-time speed of the traction unit in step 3, the present method has the following characteristics: Since the minimum value needs to be discarded when calculating the real-time speed of a single traction unit, when the number of valid real-time speeds of a single vehicle is not less than three (the traction unit consists of four vehicles), the real-time speed of the traction unit can be calculated.

[0022] (5) In step 4, real-time speed data is screened. Furthermore, if the real-time speed data of each axle of each vehicle fails, the EBCU does not recognize the failure and still sends the actual failed real-time data to the TCMS and feedbacks that the data is valid, which will lead to inaccurate real-time speed calculation. After testing the current vehicle, it is found that the failed data is usually 0. In order to avoid failures and safety problems caused by abnormal failure of the EMU speed, the following features are supplemented in the process of single vehicle real-time speed calculation:

[0023] 1. If the real-time speed data of only one axis among the four axes of a bicycle is 0, the real-time speed data of this axis is considered invalid, and the bicycle is calculated according to the normal real-time speed calculation process;

[0024] 2. When the real-time speed data of any two axes of the four axes of a single vehicle is 0, considering that the EMU may tend to be stationary, for safety reasons, the larger of the real-time speed data of the other two axes is selected as the real-time speed of the single vehicle;

[0025] 3. When the real-time speed data of more than two axles among the four axles of a single vehicle is 0, this method considers that the EMU is close to being stationary, and the real-time speed output of the single vehicle is 0.

[0026] The present invention has the following advantages and progress over the prior art:

[0027] The method is a real-time speed calculation method for EMUs based on the EMU TCMS logic operation and brake system speed acquisition. The real-time speed of the EMU can be quickly and accurately determined through the TCMS software operation, and the real-time speed deviation caused by the special state of the axle during the EMU's travel can be effectively avoided. It is not only more suitable for the intelligent control of the EMU, but also improves the safety and reliability of the EMU.

[0028] This method does not require the EMU to be equipped with additional pure drag axles, effectively saving the manpower and material resources consumed in arranging pure drag axles, and can complete the real-time speed calculation of the EMU by relying on the existing equipment of the EMU, which is suitable for promotion and popularization in this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the EMU marshaling and traction unit composition;

[0030] Figure 2 It is a flow chart of the overall technical solution for calculating the real-time speed of the EMU in the present invention;

[0031] Figure 3 A flow chart showing how each traction unit calculates its own real-time speed in the present invention;

[0032] Figure 4 It is a schematic diagram of the effectiveness analysis of the real-time speed of a bicycle according to the present invention. DETAILED DESCRIPTION

[0033] Reference Figure 1 The present invention is widely applicable to EMUs with 8 cars in one marshaling and every 4 cars forming a traction unit, and is also applicable to double-coupled or short- or long-marshaling EMUs.

[0034] Reference Figure 2 The overall scheme for calculating the real-time speed of the EMU in the present invention is specifically as follows: after the pure trailing axle is eliminated, the source of the real-time speed of the EMU is the speed sensor installed at each axle end of the braking system, and the speed signal line is connected to the braking control unit (EBCU) of each vehicle through a shielded cable. The initial speed of the single vehicle and single axle calculated by the EBCU of each vehicle is then transmitted to the train network control system (TCMS) through a network cable; TCMS performs a series of validity judgments, comparative calculations, etc. based on the obtained data to obtain the single vehicle speed, and then obtains the real-time speed of each traction unit through comparative calculation; when the real-time speed of the first traction unit is valid, the EMU gives priority to using the real-time speed of the first traction unit as the real-time speed of the EMU, and if it is invalid, the real-time speeds of the second, third, and fourth traction units are selected in turn as the real-time speed of the EMU.

