JP2024114874A - Pneumatic pressure control device, pneumatic circuit and brake control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic pressure control device for coping with an abnormality, which is easily retrofitted to even an existing vehicle, a pneumatic circuit and a brake control system.

SOLUTION: A pressure control module 20 includes: a pneumatic circuit 22 that has a first port P1 connected to an air tank of a vehicle, a second port P2 connected to a brake valve outputting a pneumatic pressure signal when a braking operation is performed and a third port P3 connected to a brake mechanism applying braking force to a wheel on the basis of the pneumatic pressure signal and that enables switching between a first communication state for communicating air from the second port P2 to the third port P3 and a second communication state for communicating air from the first port P1 to the third port P3; and a sub ECU 32 that switches the pneumatic circuit 22 from the first communication state to the second communication state on the basis of an abnormal signal indicating an abnormality of a driver.

SELECTED DRAWING: Figure 9

COPYRIGHT: (C)2024,JPO&INPIT

Description

This disclosure relates to an air pressure control device, an air pressure circuit, and a brake control system.

Guidelines have been established for a system that can be operated by a passenger other than the driver to stop the vehicle as an emergency measure in the event that the driver is suddenly unable to continue driving safely due to a sudden change in the driver's physical condition, etc. (see, for example, Non-Patent Document 1). In addition, various brake systems, etc. have been proposed in accordance with these guidelines.

Basic Design Document for Driver Abnormality Response System (Deceleration and Stop Type), March 2016, Ministry of Land, Infrastructure, Transport and Tourism, Road Transport Bureau, Advanced Safety Vehicle Promotion Study Group

Many of the brake systems that have already been proposed are intended for application to new vehicles equipped with an EBS (Electronically Controlled Brake System). For this reason, the reality is that application of these systems to vehicles that control the command system for the brake mechanism with air pressure, particularly to existing vehicles that are already in use, has been delayed in responding to abnormal conditions.

The objective of this disclosure is to provide an air pressure control device, air pressure circuit, and brake control system for emergency response that can be easily installed on a vehicle in use.

In one aspect, an air pressure control device that solves the above problem has a first port that connects to an air tank of a vehicle, a second port that connects to a brake valve that outputs an air pressure signal when the brakes are applied, and a third port that connects to a brake mechanism that applies a braking force to a wheel based on the air pressure signal, and is equipped with an air pressure circuit that can be switched between a first communication state in which air is supplied from the second port to the third port and a second communication state in which air is supplied from the first port to the third port, and a control unit that switches the air pressure circuit from the first communication state to the second communication state based on an abnormality signal indicating an abnormality of the driver.

The air pressure control device may have a case that houses the control unit, and a body that is connected to the case and has the first port, the second port, the third port, and flow paths that connect these ports.

The air pressure control device may include a first control unit that acquires vehicle speed information and calculates a target pressure by comparing the vehicle speed information with a target value, and a second control unit that controls the air pressure circuit so that the detection value of the pressure sensor approaches the target pressure.

For the above air pressure control device, the first control unit may calculate the target pressure so that the deceleration of the vehicle approaches a first target deceleration during a predetermined period after the abnormal signal is input, and may calculate the target pressure so that the deceleration of the vehicle approaches the second target deceleration, the absolute value of which is greater than that of the first target deceleration, after the predetermined period has elapsed.

In the above air pressure control device, the air pressure circuit may include a pneumatically driven air pressure valve connected to the air tank, a solenoid valve for applying air pressure to the air pressure valve, and a directional control valve that allows air to flow from either the second port side or the air pressure valve side, whichever has a higher pressure, and the air pressure valve may switch between a supply state that supplies air to the directional control valve side and an exhaust state that exhausts air from the directional control valve side according to the air pressure applied by the solenoid valve.

In the above air pressure control device, the solenoid valve may be composed of an intake solenoid valve that communicates with a passage for applying air pressure to the pneumatically driven valve, and an exhaust solenoid valve that can exhaust air from within the passage.

In another aspect, the pneumatic circuit that solves the above problem is a pneumatic circuit that is driven based on an abnormality signal indicating an abnormality in the driver, and includes an air-pressure-driven pneumatic valve connected to an air tank of the vehicle, an electromagnetic valve for applying air pressure to the pneumatic valve, and a directional control valve that allows air to flow from either a port side connected to a brake valve that outputs an air pressure signal when the brakes are applied or the pneumatic valve side, whichever has a higher pressure, and the pneumatic valve switches between a supply state in which air is supplied from the air tank to the directional control valve side and an exhaust state in which air is exhausted from the directional control valve side, depending on the air pressure applied by the electromagnetic valve.

In another aspect, a vehicle brake control system that solves the above problem includes a brake control circuit that controls a brake drive unit that applies a braking force to the wheels based on the driver's brake operation, a detection unit that detects an abnormality in the driver, an abnormality brake control circuit that controls the brake drive unit when the driver is abnormal and includes a circuit separate from the brake control circuit, and a control unit that operates the abnormality brake control circuit so that the vehicle decelerates at a predetermined deceleration based on an abnormality signal that indicates the driver's abnormality output from the detection unit.

