Train traction calculation method and device based on interval speed limit correction

Abstract

The invention belongs to the technical field of rail transit, and particularly relates to a train traction calculation method and device based on interval speed limit correction. Under the service braking performance of the train, the maximum allowable speed of each speed limiting starting point in the current position and the follow-up set range is calculated in an iterative mode, it can be guaranteed that overspeed does not occur at the next speed limiting starting point after service braking is conducted at the current position as long as the speed of the train is controlled not to exceed the maximum allowable speed of the current position, and the speed limiting effect is guaranteed. And the overspeed is avoided in the subsequent speed limit interval. In the whole iteration process, automatic iteration can be completely achieved through the algorithm, and manual repeated attempts are not needed. The technical problem that in the prior art, the overspeed problem can be avoided only by manually trying to adjust the calculation step length for multiple times is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail transit, and in particular relates to a train traction calculation method and device based on section speed limit correction. Background Art

[0002] In modern railway transportation, train traction calculation has become an indispensable technical means, which is of great significance for improving railway transportation efficiency, reducing operating costs, and ensuring driving safety. In this context, the China Academy of Railway Sciences developed the "Traction Computer" software in 2000. This software has an "automatic calculation" function, similar to the function of subways or locomotives with ATO control. It can automatically adjust the traction and braking parameters according to the line speed limit, stop stations, and line longitudinal sections to achieve the purpose of safe driving and precise stopping. This is also the only simulation software with similar ATO control used in railway enterprises.

[0003] According to the application and usage feedback from the railway operation departments, the "traction computer" software is prone to major defects such as jamming, speeding, and inaccurate parking in the "automatic calculation" mode. It is necessary to manually try to adjust the calculation step size and the interval of times many times to avoid the speeding problem. After understanding, the automatic calculation method of this software is to obtain the speed limit change point ahead according to the set automatic calculation parameters, and obtain the speed adjustment location by calculating the braking distance during electric braking or superimposed air braking. Since it only takes the longitudinal section information of each speed limit starting point, if the speed limit starting point has a small slope, the subsequent downhill slope suddenly increases, which will cause it to be under the set automatic calculation parameters. It cannot effectively avoid the speeding problem. Sometimes after the speed adjustment point is passed, there is a large uphill slope, and overshoot problems will also occur. Summary of the invention

[0004] The purpose of the present invention is to provide a train traction calculation method and device based on section speed limit correction to solve the technical problem in the prior art that multiple manual attempts are required to adjust the calculation step size in order to avoid the overspeed problem.

[0005] In order to solve the above technical problems, the present invention provides a technical solution of a train traction calculation method based on interval speed limit correction: a train traction calculation method based on interval speed limit correction, the method comprising: 1) Set the initial value of the speed step and V The initial value of 0; the two initial values ​​set are used as the current speed step and V The current value of 0 executes 2); 2) Update according to the current speed step V 0 is: V The sum of the current value of 0 and the current speed step; 3) Calculate the speed of the train from V0 down to V t Braking distance S 1; 4) If S 1≤ S And∣ S 1- S ∣≤ S s , then V 0 is the speed limit value of the current speed limit section of the train; like S 1> S , then V 0 is updated to V 0- V After 1, reduce the current speed step and execute 2 again); like S 1≤ S And∣ S 1- S ∣> S s , then reduce the current speed step and re-execute 2); in, V The speed limit of the current speed limit interval; V 1 is the speed step; V t The speed limit for the next speed limit zone; S is the length of the current speed limit interval; V 0 is the corrected speed limit of the current speed limit interval; S s To allow distance error.

[0006] The beneficial effect of the above technical solution is that the technical solution of the train traction calculation method based on interval speed limit correction of the present invention is a pioneering invention. Under the common braking performance of the train, the present invention iteratively calculates the maximum allowable speed of each speed limit starting point at the current position and the subsequent set range. As long as the train speed is controlled not to exceed the maximum allowable speed at the current position, it can be ensured that after common braking at the current position, no overspeeding occurs at the next speed limit starting point, and no overspeeding occurs in the subsequent speed limit interval. The entire iterative process can be completely automatically iterated by the algorithm without multiple manual attempts. The present invention solves the technical problem in the prior art that it is necessary to manually try multiple times to adjust the calculation step size in order to avoid the problem of overspeeding.

