JP2023146126A - air brake system - Google Patents

Abstract

To provide a redundant air brake system even in an unmanned automatic operation vehicle.SOLUTION: An air brake system 200 has a buck-up air system. The air brake system includes: a double check valve 500 provided at a first air passage 301 which connects a brake valve 212 with a front axle module 240 in a buck-up air system; air passages 303, 306 forming a second air passage which connects the double check valve 500 with an air tank 270; a front electromagnetic valve 510 provided at the air passage 303; and a pressure reduction valve 700 provided at the air passage 306.SELECTED DRAWING: Figure 2

Description

One aspect of the present invention relates to an air brake system for a vehicle.

As an air brake system, a configuration having a backup air system is known (see, for example, Patent Document 1).

Patent No. 6894919 Publication

In the backup air system of the air brake system, for example, brake air pressure is generated in response to the driver's depression of the brake pedal to achieve emergency braking.

Here, for example, in an unmanned automatic driving vehicle, since there is no driver, the brake pedal operation as described above cannot be performed. For this reason, there is a possibility that a redundant brake system cannot be provided in an unmanned automatic driving vehicle.

One aspect of the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a redundant air brake system even in an unmanned automatic driving vehicle.

An air brake system according to one aspect of the present invention is an air brake system having a backup air system, in which a double check valve is provided in a first air flow path connecting a brake valve and an axle modulator in the backup air system. a second air flow path connecting the double check valve and the air tank; a solenoid valve provided in the second air flow path; and a pressure reducing valve provided upstream of the solenoid valve in the second air flow path. , is provided.

In the air brake system according to one aspect of the present invention, a double check valve is provided in the first air flow path that connects the brake valve in the backup air system and the axle modulator (which distributes brake pressure to the brake chambers of each wheel). A solenoid valve is provided in a second air passage connecting the double check valve and the air tank, and a pressure reducing valve is provided upstream of the solenoid valve in the second air passage. According to such a configuration, since the first air flow path and the second air flow path are connected to the double check valve, the pressure of the air flowing through the first air flow path and the second air flow path is reduced. Air that has a high value will flow to the axle modulator side. Since the second air flow path is provided with a solenoid valve, when the solenoid valve is operated, air flows out of the air tank and has its pressure adjusted by the pressure reducing valve, and flows through the second flow path. It flows to the axle modulator side via a double check valve. In this way, air from the air tank is supplied to the axle modulator by operating the solenoid valve, and brake control in the backup air system is realized. Such a solenoid valve operation can be carried out even in an unmanned automatic driving vehicle without a driver. As described above, according to the air brake system according to one aspect of the present invention, a redundant brake system can be provided even in an unmanned automatic driving vehicle. In addition, in order to realize a redundant configuration, there is no need for large-scale repair work or the preparation of a new vehicle (it can be achieved by only adding parts such as solenoid valves and pressure reducing valves, and can be achieved by small-scale modification). , it is possible to reduce modification man-hours and introduction costs.

The air brake system is configured to determine whether or not a solenoid valve operating condition is satisfied, and to execute a first control for operating the solenoid valve when the solenoid valve operating condition is satisfied. It may further include a section. According to such a configuration, for example, in a state where the brake cannot be operated by an electric command (such as a failure of the electronic brake system (EBS) or an abnormality in the automatic operation control unit), the electromagnetic valve operating conditions are changed. By determining that this is true, the brake control in the backup air system described above can be reliably performed.

When the control unit detects that the vehicle is decelerating after the first control, the control unit determines whether a predetermined ABS control operating condition is satisfied, and if the ABS control operating condition is satisfied, The solenoid valve is configured to operate the solenoid valve so that the ABS control is executed, and further execute a second control that operates the solenoid valve so that the ABS control is not executed when the ABS control operation condition is not satisfied. It's okay. In this way, by changing the mode of solenoid valve control depending on whether or not the ABS control operating conditions are satisfied, ABS control can be appropriately performed also by solenoid valve control.