1 is a schematic diagram showing an overall configuration of a pneumatic brake system including a pneumatic control device according to an embodiment; FIG. 2 is a perspective view showing the appearance of the air pressure control device according to the embodiment. FIG. 2 is a front view showing the appearance of the air pressure control device according to the embodiment; FIG. 2 is a plan view showing the appearance of the air pressure control device according to the embodiment. FIG. 2 is a left side view showing the appearance of the air pressure control device according to the embodiment; FIG. 2 is a right side view showing the appearance of the air pressure control device according to the embodiment. FIG. 2 is a bottom view showing the appearance of the air pressure control device according to the embodiment. FIG. 2 is a rear view showing the appearance of the air pressure control device according to the embodiment. FIG. 2 is a schematic diagram of the emergency response system according to the embodiment. FIG. 2 is a circuit diagram of the pneumatic circuit of the embodiment, in a first communication state in which the brake valve is connected to the brake mechanism; FIG. 11 is a circuit diagram of the pneumatic circuit of FIG. 10 in a second communication state in which the air tank is connected to the brake mechanism. 4 is a flowchart showing a processing procedure of the abnormality response system according to the embodiment. 4 is a flowchart showing a processing procedure of the abnormality response system according to the embodiment. FIG. 11 is a schematic diagram showing a part of a pneumatic brake system including a pneumatic control device according to a modified example of the pneumatic control device. FIG. 11 is a schematic diagram showing a part of a pneumatic brake system including a pneumatic control device according to a modified example of the pneumatic control device. 13 is a perspective view showing the appearance of an air pressure control device in a modified example in which the air pressure control device has a case made up of a first case member and a second case member. FIG. FIG. 17 is a front view showing the appearance of the air pressure control device of FIG. 16 . FIG. 17 is a plan view showing the appearance of the air pressure control device of FIG. 16 . FIG. 17 is a left side view showing the appearance of the air pressure control device of FIG. 16 . FIG. 17 is a right side view showing the appearance of the air pressure control device of FIG. 16 . FIG. 17 is a bottom view showing the appearance of the air pressure control device of FIG. 16 . FIG. 17 is a rear view showing the appearance of the air pressure control device of FIG. 16 .

The following describes one embodiment of an air pressure control device and an air pressure circuit provided in the air pressure control device. The air pressure control device is provided in a pneumatic brake system mounted on a vehicle such as a bus.

As shown in FIG. 1, the pneumatic brake system 11 mounted on the vehicle 10 is a full air brake system that controls the command system of the brake mechanism with air pressure and has an air-driven brake mechanism. The pneumatic brake system 11 is equipped with an air tank 12 that stores compressed air generated by a compressor (not shown). The air tank 12 has a first tank 12A, a second tank 12B, and a third tank 12C. For example, the first tank 12A is a tank that stores compressed air for applying a braking force to the front wheels of the vehicle 10, and the second tank 12B is a tank that stores compressed air for applying a braking force to the rear wheels of the vehicle 10. The third tank 12C is a tank that stores compressed air used for other purposes. The first tank 12A and the second tank 12B are connected to the front pressure chamber 13A and the rear pressure chamber 13B of the brake valve 13. In addition, the first tank 12A and the second tank 12B are connected to the air horn device 14B via a protection valve 14A.

The brake valve 13 is also connected to a pair of relay valves 15 via a pair of air pipes 18. When the driver operates the brake pedal 13C of the brake valve 13, an air pressure signal is output from the brake valve 13 to the relay valve 15. Each relay valve 15 is also connected to the air tank 12 via an air pipe (not shown). When an air pressure signal from the brake valve 13 is input to the relay valve 15, a large amount of compressed air stored in the air tank 12 is supplied to the relay valve 15 via the air pipe. The large amount of compressed air supplied to the relay valve 15 is supplied to the brake chamber 17 via the ABS (Anti-lock Brake System) control valve 16. The brake chamber 17 generates a braking force on the wheels by the air being supplied to it. The ABS control valve 16 and the brake chamber 17 constitute an air pressure-driven brake mechanism.

When the pneumatic brake system 11 of a vehicle in use (existing vehicle) is equipped with an emergency response system that stops the vehicle through the operation of a passenger other than the driver, a pressure control module (PCM: Pressure Control Module) 20 is provided in the air piping 18 of the command system that connects the brake valve 13 and the relay valve 15. The pressure control module 20 has a first port P1 that connects to the air tank 12 (third tank 12C), a second port P2 that connects to each of the brake valves 13, and a third port P3 that connects to each of the brake mechanisms including the relay valve 15. The pressure control module 20 corresponds to an air pressure control device. Note that since the pressure control module 20 is provided between the brake valve 13 and the relay valve 15, it can also be installed in a pneumatic brake system 11 that has a brake mechanism other than an air pressure-driven type.

Next, the pressure control module 20 will be described, including its external appearance, with reference to Figures 2 to 8. As shown in Figures 2 to 6, the pressure control module 20 has a case 210 that houses a control device and the like. The case 210 is made of, for example, resin. A body 211 in which a flow path and the like are formed is connected to the case 210. The body 211 is made of, for example, aluminum, and is manufactured by a casting method such as aluminum die casting. The body 211 is provided with a port connection section 212 that is connected to various ports. A pair of second ports P2 to which the front air supply passage 37 and the rear air supply passage 38 of the brake valve 13 are respectively connected are provided on a first surface 213 of the port connection section 212.

A pair of third ports P3 connected to the front signal supply path 24A and the rear signal supply path 24B are provided on the second surface 214 of the port connection portion 212, which is perpendicular to the first surface 213 on which the second port P2 is provided. Next to the third port P3, a first port P1 is provided to which the first supply path 23, to which compressed air is supplied from the air tank 12, is connected.

