Control method for keeping real-time change of braking stage during train starting

Abstract

The invention provides a control method for keeping real-time change of a braking stage when a train is started, which comprises the following steps that: when the train is started, a braking control unit receives a traction command signal and does not receive a braking command signal; acquiring traction force, temperature, humidity and load information of the train, and calculating and keeping braking force in real time according to the acquired information; designing a main control strategy and a standby control strategy; and based on the calculated holding braking force and the real-time traction force, selecting to execute a main control strategy or a standby control strategy according to 110% of the maximum ramp sliding force of the current load. According to the main control strategy, when the traction force plus the holding braking force is larger than or equal to 110% of the ramp gliding force, the holding braking force starts to be reduced according to increase of the traction force, and when the traction force is larger than the ramp gliding force, braking is kept to be completely relieved. Backup logic is added, it is guaranteed that when a fault occurs and braking force cannot be adjusted and kept in real time, the braking force can be reduced and kept through a delay stage, and when the vehicle speed is larger than or equal to 2 km / h, the braking force is completely relieved.

Description

Technical Field

[0001] The present invention relates to the technical field of urban rail transit vehicles, and in particular to a control method for maintaining real-time changes in a braking phase when a train starts. Background Art

[0002] When designing the braking system for urban rail transit vehicles, a holding braking scheme will be designed. This is a pure air brake applied after the train stops and during the start-up process to prevent the train from slipping, which can ensure that the train can stop safely on the maximum slope.

[0003] When the train starts, the holding brake needs to be released. The existing holding brake force is a relatively fixed value based on the commonly used braking force. When the train starts, when encountering a large slope or a large passenger flow and load, the holding brake may not be released normally due to insufficient traction, resulting in the train being unable to start normally and only requiring rescue, affecting operations; or when the holding brake force is suddenly released from a fixed value to 0, the vehicle may have a forward impact, affecting comfort. Summary of the invention

[0004] According to the above technical problem that the train cannot maintain braking when it is on a steep slope, has a large passenger flow and a heavy load, or has insufficient traction, and the vehicle cannot start normally, leading to rescue, a control method for maintaining real-time changes in the braking phase when the train starts is provided, so that the train can start normally, reduce the impact during starting, and reduce the number of times the train goes offline and the number of rescues during operation.

[0005] The technical means adopted by the present invention are as follows:

[0006] A control method for maintaining real-time changes in the braking phase when a train starts, comprising:

[0007] S1: When the train starts, the brake control unit (BCU) receives the traction command signal but does not receive the braking command signal;

[0008] S2, obtaining the train traction, temperature, humidity and load information, and calculating the braking force in real time based on the obtained information;

[0009] S3, setting the main control strategy and the backup control strategy;

[0010] S4. Based on the calculated holding braking force and the real-time traction force, and according to the current load of 110% of the maximum slope sliding force, select to execute the main control strategy or the backup control strategy.

[0011] Furthermore, in step S2, the process of calculating the maintaining braking force is as follows:

[0012] Initial holding braking force = (pressure of each friction pair * friction coefficient * friction radius * 2 / D) * number of friction pairs * number of basic braking equipment * number of bogies / car;

[0013] Among them, the friction coefficient corresponds to different values ​​under different temperatures, humidity and positive pressures according to the materials used for the brake shoes of each project.

[0014] Furthermore, in step S3, the main control strategy is designed as follows:

[0015] The braking force starts to decrease as the traction increases, and when the traction is greater than the downward force on the slope, the braking is completely released.

[0016] Furthermore, in step S3, the designed standby control strategy is as follows:

[0017] Delay and reduce some of the holding braking force. When the vehicle speed is ≥2km / h, keep the brakes fully relieved.

[0018] Furthermore, the delay time in the standby control strategy is the time to fully establish the traction force.

[0019] Furthermore, reducing part of the holding braking force in the standby control strategy is to reduce the holding braking force to 30% of the maximum common holding braking force.

[0020] Furthermore, step S4 specifically includes:

[0021] When the sum of the braking force and the real-time traction force is greater than or equal to 110% of the maximum slope sliding force of the current load, the main control strategy is executed;

[0022] When the sum of the braking force and the real-time traction force is less than 110% of the maximum slope sliding force of the current load, the backup control strategy is executed.

