Pre-braking control method and device for railway vehicle and storage medium

Abstract

The invention discloses a pre-braking control method and device for a railway vehicle and a storage medium, and the method comprises the steps that before an electro-pneumatic conversion signal is received, the actual running speed of the current railway vehicle is obtained in response to a braking instruction; when the actual running speed is smaller than a preset speed, pre-braking operation is applied to the railway vehicle according to initial braking force; and the initial braking force is adjusted according to the actual deceleration of the railway vehicle and / or the actual pressure of the brake cylinder after the pre-braking operation is applied, and the pre-braking application state is maintained according to the adjusted braking force until the electro-pneumatic conversion starts. According to the method, pre-braking control is applied to the railway vehicle before electro-pneumatic conversion, the response time of air braking can be shortened to the maximum extent, interference on the final parking position accuracy due to improper setting of the initial braking force can be thoroughly avoided, and collaborative optimization of the response speed and the parking accuracy is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of urban rail vehicle braking systems, and in particular to a pre-braking control method and device for a rail vehicle and a storage medium. BACKGROUND

[0002] In recent years, with the rapid development of urban rail transit technology, more and more rail vehicle lines use full-automatic unmanned operation, and the number of network trains is large. In order to improve the efficiency of train operation, the precise parking time is an important consideration factor.

[0003] During the parking braking process of the vehicle, the vehicle usually relies on the cooperative operation of the electric brake and the air brake. In particular, for the low-speed stage, a complex electric-air conversion process is involved, and there is a coupling effect of multiple links such as signal transmission, electric brake force withdrawal, and air brake takeover during the process, so that the establishment of the air brake force needs a certain response time delay.

[0004] The currently widely used braking control strategy lacks real-time perception and dynamic adjustment capability for the actual state of the braking system when facing different loads, mechanical wear states, and environmental changes, and it is difficult to always consider the dual goals of fast response and precise parking under complex operating conditions, thereby restricting the further improvement of the overall operation efficiency and parking performance. SUMMARY

[0005] One of the purposes of the present application is to provide a rail vehicle braking control method to solve the technical problem that the pre-braking operation of the vehicle lacks self-adaptive adjustment capability before the establishment of the air brake of the rail vehicle in the prior art, resulting in the air brake response time and the deviation from the ideal state of the parking.

[0006] In order to achieve one of the above-mentioned purposes, the present application provides a pre-braking control method for a rail vehicle, the rail vehicle comprising a brake cylinder, the braking control method comprising: before receiving an electric-air conversion signal, in response to a braking instruction, obtaining an actual running speed of the current rail vehicle; when the actual running speed is less than a preset speed, applying a pre-braking operation to the rail vehicle according to an initial braking force; adjusting the initial braking force according to the actual deceleration of the rail vehicle after the pre-braking operation is applied and / or the actual pressure of the brake cylinder, and maintaining the pre-braking application state according to the adjusted braking force until the electric-air conversion starts.

[0007] As a further improvement of an embodiment of the present application, before the pre-braking operation is applied to the rail vehicle according to the initial braking force, the method comprises: determining the initial braking force according to the size required to overcome the maximum friction force and / or mechanical clearance of the brake cylinder.

[0008] As a further improvement of the embodiment of the present application, the adjusting the initial braking force based on the comparison result of the actual deceleration and the preset deceleration threshold value, and / or the comparison result of the actual pressure value and the preset pressure threshold value, and maintaining the pre-braking application state according to the adjusted braking force until the start of the electro-pneumatic conversion comprises: obtaining a first actual running speed of the rail vehicle before the pre-braking operation is applied and a second actual running speed after the pre-braking operation is applied, and determining the corresponding actual deceleration; adjusting the initial braking force based on the comparison result of the actual deceleration and the preset deceleration threshold value, and / or the comparison result of the actual pressure value and the preset pressure threshold value, and maintaining the pre-braking application state according to the adjusted braking force until the start of the electro-pneumatic conversion.

[0009] As a further improvement of the embodiment of the present application, the adjusting the initial braking force based on the comparison result of the actual deceleration and the preset deceleration threshold value, and / or the comparison result of the actual pressure value and the preset pressure threshold value, and maintaining the pre-braking application state according to the adjusted braking force until the start of the electro-pneumatic conversion comprises: determining whether the actual deceleration is greater than the preset deceleration threshold value; if yes, then down-regulating the initial braking force and maintaining the pre-braking application state according to the down-regulated braking force until the start of the electro-pneumatic conversion; and if no, then keeping the initial braking force unchanged and maintaining the pre-braking application state according to the initial braking force until the start of the electro-pneumatic conversion.