As shown in FIG. 7, the underside of the body 211 is provided with an exhaust section 58 housing a silencer. Also, as shown in FIG. 8, the rear surface of the body 211 is provided with a protrusion 215 protruding from the body 211. Also, the underside of the case 210 is provided with a connection section 216 for connecting the control device housed in the case 210 to an external power source or an electrical system cable for an in-vehicle network.

As described above, the pressure control module 20 is a unit that integrates a control device that controls the pneumatic circuit and a flow path. When attaching the pressure control module 20 to the vehicle 10, the protrusion 215 is fixed to a predetermined position on the vehicle body. The first port P1 is connected to a pipe that connects to the air tank 12, the second port P2 is connected to a pipe that connects to the brake valve 13, and the third port P3 is connected to the relay valve 15. The cable of the electrical system is also connected to the connection part 216. In other words, the pressure control module 20 is the only major component that needs to be retrofitted to the pneumatic brake system 11 to respond to abnormalities.

The pneumatic circuit of the pressure control module 20 will be described in detail with reference to FIG. 9. The pressure control module 20 includes a pneumatic circuit 22 and a sub-ECU (electronic control unit: electronic control unit) 32. The pressure control module 20, together with the main ECU 31, constitutes an abnormality response system 50. The main ECU 31 may be provided outside the case 210 or may be housed within the case 210.

The main ECU 31 and the sub ECU 32 each include a calculation unit, a communication interface unit, a volatile storage unit, and a non-volatile storage unit. The calculation unit is a computer processor, and controls the pneumatic brake system 11 according to a control program stored in the non-volatile storage unit (storage medium). The calculation unit may realize at least a part of the processing it executes by using a circuit such as an ASIC. The control program may be executed by one computer processor, or may be executed by multiple computer processors. In addition, the main ECU 31 and the sub ECU 32 are connected to an in-vehicle network such as a CAN (Controller Area Network) 33, and transmit and receive various information to and from each other.

When the operation switch 51 and the release switch 52 are turned on, the on signals output from them are input to the main ECU 31. The operation switch 51 and the release switch 52 are intended to be operated by the driver and are located near the driver's seat. When the operation switch 51 is turned on, the emergency response system 50 is activated. The release switch 52 is a switch for stopping the operation of the emergency response system 50 in the event that the system is erroneously activated, etc.

When the passenger seat operation switch 53 is turned on, an on signal is output from it and input to the main ECU 31. The passenger seat operation switch 53 is a switch that is intended to be operated by a passenger other than the driver. The passenger seat operation switch 53 is provided in a position other than the driver's seat and in a position that can be operated by a passenger other than the driver.

The main ECU 31 acquires vehicle speed information indicating the vehicle speed from the vehicle speed sensor 55 via the CAN 33. When the abnormality response system 50 starts to operate, the main ECU 31 calculates the air pressure of the pneumatic brake system 11 so that the deceleration obtained from the vehicle speed information approaches the target deceleration, which is a target value, and instructs the sub ECU 32 of the calculated air pressure. This target deceleration can be changed by updating the data stored in the memory unit of the main ECU 31, etc. For example, when the vehicle 10 is a public bus, it is assumed that there are passengers standing inside the vehicle, so the absolute value of the target deceleration is made small. Also, when the vehicle 10 is an express bus in which all passengers are seated, the absolute value of the target deceleration may be made larger than that of a public bus. It is also possible to change the target deceleration depending on the weight and length of the vehicle 10.

Furthermore, when the abnormality response system 50 is activated, the main ECU 31 outputs an instruction signal to the in-vehicle device 56 and the outside-vehicle device 57. The in-vehicle device 56 is, for example, an accelerator interlock mechanism that disables the operation of the accelerator pedal. The main ECU 31 activates the accelerator interlock mechanism when an abnormality occurs. In addition, an alarm buzzer, an alarm lamp, etc. may be provided in the vehicle cabin as the in-vehicle device 56. For example, when an abnormality occurs, the main ECU 31 outputs a sound from the alarm buzzer and turns on or blinks the alarm lamp. The outside-vehicle device 57 is, for example, an air horn device 14B, a hazard lamp, a brake lamp, etc. For example, when an abnormality occurs, the main ECU 31 drives the protection valve 14A, etc., supplies air to the air horn device 14B to generate an alarm sound, and turns on or blinks the hazard lamp and the brake lamp.

The sub-ECU 32 is housed in the case 210 of the pressure control module 20 and controls various valves of the pressure control module 20. The pressure control module 20 has a first supply passage 23 that connects to the air tank 12. The first supply passage 23 is connected to a front air supply passage 37 that connects via a relay valve 15 to the brake chamber 17 provided on the front wheel, and a rear air supply passage 38 that connects to the brake chamber 17 provided on the rear wheel.

A relay valve 25 is connected to the first supply path 23. The relay valve 25 has an exhaust port 25A, which is connected to an exhaust section 58 having a silencer. The relay valve 25 also has a pilot port 25B. The pilot port 25B is connected to a branch path 26 that branches off from the first supply path 23. When the air pressure applied to the pilot port 25B from the branch path 26 is a predetermined pressure such as atmospheric pressure, the relay valve 25 is in an exhaust state in which the first supply path 23 is blocked by the biasing force of a biasing spring or the like. When the relay valve 25 is in an exhaust state, the flow of air from the air tank 12 to the front air supply path 37 and the rear air supply path 38 is blocked. When the relay valve 25 is in an exhaust state, the first portion of the first supply path 23 downstream of the relay valve 25 is connected to the exhaust section 58, and compressed air is discharged from the first portion of the first supply path 23. As a result, the pressure in the first portion of the first supply path 23 becomes a predetermined pressure, such as atmospheric pressure.

