A braking system and method for automatic switching between train pipe control and microcomputer control

Abstract

The present invention provides a braking system with automatic switching between train pipe control and microcomputer control and its control method, including: an integrated controller, a BP braking subsystem, a microcomputer braking subsystem, and an electromagnetic valve; the integrated controller includes a controller and an engineer's brake valve, and the engineer's brake valve and the controller form an integral motion structure by a connecting pin; the integrated controller can send an electrical signal command to the TCMS, and at the same time can also control the pressure of the BP pipe to generate an air signal command; the electromagnetic valve is used for switching between the microcomputer braking subsystem and the BP braking subsystem, and through electrical connection, interlocks the electric braking and the BP braking actions. In the present invention, the same controller is used for sharing the microcomputer control and the BP control air braking. At the same time, in the case of a failure of the microcomputer braking control unit on a single vehicle, the BP braking can be automatically used for braking, and it can be interlocked with the electric braking to prevent over-braking caused by the superposition of the BP braking and the electric braking, realizing the automatic switching between train pipe control and microcomputer control.

Description

Technical Field

[0001] The present invention relates to the technical field of train braking, and particularly to a braking system and method for automatically switching between train pipe control and microcomputer control. Background Art

[0002] Subway vehicles generally have two braking modes: electric braking and air braking, with electric braking as the main mode and air braking as the auxiliary mode. At present, many subway vehicles adopt a direct-acting braking mode controlled by a microcomputer for air braking. The brake control unit (BCU) is controlled by the electronic brake control unit (EBCU) to charge air (brake) / vent air (release) into the brake cylinder of the basic brake unit. Specifically, in the braking control scheme controlled by a microcomputer, as Figure 1 shown, the EBCU and the traction control unit (TCU) receive the electrical signal control instructions from the driver controller through the train control and management system (TCMS). The EBCU calculates the total braking force according to the vehicle load and the braking instruction, and sends an electric braking demand to the TCU. The TCU applies electric braking according to the electric braking demand and sends the actually exerted electric braking force to the EBCU. The EBCU controls the BCU to perform air braking according to the total braking force demand and the already exerted electric braking force. This scheme has the following disadvantages: when a single EBCU or BCU fails, the air braking and electric braking of this car will not be able to function; when the control power supply of the train EBCU fails, the entire train will lose the service braking force, and after applying the emergency brake, it will not be able to be released until the train stops, and the normal operation of the train cannot be controlled; when the train is being rescued, the faulty train cannot control the application / release of air braking by the rescue train through its own system, which has a certain safety risk.

[0003] In some other existing technologies, in addition to requiring an air braking mode controlled by a microcomputer, an air braking function controlled by the train pipe (BP) is also required to ensure that in the case of a microcomputer failure, the vehicle air braking is controlled by the variable BP pipe pressure. However, only manual switching can be achieved between the braking mode controlled by the change of BP pressure and the braking mode controlled by the microcomputer, and only the entire train can be controlled for switching, and automatic switching cannot be realized, nor can the faulty car be switched individually. Specifically, in addition to the original control system, a BP braking system controlled by the driver's brake is added separately, as Figure 2As shown in the figure, the driver's brake controls the pressure of the BP through a pressure conversion device, and changes the pre-control pressure to the BCU through the STV valve, thereby controlling the pressure output by the BCU to the brake cylinder. This solution can solve the problem that the train cannot be controlled when the BCU of the entire train fails. The BP brake is used as an alternative braking method when major failures occur in the train braking system. This control solution has the following disadvantages: There are two controllers on the console, one is the driver controller and the other is the driver's brake. These two controllers can only function independently and are not allowed to be used in combination; when the EBCU of a single vehicle fails, this vehicle cannot perform independent BP brake control, and can only be controlled by the driver controller in the fault state, or switched to BP brake control; if the driver controller is used for control, then the fault of one vehicle's brake failure has to be accepted; if the driver's brake is switched to BP brake control, then the state where all electric brakes are not put into use has to be accepted, and the brake shoe wear will increase; the BP brake and the braking method controlled by the microcomputer cannot be interlocked, and the electric brake cannot be used more effectively under safe conditions. Summary of the Invention

[0004] In view of this, the present invention provides a braking system and method for automatic switching between train pipe control and microcomputer control, which uses the same driver controller for sharing microcomputer control and BP control of air brakes. At the same time, in the case of an EBCU failure in a single vehicle, the BP brake can be automatically used for braking, and can be interlocked with the electric brake to prevent over-braking caused by the superposition of the BP brake and the electric brake.

