Multiple unit vehicle brake control system and control method

Abstract

A multiple unit vehicle brake control system, comprising a brake control device (1), an operating air reservoir (21), an auxiliary air reservoir (22), an air brake valve (11) and an electro-pneumatic brake module (12), wherein the electro-pneumatic brake module (12) includes an electronic brake control unit (121), an electro-pneumatic valve (124), a changeover valve (125), a shutoff valve (127) and a two-way valve (126), and further comprises a pressure relief valve (15) and a relay valve (13). The system can switch between electro-pneumatic braking and air braking, and transmits a pre-control pressure to the relay valve by means of the two-way valve. The system integrates two braking control modes: automatic air braking and direct electro-pneumatic braking, wherein the electro-pneumatic braking serves as the main braking mode, and the automatic air braking serves as hot standby redundancy, thereby improving the braking reliability, and ensuring the operational safety of a multiple unit train.

Description

Braking control system and control method of high-speed train

[0001] This application claims priority to Chinese Patent Application No. 2024117484956, filed on December 2, 2024, entitled "Adaptive Control System and Control Method for Braking Force of EMU Vehicles", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application belongs to the field of rail transit technology, and in particular relates to a braking control system and control method for high-speed trains. Background Technology

[0003] Currently, the braking systems of the power-centralized EMU trains in mass production are hard-wired electro-pneumatic braking systems. During operation, the brake cylinder pressure of this system is controlled by air brake valves based on the train pipe pressure. Because it cannot adjust braking force according to the load, there is a risk of wheel rubbing under low loads and insufficient braking force under high loads. Furthermore, the unstable output of the air brake valves results in poor synchronization of train braking and low accuracy of braking force output, and there is also a risk of no braking force output, causing significant inconvenience in field operations. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, this application provides a braking control system and control method for EMU vehicles.

[0005] This application provides a braking control system for a high-speed train, comprising: a braking control device, a working air cylinder, and an auxiliary air cylinder; the braking control device is configured to receive train pipe pressure signals and network commands, and output brake cylinder pressure; the braking control device includes: an air brake valve, the input end of which is connected to the train pipe, through which the train pipe supplies air to the working air cylinder, a first volume chamber, and the auxiliary air cylinder; and an electro-pneumatic braking module, including an electronic braking control unit, an electro-pneumatic valve, a switching valve, a shut-off valve, and a two-way valve. The electro-pneumatic valve is connected to the first input end of the switching valve, while the first output end of the air brake valve is connected to the second input end of the switching valve; the output end of the switching valve is connected to the first input end of the two-way valve; a pressure reducing valve connects the main air pipe to the shut-off valve, and the train pipe is connected to the pre-control end of the shut-off valve. The output end of the shut-off valve is connected to the second input end of the two-way valve. The output end of the two-way valve is connected to the pre-control end of a relay valve, and the output end of the relay valve is connected to the brake cylinder through the brake pipe; the switching valve switches between electro-pneumatic braking mode and air braking mode. When in electro-pneumatic braking mode, the electro-pneumatic valve is connected to the switching valve and transmits the pre-control pressure of the electro-pneumatic braking module to the relay valve; when in air braking mode, the switching valve switches to the air position and transmits the pre-control pressure of the air brake valve to the relay valve; the shut-off valve shuts off when the pressure in the train pipe is higher than the shut-off valve's operating value and connects to the atmosphere through the passage between the two-way valve.

[0006] In one embodiment, the electro-pneumatic valve includes an inflation solenoid valve, an exhaust solenoid valve, and a first sensor. The input of the inflation solenoid valve is connected to the auxiliary or main air cylinder for inflation, and its output is connected to the pre-controlled volume chamber and a switching valve. The input of the exhaust solenoid valve is connected to the connection between the inflation solenoid valve and the pre-controlled volume chamber, and its output is connected to the atmospheric passage. The first sensor is configured to detect the pre-controlled pressure in the pre-controlled volume chamber, the output of the inflation solenoid valve, and the input of the exhaust solenoid valve, and feed the detection signal back to the electronic brake control unit. The electronic brake control unit controls the pre-controlled ends of the inflation and exhaust solenoid valves to be open or closed according to the received electro-pneumatic braking command.

[0007] In one embodiment, the switching valve includes a third solenoid valve and a pneumatic control valve. The input of the third solenoid valve is connected to the auxiliary air cylinder or the main air cylinder, and the output is connected to the pre-control terminal of the pneumatic control valve. The input of the pneumatic control valve is connected to the end of the air brake valve that supplies air to the first volume chamber, and the output is connected to a two-way valve. The electronic brake control unit controls the pre-control terminal of the third solenoid valve according to the received electro-pneumatic brake command, turning it on in electro-pneumatic brake mode and turning it off in pneumatic brake mode.

[0008] Furthermore, the control system also includes an empty / loaded vehicle valve, whose input end is connected to the output end of a two-way valve, and whose output end is connected to the pre-control end of a relay valve. The control end of the empty / loaded vehicle valve is connected to the first average load pressure of the vehicle, which is output after the pressure of the four air springs passes through an averaging valve, to control the opening and closing ratio of the empty / loaded vehicle valve.

[0009] In one embodiment, four air springs are respectively mounted on two bogies; each air spring is connected to an air spring chamber. A height valve is installed for each air spring to monitor and adjust its height. Each air spring is connected to an air spring pressure sensor to collect its pressure signal in real time. An averaging valve acquires the average pressure of the air springs on each bogie and averages the average pressures of the two bogies again to generate the first average load pressure for the entire vehicle, which is then input to the control terminal of the empty / loaded vehicle valve.