On the other hand, when the air pressure applied from the branch passage 26 to the pilot port 25B reaches a driving pressure higher than a predetermined pressure such as atmospheric pressure, the relay valve 25 is in a supply state in which the first supply passage 23 is open against the biasing force of a biasing spring or the like. When the relay valve 25 is in a supply state, air is supplied from the air tank 12 to the front air supply passage 37 and the rear air supply passage 38. When the relay valve 25 is in a supply state, the first supply passage 23 is open to the front air supply passage 37 and the rear air supply passage 38. When the pressure on the outlet side (secondary side) is excessively high, the relay valve 25 is in an exhaust state in which it blocks the open state of the first supply passage 23.

The branch passage 26 has a first end connected to the first supply passage 23 and a second end connected to the exhaust section 58. An intake valve 27 and an exhaust valve 28 are provided in the middle of the branch passage 26. The intake valve 27 and the exhaust valve 28 are solenoid valves and are driven by the sub-ECU 32. The intake valve 27 is provided upstream (closer to the air tank 12) of the exhaust valve 28 in the branch passage 26. The operation of the intake valve 27 is switched according to the power on/off (driven/non-driven) from the sub-ECU 32 via the wiring 27A. The intake valve 27 is in a closed position that closes the branch passage 26 when the power is turned off and in a non-driven state. The intake valve 27 is in an open position that opens the branch passage 26 when the power is turned on and in a driven state.

The exhaust valve 28 is an electromagnetic valve whose operation is switched according to the on/off (drive/non-drive) of the power source from the sub-ECU 32 via the wiring 28A. When the exhaust valve 28 is in the non-drive state with the power turned off, it is in the open position that communicates with the branch path 26. When the exhaust valve 28 is in the drive state with the power turned on, it is in the closed position that closes the branch path 26. In other words, when the intake valve 27 is in the closed position with the intake valve 27 in the non-drive state, the exhaust valve 28 opens the downstream of the intake valve 27 and the signal supply path 29 to the atmosphere. When the exhaust valve 28 is in the drive state, the branch path 26 upstream of the intake valve 27 and the first supply path 23 upstream of the relay valve 25 are at atmospheric pressure.

In addition, a signal supply path 29 that supplies an air pressure signal to the relay valve 25 and a first pressure sensor 35 are connected to the branch path 26 between the intake valve 27 and the exhaust valve 28. The first pressure sensor 35 detects the pressure between the intake valve 27 and the exhaust valve 28 in the branch path 26 and outputs a signal indicating the detected pressure to the sub-ECU 32.

The first supply passage 23 is also connected to a third supply passage 30. The third supply passage 30 is connected to a pair of double check valves 36, i.e., double check valves 36A and 36B. The double check valve 36A is connected to the third supply passage 30, the front signal supply passage 24A connected to the front pressure chamber 13A of the brake valve 13, and the front air supply passage 37 for generating a braking force on the front wheels. This double check valve 36A allows the supply of compressed air from one of the third supply passage 30 and the front signal supply passage 24A, i.e., the one with the higher pressure, and blocks the supply of compressed air from the other, i.e., the one with the lower pressure. A second pressure sensor 39 is connected to the front air supply passage 37. The second pressure sensor 39 outputs a signal indicating the detected pressure to the sub-ECU 32.

The double check valve 36B is connected to the third supply passage 30, the rear signal supply passage 24B that connects to the rear pressure chamber 13B of the brake valve 13, and the rear air supply passage 38 that applies braking force to the rear wheels. This double check valve 36B allows the supply of compressed air from one of the third supply passage 30 and the rear signal supply passage 24B, i.e., the one with the higher pressure, and blocks the supply of compressed air from the other, i.e., the one with the lower pressure.

Next, the operation of the pressure control module 20 will be described with reference to Figures 10 and 11. Figure 10 shows the air pressure circuit 22 when the operation switch 51 and the passenger seat operation switch 53 are not turned on. In Figure 10, the air pressure circuit 22 is in a first communication state in which the brake valve 13 is connected to the brake mechanism and air is supplied from the second port P2 to the third port P3.

As shown in FIG. 10, when the operation switch 51 and the passenger seat operation switch 53 are not turned on, the sub-ECU 32 deactivates the intake valve 27 and the exhaust valve 28. In this case, the intake valve 27 is in the closed position, and the exhaust valve 28 is in the open position. As a result, the pressure downstream of the intake valve 27 in the branch path 26 becomes a predetermined pressure such as atmospheric pressure because the exhaust valve 28 is in the open position. Therefore, the air pressure applied to the pilot port 25B also becomes a predetermined pressure, and the relay valve 25 becomes in the exhaust state. When the relay valve 25 becomes in the exhaust state, the compressed air downstream of the relay valve 25 in the third supply path 30 and the first supply path 23 is discharged from the exhaust section 58, and the pressure in the third supply path 30 becomes a predetermined pressure. Furthermore, when the brake pedal 13C is depressed, an air pressure signal is supplied to the front signal supply path 24A and the rear signal supply path 24B. As a result, the pressure in the front signal supply path 24A and the rear signal supply path 24B becomes higher than the pressure in the third supply path 30, and the double check valves 36A and 36B block the flow of air from the third supply path 30 to the front air supply path 37 and the rear air supply path 38, respectively. This causes air pressure signals to be supplied from the front signal supply path 24A and the rear signal supply path 24B to the front air supply path 37 and the rear air supply path 38. As a result, a large amount of compressed air is supplied from the air tank 12 to the relay valve 15 by supplying an air pressure signal to the relay valve 15. When the relay valve 15 supplies compressed air to the brake chamber 17, a braking force is applied to the wheels. The air pressure circuit including the front signal supply path 24A and the rear signal supply path 24B corresponds to a brake control circuit.