[0010] As a further improvement of the embodiment of the present application, the adjusting the initial braking force based on the comparison result of the actual deceleration and the preset deceleration threshold value, and / or the comparison result of the actual pressure value and the preset pressure threshold value, and maintaining the pre-braking application state according to the adjusted braking force until the start of the electro-pneumatic conversion comprises: when the actual deceleration is less than or equal to the preset deceleration threshold value, determining whether the actual pressure value is less than or equal to the preset pressure threshold value; if yes, then up-regulating the initial braking force and maintaining the pre-braking application state according to the up-regulated braking force until the start of the electro-pneumatic conversion.

[0011] As a further improvement of the embodiment of the present application, the adjusting the initial braking force comprises: determining a target deceleration corresponding to a required target deceleration in response to a braking level instruction of the rail vehicle; and adjusting the initial braking force based on the target deceleration and the current load of the rail vehicle.

[0012] As a further improvement of the embodiment of the present application, the adjusting the initial braking force comprises: determining a target deceleration corresponding to a required target deceleration in response to a braking level instruction of the rail vehicle; and adjusting the initial braking force based on a ratio of the target deceleration to the actual deceleration.

[0013] As a further improvement of the embodiment of the present application, the maintaining the pre-braking application state according to the adjusted braking force until the electric-air conversion starts comprises: judging whether the actual running speed of the rail vehicle is equal to 0; if not, controlling the braking unit to maintain the pre-braking application state according to the adjusted braking force; if yes, controlling the braking unit to cancel the pre-braking operation on the rail vehicle.

[0014] To achieve one of the above-mentioned purposes, the present application further provides a pre-braking control device of a rail vehicle, the braking control device comprising a brake cylinder, the device further comprising: an input module configured to obtain an actual running speed of the rail vehicle currently in response to a braking instruction before receiving an electric-air conversion signal; a processing module configured to apply a pre-braking operation to the rail vehicle according to an initial braking force when the actual running speed is less than a preset speed; and an adjustment module configured to adjust the initial braking force according to an actual deceleration of the rail vehicle after the pre-braking operation is applied and / or an actual pressure of the brake cylinder, and maintain the pre-braking application state according to the adjusted braking force until the electric-air conversion starts.

[0015] To achieve one of the above-mentioned purposes, the present application further provides a computer readable storage medium, wherein a computer program is stored, the program being executed by a processor to implement the steps of any one of the pre-braking control methods of the rail vehicle.

[0016] Compared with the prior art, the embodiments of the present application have at least one of the following beneficial effects: The pre-braking control method of the rail vehicle is adopted, the actual deceleration generated due to the application of the initial braking force and the actual pressure of the brake cylinder are monitored, the intensity of the current pre-braking operation is intelligently judged to be too large, too small or appropriate, and the pre-braking force (i.e. the initial braking force) is dynamically adjusted accordingly, so that the braking system can adapt to different loads, friction coefficients and mechanical states, thereby not only shortening the response time of the air braking to the maximum before the electric-air conversion, but also completely avoiding the interference on the accuracy of the final stopping position caused by improper setting of the initial braking force, and realizing the collaborative optimization of the response speed and the stopping accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of a pre-braking device of a rail vehicle in an embodiment of the present application.

[0018] Figure 2 is a step schematic diagram of a pre-braking control method of a rail vehicle in an embodiment of the present application.

[0019] Figure 3 is a partial step schematic diagram of step S3 in an embodiment of the present application.

[0020] Figure 4(a) is a schematic diagram of step S32 in a specific embodiment of the present invention.

[0021] Figure 4(b) is a schematic diagram of step S32 in another specific embodiment of one embodiment of the present invention.

[0022] Figure 5(a) is a schematic diagram of step S32 in a specific embodiment of the present invention.

[0023] Figure 5(b) is a schematic diagram of step S32 in another specific embodiment of one embodiment of the present invention.

[0024] Figure 6(a) is a timing diagram of the pre-braking force reduction in one embodiment of the present invention.

[0025] Figure 6(b) is a timing diagram of pre-braking power mismatch in one embodiment of the present invention.

[0026] Figure 6(c) is a timing diagram of the pre-braking power increase in one embodiment of the present invention. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the scope of protection of the present invention.

[0028] It should be noted that the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] like Figure 1 As shown, one embodiment of the present invention provides a pre-braking control device 100 for a rail vehicle.

[0030] The pre-braking control device 100 for rail vehicles is a braking control device applied to rail vehicles. Its core function is to implement adaptive pre-braking management in the critical stage before electro-pneumatic conversion through real-time sensing and dynamic decision-making.

[0031] The pre-braking control device 100 for rail vehicles includes a brake cylinder for generating braking force to cause the rail vehicle in operation to decelerate or stop.