[0007] Further, 3) includes: 301) Set the initial distance step; execute 302 with the initial distance step as the current distance step); 302) If the current distance step is greater than the preset distance setting value, directly execute 303); otherwise, execute 303 with the distance setting value as the current distance step); 303) V 0 as the initial velocity, according to the current distance step and acceleration a Calculate the final velocity at the end of the current distance step V t1 ,make V 0= V t1 ; in, a It is the train braking acceleration in the interval with the end point of the previous distance step as the starting point and the current distance step as the length; the starting point of the initial distance step is the starting point of the current speed limit interval; 304) If V 0 and V t If the error between the speed error and the braking distance is greater than or equal to the preset speed error setting value, the current distance step is reduced, and then the process returns to 302) and executes again; otherwise, the distance step used in each 303) is superimposed and output as the braking distance. S 1.

[0008] Furthermore, the current speed step in 2) is the speed step processed in the following manner: if the current speed step is greater than the speed error setting value, then the current speed step is updated according to V 0; otherwise, the speed error setting value is used as the current speed step update V 0.

[0009] Furthermore, the initial value of the speed step set in 1) is the difference between the speed limit of the current speed limit section of the train and the speed limit of the next speed limit section.

[0010] Furthermore, the V The initial value of 0 is the speed limit of the next speed limit interval.

[0011] Furthermore, the initial distance step is half of the average length of the train.

[0012] Furthermore, the method of reducing the speed step in 4) is to reduce the speed step according to a preset first setting ratio; and / or 304) in which the distance step is reduced by reducing the distance step according to a preset second setting ratio.

[0013] Furthermore, the first set ratio and / or the second set ratio is / are half.

[0014] Furthermore, 4) also includes: if S 1≤ S ,∣S 1- S ∣> S s and V 0≥ V , then V As the speed limit value of the train’s current speed limit section.

[0015] Further, in 303), the acceleration is calculated a When the train is moving, each carriage is taken as a mass point and the multi-mass point algorithm is used to calculate the total resistance of the train.

[0016] The present invention also provides a technical solution for a train traction calculation device based on section speed limit correction: a train traction calculation device based on section speed limit correction, comprising a processor, wherein the processor is used to execute a computer program to implement the steps of the train traction calculation method based on section speed limit correction as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of a method for calculating braking distance in an embodiment of a train traction calculation method based on section speed limit correction of the present invention; Figure 2 It is a flow chart of a method for correcting the current speed limit in an embodiment of a train traction calculation method based on interval speed limit correction of the present invention; Figure 3 It is a schematic diagram of force analysis when the total resistance of a train is calculated using a multi-particle algorithm in an embodiment of a train traction calculation method based on interval speed limit correction of the present invention. DETAILED DESCRIPTION

[0018] The present invention iteratively calculates the maximum permissible speed of each speed limit starting point at the current position and in the subsequent set range under the train's common braking performance. As long as the train speed is controlled not to exceed the maximum permissible speed at the current position, it can be ensured that after common braking at the current position, no overspeeding occurs at the next speed limit starting point, and no overspeeding occurs in the subsequent speed limit interval. The entire iterative process can be completely automatically iterated by the algorithm without multiple manual attempts. The present invention solves the technical problem in the prior art that multiple manual attempts are required to adjust the calculation step size in order to avoid the overspeeding problem.

[0019] Example of a train traction calculation method based on section speed limit correction: A train traction calculation method based on interval speed limit correction, such as Figure 2 As shown, the method comprises the following steps: 1) Set the speed step and V The initial value is 0; the two initial values ​​are used as the current speed step and V The current value of 0 executes 2).

[0020] Specifically, in this embodiment, the initial value of the speed step is V - V t ; V The initial value is 0 V t .

[0021] in, V The speed limit of the train in the current speed limit section; V t The speed limit for the next speed limit zone.

[0022] In other embodiments, the speed step and V The initial value of 0 can also be set to other values ​​according to the actual situation.

[0023] 2) Update according to the current speed step V 0 is: V The sum of the current value of 0 and the current speed step.

[0024] In this embodiment, the current speed step is the speed step processed in the following manner: if the current speed step is greater than the speed error setting value, then the current speed step is updated according to the current speed step. V 0; otherwise, the speed error setting value is used as the current speed step update V 0.

[0025] 3) Calculate the speed of the train from V 0 down to V t Braking distance S 1.

[0026] In the "automatic calculation" mode of the existing "traction computer" software, since it only takes the longitudinal section information of the starting point of each speed limit when calculating the braking distance, it cannot effectively avoid the speeding problem and may also cause overshoot problems.

[0027] Therefore, in this embodiment, the braking distance is calculated in the following manner: Figure 1 As shown: 301), set the initial distance step; execute 302) with the initial distance step as the current distance step.

