JP2020033016A - Pneumatic brake system - Google Patents

Abstract

To provide a pneumatic brake system capable of enhancing redundancy.SOLUTION: There is provided a pneumatic brake system 10 for supplying air to a brake chamber 50 of a vehicle for actuating a brake, discharging air from the brake chamber 50, and releasing the brake. The pneumatic brake system comprises: security air supply parts 33 for supplying air to the brake chamber 50 and being actuated by a second EBS ECU 15B in emergency; and shuttle valves 34 which are provided between the security air supply part 33 and a brake air supply circuit, and allowing only an air flow in a direction going to the brake chamber 50 from a high pressure side out of the security air supply part 33 and the brake air supply circuit, and the security air supply part 33 and the shuttle valve 34 are provided for every wheel of the vehicle.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pneumatic brake system that operates a brake using air.

  2. Description of the Related Art In recent years, as one of advanced driving techniques, a system has been developed that realizes a row running in which a plurality of vehicles form a row while communicating with each other and run. In particular, for freight vehicles such as trucks and buses, a system has been proposed for platooning in which a platoon is formed by a leading vehicle driven by a driver and a subsequent vehicle that is unmanned or monitored by a supervisor. In the following vehicle, various controls are performed following the behavior of the leading vehicle (for example, see Patent Document 1). For example, in the brake control, when the leading vehicle operates the brake, the following vehicle follows and activates the brake.

  Many freight vehicles are equipped with a pneumatic brake system that operates a brake using air. Therefore, in a succeeding vehicle equipped with the pneumatic brake system, each actuator constituting the pneumatic brake system is controlled following the brake control of the leading vehicle.

  By the way, since the following vehicle is unmanned driving or automatic driving in which the behavior of the vehicle is monitored by a supervisor, if an abnormality occurs in the pneumatic brake system, it is not possible to expect the operation by the driver. Is required to have redundancy. For example, Patent Document 1 proposes a row running control system in which a brake system is multiplexed.

JP 2007-233965 A

  In the above-mentioned platooning control system, when the control device detects an abnormality in the electric system, such as a position detection device, it performs control to operate the emergency brake. However, abnormalities that can occur in the pneumatic brake system are not limited to electrical system abnormalities. For example, if an abnormality occurs in a part of the structure of one of the brake modules, such as a pipe or a valve device, no consideration is given to promptly switching from the brake module to the other brake module. Therefore, it is required to further increase the redundancy of the pneumatic brake system so as to cope with a case where an abnormality occurs in a part of a structure such as a pipe or a valve device.

  Note that such problems are not limited to vehicles that run in platoons, but are generally common to vehicles equipped with a pneumatic brake system, such as autonomous vehicles that travel independently without forming a platoon.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pneumatic brake system capable of increasing redundancy.

  A pneumatic brake system that solves the above-mentioned problem is a pneumatic brake system that supplies air to a brake mechanism of a vehicle to operate a brake, discharges air from the brake mechanism and releases the brake, and provides a security in an emergency. A security air supply unit that is operated by the brake control device for supplying air to the brake mechanism, supplies the air to the brake mechanism via a route different from the security air supply unit, and the security air supply unit. A shuttle valve that is connected to a brake air supply circuit and that allows a flow of air only in a direction from the high-pressure side to the brake mechanism in the security air supply unit and the brake air supply circuit. The air supply unit and the shuttle valve are provided for each wheel of the vehicle.

  According to the above configuration, the shuttle valve supplies air to the brake mechanism from the high-pressure side of the security air supply unit and other air supply circuits. Therefore, even if an abnormality occurs in one or both of the security air supply unit and the other air supply circuit or an abnormality occurs in the security brake control device, air is supplied to the brake mechanism to operate the brake. Can be done. Therefore, the redundancy of the pneumatic brake system can be increased. Further, since the security air supply circuit and the shuttle valve are provided for each wheel, the responsiveness of the brake control in an emergency can be improved.

  The above-mentioned pneumatic brake system includes a solenoid valve for forced braking controlled by a main controller that outputs a braking request to a security brake controller that controls the security air supply unit. The supply of air from the air supply source that stores compressed air in the energized state energized by the main control device to the brake mechanism side is cut off, and the air from the air supply source is de-energized in the brake mechanism side. Preferably, when air is supplied from the electromagnetic valve for forced braking, the shuttle valve permits supply of air from the electromagnetic valve for forced braking to the brake mechanism side.

  According to the above configuration, the solenoid valve for forced braking controlled by the main controller supplies air from the air supply source to the brake mechanism in a non-energized state. Further, the shuttle valve allows the supply of air from the security electromagnetic valve side to the brake mechanism side. Therefore, even if an abnormality occurs in the main control device, the brake can be forcibly operated.

  Regarding the pneumatic brake system, between the solenoid valve for forced braking and the security air supply unit, an air-driven suspension system communicates with the brake mechanism in response to an increase in the load of the vehicle. It is preferable that a valve device that changes the supply amount to be large is provided.