[0023] Furthermore, after executing the main control strategy, the holding braking force when the train starts changes in real time. Since it has been reduced in advance according to the increase in traction before the holding brake is completely released, the impact at start-up is greatly reduced.

[0024] Furthermore, when a train malfunction occurs and the braking force cannot be adjusted in real time to maintain, a backup control strategy is executed.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The present invention provides a control method for real-time changes in the braking stage when a train starts. In order to prevent the train from slipping when starting, the combined force of the train's traction and the braking force must be greater than the sliding force. At the same time, in order to leave a certain safety factor, it can be set that when the traction plus the braking force is greater than or equal to 110% of the slope sliding force, the braking force begins to decrease according to the increase in traction. When the traction is greater than the slope sliding force, the braking is completely relieved. In this way, the real-time change of the braking force when the train starts is realized. Because the braking force has been reduced in advance according to the increase in traction before the braking is completely relieved, the impact at the start can be greatly reduced.

[0027] 2. The present invention provides a control method for maintaining real-time changes in the braking stage when a train starts, which adds backup logic to ensure that when a fault occurs and the braking force cannot be adjusted in real time, the braking force can be reduced through a delay stage (the delay is the time to fully establish traction), and when the vehicle speed is ≥2km / h, it can be completely relieved.

[0028] In summary, the control logic of keeping the braking force changing when the train starts solves the problem of the train being unable to relieve the brake when starting on a large slope or when the traction is insufficient, and the braking force is kept changing in real time with the traction. This shortens the train start time, improves the train start efficiency, reduces the impact during start-up, and reduces the number of offline and rescue operations during operation.

[0029] Based on the above reasons, the present invention can be widely promoted in the fields of urban rail transit vehicles and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] like Figure 1 As shown, the present invention provides a control method for maintaining real-time changes in the braking phase when a train starts, comprising:

[0035] S1: When the train starts, the brake control unit (BCU) receives the traction command signal but does not receive the braking command signal;

[0036] S2, obtaining the train traction, temperature, humidity and load information, and calculating the braking force in real time based on the obtained information;

[0037] S3, setting the main control strategy and the backup control strategy;

[0038] S4. Based on the calculated holding braking force and the real-time traction force, and according to the current load of 110% of the maximum slope sliding force, select to execute the main control strategy or the backup control strategy.

[0039] In specific implementation, as a preferred embodiment of the present invention, in step S2, the process of calculating the maintaining braking force is as follows:

[0040] Initial holding braking force = (pressure of each friction pair * friction coefficient * friction radius * 2 / D) * number of friction pairs * number of basic braking equipment * number of bogies / car;

[0041] Among them, the friction coefficient corresponds to different values ​​under different temperatures, humidity, and positive pressure (load) according to the materials used for the brake shoes of each project.

[0042] In specific implementation, as a preferred embodiment of the present invention, in step S3, the main control strategy designed is as follows:

[0043] The braking force starts to decrease as the traction increases, and when the traction is greater than the downward force on the slope, the braking is completely released.

[0044] In this embodiment, in order to prevent the train from slipping when starting, the combined force of the train's traction and the holding brake force must be greater than the downward force. At the same time, in order to leave a certain safety factor, it can be set that when the traction plus the holding brake force is greater than or equal to 110% of the downward force on the slope, the holding brake force begins to decrease according to the increase in traction. When the traction is greater than the downward force on the slope, the holding brake is completely released. In this way, the holding brake force changes in real time when the train starts. Because the holding brake has been reduced in advance according to the increase in traction before it is completely released, the impact at the start can be greatly reduced.

[0045] In specific implementation, as a preferred embodiment of the present invention, in step S3, the designed standby control strategy is as follows:

[0046] Delay and reduce some of the holding braking force. When the vehicle speed is ≥2km / h, keep the brakes fully relieved.

[0047] In this embodiment, a backup logic is added to ensure that when a fault occurs and the braking force cannot be adjusted in real time, the braking force can be reduced through a delay phase (the delay is the time to fully establish traction), and when the vehicle speed is ≥ 2km / h, the braking force can be fully relieved. In this embodiment, the delay is preferably 3s.

