Electric pneumatic braking control system and method for rail transit vehicle

Abstract

The invention relates to the field of rail transit, in particular to a rail transit vehicle electric pneumatic braking control system and method.The control system comprises an electronic braking control unit, a common pre-control branch, an emergency pre-control branch and a relay valve, and the electronic braking control unit is used for controlling the common pre-control branch to output common pre-control pressure; the emergency pre-control branch comprises an emergency valve, a remote relief electromagnetic valve and an empty and load valve, the empty and load valve outputs emergency pre-control pressure corresponding to vehicle load information, and the relay valve receives common and emergency pre-control pressure and selects one of the common and emergency pre-control pressure to output corresponding compressed air to a brake cylinder; the electronic brake control unit analyzes the service brake instruction, the service pre-control pressure and the pressure value at the output position of the relay valve, can judge the emergency valve fault and control the remote relieving electromagnetic valve to empty compressed air of the emergency pre-control branch, and the problems that after the emergency valve fault occurs, the emergency air path pressure is not relieved, and the relieving capacity of the air path pressure is unstable are solved.

Description

Technical Field

[0001] The present application relates to the field of rail transit, and in particular to an electro-pneumatic braking control system and method for rail transit vehicles. Background Art

[0002] Urban rail vehicle braking systems often feature emergency valves, which are control components for vehicle emergency braking. Their performance directly impacts whether the vehicle can safely and reliably stop in an emergency.

[0003] In the emergency brake circuit, if the emergency valve fails, the pressure in the circuit can rise rapidly, causing an unexpected stop. Currently, the emergency valve's power is usually used as a basis for determining whether to release the pressure in the emergency brake circuit.

[0004] However, there are many reasons for the emergency valve to lose power, the error rate of judging by a single factor is high, and the ability to relieve the gas circuit pressure is unstable. Summary of the Invention

[0005] The embodiments of the present application provide a rail transit vehicle electro-pneumatic braking control system and method to at least solve the problem of alleviating the instability of emergency braking air circuit pressure in the related art.

[0006] In a first aspect, an embodiment of the present application provides an electro-pneumatic brake control system for a rail transit vehicle, the control system comprising an electronic brake control unit, a common pre-control branch, an emergency pre-control branch, and a relay valve; The electronic brake control unit is connected to the normal pre-control branch and the emergency pre-control branch respectively, and is configured to obtain and control the normal pre-control branch to output a normal pre-control pressure according to a normal braking instruction and vehicle load information; The relay valve is connected to the brake cylinder, and is respectively connected to the normal pre-control branch and the empty and loaded vehicle valve, and is configured to receive the normal pre-control pressure and the emergency pre-control pressure, select the normal pre-control pressure or the emergency pre-control pressure, and output the compressed air corresponding to the normal pre-control pressure or the emergency pre-control pressure to the brake cylinder; The emergency pre-control branch includes an emergency valve, a remote relief solenoid valve, and an empty and loaded vehicle valve; The empty and loaded vehicle valve is connected to the brake air reservoir of the vehicle and is configured to obtain vehicle load information, output an emergency pre-control pressure corresponding to the vehicle load information, and deliver compressed air corresponding to the emergency pre-control pressure from the brake air reservoir of the vehicle into the emergency pre-control branch; The emergency valve is located between the empty and loaded vehicle valve and the relay valve, and is configured so that in an emergency braking situation, the emergency valve loses power, allowing compressed air to pass through the emergency pre-control branch, reach the input pre-control end of the relay valve, and finally output to the brake cylinder; The remote relief solenoid valve is located between the emergency valve and the relay valve, and is configured to, after the electronic brake control unit obtains and analyzes the common braking instructions, the common pre-control pressure, and the pressure value at the output of the relay valve, determine that the emergency valve is faulty, and be controlled by the electronic brake control unit to be energized to exhaust the compressed air in the emergency pre-control branch. In some embodiments, the electronic brake control unit is further configured to: Determine whether the common braking command is received, if not, determine whether the common pre-control pressure is zero, if so, determine whether the pressure at the output end of the relay valve is zero, if not, the emergency valve is faulty; or, Determining whether the common braking command is received, and if so, determining whether the common pre-control pressure matches the pressure value of the output end of the relay valve, and if not, determining that the emergency valve is faulty; When it is determined that the emergency valve fails, the remote relief solenoid valve is controlled to be energized.

[0007] In some embodiments, the control system further comprises: An air spring pressure sensor is connected to the electronic brake control unit and the empty and loaded vehicle valve, and is configured to detect the air spring pressure of the vehicle bogie and send the air spring pressure to the electronic brake control unit and the empty and loaded vehicle valve. Wherein, the electronic brake control unit is further configured to calculate vehicle load information corresponding to the air spring pressure according to the air spring pressure; In the emergency pre-control branch, the air spring pressure represents the vehicle load information, and the empty and loaded vehicle valve is further configured to output the emergency pre-control pressure corresponding to the vehicle load information represented by the air spring pressure according to the air spring pressure.