Figure 11 shows the air pressure circuit 22 when at least one of the operation switch 51 and the passenger seat operation switch 53 is turned on. In Figure 11, the air pressure circuit 22 is in a second communication state in which the air tank 12 is connected to the brake mechanism and air is supplied from the first port P1 to the third port P3. When at least one of the operation switch 51 and the passenger seat operation switch 53 is turned on, the sub ECU 32 receives a pressure instruction sent from the main ECU 31. The sub ECU 32 drives the intake valve 27 and the exhaust valve 28 based on the pressure instruction. As a result, the intake valve 27 is in an open position and the exhaust valve 28 is in a closed position. The compressed air in the air tank 12 is supplied to the branch path 26 between the intake valve 27 and the exhaust valve 28 via the first supply path 23. When the pressure in the branch passage 26 between the intake valve 27 and the exhaust valve 28 reaches the drive pressure, this pressure is applied to the relay valve 25 via the pilot port 25B, causing the relay valve 25 to enter a supply state. This causes compressed air to be supplied to the third supply passage 30 via the first supply passage 23 and the relay valve 25.

When compressed air is supplied to the third supply passage 30, the pressure in the third supply passage 30 becomes higher than the pressure in the front signal supply passage 24A and the rear signal supply passage 24B. Therefore, the double check valve 36 allows air to flow from the third supply passage 30 to the front air supply passage 37 and the rear air supply passage 38, and blocks air from the front signal supply passage 24A and the rear signal supply passage 24B to the front air supply passage 37 and the rear air supply passage 38. The air pressure circuit including the third supply passage 30 and the flow paths (first supply passage 23, branch passage 26, etc.) connecting the intake valve 27, exhaust valve 28, and relay valve 25 corresponds to an abnormality brake control circuit.

In this way, by providing the pressure control module 20 between the brake valve 13 and the relay valve 15, when the operation switch 51 and the passenger seat operation switch 53 are turned on, the air pressure-driven command system switches from a system via the brake valve 13 to a system in which air is supplied directly from the air tank 12. Therefore, it is possible to operate the brake chamber 17 and generate braking force without inputting an air pressure signal from the brake valve 13 to the relay valve 15.

In addition, the sub-ECU 32 acquires the detected pressure from the first pressure sensor 35 and the second pressure sensor 39 at a predetermined timing. For example, when the relay valve 25 is maintained in a supply state, the sub-ECU 32 controls the driving or non-driving of the intake valve 27 and the exhaust valve 28 so that the pressure detected by the first pressure sensor 35 is within a predetermined range. In addition, when the main ECU 31 transmits a pressure instruction to the sub-ECU 32 to increase the pressure stepwise to stop the vehicle 10 gently, the sub-ECU 32 determines whether the pressure detected by the second pressure sensor 39 has reached the first pressure threshold. When the sub-ECU 32 determines that the detected pressure has not reached the first pressure threshold, the sub-ECU 32 drives the intake valve 27 and the exhaust valve 28 to maintain the relay valve 25 in a supply state. On the other hand, when the pressure detected by the second pressure sensor 39 reaches the first pressure threshold, the sub-ECU 32 deactivates the intake valve 27 and the exhaust valve 28 and shuts off the relay valve 25. The sub-ECU 32 then waits for the next pressure command from the main ECU 31.

Next, the procedure for the abnormality response process performed by the main ECU 31 will be described with reference to Figures 12 and 13. The process shown in Figure 12 is a process for controlling the air system, and is started when the operation switch 51 or the passenger seat operation switch 53 is operated and the operation signal transmitted from these switches is input to the main ECU 31. It is also assumed that the main ECU 31 acquires vehicle speed information from the vehicle speed sensor 55 at a predetermined timing.

As shown in FIG. 12, when an operation signal is input, the main ECU 31 determines whether the passenger seat operation switch 53 has been operated (step S1). The main ECU 31 determines whether the input operation signal is a signal from the operation switch 51 or the passenger seat operation switch 53.

When the main ECU 31 determines that the passenger seat operation switch 53 has been operated (step S1: YES), it instructs the sub ECU 32 on the pressure required for gentle braking (step S2). Gentle braking is braking with a relatively small absolute value of deceleration or braking time that is short, and allows the vehicle to return to normal driving if the release switch 52 is operated immediately afterwards. The main ECU 31 acquires the target deceleration for gentle braking stored in its own memory, compares it with the deceleration obtained from the acquired vehicle speed information, and calculates the target air pressure. The main ECU 31 then transmits the calculated target air pressure to the sub ECU 32 as a pressure instruction. Based on the pressure instruction, the sub ECU 32 drives the intake valve 27 and the exhaust valve 28 as described above (see FIG. 11).