[0005] For this reason, the present invention adopts the following technical solutions:

[0006] On the one hand, the present invention provides a braking system for automatic switching between train pipe control and microcomputer control, including: an integrated driver controller, a BP pipe, a pressure conversion device, an STV valve, an EBCU, a BCU, a brake cylinder, and a solenoid valve arranged between the STV valve and the BCU; wherein:

[0007] The sequentially connected BP pipe, pressure conversion device, STV valve, BCU, and brake cylinder constitute a BP brake subsystem;

[0008] The EBCU, BCU, and brake cylinder constitute a microcomputer brake subsystem. There are data communication connections between the EBCU and the TCMS, and between the EBCU and the TCU respectively; there is also a data communication connection between the EBCU and the BCU, and the BCU is connected to the brake cylinder;

[0009] The integrated driver controller includes a driver controller and a driver's brake valve. The driver's brake valve and the driver controller are composed of an integral motion structure by a connecting pin; the integrated driver controller can send an electrical signal command to the TCMS, and at the same time can also control the pressure of the BP pipe to generate an air signal command;

[0010] The solenoid valve is used for switching between the microcomputer brake subsystem and the BP brake subsystem, and through electrical connection, it interlocks the electric brake and the BP brake functions.

[0011] Furthermore, a coupling is used to connect the traction camshaft of the controller and the brake valve interface. When the driver controller handle is operated to the running position or the braking position, the rotation of the traction camshaft will drive the coupling to rotate, thereby driving the rotation of the brake valve cam rod of the driver.

[0012] Furthermore, the integrated controller controls the rotation of the mechanical structure of the driver brake valve, drives the internal cam for pressure regulation, changes the BP pressure through the pressure conversion device, and adjusts the pre-control pressure entering the BCU through the STV valve.

[0013] Furthermore, the integrated controller sends a braking instruction to the TCMS. The TCMS sends the braking instruction to the EBCU and the TCU. The EBCU calculates the total braking force according to the vehicle load and the braking instruction, sends an electric brake demand to the TCU. The TCU applies the electric brake according to the electric brake demand and sends the actually exerted electric braking force to the EBCU. The EBCU controls the BCU to perform air braking according to the total braking force demand and the already exerted electric braking force.

[0014] Furthermore, the solenoid valve has two power supplies. Under normal circumstances, it is powered by the EBCU. When the EBCU loses power, it will automatically switch to the state of being powered by the electric brake activation signal of the TCU.

[0015] On the other hand, the present invention also provides a control method for automatic switching between train pipe control and microcomputer control, which is characterized in that it is applied to the braking system for automatic switching between train pipe control and microcomputer control as described above. The method includes:

[0016] In the microcomputer control mode, the solenoid valve is in the powered-on state, cuts off the pipeline between the STV valve and the BCU, and evacuates the pre-control pressure on the left side of the check valve in the BCU to prevent affecting the pre-control pressure generated by the electro-pneumatic converter.

[0017] When the electro-pneumatic converter in the BCU fails to control the pressure of the brake cylinder, the EBCU cuts off the power supply of the solenoid valve. At this time, this car is in the BP braking mode, and the EBCU will limit the exertion of the electric brake to prevent over-braking caused by the combined action of the electric brake and the BP brake.

[0018] Furthermore, when the EBCU loses power, the solenoid valve automatically switches to be powered by the electric brake activation signal. At this time, if the electric brake is not exerted, this car will apply and release air braking according to the BP pressure controlled by the integrated controller; if the electric brake is being applied, the electric brake activation will supply power to the solenoid valve to prevent the application of the BP brake.