[0032] The pre-braking control device 100 of the rail vehicle comprises an input module 11, which is configured to obtain an actual running speed of the rail vehicle in response to a braking instruction before receiving an electric-air conversion signal.

[0033] The input module 11 is responsible for collecting the braking instruction from the vehicle network and the speed sensor signal as a sensing structure of the pre-braking control device 100 of the rail vehicle, and accurately capturing the timing of the vehicle entering the low-speed pre-braking state.

[0034] The pre-braking control device 100 of the rail vehicle comprises a processing module 12, which is configured to actually pre-brake the rail vehicle according to an initial braking force when the actual running speed is less than a preset speed.

[0035] The processing module 12 is an execution engine of the control logic, which generates an initial pre-braking instruction according to a preset control measure and drives the braking unit to perform a mechanical pre-action, which is essentially to complete the mapping from an electric signal to a physical action.

[0036] The pre-braking control device 100 of the rail vehicle comprises an adjustment module 13, which is configured to adjust the initial braking force according to the actual deceleration of the rail vehicle and / or the actual pressure of the brake cylinder after the braking operation is applied, and maintain the pre-braking application state according to the adjusted braking force until the electric-air conversion of the vehicle begins.

[0037] The adjustment module 13 constitutes the intelligent closed-loop core of the system, which continuously monitors the output of the brake cylinder pressure sensor and the vehicle inertia test unit to diagnose and evaluate the actual effect of the pre-braking operation (i.e., the mechanical establishment state and the vehicle dynamic response), and dynamically corrects the output instruction according to the built-in algorithm, so as to ensure that the pre-braking force applied to the vehicle is always maintained in an optimal interval that is sufficient to overcome the system static friction resistance and does not cause unintended vehicle deceleration.

[0038] As shown in Figure 2 An embodiment of the present application provides a pre-braking control method of a rail vehicle.

[0039] The pre-braking control method of the rail vehicle is applied to a pre-braking control device of a rail vehicle.

[0040] In an embodiment, the pre-braking control device of the rail vehicle can be configured as Figure 1 and described above, and the corresponding technical solutions are arranged to be referred to the control method provided by the present application. Of course, the pre-braking control device of the rail vehicle to which the pre-braking control method of the rail vehicle provided by the present application is applied is not limited to this configuration structure.

[0041] As shown in Figure 2As shown, an embodiment of the present application provides a pre-braking control method for a rail vehicle, including but not limited to the following steps.

[0042] Step S1, before receiving the electric-air conversion signal, obtaining the actual running speed of the rail vehicle in response to the braking instruction.

[0043] Step S2, when the actual running speed is less than the preset speed, applying a pre-braking operation to the rail vehicle according to an initial braking force.

[0044] Step S3, adjusting the initial braking force according to the actual deceleration of the rail vehicle and / or the actual pressure of the brake cylinder after applying the pre-braking operation, and maintaining the pre-braking application state according to the adjusted braking force until the electric-air conversion starts.

[0045] In this way, by monitoring the actual deceleration and the actual pressure of the brake cylinder caused by the application of the initial braking force, it is intelligently judged whether the current pre-braking operation is too large, too small or appropriate, and the pre-braking force (i.e. the initial braking force) is dynamically adjusted accordingly, so that the braking system can adapt to different loads, friction coefficients and mechanical states, thereby both shortening the response time of air braking to the maximum extent before electric-air conversion and completely avoiding the interference on the final parking position accuracy caused by improper initial braking force setting, realizing the coordinated optimization of response speed and parking accuracy.

[0046] In step S1, electric-air conversion is a process of converting an electric control signal into an air pressure control signal in the rail vehicle braking system. Specifically, in the rail vehicle braking system, there are two ways of electric braking and air braking. During vehicle braking, the braking force mainly transitions from electric braking (regenerative braking or resistance braking generated by traction motor) which is fast in response and accurate in control to air braking which is driven by compressed air and has fixed mechanical delay characteristics, so that the vehicle can decelerate or stop as required.

[0047] For example, when the vehicle needs to be braked with a large force during high-speed driving, the initial stage may mainly rely on electric braking (i.e. converting the kinetic energy of the vehicle into electrical energy), and as the speed decreases, the effect of electric braking weakens, at which time air braking needs to be started through electric-air conversion to further reduce the speed until the vehicle stops.

[0048] The braking instruction is a signal that triggers the rail vehicle braking system to start working. It can be generated in many ways, such as the driver issuing a manual braking instruction by operating a brake controller (such as a brake pedal, a handle, etc.); it can also be a braking instruction automatically issued by an automatic control system (such as a train automatic protection system) on the vehicle according to the running conditions (such as obstacles in front, the need to stop at the time, etc.).