The main ECU 31 determines whether a predetermined time has elapsed from the time when the pressure command was sent to the sub ECU 32, the time when the vehicle 10 started to decelerate, or the time when a predetermined response signal was received from the sub ECU 32 (step S3). This predetermined time is the time required for the driver to operate the release switch 52 if the passenger seat operation switch 53 is erroneously operated even though the driver is in a normal state. If the predetermined time has not elapsed (step S3: NO), the main ECU 31 continues gentle braking while instructing the sub ECU 32 on the air pressure according to the vehicle speed (step S2).

On the other hand, when the main ECU 31 determines that the predetermined time has elapsed (step S3: YES), it instructs the sub ECU 32 of the pressure required for main braking (step S4). Main braking is intended to decelerate the vehicle 10 at a deceleration whose absolute value is greater than the deceleration for gentle braking, and ultimately stop the vehicle. The main ECU 31 acquires the target deceleration for main braking stored in its own memory, compares it with the deceleration obtained from the acquired vehicle speed information, and calculates the target air pressure. The main ECU 31 then transmits the calculated target air pressure to the sub ECU 32 as a pressure instruction. The sub ECU 32 drives the intake valve 27 and the exhaust valve 28 based on the pressure instruction (see FIG. 11).

When the main ECU 31 executes the main braking, it judges whether the emergency response has ended (step S5). The emergency response may be judged to have ended when the vehicle 10 stops and the emergency brake is activated, when the ignition switch is turned off, or at other times. If the main ECU 31 judges that the emergency response has not ended (step S5: NO), it continues the main braking while instructing the sub ECU 32 on the air pressure according to the vehicle speed (step S4). If the main ECU 31 judges that the emergency response has ended (step S5: YES), it ends the emergency response processing.

In addition to responding to abnormalities in the air system, the main ECU 31 also activates the vehicle interior device 56 and the vehicle exterior device 57 at a predetermined timing, such as the timing to start executing the main braking. This notifies the occupants of the vehicle 10 that an abnormality has occurred, and also alerts other vehicles traveling around the vehicle 10.

Next, the procedure for the release process when the release switch 52 is operated will be described with reference to FIG. 13. The process shown in FIG. 13 is started when the operation switch 51 or the passenger seat operation switch 53 is operated and the operation signal is input to the main ECU 31.

As shown in FIG. 13, the main ECU 31 determines whether the release switch 52 has been operated (step S20). When the main ECU 31 determines that an operation signal has been input from the release switch 52 (step S20: YES), it transmits a braking release instruction to the sub ECU 32 (step S21). Having received the release instruction, the sub ECU 32 switches the intake valve 27 and the exhaust valve 28 to a non-operated state, and cuts off the supply of air from the air tank 12 to the brake chamber 17.

On the other hand, if the main ECU 31 determines that an operation signal has not been input from the release switch 52 (step S20: NO), it determines whether or not the abnormality response has been completed (step S22). If the main ECU 31 determines that the abnormality response has not been completed (step S22: NO), it returns to step S20. On the other hand, if the ECU 31 determines that the abnormality response has been completed (step S22: YES), it ends the release process.

Next, the effects of this embodiment will be described.
(1) Based on an abnormality signal indicating an abnormality of the driver, the sub-ECU 32 switches the pneumatic circuit 22 to the second communication state in which air is supplied from the first port P1 connected to the air tank 12 to the third port P3. Therefore, when an abnormality such as a change in the driver's physical condition occurs, air can be automatically supplied from the air tank 12 to the brake chamber 17 to generate braking force. Furthermore, regardless of whether the vehicle's brake mechanism is pneumatically driven or hydraulically driven, the pressure control module 20 can be easily retrofitted to the pneumatic brake system 11 by connecting each of the ports P1 to P3 of the pressure control module 20 to the corresponding air pipes.

(2) The pressure control module 20 includes a case 210 that houses the sub-ECU 32, and a body 211 that is provided with a first port P1, a second port P2, a third port P3, and flow paths that connect these ports and that is connected to the case 210. In other words, the pressure control module 20 is a unit that integrates the pneumatic circuit 22 and the sub-ECU 32, and therefore can be easily retrofitted to a vehicle that is already in use.

(3) The pressure control module 20 includes a main ECU 31 that acquires the vehicle speed and compares the deceleration obtained from the vehicle speed information with the target deceleration to calculate the target pressure. The pressure control module 20 also includes a sub-ECU 32 that controls the air pressure circuit 22 so that the pressures detected by the first pressure sensor 35 and the second pressure sensor 39 approach the target pressure. This allows the air pressure of the air pressure circuit 22 to be controlled according to the target deceleration, so that detailed abnormality responses can be implemented that take into account the vehicle type, number of passengers, etc. by changing the target deceleration according to the vehicle type, such as a public bus or an express bus.

(4) When the passenger seat operation switch 53 is turned on, gentle braking is performed within a specified period of time after the abnormality signal is input, and after the specified period has elapsed, full braking with a greater deceleration can be performed. As a result, even if the passenger seat operation switch 53 is operated by mistake, the abnormality response can be released within the specified period of time by operating the release switch 52.