[0019] Furthermore, when the train is being rescued, after the braking system receives the backup mode hardwired signal, the EBCU of each car cuts off the power supply to the solenoid valve. At the same time, the electric braking is cut off by sending a hardwired signal for electric braking cut-off to the TCU, and it fully enters the BP braking mode. Under the condition that the rescued train is completely powered off, by cutting off the isolating cocks of each car, the driver controller of the rescue train controls the train pipe pressure of the rescued train to control the braking force. In this mode, all the brakes of the rescued train are completely borne by the air braking force, and the air braking control adopts the BP braking control mode.

[0020] Advantages and positive effects of the present invention:

[0021] (1) The integrated driver controller reduces the number of driver controllers and realizes the simultaneous output of electric signals and air control signals by one controller.

[0022] (2) When the electro-pneumatic converter A of the BCU of a single vehicle fails, the EBCU will automatically control this car to enter the BP braking mode, and the train will not lose braking force.

[0023] (3) When a single EBCU fails or loses power, this car can automatically enter the BP braking mode, and the train will not lose braking force.

[0024] (4) The BP braking can be interlocked with the electric braking of the traction system and will not cause over-braking.

[0025] (5) When the train enters the backup mode, the air braking system can control the magnitude of the air braking force according to the instructions of the integrated driver controller, and the train can run freely. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a structural block diagram of a microcomputer-controlled braking system in the prior art;

[0028] Figure 2 It is a structural block diagram of a braking system of a separate driver brake in the prior art;

[0029] Figure 3 It is a structural block diagram of a braking system with an integrated driver controller in the embodiment of the present invention;

[0030] Figure 4Schematic diagram of the connection structure between the driver controller and the driver's brake valve in the embodiment of the present invention;

[0031] Figure 5 Structural diagram of the driver's brake valve in the embodiment of the present invention;

[0032] Figure 6 Schematic diagram of the brake control principle of microcomputer control in the embodiment of the present invention;

[0033] Figure 7 Schematic diagram of the BP brake control principle in the embodiment of the present invention. Detailed implementation manners

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0036] As Figure 3 shown, the brake system with automatic switching between train pipe control and microcomputer control in the embodiment of the present invention is a brake system with dual control functions of microcomputer control and BP control, including: an integrated driver controller, a BP pipe, a pressure conversion device, a distribution valve (STV valve), an EBCU, a BCU, a brake cylinder, and a solenoid valve provided between the STV valve and the BCU. Among them:

[0037] The sequentially connected BP pipe, pressure conversion device, STV valve, BCU, and brake cylinder constitute a BP brake subsystem. The integrated driver controller controls the pressure of the BP through the pressure conversion device and changes the pre-control pressure to the BCU through the STV valve, thereby controlling the pressure output from the BCU to the brake cylinder.

[0038] The EBCU, BCU, and brake cylinder constitute the microcomputer braking subsystem. There are data communication connections between the EBCU and the TCMS and TCU respectively, and it can transmit the braking instructions issued by the integrated controller to the TCU and the microcomputer braking unit respectively; there is also a data communication connection between the EBCU and the BCU. The BCU is connected to the brake cylinder. The EBCU calculates the total braking force according to the vehicle load and braking instructions, sends the electric braking demand to the TCU. The TCU applies electric braking according to the electric braking demand and sends the actually exerted electric braking force to the EBCU. The EBCU controls the BCU to perform air braking according to the total braking force demand and the already exerted electric braking force.

[0039] The solenoid valve is used for switching between the microcomputer braking subsystem and the BP braking subsystem, and through electrical connection, it interlocks the electric braking and the BP braking functions.

[0040] The integrated controller includes a controller and a driver's brake valve, and the driver's brake valve and the controller are composed of an integral motion structure by a connecting pin. As Figure 4 shown, a coupling is used to connect between the traction camshaft of the controller and the brake valve interface. When the driver's controller handle is operated to the running position or the braking position, the rotation of the traction camshaft will drive the coupling to rotate, thereby driving the rotation of the driver's brake valve cam rod.