  According to the above configuration, the supply amount of air to the brake mechanism increases in accordance with the load of the vehicle, so that when the load is large, the braking force can be increased. The valve device communicates with an air-driven suspension system, and changes a supply amount of air according to the air pressure of the suspension system. For this reason, even when an abnormality occurs in the electric system such as the control device, the braking force according to the loaded load can be mechanically changed, so that the redundancy of the pneumatic brake system can be further enhanced.

  In the pneumatic brake system, the security brake control device detects an abnormality in a brake control device that controls an air supply circuit different from the security air supply unit, and based on a braking request from the main control device, controls the brake. Preferably, air is supplied to a mechanism to cause the vehicle to run or stop at a predetermined speed.

  According to the above configuration, since the security brake control device is controlled based on the braking request of the main control device, the vehicle can run even if an abnormality occurs in the brake control device. Therefore, the redundancy of the pneumatic brake system can be further increased.

  With respect to the pneumatic brake system, when an abnormality occurs in a brake control device that controls an air supply circuit different from the security air supply unit and the main control device, the solenoid valve for forced braking is de-energized and the brake is released. Is preferably forcibly activated.

  According to the above configuration, even when no abnormality has occurred in the security brake control device, the brake is forcibly operated when an abnormality has occurred in the brake control device and the main control device. For this reason, the redundancy of the pneumatic brake system can be further increased.

  According to the present invention, the redundancy of the pneumatic brake system can be increased.

FIG. 1 is a schematic diagram of a vehicle on which the pneumatic brake system is mounted and which forms a platoon according to an embodiment of the pneumatic brake system. FIG. 2 is a schematic diagram showing a connection state of an ECU of the pneumatic brake system of the embodiment. The schematic diagram showing the composition of the pneumatic brake system of the embodiment. 4 is a flowchart showing the operation of a second EBSECU in the embodiment. FIG. 7A is a conceptual diagram illustrating a state transition when an abnormality occurs in a first EBS ECU first, and FIG. 7B is a conceptual diagram illustrating a state transition when an abnormality occurs in a first EBS ECU first. The conceptual diagram which shows a state transition. FIG. 3 is a conceptual diagram showing a state transition when an abnormality of a towing ECU first occurs in the embodiment.

Hereinafter, an embodiment of a vehicle including a pneumatic brake system will be described.
The platooning will be described with reference to FIG. Here, the vehicles 100 forming the platoon are freight vehicles, and are trucks (also referred to as cargo vehicles) integrally provided with a loading platform. The platoon is formed of a leading vehicle 100a driven by a driver and a following vehicle 100b on which an unmanned or monitored person rides. The observer monitors the behavior of the vehicle and basically does not drive. The leading vehicle 100a and the following vehicle 100b travel while maintaining a preset inter-vehicle distance.

  As shown in FIG. 2, the vehicle 100 includes a first traction ECU (Electronic Control Unit) 11A as a main control device and a second traction ECU 11B as a main control device. Various systems of the vehicle 100 are controlled by one of the commands of the first towing ECU 11A and the second towing ECU 11B, and the platooning is performed. For example, even if an abnormality occurs in the first traction ECU 11A, the second traction ECU 11B controls the vehicle 100. Note that, when the first tow ECU 11A and the second tow ECU 11B are described without distinction, they will be simply described as the tow ECU 11.

  The traction ECU 11 of the leading vehicle 100a and the traction ECU 11 of the following vehicle 100b transmit and receive various information by wireless communication. The leading vehicle 100a operates the brake by a driver's brake operation, and the following vehicle 100b operates the brake following the vehicle 100 when the immediately preceding vehicle 100 decelerates. That is, the succeeding vehicle 100b is provided with a pneumatic brake system capable of operating the brake following the vehicle 100 immediately before. In addition, since the leading vehicle 100a is a vehicle that is driven by the driver, it is not necessary to include the pneumatic brake system as in the following vehicle 100b, but may include the pneumatic brake system having the same configuration. . In the present embodiment, the pneumatic brake system of the leading vehicle 100a and the pneumatic brake system of the following vehicle 100b have the same configuration. Further, in FIG. 1, a row is formed by three vehicles 100, but a plurality other than three may be used.

  The schematic configuration of the pneumatic brake system of the vehicle 100 will be described with reference to FIGS. The pneumatic brake system operates a service brake that varies a braking force by air pressure and a parking brake (parking brake) that applies a predetermined braking force to wheels by the biasing force of a spring.

  As shown in FIG. 2, the pneumatic brake system 10 includes, in addition to the traction ECU 11, a first EBS ECU 15A as a brake control device and a second EBS ECU 15B as a security brake control device. The first EBS ECU 15A is an ECU having a higher priority than the second EBS ECU 15B, and controls an actuator constituting the pneumatic brake system 10 in normal time when there is no abnormality in itself. The second EBS ECU 15B controls the pneumatic brake system 10 in an emergency when an abnormality occurs in the first EBS ECU 15A. The term “emergency” refers to all of the first EB ECU 15A, the first traction ECU 11A, and the second traction ECU 11B when an abnormality occurs in both the first traction ECU 11A and the second traction ECU 11B other than when an abnormality occurs in the first EB ECU 15A. Includes when an abnormality occurs.