(5) The pneumatic circuit 22 is provided with a double check valve 36 that switches between the supply of air from the brake valve 13 to the brake chamber 17 and the supply of air from the air tank 12 to the brake chamber 17. This allows the pressure control module 20 to be applied to a pneumatic brake system 11 in which a command system is formed by a pneumatic circuit. In addition, the command system of the pneumatic brake system 11 can be controlled with little power.

The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.
In the above embodiment, the air pressure control device and the air pressure circuit are applied to the vehicle 10 having a full air brake brake system. However, the air pressure control device and the air pressure circuit can be applied to vehicles having other types of brake systems. As shown in FIG. 14, the pressure control module 20 can be applied to the vehicle 10 having an air-over-hydraulic brake mechanism. In this brake mechanism, the pressure control module 20 is connected to brake boosters 100-102 via an ABS control valve 16. The brake boosters 100-102 are boosters for the front wheels, the left rear wheel, and the right rear wheel, respectively, and generate braking force on the wheels by increasing the hydraulic pressure of the hydraulic circuit using air pressure. Also, as shown in FIG. 15, the pressure control module 20 may be applied to a brake mechanism including a brake booster 103 for the front wheels, a brake booster 104 for the rear wheels, and an ABS control valve 105 provided in the hydraulic circuit. Alternatively, the air pressure control device and the air pressure circuit can be applied to brake mechanisms other than those shown in FIG. 14 and FIG. 15.

- In the above embodiment, the body 211 is made of metal, but instead, the body 211 may be made of resin. For example, the body 211 is formed by casting, but instead of or in addition to this, the body 211 may be formed by combining parts formed by pressing or cutting.

- In the above embodiment, the air tank 12 is divided into three tanks, but the air tank 12 may be a single tank, or may be divided into two or four or more tanks. The connection relationship between the air tank 12 and the pneumatic equipment can be changed as appropriate. For example, the first port P1 of the pressure control module 20 may be connected to a tank other than the third tank 12C.

- As shown in Figures 16 to 22, the pressure control module 20 may have a case 210 consisting of a first case member 217 made of aluminum die casting and a second case member 218 made of resin. The first case member 217 and the body 211 are integrally formed. In addition, the first case member 217 and the second case member 218 are connected to each other by a fastening member.

- The main ECU 31 may receive an on signal or the like from the operation switch 51, the release switch 52, and the passenger seat operation switch 53 via an in-vehicle network such as CAN 33. As the in-vehicle network, networks such as FlexRay (registered trademark), Ethernet (registered trademark), etc., other than CAN 33 may also be used.

In the above embodiment, the main ECU 31 acquires vehicle speed information from the vehicle speed sensor 55. Alternatively or additionally, the main ECU 31 may acquire acceleration information from an acceleration sensor. In other words, the vehicle speed information is information related to the vehicle speed, and may include information representing acceleration instead of or in addition to information representing the vehicle speed itself.

- In the above embodiment, the abnormality response system 50 is provided with a main ECU 31 that executes the functions of the first control unit and a sub-ECU 32 that executes the functions of the second control unit. Alternatively, the main ECU 31 and the sub-ECU 32 may be configured as one ECU or one other control circuit having the functions of the first control unit and the functions of the second control unit. Or, these functions may be distributed among three or more ECUs or three or more other control circuits.

- The emergency response system 50 may be equipped with a main switch (not shown) that can turn the functions of the system on and off. By performing a specified operation on the main switch or controlling the main switch with a specified control device, for example, the operation of the operation switch 51, the release switch 52, and the seat operation switch 53 can be disabled.

- The pneumatic circuit 22 drives the pneumatically driven relay valve 25 by the intake valve 27 and the exhaust valve 28. Alternatively, a solenoid valve may be provided in the first supply path 23, and the first supply path 23 may be opened and closed by this solenoid valve.

- The air pressure circuit 22 is provided with a double check valve 36 that switches the air supply direction depending on the air pressure. Instead of the double check valve 36, a solenoid valve that is activated and deactivated by the sub-ECU 32 may be provided. When the operation switch 51 or the passenger seat operation switch 53 is turned on, the sub-ECU 32 activates (or deactivates) the solenoid valve to switch the air supply direction.

- In the above embodiment, an abnormality response is performed by turning on the operation switch 51 and the passenger seat operation switch 53. Instead of or in addition to this, a live body detection device that detects the driver's fatigue state or health state may be used. The live body detection device detects the driver's driving state using one or more parameters, such as the position and posture of the driver's face and head, eyelids, eye gaze and other eye conditions, pulse rate, heart rate, body temperature, etc. In this aspect, the live body detection device transmits an abnormality signal when it detects an abnormality in the driver. Alternatively, an ECU mounted on the vehicle may compare the vehicle state, such as the vehicle speed and the presence or absence of operation of the accelerator pedal or brake pedal, with road information, and transmit an abnormality signal when it detects an abnormality in driving operation.

- In the above embodiment, the air pressure control device is described as being retrofitted to a vehicle in use that controls the brake command system with air pressure, but the air pressure control device may also be retrofitted to a vehicle equipped with an EBS. The air pressure control device may also be installed in a new vehicle.

- In the above embodiment, the air pressure control device is described as being mounted on a vehicle such as a bus. The vehicle may be a truck, construction equipment, or other vehicle other than a bus. The air pressure control device may also be mounted on other vehicles such as passenger cars and railroad cars.