[0028] 302), if the current distance step is greater than the preset distance setting value, directly execute 303); otherwise, execute 303) with the distance setting value as the current distance step.

[0029] 303) V 0 as the initial velocity, according to the current distance step and acceleration a Calculate the final velocity at the end of the current distance stepV t1 ,make V 0= V t1 .

[0030] in, a It is the train braking acceleration within the interval starting from the end point of the previous distance step and with the current distance step as the length; the starting point of the initial distance step is the starting point of the current speed limit interval.

[0031] Specifically, when calculating the acceleration a When the train is moving, the multi-particle algorithm is used to calculate the total resistance of the train, including total slope resistance, curve resistance, basic resistance, braking force, etc., and then the acceleration can be obtained according to Newton's second law. a ,like Figure 3 Using multiple mass points to calculate the total resistance of the train can further reduce the calculation error of the braking distance.

[0032] 304) If V 0 and V t If the error between the speed error and the braking distance is greater than or equal to the preset speed error setting value, the current distance step is reduced, and then the process returns to 302) and executes again; otherwise, the distance step used in each 303) is superimposed and output as the braking distance. S 1.

[0033] Specifically, in this embodiment, the distance step length is reduced by halving the distance step length (ie, the second set ratio is one-half).

[0034] In other implementations, the second set ratio may be set to other values, such as one quarter or one third, etc.; or other methods may be used to reduce the distance step, such as reducing the distance step by a fixed value each time.

[0035] When calculating the braking distance, the present invention adopts a method of automatically calculating the step length in stages to calculate the speed from V 0 to V t Braking distance. First, take the running distance of half the average vehicle length as the calculation step length. V t When the error is greater than the accuracy set by the system, the step length is modified to half of the original one. When the step length accuracy reaches the set minimum value, it will no longer be halved and the final speed will be recalculated until the calculated final speed is consistent with the accuracy set by the system. V t The error is within the accuracy requirement. In this process, the calculation is not only based on the longitudinal section information at the starting point of the speed limit, but also comprehensively considers the information within each distance step, which greatly improves the accuracy of the calculation and effectively avoids overspeed and overshoot problems.

[0036] 4) If S 1≤ S and S 1- S The absolute value of S 1- S ∣) Less than or equal to S s , then V 0 is the speed limit value of the current speed limit section of the train.

[0037] In this case, if V If the train brakes at a speed of , the train speed at the starting point of the next speed limit section will definitely be greater than the speed limit of the next speed limit section. V t Therefore, it is necessary to adjust the speed in advance so that the braking speed is lower than V 0 can ensure that the speed of the train at the starting point of the next speed limit interval is lower than V t or just V t .

[0038] It should be noted that during the entire iteration process, V 0 must be less than or equal to V Therefore, no V 0 and V The judgment between V 0 is the speed limit value of the current speed limit section of the train. V 0= V This means that there is no need to revise the speed limit.

[0039] like S 1> S , then V The value of 0 is updated to V 0- V After 1, reduce the speed step size and then execute 2) again.

[0040] Braking distance at this time S 1 is too large and needs to be iterated further.

[0041] like S 1≤ S And∣ S 1- S ∣> S s , then reduce the current speed step and re-execute 2).

[0042] Although the braking distance is short, the speed V 0 may not be the maximum, and further iteration is required.

[0043] in, S is the length of the current speed limit section of the train.

[0044] Specifically, in this embodiment, the speed step length is reduced by halving the speed step length (ie, the first set ratio is one-half).

[0045] In other implementations, the first fixed ratio may be set to other values, such as one quarter or one third, etc.; or the speed step may be reduced in other ways, such as reducing the speed step by a fixed value each time.

[0046] Based on the speed limit value obtained above, it is only necessary to control the train speed not to exceed the speed limit value.

[0047] The speed limit of the train's current position is calculated in real time, and the speed limit of the train's next speed limit interval is calculated by continuously shifting the calculation range based on the train's position, introducing new speed limit information ahead.

[0048] Automatic calculation takes into account the actual situation that the locomotive will be electrically braked for speed regulation. Combined with the calculation method described in this article, when the electric brake speed regulation can be performed within the set distance to achieve no overspeeding, the electric brake speed regulation is performed. If the calculation result shows that the electric brake cannot complete the speed regulation within the set distance, the braking starting point is calculated according to the air brake performance, and the air brake is used for braking.

[0049] When the train is running, the braking distance to the speed limit point ahead is calculated in real time. When the braking distance is less than or equal to the current distance to the speed limit point, braking begins, which ensures accurate speed control to the next speed limit point without exceeding the speed limit. When it is necessary to stop, the speed limit at the stop point is set to 0. The same method can also ensure that the speed is exactly 0 when braking to the stop point.