[0008] In some embodiments, the control system includes a plurality of air spring pressure sensors, each of which is disposed at an air spring pressure input port, and further includes: an averaging valve, located between the air spring pressure sensor and the empty and loaded vehicle valve, configured to be connected to a plurality of the air spring pressure sensors and the empty and loaded vehicle valve, respectively, for receiving a plurality of the air spring pressures, averaging the air spring pressures, and transmitting the averaged air spring pressures to the empty and loaded vehicle valve; The empty and loaded vehicle valve is further configured to receive the processed air spring pressure and output the emergency pre-control pressure according to the processed air spring pressure.

[0009] In some embodiments, the vehicle load information includes a gross vehicle weight, and the electronic brake control unit is further configured to: Obtaining the common braking command, the gross vehicle weight, and the minimum pressure of the return spring of the foundation brake device; Set the idle delay system and proportional coefficient; The product of the idle delay system, the common braking command, the gross vehicle weight, and the proportional coefficient is calculated, and the product is summed with the minimum pressure of the return spring of the foundation brake device to obtain a value of the common pre-control pressure.

[0010] In some embodiments, the common pre-control branch is connected to the brake air storage cylinder of the vehicle, and includes a common pre-control charging solenoid valve, a common pre-control exhaust solenoid valve and a pressure reducing valve; The common pre-control charging solenoid valve and the common pre-control exhaust solenoid valve are respectively connected to the electronic brake control unit and the relay valve. The common pre-control charging solenoid valve and the common pre-control exhaust solenoid valve obtain the compressed air from the brake air storage cylinder of the vehicle, and under the control of the electronic brake control unit, jointly form a common pre-control pressure according to the value of the common pre-control pressure, and output the compressed air corresponding to the common pre-control pressure to the relay valve. The pressure reducing valve is located between the brake air storage cylinder and the common pre-control air charging solenoid valve, and is configured to communicate with the brake air storage cylinder and control the compressed air in the brake air storage cylinder to enter the common pre-control branch.

[0011] In a second aspect, an embodiment of the present application provides a rail transit vehicle electro-pneumatic braking control method, which is applied to the rail transit vehicle electro-pneumatic braking control system described above, comprising: a normal braking step of obtaining a normal braking command and vehicle load information, calculating a value of a normal pre-control pressure according to the normal braking command and the vehicle load information, and outputting the normal pre-control pressure by the normal pre-control branch according to the value of the normal pre-control pressure; an emergency braking step, obtaining a value of an emergency pre-control pressure corresponding to the vehicle load information according to the vehicle load information, and outputting the emergency pre-control pressure by the emergency pre-control branch according to the value of the emergency pre-control pressure; obtaining the common pre-control pressure and the emergency pre-control pressure, comparing the common pre-control pressure and the emergency pre-control pressure, and outputting compressed air corresponding to the common pre-control pressure to the brake cylinder if the common pre-control pressure is greater than the emergency pre-control pressure; and outputting compressed air corresponding to the emergency pre-control pressure to the brake cylinder if the common pre-control pressure is less than the emergency pre-control pressure; The emergency braking relief step is to determine whether the emergency pre-control branch is faulty according to the common braking instruction, the common pre-control pressure, and the pressure value output to the brake cylinder. If so, the compressed air in the emergency pre-control branch is exhausted.

[0012] In some embodiments, the step of alleviating emergency braking further comprises: Determine whether the common braking command is received, if not, determine whether the common pre-control pressure is zero, if so, determine whether the pressure at the output end of the relay valve is zero, if not, the emergency valve is faulty; or, determining whether the common braking command is received, and if so, determining whether the common pre-control pressure matches the pressure at the relay valve output, and if not, determining that the emergency valve is faulty; When it is determined that the emergency valve fails, the compressed air in the emergency pre-control branch is exhausted.

[0013] In some embodiments, the vehicle load information includes a gross vehicle weight, and the service braking step further includes: Obtaining the common braking command, the gross vehicle weight, and the minimum pressure of the return spring of the foundation brake device; Set the idle delay system and proportional coefficient; The product of the idle delay system, the common braking command, the gross vehicle weight, and the proportional coefficient is calculated, and the product is summed with the minimum pressure of the return spring of the foundation brake device to obtain a value of the common pre-control pressure.

[0014] In some embodiments, the control method further includes: Adjustment steps: obtain the real-time deceleration of the vehicle and set the deceleration threshold; comparing the vehicle's real-time deceleration with a deceleration threshold, and adjusting the common pre-control pressure in the common pre-control branch if the vehicle's real-time deceleration is less than the deceleration threshold; When the adjusted common pre-control pressure is greater than the emergency pre-control pressure, the compressed air corresponding to the adjusted common pre-control pressure is output to the brake cylinder.

[0015] Compared with the related technologies, the embodiment of the present application provides an electro-pneumatic braking control system and method for rail transit vehicles, which takes into account the commonly used braking instructions, the pressure value at the output of the relay valve, and the commonly used pre-control pressure, and comprehensively judges whether the emergency valve has failed, and then controls the remote relief solenoid valve to relieve the pressure in the emergency pre-control branch, solving the problem of unstable relief ability of the emergency brake air circuit pressure, and realizing accurate relief of the pressure in the emergency pre-control branch when the emergency valve fails, preventing abnormal emergency braking of the vehicle and ensuring smooth operation of the train.

[0016] The details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 This is a structural diagram of an electro-pneumatic braking control system for a rail transit vehicle according to an embodiment of the present application; Figure 2 This is a flow chart of a rail transit vehicle electro-pneumatic braking control method according to an embodiment of the present application.