According to one aspect of the present invention, a redundant air brake system can be provided even in an unmanned automatic driving vehicle.

It is a block diagram showing an example of composition of an automatic driving system concerning this embodiment. 2 is a schematic configuration diagram of an air brake system included in the automatic driving system shown in FIG. 1. FIG. It is a flowchart which shows the braking procedure by electromagnetic valve control performed by an air brake system.

Embodiments of the present invention will be described in detail below with reference to the drawings. In addition, in the following description, the same or equivalent elements are given the same reference numerals, and redundant description will be omitted.

FIG. 1 is a block diagram showing a configuration example of an automatic driving vehicle 1. As shown in FIG. In this embodiment, the description will be made assuming that the vehicle is an unmanned automatic driving vehicle that runs without a driver. Further, in the automatic driving vehicle 1, an air brake system described later provides a redundant brake system even in an unmanned automatic driving vehicle (details will be described later). The automated driving vehicle 1 includes, for example, a GPS (Global Positioning System) receiver 20, a map database 30, a surrounding situation sensor 40, a vehicle condition sensor 50, a communication device 60, a traveling device 70, and a control device 10. , is equipped with.

The GPS receiver 20 receives signals transmitted from a plurality of GPS satellites, and calculates the position and orientation of the vehicle based on the received signals. The GPS receiver 20 transmits the calculated information to the control device 10.

The map database 30 is a database that stores in advance information indicating the boundary position of each lane on the road. The map database 30 is stored, for example, in a predetermined storage device.

The surrounding situation sensor 40 detects the surrounding situation of the vehicle. As the surrounding situation sensor 40, for example, a lidar, a radar, a camera, etc. are used. Lidar uses light to detect targets around the vehicle. Radar uses radio waves to detect targets around a vehicle. The camera captures images of the surroundings of the vehicle. The surrounding situation sensor 40 transmits detected information to the control device 10.

Vehicle condition sensor 50 detects the driving condition of the vehicle. Examples of the vehicle condition sensor 50 include a vehicle speed sensor, a steering angle sensor, a yaw rate sensor, an acceleration sensor, a steering torque sensor, and a motor output torque sensor. The vehicle speed sensor detects the speed of the vehicle. The steering angle sensor detects the steering angle of the vehicle. The yaw rate sensor detects the yaw rate of the vehicle. The acceleration sensor detects acceleration acting on the vehicle. Vehicle condition sensor 50 transmits detected information to control device 10 .

The communication device 60 performs, for example, V2X communication (vehicle-to-vehicle communication and road-to-vehicle communication). Specifically, the communication device 60 performs V2V communication (vehicle-to-vehicle communication) with other vehicles. Furthermore, the communication device 60 performs V2I communication (road-to-vehicle communication) with surrounding infrastructure. Through V2X communication, the communication device 60 can obtain information regarding the environment around the vehicle. The communication device 60 transmits the acquired information to the control device 10. Note that the communication device 60 may receive information indicating a travel route instruction and a road surface condition from the outside, for example, through V2X communication.

The traveling device 70 includes a steering device, a drive device, a braking device, a transmission, and the like. The steering device steers the wheels. The drive device is a power source that generates driving force. Examples of the drive device include an engine and an electric motor. The braking device generates braking force. Further, the traveling device 70 may include a microcomputer equipped with a processor, a storage device, and an input/output interface so that the steering device, drive device, braking device, transmission, etc. can be operated by electrical commands. These microcomputers are also called ECUs (Electronic Control Units). More specifically, the braking device may include an EBS ECU.

The control device 10 performs automatic driving control that controls automatic driving of a vehicle. The control device 10 is a microcomputer equipped with a processor, a storage device, and an input/output interface. The control device 10 is also called an ECU (Electronic Control Unit). The control device 10 receives various information through an input/output interface. The control device 10 then performs automatic driving control based on the received information.