[0049] For example, when the driver sees a red light at the front, he steps on the pedal. At this moment, the pedal sensor converts the driver's operation into an electrical signal, which is a brake command, and transmits it to the vehicle's brake control system to start the brake operation.

[0050] The actual running speed refers to the real running speed of the rail vehicle at the current time. It can be obtained by testing the speed sensor installed on the vehicle. The speed sensor can sense the rotation speed of the wheel or the running speed of the vehicle relative to the ground in real time and convert it into an electrical signal transmitted to the control system of the vehicle.

[0051] In step S2, the actual running speed being less than the preset speed means that the vehicle has entered the low-speed running stage (for example, the speed is less than 5 km / h), at which time the electric brake efficiency may decrease or will be withdrawn, which is the key time for the subsequent air brake to establish a pre-preparation.

[0052] In one embodiment, the preset speed is 10 km / h, that is, before the electric-air conversion, in response to the brake command, when the actual running speed of the vehicle is less than 10 km / h, the pre-brake operation process is automatically triggered, that is, the "apply pre-brake signal" is in the set state. In other embodiments, when the actual running speed of the rail vehicle is greater than or equal to 10.5 km / h, the pre-brake operation process will not be triggered, that is, the "apply pre-brake signal" is in the reset state.

[0053] The pre-brake operation refers to that before the formal electric-air conversion starts, the brake control system applies a tentative air pressure lower than the formal brake force to the brake cylinder according to the initial brake force.

[0054] Specifically, the air pressure is intended to cause subtle and orderly deformation and position adjustment of mechanical components related to air braking, such as the piston in the brake cylinder, the spring assembly, and the connecting mechanism between the brake shoe and the wheel, etc. For example, the spring in the brake cylinder will be moderately compressed under the initial force, causing the piston to produce a slight displacement, which in turn drives the transmission components connected to it to move, gradually reducing the gap between the brake shoe and the wheel tread.

[0055] This adjustment makes the entire brake system in a "one-touch" critical state, that is, although it has not yet generated a macroscopic brake force sufficient to change the running state of the vehicle (that is, it will not affect the actual running speed of the current vehicle), but the mechanical components are accurately in place, with the condition of quickly responding and converting into effective brake force. When the electric-air conversion signal is triggered, the brake system can quickly and seamlessly establish a complete air braking effect, greatly shortening the brake response time, effectively improving the brake efficiency and the safety of vehicle operation; at the same time, it avoids the vehicle impact and instability that may be caused by the sudden start of the brake system, ensuring the stability and comfort of the brake process.

[0056] In one embodiment, the initial braking force in step S2 can be determined based on the magnitude required to overcome the maximum frictional force and / or mechanical clearance of the brake cylinder.

[0057] In this way, the initial braking force is limited to a threshold force designed to overcome the static friction resistance and mechanical transmission clearance within the braking system, thereby enabling the braking system to complete the internal preparation from a relaxed state to a critical operating state without causing external interference to the vehicle's current operation.

[0058] It should be noted that the application of initial braking force eventually transforms into the application of pressure to the brake cylinder, so in this application, the initial braking force can be understood as the initially applied pre-pressure or pre-braking force.

[0059] In one specific embodiment, both the initial braking force and the adjusted braking force are air braking forces.

[0060] like Figure 3 As shown, in one embodiment, step S3 may specifically include the following steps.

[0061] Step S31: Obtain the first actual running speed of the rail vehicle before the pre-braking operation and the second actual running speed after the pre-braking operation, and determine the corresponding actual deceleration. Step S32: Adjust the initial braking force based on the comparison result of the actual deceleration and the preset deceleration threshold, and / or based on the comparison result of the actual pressure value and the preset pressure threshold.

[0062] Thus, by constructing a dual feedback closed loop based on vehicle dynamic response and the internal state of the braking system, online automatic correction and dynamic optimization of pre-braking force can be achieved. This enables intelligent diagnosis of the mismatch state of pre-braking force (i.e., initial braking force) and execution of precise directional correction.

[0063] In step S31, the actual deceleration refers to the reduction in the actual operating speed of the rail vehicle before and after the pre-braking operation, reflecting the actual effect of the pre-braking operation on vehicle deceleration. The actual pressure of the brake cylinder refers to the actual air pressure value present in the brake cylinder after the pre-braking operation is applied, which can be obtained by testing a pressure sensor installed on the brake cylinder.

[0064] As shown in Figure 4(a), in one specific embodiment, step S32 may specifically include the following steps.

[0065] Step S3211: Determine whether the actual deceleration is greater than a preset deceleration threshold; If so, proceed to step S3212A, reduce the initial braking force, and maintain the pre-braking application state according to the reduced braking force until the electro-pneumatic conversion begins; If not, jump to step S3212B, keep the initial braking force unchanged, and maintain the pre-braking application state according to the initial braking force until the electric air conversion starts.