[0010] In one embodiment, the air brake valve includes a main valve and an auxiliary valve, the main valve being connected to the reduction chamber and the first volume chamber, and the auxiliary valve being connected to the auxiliary chamber.

[0011] In one embodiment, during braking, the electro-pneumatic braking module adjusts the electronic empty / loaded vehicle based on the values ​​collected by four air spring pressure sensors. It calculates the required pre-control pressure based on the vehicle weight and the electro-pneumatic braking command, and controls the electro-pneumatic valve to output this required pre-control pressure, which then reaches the bidirectional valve via a switching valve. The vehicle weight is the second average load pressure calculated based on the values ​​collected by the four air spring pressure sensors.

[0012] The second aspect of this application provides a braking control method for high-speed trains, employing the control system described in any of the above embodiments. This control method includes the following steps: An electronic brake control unit reads a preset target pressure of the brake cylinder under full load conditions via network instructions, and calculates the deceleration according to a formula, where the cross-sectional area of ​​the brake cylinder and the total mass of the vehicle under full load are parameters. Pressure signals from four air spring pressure sensors are collected, and the second average load pressure of the vehicle is calculated. Based on the current second average load pressure and deceleration, the required braking force output is calculated and converted into a target pre-control pressure. Based on the calculated target pre-control pressure, the electro-pneumatic valve is controlled to inflate or deflate to achieve the target pre-control pressure. If the target pre-control pressure is less than the limiting pressure of the empty / loaded car valve, the target pre-control pressure is output; otherwise, the limiting pressure of the empty / loaded car valve is output. Based on the pre-control pressure output by the empty / loaded car valve, the relay valve is controlled to perform braking, pressure holding, or release operations.

[0013] The control system provided in at least one embodiment of this application incorporates two braking control modes: automatic air braking and direct electro-pneumatic braking. The electro-pneumatic braking mode serves as the primary braking mode, while the air braking mode provides hot-standby redundancy, thereby improving the reliability of braking action and ensuring the safe operation of the EMU train.

[0014] The control system and method provided in at least one embodiment of this application integrate components such as air brake valve, electro-pneumatic brake module, relay valve, empty / loaded vehicle pressure limiting valve, air spring pressure sensor, and emergency pressure reducing valve into a single integrated design. This achieves hot-standby redundancy for both direct-flow electro-pneumatic braking and automatic air braking, enabling adaptive adjustment of braking force output based on load conditions. This improves the synchronicity of vehicle braking release and solves the problem of inaccurate braking force output under different loads. In some embodiments, an emergency main air pressure boosting path (via a shut-off valve) is also added to ensure effective braking force output during emergency braking, guaranteeing the vehicle's safety baseline. Attached Figure Description

[0015] Figure 1 is a schematic diagram of the pneumatic circuit of a control system according to one embodiment;

[0016] Figure 2 is a schematic diagram of the control system according to one embodiment;

[0017] Figure 3 is a flowchart of a control method according to one embodiment.

[0018] In the diagram: 1. Braking control device; 11. Air brake valve, 111. Main valve, 112. Auxiliary valve; 12. Electro-pneumatic brake module, 121. Electronic brake control unit, 122. Filter, 123. Pre-control volume chamber, 124. Electro-pneumatic valve, 1241. Inflation solenoid valve, 1242. Exhaust solenoid valve, 1243. First sensor, 125. Switching valve, 1251. Third solenoid valve, 1252. Pneumatic control valve, 126. Two-way valve, 127. Shutdown valve; 13. Relay valve, 14. Empty / loaded vehicle valve, 15. Pressure reducing valve; 21. Working air cylinder, 22. Auxiliary air cylinder, 23. First volume chamber, 24. Main air cylinder, 25. Local reduction chamber, 26. Auxiliary chamber, 27. Brake cylinder; 3. Air spring, 301. Air spring volume chamber, 302. Height valve, 303. Second sensor; 401. First averaging valve, 402. Second averaging valve, 403. Third averaging valve; 404. Differential pressure valve. Detailed Implementation

[0019] The technical solutions of this application are described in detail below with reference to specific embodiments. However, it should be understood that, without further description, the elements, structures and features in one embodiment can also be beneficially incorporated into other embodiments.

[0020] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0021] In the description of this application, it should be understood that the terms "upper", "lower", "bottom", "inner", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] The relay valve in this application has a flow amplification function, providing an air source through the input end to ensure that the pressure of the gas output at the output end matches the pressure provided by the pre-control end. The two-way valve in this application has a pressure comparison and selection function, automatically comparing the pressures at the two input ends and selecting the higher pressure for output. Both the relay valve and the two-way valve are mechanical valves, which can effectively cope with power failure conditions, and their functions are well known to those skilled in the art.

[0024] To address the insufficient reliability of existing single braking modes, this application provides a train control system and method capable of adaptive braking force.

[0025] As shown in Figures 1-2, the first embodiment of this application provides a braking control system for a high-speed train (which may be referred to as a control system), comprising: a braking control device 1 configured to receive train pipe pressure signals and network commands (electro-pneumatic braking commands from the driver's cab) and output brake cylinder pressure; a working air cylinder 21 and an auxiliary air cylinder 22.