[0035] Reference Figure 3 , taking each traction unit calculating its own real-time speed as an example, the method includes the following execution steps:

[0036] Step 1: Obtain the real-time speed data and real-time speed validity of each axle of each EBCU of each vehicle in the braking system of the traction unit on the target EMU;

[0037] Step 2: Determine the validity of the real-time speed of each vehicle in the traction unit. The basis for determination is whether the sum of the number of real-time speed validity of each axle sent by each EBCU of the single vehicle in step 1 meets the required number for calculating the real-time speed of the single vehicle. If so, the real-time speed of the vehicle is considered valid. Otherwise, the real-time speed of the vehicle is considered invalid.

[0038] Step 3: Determine the validity of the real-time speed of the traction unit. The basis for the determination is that the sum of the number of valid real-time speeds of each vehicle in step 2 is not less than three. If the condition is satisfied, the real-time speed of the traction unit is considered valid and step 4 is executed. Otherwise, the real-time speed of the traction unit is considered invalid and step 9 is executed.

[0039] Step 4: In order to obtain the data source for calculating the real-time speed of each vehicle in this traction unit, the real-time speed data of each axle of each vehicle in this traction unit needs to be screened. The specific method is: for the real-time speed data of each axle sent by each EBCU of a single vehicle in step 1 and its validity, if the real-time speed validity of any axle is invalid, the real-time speed data of the axle is discarded, otherwise, the real-time speed data of the axle is retained for the calculation in step 5;

[0040] Step 5: sort the effective real-time speed data of each axle of the single vehicle obtained in step 4, and record the second largest data in the obtained data list as braking condition data, and the second smallest data as traction condition data, which are used for calculation in step 6;

[0041] Step six: Obtain the driving status of the EMU of this traction unit through TCMS, which is used to calculate the real-time speed data of each vehicle of this traction unit. When it is obtained that the EMU is in a braking condition, in order to avoid the real-time speed data being too small due to special working condition data such as locking of each vehicle and each axle, the braking working condition data in step five is selected as the real-time speed data of each vehicle; when it is obtained that the EMU is in a traction condition, in order to avoid the real-time speed data being too large due to special working condition data such as idling of each vehicle and each axle, the traction working condition data in step five is selected as the real-time speed data of each vehicle; if it is obtained that the EMU is in an idling condition, the real-time speed data used by the EMU in the previous condition is selected as the real-time speed data of each vehicle;

[0042] Step 7: In order to obtain a data source for calculating the real-time speed of the traction unit, the real-time speed data of each vehicle in the traction unit needs to be screened. The specific method is: judging the validity of the real-time speed of each vehicle in the traction unit obtained in step 2. If the real-time speed of the vehicle is invalid, the real-time speed data of the vehicle is discarded. Otherwise, the real-time speed data of the vehicle is retained for calculation in step 8.

[0043] Step 8: Sort the real-time speed data of each vehicle obtained in step 7, remove the minimum value for safety considerations, and calculate the average value of the remaining real-time speed data of each vehicle as the real-time speed of the traction unit;

[0044] Step nine: If the real-time speed of the traction unit is invalid, the real-time speed of the traction unit is 0, and the failure information of the real-time speed of the traction unit is sent to TCMS via a message, prompting maintenance personnel to handle it in the form of a fault.

[0045] Reference Figure 4 , for the effective number of real-time speeds of each axle of a single vehicle required to calculate the real-time speed of a single vehicle (here, the case of a single vehicle with dual-channel EBCU redundancy and four axles is taken as an example), this method performs the following analysis:

[0046] The dual EBCU (denoted as EBCU1 and EBCU2) sends 4 real-time speed validity information of each axis to TCMS respectively. TCMS receives a total of 8 dual-channel redundant real-time speed validity information. The real-time speed of the axis fails only when the speed sensors at both ends of a single axis fail. Considering that it may contain several real-time speed failure information, the single vehicle real-time speed failure judgment is as follows:

[0047] ① When there is only one piece of real-time speed failure information, due to the existence of the redundancy mechanism, the acquisition of real-time speed data of each axis of the bicycle is not affected, and the real-time speed of the bicycle is valid;

[0048] ② When there are two pieces of real-time speed failure information, the real-time speed data of a certain axle of a single vehicle may not be obtained. However, in steps 5 and 6, no matter what working condition the EMU is in, the selected single vehicle real-time speed is the more reliable intermediate data in the data set. The failure to obtain the real-time speed of a single axle has little effect on the selection of the real-time speed of the single vehicle, and the real-time speed of the single vehicle is still valid.