[0066] In this way, by comparing the actual deceleration with the preset deceleration threshold, the "over-energized" state caused by excessive pre-braking force leading to unexpected deceleration of the vehicle can be sensitively identified, and the down-regulation mechanism is triggered to eliminate the interference to the parking precision.

[0067] Need to be explained, the actual deceleration is taken as a direct observation of whether the pre-braking operation produces interference effect, when the actual deceleration is detected to exceed the preset safety threshold, it is determined that the current initial braking force is in the "over-energized" state, which will trigger the active down-regulation instruction to attenuate the pre-pressure to a safe level that does not affect the intended deceleration curve of the vehicle; otherwise, the current pre-pressure state is maintained to ensure the pre-braking effect of the braking system.

[0068] This closed-loop control logic ensures that the force applied in the pre-braking stage is always constrained within a reasonable range that is only used to overcome mechanical inertia without affecting the parking precision, thereby maintaining the rapid response capability of the braking system while fundamentally avoiding the risk of early braking and inaccurate marking caused by excessive pre-braking force.

[0069] In step S322, the preset deceleration threshold refers to a limit value that the actual deceleration of the rail vehicle should reach or not exceed during the pre-braking stage. Specifically, when the actual deceleration exceeds this threshold, it means that the preset initial braking force is too high, which has already produced an unexpected and significant braking effect before the main braking instruction of the electric air conversion is officially issued. This will cause the calculation of the remaining braking distance by the train automatic driving system to deviate, thereby affecting the final parking precision.

[0070] When the actual deceleration is lower than this threshold, it may mean that the applied initial braking force is too small, so as to fail to effectively overcome the static friction and mechanical clearance of the braking system, and the brake cylinder piston may not be pushed or the stroke is insufficient. The initial braking force (or pre-pressure) fails to play the role of "pre-filling" and eliminating the air gap, and the inherent response delay of the air brake cannot be effectively shortened, thereby weakening the core value of the pre-pressure control.

[0071] In a specific embodiment, the preset deceleration threshold is determined based on the target deceleration required for braking of the rail vehicle.

[0072] In a specific embodiment, the preset deceleration threshold is equal to the sum of the target deceleration required for braking of the rail vehicle and a preset amplitude, wherein the preset amplitude is the allowable deceleration fluctuation, i.e., a safety buffer interval.

[0073] If the target deceleration is equal to the preset deceleration threshold, any minor over-standard of the actual deceleration caused by measurement noise, track micro-unevenness or inherent fluctuation of the transmission system will immediately trigger the down-regulation instruction of the pre-braking force. Such overly sensitive feedback will cause the control system to frequently switch between the "adjustment" and "maintenance" states, resulting in oscillation and thus destroying the smoothness of the braking process.

[0074] In a specific embodiment, the target deceleration is determined based on a braking level instruction of the rail vehicle.

[0075] In this embodiment, the braking level instruction is an instruction issued by the vehicle automatic control system for controlling the braking intensity and effect, which is divided into multiple levels, such as a normal braking, a rapid braking, and a braking light only, each corresponding to a different target deceleration and expected braking effect.

[0076] In a specific embodiment, when the actual deceleration is equal to 0, the initial braking force is kept unchanged and the pre-braking application state is maintained according to the initial braking force until the electro-pneumatic conversion starts.

[0077] As shown in FIG. 4(b), in a specific embodiment, step S32 can specifically include the following steps.

[0078] Step S3221: When the actual deceleration is less than or equal to the preset deceleration threshold, it is determined whether the actual pressure value is less than or equal to the preset pressure threshold. If yes, step S3222 is jumped to, the initial braking force is up-regulated, and the pre-braking application state is maintained according to the up-regulated braking force until the electro-pneumatic conversion starts.

[0079] In this way, by establishing a detection and compensation mechanism for the "invalid pressurization" state of the pre-braking system, it is ensured that the pre-braking operation can effectively reduce the response delay of the air braking.

[0080] It should be noted that in this embodiment, after the system first confirms that the pre-braking force does not produce over-limit interference on the vehicle dynamics (the actual deceleration does not exceed the preset deceleration threshold), it immediately enters the diagnosis of the internal state of the braking system, and determines whether the initial pre-pressure is too small to overcome the static friction resistance of the brake cylinder and the mechanical transmission gap by detecting whether the actual pressure of the brake cylinder is lower than or equal to a preset threshold representing "invalidity" (usually zero or a very small value).