- Similar issues exist in new cars or used cars in which the brake mechanism is controlled by a hydraulic circuit, because driver abnormalities can occur. For this reason, the pressure control module 20 of the above embodiment may be applied to a vehicle in which the command system to the brake mechanism is hydraulically controlled. In a hydraulic circuit, the pressure control module 20 operates in the same manner as in the above embodiment. In this aspect, the brake mechanism to be controlled may be a mechanism other than the brake chamber. Note that the hydraulic circuit and the pneumatic circuit are examples of circuits driven by fluid pressure.

-ECUs 31 and 32 are not limited to those that perform software processing for all of the processes they execute. For example, ECUs 31 and 32 may be equipped with dedicated hardware circuits (e.g., application specific integrated circuits (ASICs)) that perform hardware processing for at least some of the processes they execute. That is, ECUs 31 and 32 may be configured as circuitry that includes 1) one or more processors that operate according to computer programs (software), 2) one or more dedicated hardware circuits that execute at least some of the various processes, or 3) a combination thereof. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions that are configured to cause the CPU to execute processes. Memory, i.e., computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

10...vehicle, 11...pneumatic brake system, 12...air tank, 13...brake valve, 13A...front pressure chamber, 13B...rear pressure chamber, 13C...brake pedal, 14A...protection valve, 14B...air horn device, 15...relay valve, 16...ABS control valve, 17...brake chamber, 18...air piping, 20...pressure control module, 21...case, 21A...port connection, 21D...projection, 22...pneumatic circuit, 23...first supply path, 24A...front signal supply path, 24B...rear signal supply path, 25...relay valve, 25A...exhaust port, 25B...pilot port, 26...branch path, 27...intake valve, 27A... Wiring, 28...exhaust valve, 28A...wiring, 29...signal supply path, 30...third supply path, 31...main ECU, 32...sub ECU, 33...CAN, 35...first pressure sensor, 36, 36A, 36B...double check valve, 37...front air supply path, 38...front air supply path, 39...second pressure sensor, 39...pressure sensor, 50...abnormality response system, 51...operation switch, 52...release switch, 53...passenger seat operation switch, 55...vehicle speed sensor, 56...interior device, 57...exterior device, 58...exhaust section, 100-104...brake booster, 105...ABS control valve, P1...first port, P2...second port, P3...third port.

Claims (8)

an air pressure circuit having a first port connected to an air tank of a vehicle, a second port connected to a brake valve that outputs an air pressure signal when a brake operation is performed, and a third port connected to a brake mechanism that applies a braking force to a wheel based on the air pressure signal, the air pressure circuit being switched between a first communication state in which air is supplied from the second port to the third port and a second communication state in which air is supplied from the first port to the third port;
a control unit that switches the air pressure circuit from the first communication state to the second communication state based on an abnormality signal that indicates an abnormality of a driver. 2. The air pressure control device according to claim 1, comprising: a case that houses the control unit; and a body that is connected to the case and that has flow paths that communicate the first port, the second port, the third port, and the first port, the second port, and the third port. the pneumatic circuit includes a pressure sensor;
a first control unit that acquires vehicle speed information and compares the vehicle speed information with a target value to calculate a target pressure;
The air pressure control device according to claim 1 or 2, further comprising: a second control unit that controls the air pressure circuit so that the detection value of the pressure sensor approaches the target pressure. 4. The air pressure control device according to claim 3, wherein the first control unit calculates the target pressure so that the deceleration of the vehicle approaches a first target deceleration during a predetermined period after the abnormality signal is input, and calculates the target pressure so that the deceleration of the vehicle approaches a second target deceleration having an absolute value greater than that of the first target deceleration after the predetermined period has elapsed. The pneumatic circuit includes:
an air-operated valve connected to the air tank;
a solenoid valve for applying air pressure to the pneumatically driven valve;
a directional control valve that allows air to flow from either the second port side or the pneumatically driven valve side, whichever has a higher pressure,
5. The air pressure control device according to claim 1, wherein the pneumatically driven valve switches between a supply state in which air is supplied to the directional control valve side and an exhaust state in which air is exhausted from the directional control valve side, depending on the air pressure applied by the solenoid valve. 6. The air pressure control device according to claim 5, wherein the solenoid valve comprises an intake solenoid valve that communicates with a passage for applying air pressure to the pneumatically driven valve, and an exhaust solenoid valve that can exhaust air from within the passage. A pneumatic circuit that is driven based on an abnormality signal indicating an abnormality of a driver,
a pneumatically actuated valve connected to an air tank of the vehicle;
a solenoid valve for applying air pressure to the pneumatically driven valve;
a directional control valve that allows air to flow from either a port side connected to a brake valve that outputs an air pressure signal when a brake operation is performed or the air pressure driven valve side, whichever has a higher pressure;
The pneumatically driven valve switches between a supply state in which air is supplied from the air tank to the directional control valve side and an exhaust state in which air is exhausted from the directional control valve side, depending on the air pressure applied by the solenoid valve. In a vehicle brake control system,
a brake control circuit that controls a brake drive unit that applies a braking force to the wheels based on a brake operation by a driver;
A detection unit for detecting an abnormality of the driver;
an abnormality brake control circuit that controls the brake drive unit when an abnormality occurs in the driver and includes a circuit separate from the brake control circuit;
a control unit that operates the abnormality brake control circuit so that the vehicle decelerates at a predetermined deceleration based on an abnormality signal that indicates an abnormality in the driver output from the detection unit.

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