[0018] In the picture: 101. Emergency valve; 102. Remote relief solenoid valve; 103. Common pre-control inflation solenoid valve; 104. Common pre-control exhaust solenoid valve; 105. Pressure reducing valve; 106. Relay valve; 107. Simulation measurement point; 108. Average valve; 109. Empty and loaded vehicle valve; 110. Common pre-control pressure measuring point; 111. Common pre-control pressure sensor; 112. Emergency pre-control pressure measuring point; 113. Emergency pre-control pressure sensor; 114. Brake cylinder pressure measuring point; 115. Brake cylinder pressure sensor; 116. First input interface; 117. Second input interface; 118. Third input interface; 119. Output interface; 120. First air spring pressure sensor; 121. Second air spring pressure sensor. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts are within the scope of protection of this application.

[0020] Obviously, the drawings described below are merely examples or embodiments of the present application. Those skilled in the art can, without inventive effort, apply the present application to other similar scenarios based on these drawings. Furthermore, it is also understood that, although the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, changes in design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as an insufficiency of the content disclosed in this application.

[0021] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments unless there is a conflict.

[0022] Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by persons of ordinary skill in the art to which this application belongs. The terms "a," "an," "an," "the," and similar expressions used herein do not denote quantitative limitations and may refer to either the singular or the plural. The terms "comprise," "include," "have," and any variations thereof, used herein, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or modules (units) is not limited to the listed steps or units but may also include steps or units not listed, or may include other steps or units inherent to the process, method, product, or apparatus. The terms "connected," "connected," "coupled," and similar expressions used herein are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. As used herein, "plurality" means two or more. "And / or" describes an association between associated objects, indicating that three possible relationships exist. For example, "A and / or B" may mean: A exists alone; A and B exist simultaneously; or B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0023] Emergency braking is crucial for the safe operation of urban rail transit vehicles, requiring high reliability and fast response times. Most existing urban rail vehicle braking systems are equipped with an emergency valve 101, which serves as the control component for emergency braking. Its performance directly impacts the vehicle's ability to safely and reliably stop in an emergency.

[0024] The emergency valve 101 can be a standalone solenoid valve or a combination of a solenoid valve and a pneumatic control valve. During normal vehicle operation, the emergency solenoid valve remains energized. If the driver's control or other factors cause the emergency solenoid valve to lose power, the emergency valve 101 connects the emergency pre-control branch to the relay valve 106, applying emergency braking.

[0025] When a train is running on the main line, if the emergency solenoid valve is in a power-off state due to its own fault, the emergency brake will be accidentally applied, seriously affecting the normal operation of the vehicle. After the emergency brake is released, the vehicle's normal braking function will also be lost.

[0026] To overcome this problem, it is necessary to add a device that can relieve emergency braking to the emergency pre-control branch. However, since there are many reasons for the emergency valve 101 to lose power, judging the emergency braking relief only from the power loss of the emergency valve 101 is not stable, and the emergency pre-control branch has poor relief capability.

[0027] To address the aforementioned issues, this application provides a rail transit vehicle electro-pneumatic brake control system and method. In the event of an emergency solenoid valve failure, the system vents the pressure in the emergency pre-control branch, preventing the vehicle from initiating emergency braking. Furthermore, when emergency braking is applied, the emergency pre-control branch and the normal pre-control branch are redundant, both outputting pressure to relay valve 106. Relay valve 106 then selects the path with the optimal pressure, ensuring rapid and reliable application of emergency braking.

[0028] like Figure 1 As shown, an embodiment of the present application provides an electro-pneumatic brake control system for a rail transit vehicle, including an electronic brake control unit (EBCU) and a pneumatic brake control unit.

[0029] The pneumatic brake control unit includes a normal pre-control branch, an emergency pre-control branch and a relay valve 106 .

[0030] The pneumatic brake control unit of the control system is provided with four air circuit interfaces, including a first input interface 116 , a second input interface 117 , a third input interface 118 and an output interface 119 .

[0031] The first input interface 116 is connected to the brake air storage cylinder of the vehicle, and compressed air is input into the normal pre-control branch and the emergency pre-control branch through the first input interface 116 .

[0032] The second input interface 117 and the third input interface 118 are both air spring pressure input ports.

[0033] The output interface 119 is connected to the brake cylinder, and compressed air enters the brake cylinder from the control system through the output port 2.

[0034] Among them, the electronic brake control unit is connected to the normal pre-control branch and the emergency pre-control branch respectively, and is configured to obtain and control the normal pre-control branch to output the normal pre-control pressure according to the normal braking instruction and vehicle load information.

[0035] The relay valve 106 includes an output end and an input pre-control end. The output end is connected to the brake cylinder via the output interface 119, and the input pre-control end is respectively connected to the normal pre-control branch and the emergency pre-control branch. It is configured to receive the normal pre-control pressure and the emergency pre-control pressure, select the normal pre-control pressure or the emergency pre-control pressure, amplify the compressed air flow corresponding to the normal pre-control pressure or the emergency pre-control pressure, and then output it to the brake cylinder.

[0036] The relay valve 106 compares the common pre-control pressure and the emergency pre-control pressure, and selects the larger one to output the corresponding compressed air to the brake cylinder.