[0026] The braking control device 1 includes an air brake valve 11 and an electro-pneumatic braking module 12. The input end of the air brake valve 11 is connected to the train pipe, which supplies air to the working air cylinder 21, the first volume chamber 23, and the auxiliary air cylinder 22 via the air brake valve 11. The electro-pneumatic braking module 12 includes: an electronic brake control unit 121 for receiving electro-pneumatic braking commands from the system; an electro-pneumatic valve 124; a switching valve 125; a shut-off valve 127; and a two-way valve 126. The electro-pneumatic valve 124 is connected to the first input end of the switching valve 125, the first output end of the air brake valve 11 is connected to the second input end of the switching valve 125, and the output end of the switching valve 125 is connected to the first input end of the two-way valve 126. The main air duct is connected to the input end of the shut-off valve 127 via the pressure reducing valve 15 to provide the main air from the main air reservoir 24. The train pipe is connected to the pre-control end of the shut-off valve 127 to provide the control air source. The output end of the shut-off valve 127 is connected to the second input end of the two-way valve 126. The output end of the two-way valve 126 is connected to the pre-control end of the relay valve 13. The output end of the relay valve 13 is connected to the brake cylinder 27 via the brake pipe for braking.

[0027] With the above configuration, the switching valve 125 can switch between its first and second input terminals, outputting one of its inputs to the first input terminal of the two-way valve 126. The two-way valve 126 can select the input with the higher pressure from its first and second input terminals and output it to the pre-control terminal of the relay valve 13. Furthermore, the input terminal of the relay valve 13 is connected to the auxiliary air cylinder 22 or the main air cylinder 24 to amplify the flow rate and output it to the brake cylinder 27.

[0028] In one embodiment, the air brake valve 11 includes a main valve 111 and an auxiliary valve 112. The main valve 111 is connected to the reduction chamber 25 and the first volume chamber 23, and the auxiliary valve 112 is connected to the auxiliary chamber 26.

[0029] The air brake valve 11 can be an existing F8 series air distribution valve, which is a mechanical valve. On one hand, it enables dynamic balance between the train pipe, the working air cylinder 21, and the first volume chamber 23, where the train pipe can supply air to the working air cylinder 21; when the train pipe depressurizes, the pressure in the first volume chamber 23 increases. On the other hand, the train pipe can supply air to the auxiliary air cylinder 22 through the main valve 111, functioning similarly to a check valve; alternatively, a check valve can be directly installed between the train pipe and the auxiliary air cylinder 22 to supply air to the auxiliary air cylinder 22 in one direction. The main valve 111 is also connected to a partial pressure reduction chamber 25; when the air brake is released, the pressure in the partial pressure reduction chamber 25 is zero; after the air brake begins, the train pipe depressurizes, supplying air to the partial pressure reduction chamber 25, causing the train pipe to depressurize more quickly, until the two pressures are approximately equal; when the air brake ends, the pressure in the partial pressure reduction chamber 25 can be vented. Auxiliary valve 112 does not operate during air brake release (train pipe pressure approximately 600 kPa) and normal air brake operation (train pipe pressure drops to approximately 430 kPa). During emergency air brake operation (train pipe pressure drops to approximately 0 kPa), auxiliary valve 112 rapidly empties the train pipe pressure. During air brake release, the train pipe supplies air to the working air cylinder 21 and auxiliary chamber 26; during air brake operation, the pressure in both remains essentially unchanged; during emergency air brake operation, auxiliary chamber 26 is emptied, and the pressure in working air cylinder 21 remains essentially unchanged.

[0030] In one embodiment, the electro-pneumatic valve 124 includes: an inflation solenoid valve 1241, an exhaust solenoid valve 1242, and a first sensor 1243.

[0031] The input end of the inflation solenoid valve 1241 is connected to the auxiliary air cylinder 22 or the main air cylinder 24, and the output end is connected to the first input end of the pre-controlled volume chamber 123 and the switching valve 125; the input end of the exhaust solenoid valve 1242 is connected to the connection end of the inflation solenoid valve 1241 and the pre-controlled volume chamber 123, and its output end is connected to the atmospheric passage.

[0032] The first sensor 1243 is configured to detect the pre-control pressure at the output of the pre-control chamber 123, the output of the inflation solenoid valve 1241, and the input of the deflation solenoid valve 1242, and feed the detection signal back to the electronic brake control unit 121. The electronic brake control unit 121 controls the pre-control terminals of the inflation solenoid valve 1241 and the deflation solenoid valve 1242 to be electrically connected or disconnected according to the received electro-pneumatic braking command, thereby controlling the output or disconnection of the pre-control pressure; this is a well-known inflation / deflation method to those skilled in the art, and can be understood with reference to CN111634304A.

[0033] The electronic brake control unit 121 includes a processor and a memory, and is capable of controlling the entire brake control system. The processor is, for example, a CPU, PLC, industrial computer, or other hardware. It is programmed and stores programs that can perform corresponding functions in the memory. The processor executes these programs to achieve various functions; this is well known to those skilled in the art.

[0034] The switching valve 125 is configured as follows:

[0035] In electro-pneumatic braking mode, the circuit is switched to the electro-pneumatic position, connecting the passage of electro-pneumatic valve 124 and switching valve 125, and transmitting the pre-control pressure of electro-pneumatic braking module 12 to relay valve 13; that is, the first input end of switching valve 125 is connected, transmitting the pre-control pressure from electro-pneumatic valve 124 to the first input end of bidirectional valve 126, and reaching the pre-control end of relay valve 13.