[0048] In specific implementation, as a preferred embodiment of the present invention, the reducing part of the holding braking force in the backup control strategy is to reduce the holding braking force to 30% of the maximum common holding braking force.

[0049] In specific implementation, as a preferred embodiment of the present invention, step S4 specifically includes:

[0050] When the sum of the braking force and the real-time traction force is greater than or equal to 110% of the maximum slope sliding force of the current load, the main control strategy is executed;

[0051] When the sum of the braking force and the real-time traction force is less than 110% of the maximum slope sliding force of the current load, the backup control strategy is executed.

[0052] In specific implementation, as a preferred embodiment of the present invention, after executing the main control strategy, the holding braking force when the train starts changes in real time. Since it has been reduced in advance according to the increase in traction before the holding brake is completely released, the impact at start-up is greatly reduced.

[0053] In summary, the present invention provides a control method for maintaining real-time changes in the braking stage when a train starts. By maintaining the control logic of the change in the magnitude of the braking force when the train starts, the problem that the train cannot relieve the braking start when the train is on a large slope or the traction is insufficient is solved, and the braking force is maintained to change in real time with the traction. The train start time is shortened, the train start efficiency is improved, the impact at the start is reduced, and the number of offline and rescue times during operation is reduced.

[0054] It should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0055] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0056] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0057] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for maintaining real-time changes in the braking phase when a train starts, characterized in that: include: S1: When the train starts, the brake control unit receives a traction command signal but does not receive a braking command signal; S2, obtaining the train traction, temperature, humidity and load information, and calculating the braking force in real time based on the obtained information; S3. Design the main control strategy and backup control strategy; S4. Based on the calculated holding braking force and real-time traction force, and according to the current load of 110% of the maximum slope sliding force, select to execute the main control strategy or the backup control strategy.

2. A control method for maintaining real-time changes in the braking phase when a train starts according to claim 1, characterized in that: In step S2, the process of calculating the holding braking force is as follows: Initial holding braking force = (pressure of each friction pair * friction coefficient * friction radius * 2 / D) * number of friction pairs * number of basic braking equipment * number of bogies / car; Among them, the friction coefficient corresponds to different values ​​under different temperatures, humidity and positive pressures according to the materials used for the brake shoes of each project.

3. A control method for maintaining real-time changes in the braking phase when a train starts according to claim 1, characterized in that: In step S3, the main control strategy is designed as follows: The braking force starts to decrease as the traction increases, and when the traction is greater than the downward force on the slope, the braking is completely released.

4. A control method for maintaining real-time changes in the braking phase when a train starts according to claim 1, characterized in that: In step S3, the designed standby control strategy is as follows: Delay and reduce some of the holding braking force. When the vehicle speed is ≥2km / h, keep the brakes fully relieved.

5. A control method for maintaining real-time changes in the braking phase when a train starts according to claim 4, characterized in that: The delay time in the backup control strategy is the time to fully establish the traction force.

6. A control method for maintaining real-time changes in the braking phase when a train starts according to claim 4, characterized in that: The reducing part of the holding braking force in the backup control strategy is to reduce the holding braking force to 30% of the maximum common holding braking force.

7. A control method for maintaining real-time changes in the braking phase when a train starts according to claim 1, characterized in that: Step S4 specifically includes: When the sum of the braking force and the real-time traction force is greater than or equal to 110% of the maximum slope sliding force of the current load, the main control strategy is executed; When the sum of the braking force and the real-time traction force is less than 110% of the maximum slope sliding force of the current load, the backup control strategy is executed.

8. A control method for maintaining real-time changes in the braking phase when a train starts according to claim 7, characterized in that: After executing the main control strategy, the holding braking force when the train starts changes in real time. Since it has been reduced in advance according to the increase in traction before the holding brake is completely released, the impact at start-up is greatly reduced.

9. A control method for maintaining real-time changes in the braking phase when a train starts according to claim 7, characterized in that: When a train malfunctions and the braking force cannot be adjusted in real time, the backup control strategy is executed.

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