[0037] The emergency pre-control branch includes an emergency valve 101 , a remote relief solenoid valve 102 , and an empty and loaded vehicle valve 109 .

[0038] Among them, the empty and loaded vehicle valve 109 is connected to the vehicle's brake air storage cylinder through the first input interface 116, and is configured to obtain vehicle load information and output an emergency pre-control pressure corresponding to the vehicle load information, and transport compressed air corresponding to the emergency pre-control pressure from the vehicle's brake air storage cylinder into the emergency pre-control branch.

[0039] The control system further comprises a simulation measuring point 107 , through which the setting value of the emergency pre-control pressure in the empty and loaded vehicle valve 109 can be calibrated.

[0040] The control system further includes a brake cylinder pressure measuring point 114 and a brake cylinder pressure sensor 115 , both located between the relay valve 106 and the output interface 119 , for detecting the pressure at the output end of the relay valve 106 .

[0041] The emergency valve 101 is located between the empty and loaded vehicle valve 109 and the relay valve 106. It is configured so that in an emergency braking situation, the emergency valve 101 loses power, allowing compressed air to pass through the emergency pre-control branch, reach the input pre-control end of the relay valve 106, and finally output to the brake cylinder.

[0042] The remote relief solenoid valve 102 is located between the emergency valve 101 and the relay valve 106. It is configured to obtain the common braking instructions, common pre-control pressure, and the pressure value at the output of the relay valve 106 through the electronic brake control unit and analyze them, and then determine that the emergency valve 101 is faulty. The electronic brake control unit controls the remote relief solenoid valve 102 to be energized and the compressed air in the emergency pre-control branch is exhausted. The power supply for the remote relief solenoid valve 102 is provided by the emergency safety loop.

[0043] The common and emergency pre-control branches operate independently and collaboratively, preventing brake failure caused by a single branch failure and providing dual-branch redundancy. During emergency braking, emergency valve 101 quickly opens, significantly shortening brake response time and reducing the risk of emergency conditions. The remote relief solenoid valve 102 actively vents compressed air from the emergency pre-control branch when the EBCU detects an anomaly, preventing brake drag or mis-braking caused by residual pressure in the branch and extending the service life of the brake system.

[0044] Furthermore, an emergency pre-control pressure measuring point 112 is provided in the emergency pre-control branch, and an emergency pre-control pressure sensor 113 is provided near the emergency pre-control pressure measuring point 112 .

[0045] In some embodiments, the electronic brake control unit is further configured to: Determine whether a common braking command is received. If not, determine whether the common pre-control pressure is zero. If so, determine whether the pressure at the output end of the relay valve 106 is zero. If not, the emergency valve 101 is faulty.

[0046] Alternatively, it is determined whether a common braking command is received. If so, it is determined whether the common pre-control pressure matches the pressure at the output end of the relay valve 106 . If not, the emergency valve 101 is faulty.

[0047] When it is determined that the emergency valve 101 fails, the remote relief solenoid valve 102 is controlled to be energized.

[0048] Through dual verification logic for both command and pressure, the system covers both braking and non-braking scenarios, avoiding misjudgments caused by a single criterion and improving recognition accuracy. Furthermore, the response time from fault determination to remote relief of solenoid valve 102 is short, preventing the fault branch from interfering with brake cylinder pressure and ensuring vehicle stability.

[0049] In some embodiments, the control system further comprises: The air spring pressure sensor is connected to the electronic brake control unit and the empty and loaded vehicle valve 109 , and is configured to detect the air spring pressure of the vehicle bogie and transmit the air spring pressure to the electronic brake control unit and the empty and loaded vehicle valve 109 .

[0050] The electronic brake control unit is further configured to calculate vehicle load information corresponding to the air spring pressure based on the air spring pressure.

[0051] In the emergency pre-control branch, the air spring pressure represents vehicle load information, and the empty-load vehicle valve 109 is further configured to output an emergency pre-control pressure corresponding to the vehicle load information represented by the air spring pressure.

[0052] The air spring pressure sensor has a fast response speed and can track changes in vehicle load in real time, providing real-time data support for the dynamic adjustment of the pre-control pressure of the empty and loaded vehicle valve 109, ensuring that the braking pressure is synchronously matched with the load.

[0053] In some embodiments, the control system includes a plurality of air spring pressure sensors, each of which is disposed at an air spring pressure input port of the pneumatic brake control unit, and further includes: The averaging valve 108 is located between the air spring pressure sensor and the empty and loaded vehicle valve 109 and is configured to be connected to multiple air spring pressure sensors and the empty and loaded vehicle valve 109 respectively, for receiving multiple air spring pressures, averaging them, and transmitting the processed air spring pressures to the empty and loaded vehicle valve 109.

[0054] The empty and loaded vehicle valve 109 is further configured to receive the processed air spring pressure and output the emergency pre-control pressure according to the processed air spring pressure.

[0055] Abnormal data of a single sensor is eliminated through averaging processing, the problem of high or low pressure caused by sensor failure is overcome, the empty and loaded vehicle valve 109 is prevented from calculating the wrong pre-control pressure based on the deviation data, and the stability of the brake pressure regulation is improved.