[0049] ③ When three pieces of real-time speed information fail, according to the above discussion, at most the real-time speed of one axis cannot be obtained. Similar to ②, the real-time speed of a single vehicle is still valid;

[0050] ④ When there are four real-time speed failure messages, there are two possible sources of these four messages: the first is that the four messages come from EBCU1 and EBCU2 respectively. In this case, the real-time speed data of at least two axles of the vehicle may not be obtained, which will greatly affect the accuracy of the vehicle's real-time speed. In this case, the vehicle's real-time speed is considered invalid. The second is that the four messages all come from the same EBCU. In this case, the more common problem is that a single EBCU fails to communicate with TCMS. Although the communication of a single EBCU fails, the other EBCU in this section of the vehicle can correctly send the real-time speed data of each axle to TCMS, and the vehicle's real-time speed is still valid.

[0051] In summary, when the number of invalid real-time speed information of each axle of a single vehicle does not exceed 3, or when at least one EBCU communicates normally and the real-time speeds of each axle are all valid, the real-time speed of a single vehicle can be obtained and calculated.

Claims

1. A method for calculating the real-time speed of a train without pure drag axles, characterized by: The real-time speed of the EMU is derived from the speed sensor installed at each axle end of the braking system. The speed signal line is connected to each vehicle EBCU through a shielded cable. The initial speed of each vehicle and axle calculated by the EBCU of each vehicle is then transmitted to the TCMS through a network cable. TCMS makes validity judgment and comparative calculation based on the obtained data to obtain the single vehicle speed, and then obtains the real-time speed of each traction unit through comparative calculation; when the real-time speed of the first traction unit is valid, the EMU will preferentially use the real-time speed of the first traction unit as the real-time speed of the EMU; if it is invalid, the real-time speeds of the second, third, and fourth traction units will be used in turn as the real-time speed of the EMU; Wherein: the method for each traction unit to calculate its own real-time speed includes the following execution steps: Step 1: Obtain the real-time speed data and real-time speed validity of each axle of each EBCU of each vehicle in the braking system of the traction unit on the target EMU; Step 2: Determine the validity of the real-time speed of each vehicle in the traction unit. The basis for determination is whether the sum of the number of real-time speed validity of each axle sent by each EBCU of the single vehicle in step 1 meets the required number for calculating the real-time speed of the single vehicle. If so, the real-time speed of the vehicle is considered valid. Otherwise, the real-time speed of the vehicle is considered invalid. Step 3: Determine the validity of the real-time speed of the traction unit. The basis for the determination is that the sum of the number of valid real-time speeds of each vehicle in step 2 is not less than three. If the condition is satisfied, the real-time speed of the traction unit is considered valid and step 4 is executed. Otherwise, the real-time speed of the traction unit is considered invalid and step 9 is executed. Step 4: In order to obtain the data source for calculating the real-time speed of each vehicle in this traction unit, the real-time speed data of each axle of each vehicle in this traction unit needs to be screened. The specific method is: for the real-time speed data of each axle sent by each EBCU of a single vehicle in step 1 and its validity, if the real-time speed validity of any axle is invalid, the real-time speed data of the axle is discarded, otherwise, the real-time speed data of the axle is retained for the calculation in step 5; Step 5: sort the effective real-time speed data of each axle of the single vehicle obtained in step 4, and record the second largest data in the obtained data list as braking condition data, and the second smallest data as traction condition data, which are used for calculation in step 6; Step 6: Obtain the driving status of the EMU of the traction unit through TCMS, which is used to calculate the real-time speed data of each car of the traction unit; when it is obtained that the EMU is in a braking condition, in order to avoid the real-time speed data being too small due to special working condition data such as locking of each car and each axle, the braking working condition data in step 5 is selected as the real-time speed data of each car; when it is obtained that the EMU is in a traction condition, in order to avoid the real-time speed data being too large due to special working condition data such as idling of each car and each axle, the traction working condition data in step 5 is selected as the real-time speed data of each car; if it is obtained that the EMU is in an idling condition, the real-time speed data used by the EMU in the previous condition is selected as the real-time speed data of each car; Step 7: In order to obtain a data source for calculating the real-time speed of the traction unit, the real-time speed data of each vehicle in the traction unit needs to be screened. The specific method is: judging the validity of the real-time speed of each vehicle in the traction unit obtained in step 2. If the real-time speed of the vehicle is invalid, the real-time speed data of the vehicle is discarded. Otherwise, the real-time speed data of the vehicle is retained for calculation in step 8. Step 8: Sort the real-time speed data of each vehicle obtained in step 7, remove the minimum value, and calculate the average value of the remaining real-time speed data of each vehicle as the real-time speed of the traction unit; Step nine: If the real-time speed of the traction unit is invalid, the real-time speed of the traction unit is 0, and the failure information of the real-time speed of the traction unit is sent to TCMS via a message, prompting maintenance personnel to handle it in the form of a fault.