  The first tow ECU 11A, the second tow ECU 11B, the first EBS ECU 15A, and the second EBS ECU 15B are connected to the vehicle-mounted network 19. A vehicle speed sensor 53 is connected to the vehicle-mounted network 19. When the first tow ECU 11A, the second tow ECU 11B, the first EBS ECU 15A, and the second EBS ECU 15B are not distinguished from each other and are simply described as nodes connected to the vehicle-mounted network 19, they will be simply described as the ECU 20. For example, the in-vehicle network is a CAN (Controller Area Network), but may be another in-vehicle network such as FlexRay (registered trademark) or Ethernet (registered trademark). A communication control unit (not shown) for detecting a communication error or the like is connected to the vehicle-mounted network 19. Each ECU 20 sends a predetermined communication message to the in-vehicle network 19 with its own ID, and acquires a communication message to be acquired from the in-vehicle network 19.

  Next, as shown in FIG. 3, the pneumatic brake system 10 supplies the air stored in the air storage tank 21 and other tanks to a brake chamber 50 as a brake mechanism. FIG. 3 shows only one pair of front wheels 51 and one pair of rear wheels 52 as drive wheels, but the number of front wheels 51 and the number of rear wheels 52 are not particularly limited. For example, the vehicle 100 may be provided with a pair of front wheels 51 and two pairs of rear wheels 52. The brake chamber 50 is provided for each wheel. The brake chamber 50 has an air storage chamber for a service brake and an air storage chamber for a parking brake. The brake chamber 50 is provided with a spring that applies a biasing force to the wheel to stop the rotation of the wheel. When air is supplied to the air storage chamber for the service brake, the service brake is activated, and the braking force increases in accordance with an increase in the amount of supplied air. When the air is discharged from the service brake air storage chamber, the service brake is released. On the other hand, when a predetermined amount of air is supplied to the parking brake air storage chamber, the biasing force of the spring is released, and when the air is discharged from the parking brake air storage chamber, the spring biasing force is applied to the wheels. Granted.

  The front wheel 51 and the rear wheel 52 are provided with a vehicle speed sensor 53 for detecting the rotation speed of the wheel. The vehicle speed sensor 53 outputs a vehicle speed pulse signal to the vehicle-mounted network 19 (see FIG. 2). Further, a pressure sensor 54 for detecting the pressure of the supply passage is provided in the supply passage connected to the service brake air storage chamber of the brake chamber 50.

  The air stored in the air storage tank 21 is compressed by the compressor 22 and dried by the air dryer 23 having a desiccant. The air storage tank 21 is connected to a protection valve (protection valve) 24 via a pipe. The protection valve 24 distributes the air supplied from the air storage tank 21 to a parking brake tank 25, a rear wheel brake tank 26, and a front wheel brake tank 27.

  The front wheel brake tank 27 is connected to an axle modulator 30 via a brake valve 31. The axle modulator 30 controls supply and discharge of air to and from a brake chamber 50 provided in the front wheels 51. The brake valve 31 includes a front wheel control unit 31A and a rear wheel control unit 31B, and is controlled by the first EBS ECU 15A. The axle modulator 30 is controlled by the first EB ECU 15A.

  The front wheel brake tank 27 is connected to an axle modulator 30 via a brake valve 31. When the vehicle 100 is driven by a driver in manned driving, the first EBS ECU 15A inputs a position detection signal from a sensor that detects the position of a brake pedal (not shown) operated by the driver, and controls the brake valve 31. Thus, air is supplied to the axle modulator 30. When the vehicle 100 is driving unmanned, the first EBS ECU 15A controls the brake valve 31 based on information such as deceleration information transmitted from the leading vehicle or the like.

  The axle modulator 30 has a first input port connected to a supply path 60 communicating with the front wheel control unit 31A of the brake valve 31, and a second input port connected to a supply path 61 communicating with the front wheel brake tank 27. ing. The axle modulator 30 includes an output port connected to the security modulator 32L provided corresponding to the left front wheel 51, and an output port connected to the security modulator 32R provided corresponding to the right front wheel 51. ing. When the air pressure signal sent from the front wheel control unit 31A of the brake valve 31 is input to the first input port, the axle modulator 30 converts the air supplied from the front wheel brake tank 27 to the second input port into the safety modulator 32L, 32R each.

  Since the left front wheel security modulator 32L and the right front wheel security modulator 32R have the same configuration, only the left front wheel security modulator 32L will be described. The security modulator 32 </ b> L includes a security air supply unit 33 and a shuttle valve 34. The security air supply unit 33 includes an electromagnetic valve (not shown) controlled by the second EB ECU 15B. The security air supply unit 33 is connected to a suspension tank 28 provided in an air suspension system (pneumatically driven suspension system) of the vehicle 100. The security air supply unit 33 is connected to the brake chamber 50 via a shuttle valve 34. Air supplied from the compressor 22 via the air dryer 23 is stored in the suspension tank 28. In the event of an abnormality in the first EB ECU 15A or the like, the second EB ECU 15B controls the security air supply unit 33 to supply air to the brake chamber 50 side.