[0056] The plurality of air spring pressure sensors include a first air spring pressure sensor 120 and a second air spring pressure sensor 121 .

[0057] The pressure generated by the air springs of the two bogies is detected by the first air spring pressure sensor 120 and the second air spring pressure sensor 121, and transmitted to the averaging valve 108. After averaging processing by the averaging valve 108, it is input into the empty and loaded vehicle valve 109 as the emergency pre-control pressure output by the empty and loaded vehicle valve 109.

[0058] In some embodiments, the vehicle load information includes a gross vehicle weight, and the electronic brake control unit is further configured to: Obtain the service brake command, gross vehicle weight, and minimum foundation brake return spring pressure.

[0059] The spring in the minimum pressure of the return spring of the foundation brake device includes the spring in the foundation brake device.

[0060] Set the idle delay system and proportional coefficient.

[0061] Calculate the product of the idle delay system, common brake command, gross vehicle weight and proportional coefficient, and sum the product with the minimum pressure of the return spring of the basic brake device to obtain the value of the common pre-control pressure.

[0062] Formulas quantify factors such as braking commands and load, ensuring that commonly used pre-control pressure is perfectly matched to braking requirements, resulting in more stable braking distances. Adjustments to the idle delay system and proportional coefficients allow for adaptability to the braking characteristics of different types of vehicles, including passenger cars, trucks, and EMUs, ensuring high versatility. A minimum return spring pressure for the basic brake system is incorporated to ensure that the output pre-control pressure effectively actuates the brakes, preventing brake failure due to mechanical resistance.

[0063] Specifically, the required braking force of the vehicle is calculated based on the idle delay system, the common braking command, and the total vehicle weight. The calculation formula is: Where F is the braking force required by the vehicle, k is the idle delay system, a is the common braking command, and M is the total weight of the vehicle. During emergency braking, a is generally taken as 1.2m / s 2 .

[0064] The brake cylinder target pressure is calculated using the same formula as the commonly used pre-control pressure: .in, is the proportional coefficient, b is the minimum pressure of the return spring of the basic brake device, It is the target pressure of the brake cylinder or the commonly used pre-control pressure.

[0065] In some embodiments, the common pre-control branch is connected to the brake air storage cylinder of the vehicle, including a common pre-control charging solenoid valve 103 and a common pre-control exhaust solenoid valve 104 .

[0066] Among them, the commonly used pre-control inflation solenoid valve 103 and the commonly used pre-control exhaust solenoid valve 104 are respectively connected to the electronic brake control unit and the relay valve 106. The commonly used pre-control inflation solenoid valve 103 and the commonly used pre-control exhaust solenoid valve 104 obtain compressed air from the vehicle's brake air storage cylinder, and are controlled by the electronic brake control unit to jointly form a commonly used pre-control pressure according to the value of the commonly used pre-control pressure, and output the compressed air corresponding to the commonly used pre-control pressure to the relay valve 106.

[0067] The common pre-control inflation solenoid valve 103 and the common pre-control exhaust solenoid valve 104 work together to quickly generate or adjust the common pre-control pressure according to the common braking command, with good responsiveness and high pressure feedback efficiency. During the coordinated regulation of the dual solenoid valves, if one solenoid valve fails, the other solenoid valve can temporarily maintain the pressure within a safe range through reverse regulation, preventing the common pre-control branch from completely failing.

[0068] During normal braking, the emergency valve 101 is energized. At this time, the EBCU calculates the required normal pre-control pressure value based on the normal braking instruction and vehicle load information, and then controls the operation of the normal pre-control inflation solenoid valve 103 and the normal pre-control exhaust solenoid valve 104. According to the calculated normal pre-control pressure value, the normal pre-control pressure is adjusted and output to an input port of the relay valve 106.

[0069] The pressure reducing valve 105 is located between the brake air reservoir cylinder and the common pre-control air charging solenoid valve 103 , and is configured to communicate with the brake air reservoir cylinder and control the compressed air in the brake air reservoir cylinder to enter the common pre-control branch.

[0070] Prevent the high-pressure air of the brake air storage cylinder from directly impacting the commonly used pre-control charging solenoid valve 103, relay valve 106 and other components, avoid the components from being damaged due to long-term high pressure, and extend the service life of the branch components.

[0071] A pressure reducing valve 105 is provided in the common pre-control branch to protect downstream components. The pressure value of the pressure reducing valve 105 is generally set to a value that exceeds the maximum emergency pre-control pressure of the AW3 load by 30 kPa.

[0072] The commonly used pre-control branch also includes a commonly used pre-control pressure measuring point 110 and a commonly used pre-control pressure sensor 111. The commonly used pre-control pressure measuring point 110 is close to the commonly used pre-control inflation solenoid valve 103 and the commonly used pre-control exhaust solenoid valve 104. The commonly used pre-control pressure sensor 111 is arranged next to the commonly used pre-control pressure measuring point 110, and is used to monitor the commonly used pre-control pressure generated by the commonly used pre-control inflation solenoid valve 103 and the commonly used pre-control exhaust solenoid valve 104 in real time, forming a closed loop.

[0073] If the common pre-control pressure sensor 111 fails, the brake cylinder pressure sensor 115 can be used for closed-loop regulation to play a redundant control role and improve the reliability of common braking.