The control device 10 includes an acquisition section 101 and an automatic operation control section 102 as functional blocks related to automatic operation control. These functional blocks are realized by the processor of the control device 10 executing a control program stored in a storage device. The control program may be stored in a computer-readable recording medium.

The acquisition unit 101 acquires information necessary for automatic driving control. The information acquisition process by the acquisition unit 101 is repeatedly executed in a predetermined or arbitrary cycle. The acquisition unit 101 acquires the position and direction of the vehicle from the GPS receiver 20. The acquisition unit 101 acquires information regarding road lanes and the like from the map database 30. The acquisition unit 101 acquires information about the surroundings of the vehicle detected by the surrounding situation sensor 40. The acquisition unit 101 acquires information indicating the state of the vehicle detected by the vehicle state sensor 50. The acquisition unit 101 acquires information such as driving route instructions and road surface conditions from the communication device 60 .

The automatic driving control unit 102 generates an overall route (the entire route traveled by the vehicle) based on the information acquired by the acquisition unit 101. In addition to the driving route instructions, the automatic driving control unit 102 takes into account information such as the position and direction of the vehicle, road lane information, information about the surroundings of the vehicle, and information indicating the state of the vehicle, and determines the overall route. May be generated. The automatic driving control unit 102 generates a target route on which the vehicle will actually travel in real time based on the generated overall route. Target route generation is repeatedly executed in a predetermined or arbitrary cycle while the vehicle is traveling. The automatic driving control unit 102 performs route following control of the vehicle based on the generated target route. The automatic driving control unit 102 uses a well-known tracking control technique to control each device included in the traveling device 70 so that the vehicle follows the target route.

FIG. 2 is a schematic configuration diagram of an air brake system 200 included in the automatic driving vehicle 1 shown in FIG. 1. Air brake system 200 may be included in traveling device 70. In order to operate the air brake system 200, the automatic driving vehicle 1 has at least a function of controlling the electromagnetic valve of the air brake system 200 (electromagnetic valve control function). Solenoid valve control is to control the power output supplied to the solenoid valve or the electric signal to the solenoid valve, and by operating the solenoid valve, air whose pressure has been adjusted by the pressure reducing valve is supplied to the axle modulator to achieve a predetermined braking force. This is the control that realizes braking. Such electromagnetic valve control is equivalent to (replaces) air supply by the driver's brake pedal operation, and is control that enables backup air supply to the brakes even in an unmanned automatic driving vehicle. The solenoid valve control is also carried out when the EBS is out of order, for example due to an EBS electrical control failure, and brake control based on electrical commands cannot be performed. Note that in the air brake system 200, brake control based on electric commands, similar to the known EBS, may be performed.

As shown in FIG. 2, the air brake system 200 includes a brake signal transmitter 210, a multi-protection valve 220, air tanks 230, 250, a front axle modulator 240, brake chambers 241, 242, and a rear axle modulator 260. , brake chambers 261 and 262, and a trailer control valve 265.

The front axle modulator 240 includes an ECU, a solenoid valve, a pressure sensor, etc., and controls air pressure to the front brake chambers 241 and 242 based on an electric signal from the EBS ECU. In the event of an EBS failure, the front axle modulator 240 sends air from the air tank 230 to the brake chambers 241 and 242 by a relay valve that uses the air pressure from the brake valve 212 of the brake signal transmitter 210 as a signal pressure. Air from the air tank 230 flows through an air flow path 307 and flows into the front axle modulator 240 , further flows through an air flow path 310 and flows into the brake chamber 241 , and flows through the air flow path 311 and flows into the brake chamber 242 . Inflow. The brake chamber 241 operates the brake of the right front wheel RF according to air pressure. The brake chamber 242 operates the brake of the left front wheel LF according to air pressure. In this embodiment, when the EBS fails, air according to the electromagnetic valve control flows into the front axle modulator 240 and the brake is activated (details will be described later).