  The shuttle valve 34 is connected to the security air supply unit 33 and the axle modulator 30, and controls the flow of air from the higher pressure among the security air supply unit 33 and the axle modulator 30 to the brake chamber 50. Allow. Therefore, failures other than abnormality of the electric system, such as a state in which there is an air leak or a mechanical abnormality between the air storage tank 21 and the axle modulator 30 and a state in which a pipe in the axle modulator 30 is leaking, have occurred. Even in this case, since the pressure is high on either the security air supply unit 33 side or the axle modulator 30 side, the air is supplied to the brake chamber 50 from the side where the pressure is high. The shuttle valve 34 is connected to an ABS (Antilock Brake System) valve 36. The ABS valve 36 constitutes an anti-lock brake system for two front wheels. The ABS valve 36 is controlled by the first EB ECU 15A. Note that at least one of the axle modulator 30 and the security air supply unit 33 may have the ABS function.

  On the other hand, the rear wheel brake tank 26 is connected to the axle modulator 40. The axle modulator 40 controls supply and discharge of air to and from a brake chamber 50 provided on the rear wheel 52. The axle modulator 40 is controlled by the first EB ECU 15A. The axle modulator 40 has a first input port connected to a supply path 62 communicating with the rear wheel controller 31B of the brake valve 31, and a second input port connected to a supply path 63 communicating with the rear wheel brake tank 26. It has. The axle modulator 40 has an output port connected to the security modulator 42L provided on the left rear wheel 52 and an output port connected to the security modulator 42R provided on the right rear wheel 52. The axle modulator 40 is supplied with the air pressure signal sent from the rear wheel control unit 31B to the first input port connected to the supply path 62 from the rear wheel brake tank 26 to the second input port. The distributed air is distributed to the security modulators 42L and 42R, respectively.

  The rear wheel brake tank 26 is connected to an axle modulator 40 via a brake valve 31. When the vehicle 100 is driven by a driver, the first EBS ECU 15A inputs a position detection signal from a sensor that detects the position of a brake pedal (not shown) operated by the driver, and controls the brake valve 31. . When the vehicle 100 is operating unmanned, the first EBS ECU 15A controls the brake valve 31 to supply air to the axle modulator 40 based on information such as deceleration information transmitted from the leading vehicle or the like.

  Since the left rear wheel security modulator 42L and the right rear wheel security modulator 42R have the same configuration, only the left security modulator 42L will be described. The rear wheel security modulators 42L and 42R have the same configuration except that the front wheel security modulators 32L and 32R are different from the safety modulators 32L and 32R in the state of connection to tanks and the like. The security modulator 42L includes a security air supply unit 33 controlled by a deceleration command from the second EBS ECU 15B, and a shuttle valve 34. The security air supply unit 33 has the same configuration as that of the security air supply unit 33 provided for the front wheels 51, and includes an electromagnetic valve controlled by the second EB ECU 15B. The security air supply section 33 of the rear wheel 52 is also connected to the suspension tank 28.

  The parking brake tank 25 is connected to a parking brake control valve 55 and a parking brake relay valve 56. The parking brake control valve 55 outputs an air pressure signal to the parking brake relay valve 56 under the control of the first EBS ECU 15A or the like. When a pneumatic signal is input from the parking brake control valve 55, the parking brake relay valve 56 is opened to connect the parking brake tank 25 to the parking brake air storage chamber of the brake chamber 50. As a result, air is supplied to the parking brake air storage chamber, and the parking brake is released. The parking brake relay valve 56 may be an electromagnetic valve, and may be controlled by the first EB ECU 15A or the like.

  Between the parking brake control valve 55 and the parking brake relay valve 56, a signal supply path 65 of a security brake valve 71 as an electromagnetic valve for forced braking is connected. The security brake valve 71 constitutes a forced brake modulator 70 together with a load sensing valve 72 (adjustment valve) as a valve device. At least one forced brake modulator 70 is provided for one vehicle 100. In the present embodiment, one forced brake modulator 70 is provided. Further, the forced brake modulator 70 is controlled by the electronic traction ECU 11. The security brake valve 71 is an electromagnetic valve controlled by one of the first traction ECU 11A and the second traction ECU 11B. In other words, the security brake valve 71 can be controlled by either the first traction ECU 11A or the second traction ECU 11B.

  The load sensing valve 72 is provided in series with a supply path connecting the security brake valve 71 and the security modulators 42L and 42R. The load sensing valve 72 can adjust the amount of air supplied to the service brake air storage chamber of the brake chamber 50. The load sensing valve 72 is connected to the air suspension system. The pressure at the connection port of the load sensing valve 72 with the air suspension system is the same as that of the air suspension system. When the load of the load of the vehicle 100 is large, the pressure at the connection port increases. When the pressure on the connection port side of the load sensing valve 72 becomes larger than a predetermined value, the load sensing valve 72 increases the amount of air supplied to the safety modulators 42L and 42R of the rear wheels 52 that are driving wheels. If the pressure at the connection port can be adjusted according to the load of the load by using a configuration other than the load sensing valve 72, the load sensing valve 72 may be omitted.