[0081] Once the diagnosis is established, the system immediately triggers the up-regulation instruction to drive the brake cylinder piston to complete the necessary pre-stroke by enhancing the pre-brake force, eliminate the air gap, and make it enter the critical working state. This closed-loop compensation logic ensures that no matter what degree of resistance increase is caused by component wear, temperature change or initial setting deviation, the pre-brake system can be reliably activated to the standby state, thereby laying the necessary physical foundation for the rapid establishment of air brake during subsequent electric air conversion.

[0082] In a specific embodiment, the preset pressure threshold is 0 or a very small value close to 0.

[0083] As shown in FIG. 5(a), in a specific embodiment, the adjusting the initial brake force includes the following steps.

[0084] Step S3211', in response to the brake level command of the rail vehicle, determining a target deceleration corresponding to the required target deceleration; Step S3212', adjusting the initial brake force based on the target deceleration and the current load of the rail vehicle.

[0085] In this way, the rail vehicle can achieve precise brake control matching the target deceleration during braking according to the actual load of the vehicle.

[0086] In step S3211', the target deceleration is a specific deceleration value that the rail vehicle brake control system sets and expects the vehicle to reach during braking according to the received brake level command, which is a parameter determined in advance to achieve safe, smooth and operationally required braking effect, reflecting the degree of speed reduction expected by the brake operation.

[0087] In a specific embodiment, the product of the target deceleration and the current load of the rail vehicle is calculated to determine a first brake force; and the initial brake force is adjusted with reference to the first brake force.

[0088] Specifically, adjusting the initial brake force to the first brake force can build a pre-pressure reference value that matches the current vehicle mechanical characteristics (load) and driving intention (target deceleration) in the pre-brake stage, not only reducing the frequency and amplitude of subsequent closed-loop correction due to the large deviation between the initial brake force and the actual demand, improving the stability and response speed of the control system, but also ensuring that the pre-brake force can provide sufficient brake system preparation and minimize the disturbance to the vehicle dynamics caused by over-pre-braking.

[0089] As shown in FIG. 5(b), in a specific embodiment, the adjusting the initial brake force includes the following steps.

[0090] Step S3221', in response to the braking level instruction of the rail vehicle, determining a target deceleration corresponding to the required target deceleration; Step S3222', based on the ratio of the target deceleration to the actual deceleration, adjusting the initial braking force.

[0091] In this way, by introducing a proportional control algorithm, the correction amount of the pre-braking force (i.e. the initial braking force) is dynamically associated with the deviation degree of the actual deceleration, and the down-regulation amplitude is calculated in proportion according to the severity of the excessive pre-braking force, avoiding under-regulation or over-regulation of the control system, thereby achieving precise and smooth correction of the initial braking force.

[0092] Specifically, the system uses the ratio of the target deceleration to the actual deceleration as a down-regulation coefficient. When the actual deceleration is far from the target deceleration, the system recognizes a serious overexcitation state and performs a large degree of attenuation to quickly eliminate the disturbance. When the actual deceleration is slightly higher than the target deceleration, only a small degree of fine adjustment is performed. This deviation-proportional feedback mechanism enables the pre-pressure correction process to have both fast response capability and stability in the control process, effectively preventing system oscillation or insufficient response caused by improper correction, and ultimately achieving a coordinated optimization of braking response speed and stopping accuracy in dynamic balance.

[0093] In the above embodiments, the adjusted braking force is an ideal friction force (or target braking force) that is expected to act on the vehicle tread or brake disc to produce the target deceleration; the braking control unit converts the target braking force into the target pressure required to be established in the brake cylinder according to the current theoretical friction coefficient of the brake, and adjusts it accurately through an actuator such as an electromagnetic valve. Based on this, the actual friction coefficient and braking force, which cannot be directly measured, can be indirectly but accurately regulated by precisely controlling the intermediate physical quantity of brake cylinder pressure.

[0094] For ease of understanding, by way of example, assume that the initial braking force is F1, the actual deceleration is a1, and the preset deceleration threshold is a2 +△a, where a2 is the target deceleration and△a is the allowable deceleration fluctuation. After applying the pre-braking operation, if a1>a2+△a, the initial braking force F1 is corrected with reference to F2=k1*F1, where k1 is the correction coefficient and satisfies k1=a2 / a1.

[0095] In one embodiment, the step S3 of maintaining the pre-braking application state according to the adjusted braking force until the electric-hydraulic conversion starts includes the following steps.

[0096] Step S33, determining whether the actual running speed of the rail vehicle is equal to 0; If not, jump to step S34A, and control the braking unit to maintain the pre-braking application state according to the adjusted braking force; If yes, go to step S34B, control the braking unit to cancel the pre-braking operation on the rail vehicle.

[0097] In this way, by constructing a pre-braking exit mechanism strictly synchronized with the running state of the vehicle, the invalid consumption of energy and the continuous wear of the braking components after the vehicle stops can be completely avoided while ensuring that the braking system is on standby throughout the process, realizing smooth connection of the electric brake and the air brake, and ensuring smooth and reliable vehicle braking process.