[0036] In air brake mode, switch to air position to connect the passage of air brake valve 11 and switching valve 125, and transmit the pre-control pressure of air brake valve 11 to relay valve 13; that is, the second input end of switching valve 125 is connected, and the pre-control pressure from air brake valve 11 is transmitted to the first input end of bidirectional valve 126, and can reach the pre-control end of relay valve 13.

[0037] The main difference between electro-pneumatic braking mode and air braking mode is that the former mainly relies on the electrical control of various components to achieve the output of pre-controlled pressure; while the latter is related to the train pipe pressure and mainly relies on mechanical action to output pre-controlled pressure.

[0038] In one embodiment, the switching valve 125 includes a third solenoid valve 1251 and a pneumatic control valve 1252. The input end of the third solenoid valve 1251 is connected to the end of the air brake valve 11 that supplies air to the auxiliary air cylinder 22, and its output end is connected to the pre-control end of the pneumatic control valve 1252. The second input end of the pneumatic control valve 1252 is connected to the end of the air brake valve 11 that supplies air to the first volume chamber 23, and its output end is connected to the two-way valve 126.

[0039] The first input terminal of the pneumatic control valve 1252 corresponds to the first input terminal of the switching valve 125 and is connected to the pre-controlled pressure from the electro-pneumatic valve 124; its second input terminal corresponds to the second input terminal of the switching valve 125; and its output terminal corresponds to the output terminal of the switching valve 125. Furthermore, the input terminal of the third solenoid valve 1251 can also be directly connected to the auxiliary air cylinder 22 or the main air cylinder 24 to obtain an air source for controlling the switching of the pneumatic control valve 1252.

[0040] The electronic brake control unit 121 controls the pre-control terminal of the third solenoid valve 1251 according to the received electro-pneumatic brake command. In electro-pneumatic brake mode, the third solenoid valve 1251 is electrically activated; in air brake mode, the third solenoid valve 1251 is deactivated. In the above scheme, when in electro-pneumatic brake mode, the third solenoid valve 1251 is energized, controlling the pneumatic control valve 1252 to open the electro-pneumatic valve 124 to control the first pre-control pressure output; when in air brake mode, the third solenoid valve 1251 is de-energized, controlling the pneumatic control valve 1252 to open the air brake valve 11 to control the second pre-control pressure output.

[0041] The shut-off valve 127 is configured to shut off when the pressure in the train pipe is higher than the operating value of the shut-off valve 127; the passage between the shut-off valve 127 and the two-way valve 126 is open to the atmosphere; that is, at this time, there is no input at the second end of the two-way valve.

[0042] In one embodiment, the control system further includes an empty / loaded vehicle valve 14, the input of which is connected to the output of a two-way valve 126 and the output of which is connected to the pre-control terminal of a relay valve 13, in order to replace the direct connection of the output of the two-way valve 126 to the pre-control terminal of the relay valve 13 mentioned above.

[0043] The empty / loaded vehicle valve 14 can be a pressure-limiting mechanical valve in the prior art, which has an input end, an output end and a control end. When the pressure at the input end is less than or equal to the pressure at the control end, the pressure at the input end is output; when the pressure at the input end is greater than the pressure at the control end, the pressure that is limited is output.

[0044] The control terminal of the empty / loaded vehicle valve 14 is connected to the average vehicle load pressure (first average load pressure) output after the pressure of the four air springs passes through the averaging valve, so as to control the opening and closing ratio of the empty / loaded vehicle valve 14 and achieve the purpose of limiting the pressure at the output terminal.

[0045] Specifically, four air springs 3 are installed on two bogies of the vehicle; that is, two air springs are installed on each bogie. Each air spring 3 is connected to an air spring chamber 301. Each air spring 3 is equipped with a height valve 302 for monitoring and adjusting the height of the air spring.

[0046] Furthermore, each air spring 3 is connected to an air spring pressure sensor (second sensor 303) to collect the air spring pressure signal in real time and transmit the collected value to the electronic brake control unit 121.

[0047] The first averaging valve 401 is configured to acquire the average pressure of the two air springs 3 on the first bogie; the second averaging valve 402 is configured to acquire the average pressure of the two air springs 3 on the second bogie; and the third averaging valve 403 is configured to further average the output average pressure signals of the first averaging valve 401 and the second averaging valve 402 to generate the overall average pressure signal of the entire vehicle (i.e., the first average load pressure), which is then input to the control terminal of the empty / loaded vehicle valve 14. Therefore, as shown in Figure 1, the two air springs on the first bogie are respectively connected to the first and second input terminals of the first averaging valve 401, and the two air springs on the second bogie are respectively connected to the first and second input terminals of the second averaging valve 402; the output terminals of the first averaging valve 401 and the second averaging valve 402 are respectively connected to the first and second input terminals of the third averaging valve 403, and the output terminal of the third averaging valve 403 is connected to the control terminal of the empty / loaded vehicle valve 14. When the averaging valve has multiple input terminals, a single averaging valve can also be used to average the pressure of the four air springs.