[0041] The integrated controller can not only send braking instructions (electrical signal instructions) to the TCMS, but also control the BP pipe pressure to generate control pressure instructions (air signal instructions).

[0042] The integrated controller can control the rotation of the mechanical structure of the driver's brake valve, drive the internal cam to adjust the pressure, change the BP pressure through the pressure conversion device, and adjust the pre-control pressure entering the BCU through the STV valve. The integrated controller can also send braking instructions to the TCMS. The TCMS sends the braking instructions to the EBCU and the TCU. The EBCU calculates the total braking force according to the vehicle load and braking instructions, sends the electric braking demand to the TCU. The TCU applies electric braking according to the electric braking demand and sends the actually exerted electric braking force to the EBCU. The EBCU controls the BCU to perform air braking according to the total braking force demand and the already exerted electric braking force.

[0043] When in the non-emergency braking position, the states of the shut-off valve (AB valve) and the emergency braking valve (SB valve) are as Figure 5 shown. The air passage connecting L1 to the HL port, that is, the output port L of the relay valve supplies air to the BP pipe. The pressure regulator DR will adjust the pressure entering the driver's brake valve from the HB port to the pre-control pressure a, and the pre-control pressure a controls the output pressure L of the relay valve. Within the operating range, the pre-control pressure is 5.0 bar, and the output pressure of HL is also 5 bar.

[0044] After the driver's brake valve enters the braking range, as the rotation angle increases, the involute structure of the cam 1 will gradually reduce the mechanical pressure on the pressure regulator DR, adjust the pre-control pressure a to decrease it, and the BP pressure will decrease accordingly.

[0045] When the controller enters the emergency braking position, the driver's brake valve enters the SB position. At this time, the cam 3 will open the emergency braking valve (SB valve), connect HL to the large-diameter exhaust port O, and discharge the BP pipe pressure to the atmosphere; at the same time, the cam 2 will close the shut-off valve (AB valve) to prevent the BP pipe pressure from flowing back to the relay valve through the L1 port.

[0046] The technical solution of the present invention realizes the automatic switching between BP braking and microcomputer-controlled air braking by integrating the controller to control the BP pressure and the solenoid valve powered by the electrical signals of the EBCU and TCU, and can also prevent the superposition of electric braking and BP braking.

[0047] Based on the above braking system with automatic switching between train pipe control and microcomputer control, the present invention also provides a control method for realizing the automatic switching between train pipe control and microcomputer control in an embodiment.

[0048] For the convenience of understanding, first, the braking control principle of microcomputer control and the braking control principle of BP pipe pressure control will be described.

[0049] (1) Braking control principle of microcomputer control:

[0050] When all components of the braking system are normal, the EBCU is used to control the solenoid valve on the BCU to generate the required pre-control pressure, thereby controlling the pressure output by the relay valve to the brake cylinder (see Figure 6 ).

[0051] The air source from the brake cylinder is delivered to the BCU. One way is used as the air supply for the relay valve to output to the brake cylinder (the yellow pipeline in Figure 6 ), and the other way is used as the air supply for the pre-control pressure (the blue pipeline in Figure 6 ). The air supply from the brake cylinder supplies air to the electro-pneumatic converter A through the BCU R1 port. The electro-pneumatic converter A includes two solenoid valves, one for air charging and one for air exhausting. The pressure sensor J collects the output pressure of the electro-pneumatic converter A and sends it to the EBCU. The EBCU controls the air charging / air exhausting / holding actions of the electro-pneumatic converter A according to the target pre-control pressure and the feedback pressure of the pressure sensor J. The generated pre-control pressure flows through the two-way check valve G and the load limiting valve F to provide the pre-control air pressure for the relay valve D (the red pipeline in Figure 6 ), and the relay valve controls the pressure output from the brake cylinder to the brake cylinder according to the magnitude of the pre-control pressure (the green pipeline in Figure 6 ).