[0098] Specifically, the maintenance state of the pre-braking function is bound to the dynamic condition of non-zero speed of the vehicle, the pre-braking operation is started before the electric air conversion starts, and an optimal pre-braking force (i.e. the braking force after adjustment of the initial braking force) is determined through adaptive adjustment. This pre-braking force is continuously maintained as the basic braking force, and is superimposed with the main air braking force gradually established during the electric air conversion process to act on the braking system.

[0099] This process ensures that the brake cylinder is always in a "critical state" of pre-charge pressure throughout the process from the pre-braking stage to the establishment of the main braking, completely eliminating the initial delay in the establishment of the main braking force. The pre-braking force will be maintained as the basic load until the train is completely stopped (actual running speed v=0) and then canceled, thereby realizing a delay-free response throughout the braking process and maximizing the accuracy and efficiency of the stop control.

[0100] The above various embodiments, examples or specific examples provided in the present application can be combined with each other, thereby forming multiple more optimal embodiments.

[0101] FIGS. 6(a) to 6(c) show timing diagrams corresponding to the down-regulation, no regulation and up-regulation of the pre-braking force (i.e. the initial braking force). The process of pre-braking and electric air conversion connection will be described below with respect to FIGS. 6(a) to 6(c) respectively.

[0102] As shown in FIG. 6(a), before the electric air conversion, when the actual running speed V of the vehicle is less than the preset speed V1 (i.e. V

[0103] At T3, the pre-braking force is reduced from F1 to F2 and kept at F2 until the normal electric-air conversion process is connected until the vehicle stops (i.e. the actual running speed is 0) and then is cancelled. At T4, the electric braking and the air braking are converted in braking force, the electric braking force F3 is reduced at a certain rate, and the air braking force is increased at a certain rate, until T5, when the electric braking is completely withdrawn and the air braking is completely established, completing the electric-air conversion. Conversely, when V≥V1+△V, the pre-braking operation is not applied.

[0104] Similarly, as shown in Fig. 6(b), after the pre-braking force F1 (i.e. the initial braking force F1) is applied, if the actual deceleration a1 of the rail vehicle at this time is 0 or a1≤a2+△a, it indicates that the initial braking force does not affect the normal operation of the rail vehicle at this time, and the initial braking force F1 does not need to be corrected, and the initial braking force F1 is kept until the running speed of the vehicle is 0, and then is cancelled. At T4, the electric braking and the air braking are converted in braking force, the electric braking force F3 is reduced at a certain rate, and the air braking force is increased at a certain rate, until T5, when the electric braking is completely withdrawn and the air braking is completely established, completing the electric-air conversion.

[0105] As shown in Fig. 6(c), after the pre-braking force F1 (i.e. the initial braking force F1) is applied, if the actual pressure of the brake cylinder of the rail vehicle at this time is less than or equal to the pre-set pressure threshold, it indicates that the pre-braking force F1 applied is too small and cannot achieve the purpose of reducing the response time, and the pre-braking force needs to be increased to the second target braking force F4, and the second target braking force F4 satisfies F4=k2*F1, wherein k2 is an increase correction coefficient, and k2=a2 / a1. After the pre-braking force is increased to F4, the pre-braking force is kept until the train speed is 0, and then is cancelled. At T5, the electric braking and the air braking are converted in braking force, the electric braking force F3 is reduced at a certain rate, and the air braking force is increased at a certain rate, until T6, when the electric braking is completely withdrawn and the air braking is completely established, completing the electric-air conversion.

[0106] An embodiment of the present application provides a computer readable storage medium.

[0107] In an embodiment, the computer readable storage medium stores the computer program executed by the processor mentioned above, or the pre-braking control method of the rail vehicle in any one of the technical solutions.

[0108] When the processor executes the computer program, the description of the pre-braking control method of the rail vehicle in any one of the technical solutions can be executed, and therefore, the description will not be repeated here. In addition, the beneficial effects of using the same method will not be repeated.

[0109] The computer readable storage medium can include a flash disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0110] In summary, the application provides a pre-braking control method, device and storage medium for a rail vehicle. The control method intelligently determines whether the force of the current pre-braking operation is too large, too small or appropriate by monitoring the actual deceleration and the actual pressure of the brake cylinder caused by the application of the initial braking force, and dynamically adjusts the pre-braking force (i.e. the initial braking force) accordingly, so that the braking system can adapt to different loads, friction coefficients and mechanical states, thereby maximizing the response time of the air brake before the electric-air conversion and completely avoiding the interference with the accuracy of the final stopping position caused by improper initial braking force setting, achieving the coordinated optimization of the response speed and the stopping accuracy.