[0048] In one embodiment, during electro-pneumatic braking, the electro-pneumatic braking module 12 adjusts the electronic empty / loaded vehicle based on the values ​​collected by the second sensor 303. It calculates the required pre-control pressure based on the vehicle weight and the electro-pneumatic braking command, and controls the electro-pneumatic valve 124 to output this required pre-control pressure, which then reaches the bidirectional valve 126 via the switching valve 125. The vehicle weight is a second average load pressure calculated based on the values ​​collected by the four second sensors 303. The values ​​of the first and second average load pressures are approximately equal, but they are processed differently; the former comes from the averaging valve, and the latter from the sensors.

[0049] The control system also includes differential pressure valves 404, which are installed between two air springs on each bogie to ensure that the vehicle is not unevenly loaded. In another embodiment, the electronic brake control unit 121 uses pressure signals collected by the second sensor 303 on each bogie to determine whether the vehicle is unevenly loaded and to provide early warning of uneven loading.

[0050] As shown in Figure 3, the second embodiment of this application provides a braking control method for high-speed trains (hereinafter referred to as the control method), which can apply the control system of any of the above embodiments; the control method includes the following steps:

[0051] The electronic brake control unit 121 reads the preset target pressure P0 of the brake cylinder 27 under full load conditions via network commands; that is, the electronic brake control unit 121 receives network commands (electro-pneumatic brake commands) from the driver's cab and reads the preset target pressure P0 of the brake cylinder under full load conditions.

[0052] The deceleration A is calculated using the formula A = P0 * S / m, where S is the cross-sectional area of ​​the brake cylinder and m is the total mass of the vehicle under full load.

[0053] The pressure signals of the four air springs are collected, and the second average load pressure P1 of the vehicle is calculated.

[0054] Based on the vehicle's current second average load pressure P1 and the calculated deceleration A, the required braking force output F is calculated using the formula F = k * P1 * A, where k is the vehicle's air mass coefficient and A is the actual vehicle weight / the weight of the loaded vehicle.

[0055] The calculated braking force F is converted into the target pressure Pt (i.e., the pressure that is desired to reach the brake cylinder), and the calculation formula is Pt = F / S;

[0056] Based on the calculated target pressure Pt, the electro-pneumatic valve 124 is controlled to charge or depressurize to achieve the target pre-control pressure; that is, in electro-pneumatic braking mode, the pre-control pressure output by the electro-pneumatic valve is controlled to be Pt.

[0057] If the current target pressure Pt is less than the limiting pressure Px of the empty / loaded vehicle valve 14, then the output pressure Pt is sent to the pre-control end of the relay valve; otherwise, the limiting pressure Px of the empty / loaded vehicle valve is output.

[0058] Based on the pre-controlled pressure output by the empty and loaded vehicle valve, the relay valve 13 is controlled to perform braking, pressure holding, or release operations.

[0059] The control terminal of the empty / loaded vehicle valve 14 is the same as the first average load pressure, thus enabling adjustment of its pressure limit range. It primarily limits pressure during emergency braking using air braking and the shut-off valve 127; during electro-pneumatic braking, the charging / exhausting solenoid valve can directly output a suitable pre-control pressure. That is, during electro-pneumatic braking, Pt is less than or equal to Px; during air braking or emergency braking, it may be greater than or equal to Px, but more often it is greater than Px.

[0060] Introduction to the composition and principle of the control system

[0061] (1) System composition:

[0062] As shown in Figure 1, the adaptive braking control system for power-centralized EMUs includes a brake control device 1, a working air cylinder 21, an auxiliary air cylinder 22, and bogie air spring suspension equipment. Among these, the brake control device 1 is the most important component of the control system, used to realize functions such as network communication, brake cylinder pressure control, braking mode switching, empty / loaded car adjustment, and vehicle off-center load warning. The brake control device 1 mainly consists of an air brake valve 11 and its matching air cylinders (auxiliary chamber 26, local reduction chamber 25, and first volume chamber 23), an electro-pneumatic brake module 12, a relay valve 13, an empty / loaded car valve 14, and a pressure reducing valve 15.

[0063] 1) The air brake valve 11 includes a main valve 111 and an auxiliary valve 112, which can respond to changes in train pipe pressure and output corresponding pre-control pressure;

[0064] 2) The electro-pneumatic braking module 12 integrates key components such as switching valve, solenoid valve, pressure sensor, power supply and electronic control unit, and is an important component for realizing adaptive control of braking force.

[0065] a. The electro-pneumatic valve 124 (inflation solenoid valve 1241, exhaust solenoid valve 1242, sensor 1243) controls the pressure of the pre-controlled volume chamber 123.

[0066] b. Switching valve 125 (third solenoid valve 1251, pneumatic control valve 1252) enables redundant switching between electro-pneumatic braking and air brake valve control of the brake cylinder pressure. When the electro-pneumatic braking is engaged, the third solenoid valve 1251 is energized, and the pneumatic control valve 1252 is in the energized-off position. The pressure in the pre-control chamber 123 is controlled by the electro-pneumatic valve 124 and output to the relay valve 13 via the bidirectional valve 126, thus controlling the brake cylinder pressure. When the electro-pneumatic braking module malfunctions or loses power, the third solenoid valve 1251 is de-energized, the pneumatic control valve 1252 is in the air position, and the output of the air brake valve 11 is connected to the pre-control pressure of the relay valve 13, thereby controlling the brake cylinder pressure.

[0067] c. The shut-off valve 127 is controlled by the train pipe pressure to realize the emergency bypass function of the air brake.

[0068] d. The two-way valve 126 can compare the output pressures of the shut-off valve 127 and the switching valve 125, and output a larger side pressure.