The rear axle modulator 260 includes an ECU, a solenoid valve, a pressure sensor, etc., and controls air pressure to the rear brake chambers 261 and 262 based on an electric signal from the EBS ECU. In the event of an EBS failure, the rear axle modulator 260 sends air from the air tank 250 to the brake chambers 261 and 262 by a relay valve that uses the air pressure from the brake valve 212 of the brake signal transmitter 210 as a signal pressure. Air from the air tank 250 flows through an air flow path 308 and flows into the rear axle modulator 260 , further flows through an air flow path 313 and flows into the brake chamber 261 , and flows through an air flow path 314 into the brake chamber 262 . Inflow. The brake chamber 261 operates the brake of the right rear wheel RR according to air pressure. The brake chamber 262 operates the brake of the left rear wheel LR according to air pressure. In this embodiment, when the EBS fails, air according to the electromagnetic valve control flows into the rear axle modulator 260 and the brake is activated (details will be described later).

The trailer control valve 265 functions as a relay valve that uses the air pressure from the brake valve 212 of the brake signal transmitter 210 as a signal pressure to supply air from the air tank (not shown) of the trailer system to the trailer when the tractor's EBS malfunctions. feed, and activate the brakes on each wheel of the trailer.

The brake signal transmitter 210 includes a brake pedal switch 211 and a stroke sensor (not shown), and transmits the amount of depression of the brake pedal as a pedal stroke signal to the ECU of the EBS to control the effectiveness of the brake. Brake signal transmitter 210 functions as brake valve 212 at the time of EBS failure, and outputs air pressure as signal pressure to front axle modulator 240 and rear axle modulator 260. Air from brake valve 212 flows into front axle modulator 240 via air flow path 301 and air flow path 309, and flows into rear axle modulator 260 via air flow path 302 and air flow path 312.

The multi-protection valve 220 supplies the minimum necessary air pressure to other normal circuits when one or more of the vehicle air system circuits is damaged (defective). This guarantees a minimum level of braking force, allowing the vehicle to continue on its own until the repair shop can carry out emergency treatment. Multi-protection valve 220 is connected to each of air tanks 230, 250, and 270 via an air flow path.

From here on, the configuration related to electromagnetic valve control will be mainly explained. The electromagnetic valve control is performed when the EBS is out of order, and is a control that replaces the air supply by operating the brake pedal described above. Unlike air supply through brake pedal operation, electromagnetic valve control realizes backup air supply even in unmanned autonomous vehicles without a driver present.

As shown in FIG. 2, the air brake system 200 includes an air tank 270, a single protection valve 280, a double check valve 500, a front solenoid valve 510, a double check valve 600, as components related to solenoid valve control. It includes a rear solenoid valve 610, a pressure reducing valve 700, and a solenoid valve control section 900.

Double check valve 500 is provided in air flow path 301 (first air flow path) that connects brake valve 212 and front axle modulator 240 in the backup air system. An air flow path 301 and an air flow path 303 are connected to the double check valve 500, and among the air flowing through the air flow path 301 and the air flow path 303, high-pressure air flows into the air flow path 309. and flows to the front axle modulator 240. The air flow path 303 has one end connected to the double check valve 500 and the other end connected to the branch point 305. An air flow path 306 extends from the branch point 305 to the air tank 270. That is, the air flow path 303 and the air flow path 306 are continuous with each other via the branch point 305, and constitute a second air flow path that connects the double check valve 500 and the air tank 270. A single protection valve 280 is provided in the air passage 306 to prevent backflow of air.