[0050] When the front needs to slow down, electric braking can be used to adjust the speed a certain distance in advance. If electric braking cannot meet the speed adjustment to the target speed within the limited distance, the braking distance to the speed limit point ahead is calculated based on the current speed. When the braking distance is less than or equal to the distance ahead, air braking is applied to adjust the speed. When it is necessary to stop, the speed limit at the stop point is 0, and the train can stop at the stop point.

[0051] Embodiment of a train traction calculation device based on section speed limit correction: A train traction calculation device based on interval speed limit correction includes a processor, wherein the processor is used to execute a computer program to implement the steps of the train traction calculation method based on interval speed limit correction as described above. The specific train traction calculation method based on interval speed limit correction has been introduced in sufficient detail in the above train traction calculation method based on interval speed limit correction, and will not be repeated here.

[0052] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A train traction calculation method based on section speed limit correction, characterized in that: The method includes: 1) Set the initial value of the speed step and V The initial value of 0; the two initial values ​​set are used as the current speed step and V The current value of 0 executes 2); 2) Update according to the current speed step V 0 is: V The sum of the current value of 0 and the current speed step; 3) Calculate the speed of the train from V 0 down to V t Braking distance S 1; 4) If S 1≤ S And∣ S 1- S ∣≤ S s , then V 0 is the speed limit value of the current speed limit section of the train; like S 1> S , then V 0 is updated to V 0- V After 1, reduce the current speed step and execute 2 again); like S 1≤ S And∣ S 1- S ∣> S s , then reduce the current speed step and re-execute 2); in, V The speed limit of the current speed limit interval; V 1 is the speed step; V t The speed limit for the next speed limit zone; S is the length of the current speed limit interval; V 0 is the corrected speed limit of the current speed limit interval; S s To allow distance error.

2. The train traction calculation method based on section speed limit correction according to claim 1 is characterized in that: 3) Includes: 301) Set the initial distance step; execute 302 with the initial distance step as the current distance step); 302) If the current distance step is greater than the preset distance setting value, directly execute 303); otherwise, execute 303 with the distance setting value as the current distance step); 303) V 0 as the initial velocity, according to the current distance step and acceleration a Calculate the final velocity at the end of the current distance step V t1 ,make V 0= V t1 ; in, a It is the train braking acceleration in the interval with the end point of the previous distance step as the starting point and the current distance step as the length; the starting point of the initial distance step is the starting point of the current speed limit interval; 304) If V 0 and V t If the error between the speed error and the braking distance is greater than or equal to the preset speed error setting value, the current distance step is reduced, and then the process returns to 302) and executes again; otherwise, the distance step used in each 303) is superimposed and output as the braking distance. S 1.

3. The train traction calculation method based on section speed limit correction according to claim 2 is characterized in that: 2) The current speed step length is the speed step length processed in the following manner: If the current speed step length is greater than the speed error setting value, then update the current speed step length according to the current speed step length. V 0; otherwise, the speed error setting value is used as the current speed step update V 0.

4. The train traction calculation method based on section speed limit correction according to claim 1 is characterized in that: The initial value of the speed step set in 1) is the difference between the speed limit of the current speed limit section of the train and the speed limit of the next speed limit section.

5. The train traction calculation method based on section speed limit correction according to claim 1 is characterized in that: 1) Set in V The initial value of 0 is the speed limit of the next speed limit interval.

6. The train traction calculation method based on section speed limit correction according to claim 2 is characterized in that: The initial distance step is half of the average length of the train.

7. The train traction calculation method based on section speed limit correction according to claim 2 is characterized in that: 4) The method of reducing the speed step length is to reduce the speed step length according to a preset first setting ratio; and / or 304) in which the distance step is reduced by reducing the distance step according to a preset second setting ratio.

8. The train traction calculation method based on section speed limit correction according to claim 1 is characterized in that: 4) Also includes: If S 1≤ S ,∣ S 1- S ∣≤ S s and V 0≥ V , then V As the speed limit value of the train’s current speed limit section.

9. The train traction calculation method based on section speed limit correction according to claim 2 is characterized in that: 303), calculate the acceleration a When the train is moving, each carriage is taken as a mass point and the multi-mass point algorithm is used to calculate the total resistance of the train.

10. A train traction calculation device based on section speed limit correction, comprising a processor, characterized in that: The processor is used to execute a computer program to implement the steps of the train traction calculation method based on section speed limit correction as described in any one of claims 1 to 9.

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