  The security brake valve 71 has a signal input port connected to the signal supply path 65, two connection ports connected to the security modulators 32L, 32R of the front wheels 51 and the security modulators 42L, 42R of the rear wheels 52, and an air supply source. And an input port connected to a tank-side supply path 66 to which air is supplied from the suspension tank 28. The security brake valve 71 is energized by one of the first traction ECU 11A and the second traction ECU 11B in a state where there is no abnormality, that is, in a normal state, and shuts off the supply of air to the security modulators 32L, 32R, 42L, and 42R. The security brake valve 71 is de-energized in a predetermined state where an abnormality has occurred, and supplies air to the security modulators 32L, 32R, 42L, and 42R.

  When the air is discharged from the parking brake air storage chamber, the biasing force of the spring is applied to the wheels, and the parking brake is activated. At this time, no air pressure signal is input to the signal input port of the security brake valve 71. When a predetermined amount of air is introduced into the parking brake air storage chamber, the parking brake is released. At this time, an air pressure signal is input to the signal input port of the security brake valve 71 via the signal supply path 65. When the air pressure signal is input to the signal input port, the security brake valve 71 can supply the air stored in the suspension tank 28 to the security modulators 32L, 32R, 42L, and 42R. At this time, since the pressure on the security brake valve 71 side is higher than that on the axle modulators 30 and 40 side, the shuttle valve 34 allows the flow of air from the security brake valve 71 side to the brake chamber 50 side.

  Further, the second EBS ECU 15B acquires a pressure detection signal of the pressure sensor 54. The second EBS ECU 15B learns the relationship between pressure and deceleration based on the pressure detection signal. The deceleration is calculated by the second EB ECU 15B based on a vehicle speed signal obtained from the vehicle speed sensor 53 via the vehicle-mounted network 19. Alternatively, the second EB ECU 15B acquires the deceleration calculated by the towing ECU 11 from the vehicle-mounted network 19. The second EBS ECU 15B controls the security modulators 32L, 32R, 42L, 42R based on the learning request and the deceleration request of the towing ECU 11 so that the vehicle 100 decelerates to a predetermined speed. The second EB ECU 15B may learn the relationship between the speed and the pressure in addition to the relationship between the deceleration and the pressure.

  Next, with reference to FIG. 4, the operation of the second EBS ECU 15B will be described together with its procedure. The second EBSECU 15B controls the brake in a predetermined state in which an abnormality has occurred in the first EBSECU15A, and otherwise does not hinder the brake control of the first EBSECU15A. It is also assumed that no abnormality has occurred in the second EB ECU 15B. The following procedure is an example, and the control may be performed by a procedure other than the following procedure.

  For example, when the ignition switch is turned on, the second EB ECU 15B determines whether or not all the ECUs 20 connected to the on-vehicle network 19 or a predetermined ECU 20 among them has an abnormality (step S1). Each ECU 20 can determine whether there is an abnormality in the ECU 20 that is the transmission source of the communication message based on receiving a predetermined communication message via the in-vehicle network 19 or not receiving the predetermined communication message. It is possible. Alternatively, the second EB ECU 15B determines whether there is an abnormality in the ECU 20 based on a message or the like transmitted when the communication control unit that controls the communication of the in-vehicle network 19 detects an error. Alternatively, the second EB ECU 15B may determine whether or not the ECU 20 is abnormal by other methods.

  When it is determined that the abnormality has not occurred in any of the ECUs 20 to be determined (step S1: NO), the second EBS ECU 15B repeats the determination of the presence or absence of the abnormality (step S1). On the other hand, when the second EB ECU 15B determines that an abnormality has occurred in any of the ECUs 20 to be determined (step S1: YES), the second EB ECU 15B determines whether or not the ECU 20 in which the abnormality has occurred is the first EB ECU 15A (step S2). ).

  When the second EBS ECU 15B determines that an abnormality has occurred in the first EBS ECU 15A (step S2: YES), the second EBS ECU 15B determines whether an abnormality has occurred in both of the traction ECUs 11 (step S3). When an abnormality has occurred in both of the traction ECUs 11 (step S3: YES), the energization by the traction ECU 11 is not performed and the security brake valve 71 is de-energized, so that the forced braking is activated (step S4). That is, the air stored in the suspension tank 28 is supplied to the security modulators 32L, 32R, 42L, 42R via the security brake valve 71. As a result, the safety brake valve 71 has a higher pressure than the axle modulators 30 and 40, so that the shuttle valve 34 allows air to flow from the security brake valve 71 to the brake chamber 50.

  In step S3, when the second EBSECU 15B determines that both the traction ECU 11 has no abnormality or that one of the traction ECU 11 has abnormality (step S3: NO), the second EBSECU 15B determines the abnormality of the traction ECU 11. The brake control for decelerating traveling is performed based on the deceleration request (step S5). Specifically, the second EBS ECU 15B controls the solenoid valves of the security modulators 32L, 32R, 42L, 42R. Then, air is supplied from the suspension tank 28 to the brake chamber 50 via the security modulators 32L, 32R, 42L, 42R. At this time, the second EBS ECU 15B acquires the pressure value detected by the pressure sensor 54. Further, the second EBS ECU 15B adjusts the air supply amount so that the vehicle 100 reaches a predetermined speed based on the acquired pressure value and the learning result, with the deceleration or the like instructed from the towing ECU 11 as a target. As a result, the vehicle 100 decelerates to a predetermined speed within a range of, for example, 20 km / h or more and 40 km / h or less, and travels while maintaining the speed.