The front solenoid valve 510 is provided in the air flow path 303 that constitutes the second air flow path. That is, the front solenoid valve 510 is arranged in parallel with the brake valve 212 as an air circuit. Because the solenoid valve and brake valve are arranged in parallel, even when the vehicle is operated by a human driver, the driver's operation of the brake valve is effective, making it suitable for automatic and manual driving. Either way, the same safety can be ensured as a vehicle. The front solenoid valve 510 is a normally closed solenoid valve that controls the emergency brake in the event of an EBS failure by opening and closing an air circuit. The front solenoid valve 510 operates under the control of the solenoid valve control unit 900 and causes the air flowing through the air flow path 303 (i.e., the air from the air tank 270) to flow in the direction of the double check valve 500 (i.e., in the direction of the front axle modulator 240). .

Double check valve 600 is provided in air flow path 302 (first air flow path) that connects brake valve 212 and rear axle modulator 260 in the backup air system. An air flow path 302 and an air flow path 304 are connected to the double check valve 600, and among the air flowing through the air flow path 302 and the air flow path 304, high-pressure air flows into the air flow path 312. and flows to rear axle modulator 260. The air flow path 304 has one end connected to the double check valve 600 and the other end connected to the branch point 305. An air flow path 306 extends from the branch point 305 to the air tank 270. That is, the air flow path 304 and the air flow path 306 are continuous with each other via the branch point 305, and constitute a second air flow path that connects the double check valve 600 and the air tank 270.

The rear solenoid valve 610 is provided in the air flow path 304 that constitutes the second air flow path. The rear solenoid valve 610 is arranged in parallel with the brake valve 212 as an air circuit. Because the solenoid valve and brake valve are arranged in parallel, even when the vehicle is operated by a human driver, the driver's operation of the brake valve is effective, making it suitable for automatic and manual driving. Either way, the same safety can be ensured as a vehicle. The rear solenoid valve 610 is a normally closed solenoid valve that controls the emergency brake in the event of an EBS failure by opening and closing an air circuit. The rear solenoid valve 610 operates under the control of the solenoid valve control section 900 and causes the air flowing through the air flow path 304 (i.e., the air from the air tank 270) to flow in the direction of the double check valve 600 (i.e., in the direction of the front axle modulator 240). .

The pressure reducing valve 700 is a pressure regulating valve provided on the upstream side (the air tank 270 side) of the front solenoid valve 510 and the rear solenoid valve 610 in the second air flow path, specifically, in the air flow path 306. The pressure reducing valve 700 reduces the air pressure within the air tank 270 to a predetermined pressure. The pressure reducing valve 700 may have a certain pressure regulation range in order to achieve a predetermined braking force as an emergency brake, for example. Further, the pressure reducing valve 700 is required to have good time responsiveness in order to realize the ABS control function.

The solenoid valve control unit 900 is a microcomputer equipped with a processor, a storage device, and an input/output interface. Note that in this embodiment, the solenoid valve control unit 900 is included in the air brake system 200, but the solenoid valve control unit 900 may be included in at least one of the air brake system 200 and the control device 10. . The solenoid valve control unit 900 determines whether or not a solenoid valve operating condition is satisfied, and operates at least one of the front solenoid valve 510 and the rear solenoid valve 610 when the solenoid valve operating condition is satisfied. The configuration is configured to execute first control to cause The electromagnetic valve operating condition here is a condition that is satisfied in a state in which the brake cannot be operated by an electric command (EBS failure, abnormality in the automatic operation control unit 102, etc.).

After the first control, the solenoid valve control unit 900 determines whether a predetermined ABS control operating condition is satisfied, and if the ABS control operating condition is satisfied, the ABS control is executed. At least one of the front solenoid valve 510 and the rear solenoid valve 610 is operated so that ABS control is not performed when the control operation conditions are not satisfied. It is configured to further execute second control for activating one of the two. The ABS control operating conditions are, for example, vehicle speed and vehicle weight conditions. For example, the electromagnetic valve control unit 900 may determine that the ABS control operating conditions are satisfied when the vehicle speed is greater than or equal to a predetermined value and the vehicle weight is less than or equal to a predetermined value.