2. The method for calculating the real-time speed of a train without pure drag axles according to claim 1, characterized in that: The method for judging the validity of the speed of each axle of each vehicle in the EBCU in step 1 is as follows: the EBCU diagnoses the working status of the speed sensor of each axle of each vehicle, and the TCMS sets a maximum value limit on the received real-time speed data on the premise that the working status of the speed sensor is normal. If the speed exceeds the set maximum value, the speed of the axle of the vehicle is invalid, otherwise it is valid.

3. The method for calculating the real-time speed of a train without pure drag axles according to claim 1, characterized in that: The method for obtaining the real-time speed data of each axle of each vehicle in step 1 is as follows: a wheel diameter calibration interface is set on the human-machine interactive display screen in the driver's cab to calibrate the wheel diameter value in real time, and the set wheel diameter data is stored in a readable storage medium of the TCMS; The calibrated real-time speed data of each axle of each vehicle is obtained by calculating the ratio of the calibrated wheel diameter value of each vehicle and each axle with the wheel diameter value of the benchmark semi-worn EMU, and then calculating with the real-time speed data of each vehicle and each axle.

4. The method for calculating the real-time speed of a train without pure drag axles according to claim 1, characterized in that: The following provisions apply to the number of valid real-time speeds of each axle of the vehicle required for calculating the real-time speed of the vehicle in step 2: when the number of invalid real-time speed information of each axle of the vehicle does not exceed 3, or when at least one EBCU communicates normally and the real-time speeds of each axle are all valid, the real-time speed of the vehicle is obtained for calculation.

5. The method for calculating the real-time speed of a train without pure drag axles according to claim 1, characterized in that: The regulation for the valid number of real-time speeds of each vehicle required for calculating the real-time speed of the traction unit in step three is as follows: since the minimum value needs to be discarded when calculating the real-time speed of a single traction unit, the real-time speed of the traction unit is calculated when the valid number of real-time speeds of a single vehicle is not less than three.

6. The method for calculating the real-time speed of a train without pure drag axles according to claim 1, characterized in that: When the real-time speed data of only one axle among the four axles of a bicycle is 0, the real-time speed data of this axle is deemed invalid, and the real-time speed of the bicycle is still calculated according to the above principles; when the real-time speed data of any two axles among the four axles of a bicycle is 0, the larger of the real-time speed data of the other two axles is selected as the real-time speed of the bicycle; when the real-time speed data of more than two axles among the four axles of a bicycle is 0, the EMU is close to stationary, and the real-time speed output of the bicycle is 0.

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