  On the other hand, if the second EBS ECU 15B determines that the first EBS ECU 15A has not failed in the step S2 (step S2: NO), the second EBS ECU 15B determines whether or not both the towing ECU 11 has a failure (step S2). Step S6). When the second EBS ECU 15B determines that an abnormality has occurred in both the traction ECU 11 (step S6: YES), the security brake valve 71 is de-energized, so that the forced brake is mechanically activated (step S7). .

  In step S6, if the second EB ECU 15B determines that an abnormality has occurred in the first traction ECU 11A or the second traction ECU 11B (step S6: NO), an abnormality has already occurred in one of the ECUs 20 in step S1. It is determined that there is no abnormality in the first EBS ECU 15A in step S2, so that the first EBS ECU 15A and one of the traction ECUs 11 are operating normally. In this case, the first EB ECU 15A performs normal brake control (step S8).

  After any of the forced braking (steps S4 and S7), the decelerating running (step S5), and the brake control (step S8) by the first EBS ECU 15A, the second EBS ECU 15B determines an abnormality while the ignition switch is on. Is repeated (step S1 to step S8). While the abnormality determination is repeated in this manner, for example, first, only the first traction ECU 11A becomes abnormal, and then, if an abnormality occurs in the first EBS ECU 15A, the brake control by the first EBS ECU 15A shifts to deceleration driving. . That is, the brake control changes stepwise according to the level (degree) of the abnormality of the pneumatic brake system.

Next, the state transition of the brake control according to the abnormality level will be described with reference to FIGS.
FIG. 5A shows a state transition when an abnormality first occurs in the first EB ECU 15A. When there is no abnormality in any of the ECUs 20, brake control is being performed by the first EB ECU 15A (state 200). In this state, first, when an abnormality occurs in the first EBS ECU 15A, the second EBS ECU 15B detects the abnormality in the first EBS ECU 15A, and performs deceleration traveling by the second EBS ECU 15B (state 201).

  If an abnormality occurs in the second EBS ECU 15B in a state where the decelerated traveling is maintained, the first traction ECU 11A or the second traction ECU 11B detects an abnormality in the first EBS ECU 15A and the second EBS ECU 15B, and turns off the security brake valve 71, The forcible brake is operated (state 203).

  When an abnormality occurs in one of the traction ECUs 11 in a state where the deceleration traveling is maintained (state 201), the second EBS ECU 15B detects an abnormality in one of the first EBS ECU 15A and the towing ECU 11, and performs the deceleration traveling by the second EBS ECU 15B. (State 204). Further, when an abnormality occurs in the other towing ECU 11 that has been operating normally, the security brake valve 71 is de-energized, so that the forced brake is activated (state 205).

  In the state where deceleration is maintained (state 201), if an abnormality occurs in both traction ECUs 11 at the same time, the security brake valve 71 is de-energized, and the forced brake is activated (state 206).

  The operation of the forced brake when both of the traction ECUs 11 fail (for example, the state 206) is at a timing corresponding to the vehicle 100 in which both the traction ECUs 11 have failed. On the other hand, when one of the towing ECUs 11 fails, the forced braking operation (for example, the state 203) can be performed because the normal towing ECU 11 can adjust the brake timing of the vehicles constituting the platooning, so that collision with the following vehicle can be avoided. Easy.

  FIG. 5B shows a state transition when an abnormality first occurs in the second EBS ECU 15B. If there is no abnormality in any of the ECUs 20, brake control is performed by the first EB ECU 15A (state 200). In this state, if an abnormality first occurs in the second EBS ECU 15B, the second EBS ECU 15B does not hinder the brake control of the first EBS ECU 15A, so that the first EBS ECU 15A performs normal brake control (state 210).

  If an abnormality occurs in the first EB ECU 15A in a state where the normal brake control is maintained (state 210), the first traction ECU 11A, the second traction ECU 11B, or both detect the abnormality of the first EB ECU 15A and the second EB ECU 15B, and perform security. The brake valve 71 is de-energized, and the forced brake is operated (state 211).

  In a state where the normal brake control is maintained (state 210), if an abnormality occurs in one of the traction ECUs 11, the first EB ECU 15A performs the normal brake control because the brake control is possible (state 212). Next, when an abnormality occurs in the first EBSECU 15A, the normally operating traction ECU 11 turns off the security brake valve 71 and activates the forced brake (state 213).

  In the state where the normal brake control is maintained (state 210), if an abnormality occurs simultaneously in both the traction ECUs 11, the security brake valve 71 is de-energized, and the forced brake is mechanically activated (state 214). ).

  FIG. 6 shows a state transition when an abnormality occurs in one of the first traction ECU 11A and the second traction ECU 11B first. When there is no abnormality in any of the ECUs 20, brake control is being performed by the first EB ECU 15A (state 200). In this state, when an abnormality occurs in one of the traction ECUs 11 first, normal brake control is performed because the brake control by the first EB ECU 15A is possible (state 220).