[0069] e. The braking system is also equipped with multiple pressure sensors to collect pressure data from each air cylinder and control system.

[0070] f. The arrangement of multiple pressure measurement points enables testing and troubleshooting.

[0071] g. It can simulate vehicle weight pressure measurement points to realize air spring road pressure testing and empty / loaded vehicle debugging.

[0072] 3) The relay valve 13 is used to amplify the pre-controlled pressure flow. It can fill the brake cylinder 27 with compressed air from the auxiliary air cylinder (braking condition) or discharge the compressed air from the brake cylinder to the atmosphere (relaxation condition) according to the change of the pre-controlled pressure, or keep the brake cylinder at a certain pressure (pressure holding condition), so that the brake cylinder pressure is consistent with the requirements of the braking command.

[0073] 4) Empty / loaded vehicle valve 14 is used for empty / loaded vehicle adjustment and can proportionally limit the maximum pre-controlled pressure of the brake cylinder according to the air spring pressure. Under different air spring pressures, when the input pressure is lower than its maximum limit pressure, the empty / loaded vehicle valve directly outputs the input pressure; when the input pressure exceeds its maximum limit pressure, the empty / loaded vehicle valve outputs the maximum limit pressure corresponding to the air spring pressure.

[0074] 5) Pressure reducing valve 15 is used to set the emergency braking pressure.

[0075] 6) The bogie air spring suspension equipment mainly includes a height valve 302, an air spring 3, an air spring volume chamber 301, a sensor 303, and an averaging valve.

[0076] (2) Working principle:

[0077] The schematic diagram of the control system is shown in Figure 2. The control system is a highly integrated mechatronic system that transmits commands via network / air pressure signals and coordinates the operation of the electro-pneumatic system. This system has two control systems: a microcomputer-controlled electro-pneumatic brake and an automatic air brake, with the automatic air brake serving as a hot-standby redundancy. The charging and venting control of brake cylinder 27 is achieved through the train network that runs throughout the entire train and the train control pipes responding to train control commands. Under normal circumstances, braking and release control are performed using the microcomputer-controlled electro-pneumatic brake. In the event of a failure of the microcomputer-controlled electro-pneumatic brake or when the train is being hauled by the locomotive, the automatic air brake takes effect.

[0078] When the train requires no braking, the train pipes are pressurized to a constant pressure (typically 600 kPa). The braking control device 1 pressurizes the working air cylinder 21 and auxiliary air cylinder 22 via the air brake valve 11. At this time, the air brake valve 11 is released, and the first volume chamber 23 has no automatic air brake pre-control pressure. The electro-pneumatic braking module 12 controls the electro-pneumatic valve 124 according to train network commands, and the pre-control volume chamber 123 has no direct-acting braking pre-control pressure. The constant pressure in the train pipes is higher than the operating value of the shut-off valve 127, and the emergency pressure generated by the total airflow through the pressure reducing valve 15 is also cut off by the shut-off valve 127. The train has no braking force and is in a released state.

[0079] In the service brake electro-pneumatic activation mode, the electro-pneumatic braking module 12 controls the electro-pneumatic valve 124 to generate a pre-control pressure according to network commands. At this time, the switching valve 125 is switched to the neutral position, and the pre-control pressure reaches the relay valve 13 through the two-way valve 126. The flow amplification effect of the relay valve 13 generates the brake cylinder pressure. At the same time, the output pressure of the air brake valve 11 is cut off by the switching valve 125, and it is in a hot standby redundancy state. In addition, if the train pipe pressure is higher than the action value of the shut-off valve 127, the shut-off valve is in the shut-off state. The emergency pressure generated by the main air through the pressure reducing valve 15 is also cut off by the shut-off valve 127. The passage between the shut-off valve 127 and the two-way valve 126 is open to the atmosphere. The two-way valve 126 is always in the neutral position, and the service brake can be applied and released normally.

[0080] In the service brake air-in mode, the switching valve 125 is in the air position, the pre-control pressure generated by the electro-pneumatic valve 124 is cut off, and the pre-control pressure output by the air brake valve 11 reaches the relay valve 13 via the switching valve 125 and the two-way valve 126. The flow amplification effect of the relay valve 13 generates brake cylinder pressure. The train pipe pressure is higher than the operating value of the shut-off valve 127, so the shut-off valve is in the shut-off state. The emergency pressure generated by the main air supply through the pressure reducing valve 15 is also cut off by the shut-off valve 127. The passage between the shut-off valve 127 and the two-way valve 126 is open to the atmosphere, and the service brake can be applied and released normally.

[0081] During emergency braking, the pre-controlled emergency pressure generated by the electro-pneumatic valve 124 according to the emergency braking command, or the pre-controlled pressure generated by the air brake valve 11 according to the train pipe, reaches the two-way valve 126 via the switching valve 125. At the same time, when the train pipe pressure reaches a certain value, the shut-off valve 127 is in the open state, and the emergency pressure generated by the main air through the pressure reducing valve 15 reaches the two-way valve 126 via the shut-off valve 127. At this time, the two pre-controlled pressures are compared through the two-way valve 126 and reach the relay valve 13. The flow amplification effect of the relay valve 13 generates the brake cylinder pressure.