[0052] (2) Brake control principle of BP pipe pressure control

[0053] In the BP braking mode, the pre-control pressure is controlled by the BP pressure, so as to control the pressure output from the relay valve to the brake cylinder (see Figure 7 ).

[0054] The air source from the brake cylinder is delivered to the BCU. One way is used as the air supply for the relay valve to output to the brake cylinder ( Figure 7 the yellow pipeline in Figure 7 ), and the other way is used as the air supply source for the STV distribution valve ( Figure 7 the blue pipeline in Figure 7 ). The pressure of BP is used as the control pressure for the output pressure of the STV distribution valve ( Figure 7 the purple pipeline in

[0055] ), to adjust the pre-control pressure of BP braking output to the BCU. The pre-control pressure flows through the two-way check valve G and the load limiting valve F to provide the pre-control air pressure for the relay valve D (

[0056] the red pipeline in

[0057] ). The relay valve controls the pressure output from the brake cylinder to the brake cylinder according to the magnitude of the pre-control pressure ( Figure 3 the green pipeline in

[0058] ).

[0059] The control method for the automatic switching between BP braking and microcomputer-controlled braking specifically includes:

[0060] Under normal circumstances, the solenoid valve B42 is always energized, cutting off the pipeline between the STV valve and the BCU, and emptying the pre-control pressure on the left side of the two-way check valve G in the BCU to prevent affecting the pre-control pressure generated by the electro-pneumatic converter A.

[0061] The solenoid valve B42 has two power supplies. Under normal circumstances, it is powered by the EBCU. When the EBCU loses power, it will automatically switch to the state of being powered by the "electric braking activation" signal of the TCU (see Figure 3 ).

[0058] When the electro-pneumatic conversion device of the single vehicle BCU fails, the conversion method of switching the air brake from microcomputer control to BP control:

[0059] When the electro-pneumatic converter A in the BCU fails and cannot control the pressure of the brake cylinder, the EBCU can cut off the power supply of the solenoid valve B42. At this time, this vehicle is in the BP braking mode. In this case, the EBCU will limit the exertion of electric braking to prevent over-braking caused by the combined action of electric braking and BP braking.

[0060] When the single vehicle microcomputer control unit fails / loses power, the conversion method of automatically switching to BP control:

[0061] When the EBCU loses power, the solenoid valve B42 will automatically switch to be powered by the "electric braking activated" signal. At this time, if the electric braking is not in effect, then the air braking of this car will be applied and released according to the BP pressure controlled by the integrated controller; if the electric braking is being applied, then "electric braking activated" will power the solenoid valve B42 to prevent the application of BP braking.

[0062] During rescue, the method for the train pipe pressure of the rescued train to be controlled by the controller of the rescue train and to apply / release braking synchronously with the rescue train:

[0063] When the train is being rescued, when the braking system receives the "backup mode" hardwired signal, the EBCUs of each car will cut off the power supply of the solenoid valve B42, and at the same time, cut off the electric braking by sending the "electric braking cut-off" hardwired signal to the TCU, and completely enter the BP braking mode; under the condition that the rescued train is completely powered off, by cutting off the B04.2 isolating cocks of each car, the controller of the rescue train controls the train pipe pressure of the rescued train to control the braking force. In this mode, all the braking of the rescued train is completely borne by the air braking force, and the air braking control adopts the BP braking control mode.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A braking system with automatic switching between train pipe control and microcomputer control, characterized in that, Comprising: An integrated controller, a train pipe, a pressure conversion device, a distribution valve, a microcomputer brake control unit, a brake control unit, a brake cylinder, and a solenoid valve disposed between the distribution valve and the brake control unit; wherein: The train pipe, the pressure conversion device, the distribution valve, the brake control unit, and the brake cylinder connected in sequence constitute the train pipe brake subsystem; The microcomputer brake control unit, the brake control unit, and the brake cylinder constitute the microcomputer brake subsystem. The microcomputer brake control unit has data communication connections with the train control and management system and the traction control unit respectively; there is also a data communication connection between the microcomputer brake control unit and the brake control unit, and the brake control unit is connected to the brake cylinder; The integrated controller includes a controller and an engineer's brake valve, and the engineer's brake valve and the controller are composed of an integral motion structure by a connecting pin; the integrated controller can send an electrical signal command to the train control and management system, and at the same time can also control the train pipe pressure to generate an air signal command; The solenoid valve is used for switching between the microcomputer brake subsystem and the train pipe brake subsystem, and through electrical connection, interlocks the electric braking and the train pipe braking actions.