  If an abnormality occurs in the first EBS ECU 15A in a state where the normal brake control is maintained (state 220), the second EBS ECU 15B detects the abnormality of the first EBS ECU 15A and performs deceleration traveling by the second EBS ECU 15B (state 221). In a state where the deceleration traveling is maintained (state 221), if an abnormality occurs in the other traction ECU 11 and both the traction ECUs 11 are in an abnormal state, the security brake valve 71 is in a non-energized state. (State 222). Further, when the second EBS ECU 15B has an abnormality in a state where the deceleration traveling is maintained (state 221), the normal traction ECU 11 detects the abnormality of the first EBS ECU 15A and the second EBS ECU 15B, and turns off the security brake valve 71. Then, the forced brake is operated (state 223).

  In the state where the normal brake control is maintained (state 220), if an abnormality occurs in the second EB ECU 15B, the first EB ECU 15A performs the normal brake control because the brake control is possible (state 224). Next, when an abnormality occurs in the traction ECU 11 that has been operating normally, the security brake valve 71 is de-energized, and the forced brake is mechanically activated (state 225). Alternatively, even if an abnormality occurs in the first EBS ECU 15A following the one traction ECU 11 and the second EBS ECU 15B, the normally operating traction ECU 11 turns off the security brake valve 71 and activates the forced brake (state). 226).

  In the state where the normal brake control is maintained (state 220), if an abnormality occurs simultaneously in the traction ECU 11 that is operating normally, the security brake valve 71 is de-energized, so that the forced brake is mechanically activated. (State 227).

As described above, according to the above embodiment, the following effects can be obtained.
(1) The shuttle valve 34 supplies air to the brake chamber 50 from the high-pressure side of the security air supply unit 33 and other air supply circuits such as the axle modulators 30 and 40. Therefore, even when an abnormality occurs in one or both of the security air supply unit 33 and the other air supply circuit or an abnormality occurs in the second EB ECU 15B, the air is supplied to the brake chamber 50 to operate the brake. be able to. Therefore, the redundancy of the pneumatic brake system can be increased. Further, since the security air supply unit 33 and the shuttle valve 34 are provided for each wheel, the responsiveness of the brake control in an emergency can be improved.

  (2) The security brake valve 71 controlled by the traction ECU 11 supplies the air from the suspension tank 28 to the brake chamber 50 in a non-energized state. Further, the shuttle valve 34 allows the supply of air from the security brake valve 71 side to the brake chamber 50 side. Therefore, even if an abnormality occurs in the traction ECU 11, the brake can be forcibly operated.

  (3) Since the second EBS ECU 15B is controlled based on a braking request from the towing ECU 11, the vehicle 100 can run even if an abnormality occurs in the first EBS ECU 15A. Therefore, the redundancy of the pneumatic brake system 10 can be increased.

  (4) Even if no abnormality occurs in the second EB ECU 15B, the brake is forcibly activated when an abnormality occurs in the first EB ECU 15A and the traction ECU 11. Therefore, the redundancy of the pneumatic brake system 10 can be increased.

  (5) Since the amount of air supplied to the brake chamber 50 is changed by the load sensing valve 72 according to the load of the vehicle 100, the braking force can be increased when the load is large. Further, since the load sensing valve 72 communicates with the air suspension system and changes the supply amount of air according to the air pressure of the air suspension system, even when an abnormality occurs in the electric system such as the ECU 20, the load sensing valve 72 responds to the load. The braking force can be changed mechanically. Further, the braking force can be adjusted so as not to collide with the vehicle ahead.

The above-described embodiment can be implemented with appropriate modifications as described below.
The security air supply unit 33 and the security brake valve 71 use the suspension tank 28 as an air supply source, but may be the air storage tank 21 or another tank.

  In the above embodiment, the load sensing valve 72 communicating with the suspension system is provided. However, if feedback control of the braking force can be performed based on the vehicle speed acquired from the vehicle speed sensor 53, this may be omitted. Alternatively, the towing ECU 11 may acquire a load value from a load sensor that detects the load, and output a deceleration request to the second EB ECU 15B based on the load value. Alternatively, the second EB ECU 15B may directly acquire the load value from the load sensor.

  In the above embodiment, when an abnormality occurs in one of the first EBS ECU 15A and the traction ECU 11, the forcible brake is operated by the traction ECU 11 that normally operates. Alternatively, the second EB ECU 15B may perform the brake control based on a deceleration request from the normally operating traction ECU 11. Alternatively, the second EB ECU 15B may operate the brake so that the vehicle 100 runs at a predetermined speed (for example, 20 km / h).

  In the above embodiment, the second EBS ECU 15B reduces the speed to, for example, 20 km / h when an abnormality occurs in the first EBS ECU 15A. However, the second EBS ECU 15B may operate the brake to stop the vehicle 100. Further, when an abnormality occurs in the first EBS ECU 15A, the second EBS ECU 15B may control the brake in accordance with the same control as that of the first EBS ECU 15A, that is, control the brake in response to the deceleration request of the towing ECU 11, and cause the vehicle 100 to travel.