Next, with reference to FIG. 3, a braking procedure using electromagnetic valve control executed by the air brake system 200 will be described. FIG. 3 is a flowchart showing a braking procedure performed by the air brake system 200 using electromagnetic valve control.

As shown in FIG. 3, first, it is determined whether solenoid valve operating conditions are satisfied (step S1). If the electromagnetic valve operating conditions are not satisfied, the electromagnetic valve control is not performed and the process ends.

On the other hand, if the solenoid valve operating conditions are satisfied, at least one of the front solenoid valve 510 and the rear solenoid valve 610 is operated by the solenoid valve control unit 900 (step S2). As a result, the air from the air tank 270 whose pressure has been reduced by the pressure reducing valve 700 flows into the front axle modulator 240 via the double check valve 500, and also flows into the rear axle modulator 260 via the double check valve 600, causing backup air to flow into the front axle modulator 240 via the double check valve 600. Brake control in the system is realized.

Subsequently, the solenoid valve control unit 900 determines whether the ABS control operating conditions are satisfied (step S3). Specifically, for example, it is determined whether the vehicle speed is above a predetermined value and the vehicle weight is below a predetermined value. Predetermined values for vehicle speed and vehicle weight may be determined for each vehicle in advance.

In step S3, if it is determined that the vehicle speed is greater than or equal to the predetermined value and the vehicle weight is less than or equal to the predetermined value, that is, the ABS control activation conditions are satisfied, the electromagnetic valve control unit 900 controls the electromagnetic Valve actuation is performed (step S4). On the other hand, if it is determined in step S3 that the ABS control operating conditions are not satisfied, the electromagnetic valve control section 900 performs electromagnetic valve operation that is not based on ABS control (step S5). Brake control in such a backup air system causes the vehicle to decelerate and come to a stop. Note that unlike general brake operation, the braking force is constant depending on pressure regulation with the pressure reducing valve 700, so the brake control does not allow adjustment of deceleration, but this is intended for emergency response. There is no problem with this kind of brake control. Further, when ABS control is performed, braking can be performed without impairing vehicle stability even under more diverse road surface conditions and vehicle conditions.

Next, the effects of the air brake system 200 according to this embodiment will be explained.

The air brake system 200 is an air brake system having a backup air system, in which the double check valve 500 provided in the air flow path 301 connecting the brake valve 212 and the front axle modulator 240, Air passages 303 and 306 constituting a second air passage connecting check valve 500 and air tank 270, front solenoid valve 510 provided in air passage 303, brake valve 212, and rear axle modulator 260. The double check valve 600 provided in the connecting air flow path 302, the air flow paths 304 and 306 forming the second air flow path connecting the double check valve 600 and the air tank 270, and the air flow paths 304 and 306 provided in the air flow path 304. A rear solenoid valve 610 and a pressure reducing valve 700 provided in the air flow path 306 are provided.