[0074] During emergency braking, if the driver applies pressure or the emergency solenoid valve loses power for other reasons, compressed air from the brake air reservoir enters the emergency pre-control branch. After passing through the no-load valve 109, it outputs an emergency pre-control pressure corresponding to the vehicle load information. This pressure then passes through the emergency valve 101 and the remote relief solenoid valve 102 to the other input port of the relay valve 106. Simultaneously, the EBCU controls the normal pre-control branch to adjust the normal pre-control pressure corresponding to the vehicle load information. The relay valve 106 compares the emergency pre-control pressure with the normal pre-control pressure and selects the higher pressure to output to the brake cylinder.

[0075] Under normal circumstances, the solenoid valve in the emergency pre-control branch has a larger diameter, allowing the emergency pre-control branch to reach the target pressure more quickly. If emergency valve 101 becomes stuck, or if the air control valve of emergency valve 101 becomes stuck, causing the emergency pre-control branch pressure to be insufficient or rise slowly, relay valve 106 will select the normal pre-control branch pressure as the control pressure, ensuring reliable emergency braking.

[0076] The emergency pre-control pressure corresponding to the vehicle load information is the pressure output mechanically.

[0077] In the non-emergency braking state, when the emergency safety loop is closed, if the vehicle emergency valve 101 loses power due to coil burnout or other reasons, or the emergency valve 101 cannot operate normally due to low voltage, the emergency pre-control pressure sensor 113 and the brake cylinder pressure sensor 115 will monitor the increase in their respective pressure values. The EBCU will comprehensively analyze the pressure values ​​detected by the common braking instructions, the brake cylinder pressure sensor 115, and the common pre-control pressure sensor 111. If the EBCU does not receive the common braking instructions and the common pre-control pressure is zero, it can be determined that the emergency valve 101 is faulty. If the EBCU receives the common braking instructions, the difference between the pressure value at the output of the relay valve 106 and the common pre-control pressure value is too large, resulting in a mismatch, it is determined that the emergency valve 101 is faulty.

[0078] At this point, the EBCU energizes remote release solenoid valve 102, shutting off upstream pressure and exhausting compressed air from the emergency pre-control branch to prevent the generation of unintended emergency braking force. Furthermore, because remote release solenoid valve 102 is powered by the emergency safety circuit, emergency braking cannot be released during remote release, ensuring that emergency braking has the highest priority. Compressed air from the normal pre-control branch can pass through relay valve 106, allowing normal braking to continue.

[0079] like Figure 2 As shown, an embodiment of the present application provides a rail transit vehicle electro-pneumatic braking control method, which is applied to the above-mentioned rail transit vehicle electro-pneumatic braking control system, including: In the common braking step S201, a common braking instruction and vehicle load information are obtained, and a common pre-control pressure value is calculated according to the common braking instruction and vehicle load information. According to the common pre-control pressure value, the common pre-control branch outputs the common pre-control pressure.

[0080] In the emergency braking step S202 , a value of an emergency pre-control pressure corresponding to the vehicle load information is acquired according to the vehicle load information, and the emergency pre-control branch outputs the emergency pre-control pressure according to the value of the emergency pre-control pressure.

[0081] Obtain the common pre-control pressure and the emergency pre-control pressure, compare the common pre-control pressure and the emergency pre-control pressure, if the common pre-control pressure is greater than the emergency pre-control pressure, output the compressed air corresponding to the common pre-control pressure to the brake cylinder; if the common pre-control pressure is less than the emergency pre-control pressure, output the compressed air corresponding to the emergency pre-control pressure to the brake cylinder.

[0082] In the emergency braking relief step S203, it is determined whether the emergency pre-control branch is faulty according to the common braking command, the common pre-control pressure, and the pressure value output to the brake cylinder. If so, the compressed air in the emergency pre-control branch is exhausted.

[0083] By comparing and selecting between common pre-control pressure and emergency pre-control pressure, the system consistently outputs a higher pressure value to the brake cylinder, ensuring the vehicle can brake on demand and reducing the occurrence of abnormal braking conditions. This creates a complete operational process for braking, fault diagnosis, and mitigation, improving the vehicle's fault tolerance.

[0084] In some embodiments, the emergency braking relief step S203 further includes: Determine whether a common braking command is received. If not, determine whether the common pre-control pressure is zero. If so, determine whether the pressure at the output end of the relay valve 106 is zero. If not, the emergency valve 101 is faulty. Or, It is determined whether a common braking command is received. If so, it is determined whether the common pre-control pressure matches the pressure at the output of the relay valve 106 . If not, the emergency valve 101 is faulty.

[0085] When it is determined that the emergency valve 101 fails, the compressed air in the emergency pre-control branch is exhausted.

[0086] Distinguish between scenarios with and without braking commands to avoid missed faults caused by single-scenario judgment. Draining is initiated only when a fault is determined, avoiding accidental draining under normal operating conditions and ensuring the emergency pre-control branch can output pressure normally when needed.

[0087] In some embodiments, the vehicle load information includes the gross vehicle weight, and the service braking step S201 further includes: Obtain the service brake command, gross vehicle weight, and minimum foundation brake return spring pressure.

[0088] Set the idle delay system and proportional coefficient.