2. The braking system with automatic switching between train pipe control and microcomputer control according to claim 1, characterized in that A coupling is used to connect between the traction camshaft of the controller and the brake valve interface. When the driver controller handle is operated to the running position or the braking position, the rotation of the traction camshaft will drive the coupling to rotate, thereby driving the cam lever of the engineer's brake valve to rotate.

3. The braking system with automatic switching between train pipe control and microcomputer control according to claim 1, characterized in that, The integrated controller controls the rotation of the mechanical structure of the engineer's brake valve, drives the internal cam to adjust the pressure, changes the train pipe pressure through the pressure conversion device, and adjusts the pre-control pressure entering the brake control unit through the distribution valve.

4. A braking system with automatic switching between train pipe control and microcomputer control according to claim 1, characterized in that, The integrated controller sends a braking command to the train control and management system, and the train control and management system sends the braking command to the microcomputer brake control unit and the traction control unit. The microcomputer brake control unit calculates the total braking force according to the vehicle load and the braking command, sends an electric braking demand to the traction control unit, and the traction control unit applies electric braking according to the electric braking demand and sends the actually exerted electric braking force to the microcomputer brake control unit. The microcomputer brake control unit controls the brake control unit to perform air braking according to the total braking force demand and the already exerted electric braking force.

5. A braking system with automatic switching between train pipe control and microcomputer control according to claim 1, characterized in that, The solenoid valve has two power supplies. Under normal circumstances, it is powered by the microcomputer brake control unit. When the microcomputer brake control unit loses power, it will automatically switch to the state of being powered by the electric braking activation signal of the traction control unit.

6. A control method for automatic switching between train pipe control and microcomputer control, characterized in that, Applied to the braking system with automatic switching between train pipe control and microcomputer control as described in any one of claims 1 to 5, the method includes: In the microcomputer control mode, the solenoid valve is in the powered-on state, cuts off the pipeline between the distribution valve and the brake control unit, and evacuates the pre-control pressure on the left side of the two-way check valve in the brake control unit to prevent affecting the pre-control pressure generated by the electro-pneumatic converter; When the electro-pneumatic converter in the brake control unit fails and cannot control the pressure of the brake cylinder, the microcomputer brake control unit cuts off the power supply of the solenoid valve. At this time, this car is in the train pipe braking mode, and the microcomputer brake control unit will limit the exertion of electric braking to prevent over-braking caused by the combined action of electric braking and train pipe braking.

7. The control method for automatic switching between train pipe control and microcomputer control according to claim 6, characterized in that, When the microcomputer brake control unit loses power, the solenoid valve automatically switches to be powered by the electro-brake activation signal. At this time, if the electro-brake is not functioning, the air brake of this car will be applied and released according to the train pipe pressure controlled by the integrated controller. If the electro-brake is being applied, the electro-brake activation will supply power to the solenoid valve to prevent the application of the train pipe brake.

8. The control method for automatic switching between train pipe control and microcomputer control according to claim 6, characterized in that, When the train is being rescued, after the brake system receives the backup mode hard wire signal, the microcomputer brake control unit of each car cuts off the power supply of the solenoid valve. At the same time, the electro-brake is cut off by sending an electro-brake cut-off hard wire signal to the traction control unit, and it completely enters the train pipe brake mode. Under the condition that the rescued train is completely powered off, by cutting off the isolation cocks of each car, the controller of the rescue train controls the train pipe pressure of the rescued train to control the braking force. In this mode, all brakes of the rescued train are completely borne by the air braking force, and the air brake control adopts the train pipe brake control mode.

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