In the air brake system 200 according to the present embodiment, a double check valve 500 is provided in the air flow path 301 that connects the brake valve 212 and the front axle modulator 240 in the backup air system, and the double check valve 500 and the air tank 270 A front solenoid valve 510 is provided in the air flow path 303 connecting the brake valve 212 and the rear axle modulator 260, and a double check valve 600 is provided in the air flow path 302 connecting the brake valve 212 and the rear axle modulator 260. A rear electromagnetic valve 610 is provided in an air flow path 304 that connects the air flow path 600 and the air tank 270, and a pressure reducing valve 700 is provided in the air flow path 306. According to such a configuration, since the air flow path 301 and the air flow path 303 are connected to the double check valve 500, the air flowing through the air flow path 301 and the air flow path 303 has a high pressure. will flow to the front axle modulator 240 side. Since the front solenoid valve 510 is provided in the air flow path 303, when the front solenoid valve 510 is operated, the air flowing out from the air tank 270 and having its pressure adjusted by the pressure reducing valve 700 flows through the air flow path. 303, passes through the double check valve 500, and flows to the front axle modulator 240 side. Similarly, since the air flow path 302 and the air flow path 304 are connected to the double check valve 600, high pressure air among the air flowing through the air flow path 302 and the air flow path 304 is directed to the rear axle modulator. It will flow to the 260 side. Since the rear solenoid valve 610 is provided in the air flow path 304, when the rear solenoid valve 610 is operated, the air flowing out from the air tank 270 and having its pressure adjusted by the pressure reducing valve 700 flows through the air flow path. 304, passes through the double check valve 600, and flows to the rear axle modulator 260 side. In this way, by operating the front solenoid valve 510 and the rear solenoid valve 610, air from the air tank 270 is supplied to the front axle modulator 240 and the rear axle modulator 260, and brake control in the backup air system is realized. Such a solenoid valve operation can be carried out even in an unmanned automatic driving vehicle without a driver. As described above, according to the air brake system 200 according to the present embodiment, a redundant brake system can be provided even in an unmanned automatic driving vehicle.

The air brake system 200 determines whether or not a solenoid valve operating condition is met, and performs first control to operate the front solenoid valve 510 and the rear solenoid valve 610 when the solenoid valve operating condition is met. It may further include a solenoid valve control section 900 configured to perform the operation. According to such a configuration, for example, by determining that the electromagnetic valve operating condition is satisfied in a state where the brake cannot be operated by an electric command (such as an EBS failure or an abnormality in the automatic operation control unit), Brake control in the backup air system described above can be reliably performed.

When the electromagnetic valve control unit 900 detects that the vehicle is decelerating after the first control, it determines whether or not a predetermined ABS control operating condition is satisfied, and determines whether the ABS control operating condition is satisfied. In this case, at least one of the front solenoid valve 510 and the rear solenoid valve 610 (for example, the rear solenoid valve 610) is operated so that the ABS control is performed, and when the ABS control operation condition is not satisfied, the ABS control is performed. The configuration may also be configured to further execute second control for operating at least one of the front solenoid valve 510 and the rear solenoid valve 610 (for example, the rear solenoid valve 610) so that the front solenoid valve 510 and the rear solenoid valve 610 are not executed. In this way, by changing the mode of solenoid valve control depending on whether or not the ABS control operating conditions are satisfied, ABS control can be appropriately performed also by solenoid valve control.

200... Air brake system, 212... Brake valve, 240... Front axle modulator (axle modulator), 260... Rear axle modulator (axle modulator), 270... Air tank, 301, 302... Air flow path (first air flow path), 303, 304, 306...air flow path (second air flow path), 500,600...double check valve, 510...front solenoid valve (solenoid valve), 610...rear solenoid valve (solenoid valve), 700...pressure reducing valve, 900...Solenoid valve control section (control section).

Claims (3)

An air brake system having a backup air system,
a double check valve provided in a first air flow path connecting the brake valve and the axle modulator in the backup air system;
a second air flow path connecting the double check valve and the air tank;
a solenoid valve provided in the second air flow path;
An air brake system comprising: a pressure reducing valve provided upstream of the electromagnetic valve in the second air flow path. further comprising a control unit configured to determine whether or not a solenoid valve operating condition is satisfied, and to execute a first control for operating the solenoid valve when the solenoid valve operating condition is satisfied; The air brake system according to claim 1. When the control unit detects that the vehicle is decelerating after the first control, the control unit determines whether or not a predetermined ABS control operating condition is satisfied, and if the ABS control operating condition is satisfied, the control unit determines whether the ABS control operating condition is satisfied. further performing a second control of operating the solenoid valve so that ABS control is performed, and operating the solenoid valve so that the ABS control is not performed when the ABS control activation condition is not satisfied; 3. The air brake system of claim 2, wherein the air brake system is configured to:

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