  In the above embodiment, the normal brake control is performed even when an abnormality occurs in the second EB ECU 15B (state 210). Instead, when an abnormality occurs in the second EB ECU 15B, the first EB ECU 15A may perform deceleration traveling. In this way, if an abnormality occurs in the first EBS ECU 15A or the like, the vehicle can be gently stopped.

  In the above embodiment, the pneumatic brake system 10 includes the security brake valve 71 for operating the forced brake. However, if there is a mechanism for operating the brake when an abnormality occurs in all the ECUs 20, for example, May be omitted.

  The pneumatic brake system 10 only needs to include at least the second EBS ECU 15B and the security modulators 32L, 32R, 42L, 42R, and other configurations can be changed as appropriate.

  In the above embodiment, the security modulators 32L, 32R, 42L, 42R are provided so as to correspond to the respective wheels. Alternatively, the security modulator may be provided corresponding to at least one wheel. Alternatively, the security modulator may be provided corresponding to both wheels of one axle. Alternatively, the security modulator may be provided corresponding to at least one drive wheel.

  In the above embodiment, the configurations of the security modulators 32L, 32R, 42L, and 42R are the same. Instead of this, the configuration of the front wheel security modulators 32L, 32R may be different from the configuration of the rear wheel security modulators 42L, 42R. Further, the configuration of the security module may be different between the left wheel and the right wheel.

  In the above embodiment, the pneumatic brake system 10 has been described as the brake system of the vehicle 100 that performs platooning. However, the pneumatic brake system 10 may be mounted on the brake system of a vehicle that travels alone without performing platooning.

  In the above embodiment, the vehicle 100 uses the rear wheel 52 as a drive wheel, but the vehicle 100 may use the front wheel 51 as a drive wheel. In the above-described embodiment, the pneumatic brake system 10 has been described as being mounted on a cargo vehicle having a carrier. As another aspect, the air supply system may be mounted on another vehicle such as a passenger car, a connected vehicle having a trailer connected to a tractor, a railway vehicle, and the like.

  Reference Signs List 10: pneumatic brake system, 11: traction ECU, 11A: first traction ECU as main control device, 11B: second traction ECU as main control device, 15A: first EBS ECU as brake control device, 15B: security brake 2nd EBS ECU as a control device, 19 ... onboard network, 20 ... ECU, 21 ... air storage tank, 22 ... compressor, 23 ... air dryer, 24 ... protection valve, 25 ... parking brake tank, 26 ... rear wheel brake tank, 27: Front wheel brake tank, 28: Suspension tank as air supply source, 30, 40: Axle modulator, 31: Brake valve, 31A: Front wheel control unit, 31B: Rear wheel control unit, 32L, 32R, 42L , 42R ... security modulator, 33 ... security Air supply unit, 34 shuttle valve, 36 ABS valve, 50 brake chamber as a brake mechanism, 53 vehicle speed sensor, 54 pressure sensor, 55 parking brake control valve, 56 parking brake relay valve, 60 to 63 ... supply path, 65 ... signal supply path, 66 ... tank side supply path, 70 ... forced brake modulator, 71 ... security brake valve as solenoid valve for forced braking, 72 ... load sensing valve as valve device, 100 ... vehicle, 100a: Leading vehicle, 100b: Following vehicle.

Claims (5)

A pneumatic brake system that supplies air to a brake mechanism of a vehicle to operate a brake and discharges air from the brake mechanism to release the brake,
A security air supply unit that is operated by a security brake control device in an emergency and supplies air to the brake mechanism;
The security air supply unit and a brake air supply circuit that supplies air to the brake mechanism through a different path from the security air supply unit, and the security air supply unit and the brake air supply circuit A shuttle valve that allows air flow only in a direction from the high pressure side to the brake mechanism,
The pneumatic brake system, wherein the security air supply unit and the shuttle valve are provided for each wheel of the vehicle. A forced brake solenoid valve controlled by a main control device that outputs a braking request to a security brake control device that controls the security air supply unit,
The electromagnetic valve for forced braking shuts off the supply of air from the air supply source that stores compressed air to the brake mechanism side in an energized state energized by the main control device, and the air in a non-energized state. Supplying air from a supply source to the brake mechanism side,
The pneumatic brake system according to claim 1, wherein the shuttle valve permits supply of air from the solenoid valve for forced brake to the brake mechanism when air is supplied from the solenoid valve for forced brake. An air-driven suspension system is connected between the solenoid valve for forced braking and the security air supply unit so that the amount of air supplied to the brake mechanism increases in accordance with an increase in the load on the vehicle. The pneumatic brake system according to claim 2, further comprising a valve device configured to change the pressure. The security brake control device detects an abnormality of a brake control device that controls an air supply circuit different from the security air supply unit, and supplies air to the brake mechanism based on a braking request of the main control device. The pneumatic brake system according to claim 2 or 3, wherein the vehicle travels or stops at a predetermined speed. When an abnormality occurs in the brake control device that controls an air supply circuit different from the security air supply unit and the main control device, the solenoid valve for forced braking is de-energized, and the brake is forcibly activated. The pneumatic brake system according to claim 2 or 3.