[0089] Calculate the product of the idle delay system, common brake command, gross vehicle weight and proportional coefficient, and sum the product with the minimum pressure of the return spring of the basic brake device to obtain the value of the common pre-control pressure.

[0090] By quantifying the vehicle's gross weight and braking commands, we ensure optimal pre-control pressure under varying loads and braking intensities, improving braking performance consistency. Clearly defining the source of parameters and the basis for coefficient setting makes subsequent debugging and maintenance easier than with vague empirical calculations.

[0091] After the first train completes the type test, the emergency pre-control pressure and the set value of the empty and load valve 109 will be determined. The empty and load valve 109 of subsequent trains will be set according to the parameters of the first train. Since the friction pair of the first train has been fully run-in after the type test, the friction coefficient is higher than that of friction pairs that have not been effectively run-in. Therefore, when the emergency brake is applied, the subsequent trains will perform emergency braking control according to the pressure set by the empty and load valve 109. The train may experience insufficient braking force due to the low friction pair, while the emergency pre-control pressure remains unchanged throughout the braking process. This will cause the train's braking distance to increase, thereby affecting driving safety.

[0092] In the control system, the EBCU also includes a deceleration sensor for detecting the real-time deceleration of the vehicle.

[0093] In some embodiments, the control method further includes: Adjustment steps: obtain the real-time deceleration of the vehicle and set the deceleration threshold.

[0094] The real-time deceleration of the vehicle is compared with the deceleration threshold. If the real-time deceleration of the vehicle is less than the deceleration threshold, the common pre-control pressure in the common pre-control branch is adjusted.

[0095] When the adjusted common pre-control pressure is greater than the emergency pre-control pressure, compressed air corresponding to the adjusted common pre-control pressure is output to the brake cylinder.

[0096] The EBCU detects the vehicle's real-time deceleration through a deceleration sensor. When emergency braking is applied and the actual vehicle deceleration falls below the deceleration threshold, the EBCU controls the normal pre-control charging solenoid valve 103 and the normal pre-control exhaust solenoid valve 104 to increase the normal pre-control pressure, outputting a normal pre-control pressure slightly higher than the emergency pre-control pressure to accommodate the current abnormal operating condition. When the normal pre-control pressure exceeds the emergency pre-control pressure, the relay valve 106 increases the brake cylinder pressure, supplementing the braking force and shortening the braking distance.

[0097] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An electro-pneumatic braking control system for rail transit vehicles, characterized in that: It includes an electronic brake control unit, a common pre-control branch, an emergency pre-control branch and a relay valve; The electronic brake control unit is connected to the normal pre-control branch and the emergency pre-control branch respectively, and is configured to obtain and control the normal pre-control branch to output a normal pre-control pressure according to a normal braking instruction and vehicle load information; The relay valve includes an output end and an input pre-control end, the output end is connected to the brake cylinder, and the input pre-control end is connected to the normal pre-control branch and the emergency pre-control branch respectively, and is configured to receive the normal pre-control pressure and the emergency pre-control pressure, select the normal pre-control pressure or the emergency pre-control pressure, and output the compressed air corresponding to the normal pre-control pressure or the emergency pre-control pressure to the brake cylinder; The emergency pre-control branch includes an emergency valve, a remote relief solenoid valve, and an empty and loaded vehicle valve; The empty and loaded vehicle valve is connected to the brake air reservoir of the vehicle and is configured to obtain vehicle load information, output an emergency pre-control pressure corresponding to the vehicle load information, and deliver compressed air corresponding to the emergency pre-control pressure from the brake air reservoir of the vehicle into the emergency pre-control branch; The emergency valve is located between the empty and loaded vehicle valve and the relay valve, and is configured so that in an emergency braking situation, the emergency valve loses power, allowing compressed air to pass through the emergency pre-control branch, reach the input pre-control end of the relay valve, and finally output to the brake cylinder; The remote relief solenoid valve is located between the emergency valve and the relay valve, and is configured to, after the electronic brake control unit obtains and analyzes the common braking instructions, the common pre-control pressure, and the pressure value at the output of the relay valve, determine that the emergency valve is faulty, and be controlled by the electronic brake control unit to be energized to exhaust the compressed air in the emergency pre-control branch.

2. The rail transit vehicle electro-pneumatic braking control system according to claim 1, characterized in that: The electronic brake control unit is further configured to: Determine whether the common braking command is received, if not, determine whether the common pre-control pressure is zero, if so, determine whether the pressure at the output end of the relay valve is zero, if not, the emergency valve is faulty; or, determining whether the common braking command is received, and if so, determining whether the common pre-control pressure matches the pressure at the output end of the relay valve, and if not, determining that the emergency valve is faulty; When it is determined that the emergency valve fails, the remote relief solenoid valve is controlled to be energized.

3. The rail transit vehicle electro-pneumatic braking control system and method according to claim 1, characterized in that: Also includes: An air spring pressure sensor is connected to the electronic brake control unit and the empty and loaded vehicle valve, and is configured to detect the air spring pressure of the vehicle bogie and send the air spring pressure to the electronic brake control unit and the empty and loaded vehicle valve. Wherein, the electronic brake control unit is further configured to calculate vehicle load information corresponding to the air spring pressure according to the air spring pressure; In the emergency pre-control branch, the air spring pressure represents the vehicle load information, and the empty and loaded vehicle valve is further configured to output the emergency pre-control pressure corresponding to the vehicle load information represented by the air spring pressure according to the air spring pressure.