[0111] It should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

[0112] The above series of detailed descriptions are only specific descriptions of the feasible embodiments of the application, and are not intended to limit the protection scope of the application, and any equivalent embodiments or changes made without departing from the spirit of the application should be included in the protection scope of the application.

Claims

1. A pre-braking control method for a rail vehicle, characterized in that, The rail vehicle includes a brake cylinder, and the braking control method includes: Before receiving the electro-pneumatic conversion signal, the actual operating speed of the current rail vehicle is obtained in response to the braking command; When the actual operating speed is less than the preset speed, a pre-braking operation is applied to the rail vehicle according to the initial braking force. The initial braking force is adjusted based on the actual deceleration of the rail vehicle after the pre-braking operation and / or the actual pressure of the brake cylinder, and the pre-braking application state is maintained according to the adjusted braking force until the electro-pneumatic conversion begins.

2. The braking control method according to claim 1, characterized in that, Before applying the pre-braking operation to the rail vehicle according to the initial braking force, the method includes: The initial braking force is determined based on the amount required to overcome the maximum frictional force and / or mechanical clearance of the brake cylinder.

3. The braking control method according to claim 1, characterized in that, The step of adjusting the initial braking force based on the actual deceleration of the rail vehicle after the braking operation or the actual pressure of the brake cylinder, and maintaining the pre-braking application state according to the adjusted braking force until the electro-pneumatic conversion begins, includes: Obtain the first actual running speed of the rail vehicle before the pre-braking operation and the second actual running speed after the pre-braking operation, and determine the corresponding actual deceleration; Based on the comparison between the actual deceleration and the preset deceleration threshold, and / or based on the comparison between the actual pressure value and the preset pressure threshold, the initial braking force is adjusted, and the pre-braking application state is maintained according to the adjusted braking force until the electro-pneumatic conversion begins.

4. The braking control method according to claim 3, characterized in that, The adjustment of the initial braking force based on the comparison result of the actual deceleration and the preset deceleration threshold, and / or the comparison result of the actual pressure value and the preset pressure threshold, and the maintenance of the pre-braking application state according to the adjusted braking force until the electro-pneumatic conversion begins, includes: Determine whether the actual deceleration is greater than a preset deceleration threshold; If so, the initial braking force is reduced, and the pre-braking application state is maintained according to the reduced braking force until the electro-pneumatic conversion begins; If not, the initial braking force remains unchanged, and the pre-braking application state is maintained according to the initial braking force until the electro-pneumatic conversion begins.

5. The braking control method according to claim 3, characterized in that, The adjustment of the initial braking force based on the comparison result of the actual deceleration and the preset deceleration threshold, and / or the comparison result of the actual pressure value and the preset pressure threshold, and the maintenance of the pre-braking application state according to the adjusted braking force until the electro-pneumatic conversion begins, includes: When the actual deceleration is less than or equal to a preset deceleration threshold, it is determined whether the actual pressure value is less than or equal to a preset pressure threshold. If so, the initial braking force is increased, and the pre-braking application state is maintained according to the increased braking force until the electro-pneumatic conversion begins.

6. The braking control method according to claim 3, characterized in that, The adjustment of the initial braking force includes: In response to the braking level command of the rail vehicle, determine the corresponding target deceleration; The initial braking force is adjusted based on the target deceleration and the current load of the rail vehicle.

7. The braking control method according to claim 3, characterized in that, The adjustment of the initial braking force includes: In response to the braking level command of the rail vehicle, determine the corresponding target deceleration; The initial braking force is adjusted based on the ratio of the target deceleration to the actual deceleration.

8. The braking control method according to claim 1, characterized in that, Maintaining the pre-braking state according to the adjusted braking force until the electro-pneumatic conversion begins includes: Determine whether the actual operating speed of the rail vehicle is equal to 0; If not, the control braking unit maintains the pre-braking application state according to the adjusted braking force; If so, the control braking unit cancels the pre-braking operation on the rail vehicle.

9. A pre-braking control device for a rail vehicle, characterized in that, The braking control device includes a brake cylinder, and the device further includes: The input module is used to obtain the actual operating speed of the current rail vehicle in response to the braking command before receiving the electro-pneumatic conversion signal; The processing module is used to apply a pre-braking operation to the rail vehicle according to the initial braking force when the actual operating speed is less than the preset speed; The adjustment module is used to adjust the initial braking force according to the actual deceleration of the rail vehicle after the braking operation and / or the actual pressure of the brake cylinder, and maintain the pre-braking application state according to the adjusted braking force until the electro-pneumatic conversion begins.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the pre-braking control method as described in any one of claims 1 to 8.

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