[0082] The control system features empty / loaded vehicle adjustment and vehicle off-center load warning functions. During normal braking, the electro-pneumatic braking module 12 performs electronic empty / loaded vehicle adjustment based on values ​​collected by the four second sensors 303. It calculates and outputs a pre-control pressure based on vehicle weight and braking commands. This pre-control pressure passes through switching valve 125, two-way valve 126, and empty / loaded vehicle valve 14 to relay valve 13. The flow amplification effect of relay valve 13 generates a brake cylinder pressure corresponding to the vehicle weight. Since empty / loaded vehicle valve 14 only limits the maximum pressure, it is inactive during this period. During emergency braking, the electro-pneumatic braking module 12 adjusts the electronic empty / loaded car pressure based on the values ​​collected by the four air spring pressure sensors. It calculates and outputs a pre-control pressure, or the pre-control pressure for the air brake, based on the vehicle weight and emergency braking command. This pre-control pressure travels through the switching valve 125 to the two-way valve 126. Simultaneously, when the train pipe pressure falls below a certain value, the shut-off valve 127 connects the main air supply and the two-way valve 126. The emergency pressure generated by the main air supply via the pressure reducing valve 15 travels through the shut-off valve 127 to the two-way valve 126. At this point, the two pre-control pressures are compared through the two-way valve 126 and then reach the empty / loaded car valve 14. The four air spring pressures are averaged by the averaging valve and used as the control pressure for the empty / loaded car valve 14. The empty / loaded car valve 14 adjusts the emergency pre-control pressure according to the vehicle's air spring load, and finally converts it into brake cylinder pressure through the relay valve. The system can collect the pressure of the four air springs 303 on both bogies. When the difference between the four air spring pressures exceeds a threshold, the braking control device will alert the driver with a vehicle off-center load alarm.

[0083] At least some embodiments of this application have one or more of the following innovations or advantages:

[0084] Innovation Point 1: It integrates two braking control modes: automatic air braking and direct electro-pneumatic braking. Electro-pneumatic braking is the main braking mode, while automatic braking is a hot-standby redundancy, which improves the reliability of braking and ensures the safe operation of EMU trains.

[0085] Innovation Point 2: Electronic empty / load adjustment of the vehicle is achieved through the common braking system. It can dynamically output braking force according to the braking command and the vehicle's own load within the entire braking range, which improves the accuracy of braking force, greatly reduces the wear of the brake disc, and reduces maintenance costs.

[0086] Innovation Point 3: In the automatic air brake mode, a mechanical empty and loaded car pressure limiting valve is introduced to limit the maximum braking force output according to the train pipe pressure and the vehicle's own load, which improves the accuracy of the air brake circuit braking force output, reduces the wear of the brake disc, and reduces operation and maintenance costs.

[0087] Innovation Point 4: A new emergency booster path is added, which outputs emergency braking force through the main air control, ensuring the effective application of emergency braking, strengthening the safety baseline of the braking system, and improving the reliability and safety of the vehicle braking system.

[0088] Innovation Point 5: The addition of air spring pressure sensors on two bogies enables real-time comparison of pressure under different loads and provides an off-center load alarm when the load deviation is large. This avoids wheel rubbing caused by off-center load, reduces the risk of brake disc wear, reduces maintenance costs, and improves driving safety.

[0089] The vehicle braking force adaptive control system and control method described in this application, based on the existing air brake valve of the EMU vehicle braking system, adds an electro-pneumatic braking module, relay valve, empty and loaded car pressure limiting valve, air spring pressure sensor, and emergency pressure reducing valve, etc., and redesigns them in an integrated manner. It realizes hot redundancy of direct-flow electro-pneumatic braking and automatic air braking, and can adaptively adjust the braking force output according to the load conditions, improve the synchronicity of vehicle braking release, and solve the problem of inaccurate braking force output under different loads. In addition, a new main air emergency pressurization channel is added to enable effective output of braking force during emergency braking and ensure the vehicle's safety baseline.

[0090] The successful application of this technology has several advantages. Firstly, in terms of stability, the microelectro-pneumatic braking system improves the synchronization of braking and deceleration, enhancing the smoothness of train operation and passenger comfort. Secondly, in terms of safety, it integrates two braking control modes: automatic air braking and direct-acting electro-pneumatic braking. Electro-pneumatic braking serves as the primary braking mode, while automatic braking provides hot-standby redundancy. Furthermore, a new emergency pressurization path for the main air input has been added, further improving train operation safety. Thirdly, in terms of operability, the addition of direct-acting electro-pneumatic braking improves braking response speed and control precision, enabling phased deceleration and facilitating train operation by the crew. Fourthly, in terms of economy, the vehicle can adaptively adjust braking force output according to its own load, reducing brake disc wear and lowering maintenance costs to some extent. The addition of an off-center load warning function further enhances the system's intelligence level.

[0091] The described embodiments are merely preferred embodiments of this application and are not intended to limit the scope of this application. Any modifications and improvements made by those skilled in the art to the technical solutions of this application without departing from the spirit of this application should fall within the protection scope defined by the claims of this application.