4. The rail transit vehicle electro-pneumatic braking control system according to claim 3, characterized in that: The control system includes a plurality of air spring pressure sensors, each of which is arranged at an air spring pressure input port, and further includes: an averaging valve, located between the air spring pressure sensor and the empty and loaded vehicle valve, configured to be connected to a plurality of the air spring pressure sensors and the empty and loaded vehicle valve, respectively, for receiving a plurality of the air spring pressures, averaging the air spring pressures, and transmitting the averaged air spring pressures to the empty and loaded vehicle valve; The empty and loaded vehicle valve is further configured to receive the processed air spring pressure and output the emergency pre-control pressure according to the processed air spring pressure.

5. The rail transit vehicle electro-pneumatic braking control system and method according to claim 1, characterized in that: The vehicle load information includes a total vehicle weight, and the electronic brake control unit is further configured to: Obtaining the common braking command, the gross vehicle weight, and the minimum pressure of the return spring of the foundation brake device; Set the idle delay coefficient and proportional coefficient; The product of the idling delay coefficient, the common braking command, the gross vehicle weight, and the proportional coefficient is calculated, and the product is summed with the minimum pressure of the return spring of the foundation brake device to obtain a value of the common pre-control pressure.

6. The rail transit vehicle electro-pneumatic braking control system according to claim 5, characterized in that: The common pre-control branch is connected to the brake air storage cylinder of the vehicle, and includes a common pre-control charging solenoid valve, a common pre-control exhaust solenoid valve and a pressure reducing valve; The common pre-control charging solenoid valve and the common pre-control exhaust solenoid valve are respectively connected to the electronic brake control unit and the relay valve. The common pre-control charging solenoid valve and the common pre-control exhaust solenoid valve obtain the compressed air from the brake air storage cylinder of the vehicle, and under the control of the electronic brake control unit, jointly form a common pre-control pressure according to the value of the common pre-control pressure, and output the compressed air corresponding to the common pre-control pressure to the relay valve. The pressure reducing valve is located between the brake air storage cylinder and the common pre-control air charging solenoid valve, and is configured to communicate with the brake air storage cylinder and control the compressed air in the brake air storage cylinder to enter the common pre-control branch.

7. A rail transit vehicle electro-pneumatic braking control method, applied to the rail transit vehicle electro-pneumatic braking control system according to any one of claims 1 to 6, characterized in that: include: a normal braking step of obtaining a normal braking command and vehicle load information, calculating a value of a normal pre-control pressure according to the normal braking command and the vehicle load information, and outputting the normal pre-control pressure by the normal pre-control branch according to the value of the normal pre-control pressure; an emergency braking step, obtaining a value of an emergency pre-control pressure corresponding to the vehicle load information according to the vehicle load information, and outputting the emergency pre-control pressure by the emergency pre-control branch according to the value of the emergency pre-control pressure; obtaining the common pre-control pressure and the emergency pre-control pressure, comparing the common pre-control pressure and the emergency pre-control pressure, and outputting compressed air corresponding to the common pre-control pressure to the brake cylinder if the common pre-control pressure is greater than the emergency pre-control pressure; and outputting compressed air corresponding to the emergency pre-control pressure to the brake cylinder if the common pre-control pressure is less than the emergency pre-control pressure; The emergency braking relief step is to determine whether the emergency pre-control branch is faulty according to the common braking instruction, the common pre-control pressure, and the pressure value output to the brake cylinder. If so, the compressed air in the emergency pre-control branch is exhausted.

8. The rail transit vehicle electro-pneumatic braking control method according to claim 7, characterized in that: The emergency braking relief step further comprises: Determine whether the common braking command is received, if not, determine whether the common pre-control pressure is zero, if so, determine whether the pressure at the output end of the relay valve is zero, if not, the emergency valve is faulty; or, determining whether the common braking command is received, and if so, determining whether the common pre-control pressure matches the pressure at the relay valve output, and if not, determining that the emergency valve is faulty; When it is determined that the emergency valve fails, the compressed air in the emergency pre-control branch is exhausted.

9. The rail transit vehicle electro-pneumatic braking control method according to claim 7, characterized in that: The vehicle load information includes the gross vehicle weight, and the service braking step further includes: Obtaining the common braking command, the gross vehicle weight, and the minimum pressure of the return spring of the foundation brake device; Set the idle delay coefficient and proportional coefficient; The product of the idling delay coefficient, the common braking command, the gross vehicle weight, and the proportional coefficient is calculated, and the product is summed with the minimum pressure of the return spring of the foundation brake device to obtain a value of the common pre-control pressure.

10. The rail transit vehicle electro-pneumatic braking control method according to claim 7, characterized in that: Also includes: Adjustment steps: obtain the real-time deceleration of the vehicle and set the deceleration threshold; comparing the real-time deceleration of the vehicle with the deceleration threshold, and adjusting the common pre-control pressure in the common pre-control branch if the real-time deceleration of the vehicle is less than the deceleration threshold; When the adjusted common pre-control pressure is greater than the emergency pre-control pressure, the compressed air corresponding to the adjusted common pre-control pressure is output to the brake cylinder.

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