Claims

1. A braking control system for a multiple-unit vehicle, wherein, Includes a brake control device configured to receive train pipe pressure signals and network commands, and output brake cylinder pressure; working air cylinder and auxiliary air cylinder; Braking control device, including: An air brake valve, the input end of which is connected to the train pipe, and the train pipe supplies air to the working air cylinder, the first volume chamber and the auxiliary air cylinder through the air brake valve; Electro-pneumatic braking module, including: Electronic brake control unit, used to receive electro-pneumatic braking commands; and, Electro-pneumatic valve, switching valve, shut-off valve and two-way valve; wherein, the electro-pneumatic valve is connected to the first input terminal of the switching valve, the first output terminal of the air brake valve is connected to the second input terminal of the switching valve, and the output terminal of the switching valve is connected to the first input terminal of the two-way valve. The pressure reducing valve connects the main air duct to the input end of the shut-off valve, and the train pipe connects to the pre-control end of the shut-off valve; the output end of the shut-off valve connects to the second input end of the two-way valve. The output end of the relay valve is connected to the pre-control end of the two-way valve, and the output end of the relay valve is connected to the brake cylinder through the brake pipe. The switching valve is configured as follows: During electro-pneumatic braking, switch to the electro-pneumatic position, connect the electro-pneumatic valve and the switching valve, and transmit the pre-control pressure of the electro-pneumatic braking module to the relay valve; When the air brake is engaged, switch to the air position to connect the air brake valve and the switching valve, and transmit the pre-control pressure of the air brake valve to the relay valve. The shut-off valve is configured to shut off when the train pipe pressure is higher than the shut-off valve's operating value; the passage between the shut-off valve and the two-way valve is open to the atmosphere.

2. The control system of claim 1, wherein, The electro-pneumatic valve includes an inflation solenoid valve, an exhaust solenoid valve, and a first sensor. The input end of the inflation solenoid valve is connected to the end of the air brake valve that supplies air to the auxiliary air cylinder, and its output end is connected to the pre-controlled volume chamber and the switching valve. The input end of the exhaust solenoid valve is connected to the connection end between the inflation solenoid valve and the pre-controlled volume chamber, and its output end is connected to the atmospheric passage. The first sensor is configured to detect the pre-controlled pressure of the pre-controlled volume chamber, the output end of the inflation solenoid valve, and the input end of the exhaust solenoid valve, and feed the detection signal back to the electronic brake control unit. The electronic brake control unit controls the pre-controlled ends of the inflation and exhaust solenoid valves to be electrically turned on or off according to the received electro-pneumatic brake command.

3. The control system of claim 2, wherein, The switching valve includes a third solenoid valve and a pneumatic control valve; the input end of the third solenoid valve is connected to the end of the air brake valve that supplies air to the auxiliary air cylinder, and its output end is connected to the pre-control end of the pneumatic control valve; the input end of the pneumatic control valve is connected to the end of the air brake valve that supplies air to the first volume chamber, and its output end is connected to the two-way valve; the electronic brake control unit controls the pre-control end of the third solenoid valve according to the received electro-pneumatic brake command, and the third solenoid valve is turned on in electro-pneumatic brake mode and turned off in air brake mode.

4. The control system of any one of claims 1-3, wherein, It also includes an empty / loaded vehicle valve, whose input end is connected to the output end of a two-way valve, and whose output end is connected to the pre-control end of a relay valve; the control end is connected to the first average load pressure output by the four air spring pressures after passing through the averaging valve, so as to control the opening and closing ratio of the empty / loaded vehicle valve.

5. The control system of claim 4, wherein, Four air springs are installed on two bogies respectively, and each air spring is connected to an air spring pressure sensor to collect the air spring pressure signal in real time. The first averaging valve obtains the average value of the air spring pressure on the first bogie; the second averaging valve obtains the average value of the air spring pressure on the second bogie; the third averaging valve averages the output average pressure signals of the first and second averaging valves again to generate the first average load pressure, which is then input to the control terminal of the empty / loaded car valve.

6. The control system of claim 5, wherein, The air brake valve includes a main valve and an auxiliary valve. The main valve connects the reduction chamber and the first volume chamber, and the auxiliary valve connects to the auxiliary chamber.

7. The control system of claim 6, wherein, During braking, the electro-pneumatic braking module adjusts the electronic empty and loaded vehicle based on the values ​​collected by the four air spring pressure sensors. It calculates the required pre-control pressure based on the vehicle weight and electro-pneumatic braking command, and controls the electro-pneumatic valve to output the required pre-control pressure, which then reaches the two-way valve through the switching valve.

8. A method of brake control of a vehicle of a trainset, adopting the control system according to any one of claims 5 to 7, wherein Includes the following steps: The electronic brake control unit reads the preset target pressure P0 of the brake cylinder under full load conditions via network commands; The deceleration is calculated using the formula A = P0 * S / m, where S is the cross-sectional area of ​​the brake cylinder and m is the total mass of the vehicle under full load. The pressure signals from the four air spring pressure sensors are collected, and the second average load pressure P1 of the vehicle is calculated. Based on the vehicle's current second average load pressure P1 and the calculated deceleration A, the required braking force output F is calculated using the formula F = k * P1 * A, where k is the vehicle's air mass coefficient. The calculated braking force F is converted into the target pre-control pressure Pt, and the calculation formula is Pt=F / S; Based on the calculated target pre-control pressure Pt, the electro-pneumatic valve is controlled to pressurize or depressurize in order to achieve the target pre-control pressure. If the current target pre-control pressure Pt is less than the limit pressure Px of the empty / loaded vehicle valve, then output pressure Pt; otherwise, output the limit pressure Px of the empty / loaded vehicle valve. Based on the pre-controlled pressure output by the empty / loaded vehicle valve, the relay valve is controlled to perform braking, pressure holding, or release operations.

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