CN116901920A - Commercial vehicle line control redundant braking unit and control method thereof - Google Patents

Abstract

The application discloses a line-control redundant brake unit of a commercial vehicle and a control method thereof, wherein the line-control redundant brake unit comprises a proportional brake valve assembly, a redundant brake controller, a line-control redundant fault lamp and an independent power supply; the proportional brake valve assembly comprises two electric control proportional valves and two shuttle valves, wherein the two electric control proportional valves are connected with the brake foot valves in parallel through brake pneumatic pipelines and the shuttle valves, and respectively control a front axle brake loop, a middle axle brake loop and a rear axle brake loop to implement redundant braking; the redundant brake controller is powered by an independent power supply, controls the wire control redundant fault lamp to be turned on or off, and is communicated with the EBS, the EPB and the automatic driving controller; the redundant brake controller receives pressure sensor signals in the proportional brake valve assembly, simultaneously controls the current of each electric control proportional valve and adjusts the redundant brake output pressure. The application can generate the same maximum braking force as the conventional braking device, and the front braking force and the rear braking force can be adjusted as required; the system has high reliability, compact structure and low requirement on power capacity.

Description

Commercial vehicle line control redundant braking unit and control method thereof

Technical Field

The application relates to the field of commercial vehicle braking, in particular to a brake-by-wire system for an automatic driving commercial vehicle.

Background

The commercial vehicle adopts a braking system using air as a medium, an air compressor is arranged on a diesel engine, compressed air is stored after being filtered, and the compressed air is used as a power source in an air storage cylinder. Currently, an Electronic Brake System (EBS) is widely adopted in an automatic driving system, and a central controller or a brake master control unit controls a single-channel front axle module and a double-channel middle and rear axle module for service braking. And a control unit of an electronic parking brake system (EPB) is used for parking control of the vehicle. The front axle, the middle axle and the rear axle wheels are respectively provided with corresponding brakes to form actuating mechanisms of a service braking system and a parking braking system, and the actuating mechanisms receive a service braking instruction of a vehicle-mounted controller by an EBS to implement the service braking or receive a parking braking instruction by an EPB to implement the parking braking in an automatic driving mode.

Existing autopilot systems often employ two redundant braking schemes:

the first wire control redundancy braking scheme is a redundancy braking device taking EPB as service braking. When the EBS single-channel module and the double-channel module are failed, the control unit of the EPB module can receive redundant braking instructions of the automatic driving vehicle-mounted controller, exhaust air in the air chamber of the parking brake, and utilize the pressure of the energy storage spring in the brake to slow down the vehicle and stop the vehicle when necessary.

The second scheme is a braking robot scheme. According to the scheme, a mechanical and electric device is adopted to simulate manual stepping on a brake pedal, redundant braking is provided under the condition that a single point of a driving brake system fails, and the output braking force can be adjusted according to the driving working condition requirement.

For scheme one, the brake pressure generated by the EPB is typically no more than 6bar, below the service brake pressure up to 10 bar. Therefore, when EPB is used for redundant braking, the braking distance is generally increased, and the braking force is not adjustable.

When the scheme II is adopted, the motor is connected with the brake pedal through the mechanical transmission mechanism. The motor rotating speed is fed back through the encoder, the pedal stroke is determined through the mechanical mechanism, the control precision can be influenced after the kinematic pair is worn, the structure is complex, the space occupation is large, the manual driving operation is influenced, the reliability is low, and the motor has high requirement on the capacity of a driving power supply.

Disclosure of Invention

In order to solve the above problems, the present application provides a wire-controlled redundant brake unit for a commercial vehicle capable of generating the same maximum braking force as a conventional brake device, and front and rear braking forces being adjustable as needed, and a control method thereof; the system has high reliability, compact structure and low requirement on power capacity.

The application relates to a wire control Redundant Brake Unit (RBU), which consists of a proportional brake valve assembly, a redundant brake controller, a wire control redundant fault lamp, an independent power supply special for redundant braking and the like. Wherein, two proportional valves in the proportional brake valve assembly are connected with a brake foot valve (or a so-called electronic foot valve with a brake pedal stroke sensor) in parallel through a brake air pressure pipeline and a shuttle valve in the assembly, and respectively control a front axle brake circuit, a middle axle brake circuit and a rear axle brake circuit to implement redundant braking. The two electronically controlled proportional valves are individually controllable and the redundant brake output pressure can be adjusted by controlling the current to the two valves. The RBU does not affect manual braking and EBS brake-by-wire.

The application adopts the following technical scheme:

the application provides a line-control redundant braking unit for a commercial vehicle, which comprises a proportional braking valve assembly, a redundant braking controller, a line-control redundant fault lamp and an independent power supply, wherein the proportional braking valve assembly is connected with the redundant braking controller;

the proportional brake valve assembly comprises two electric control proportional valves and two shuttle valves, wherein the two electric control proportional valves are connected with the brake foot valves in parallel through brake pneumatic pipelines and the shuttle valves, and respectively control a front axle brake loop, a middle axle brake loop and a rear axle brake loop to implement redundant braking;

the redundant brake controller is powered by an independent power supply, controls the wire control redundant fault lamp to be turned on or off, and is communicated with the EBS, the EPB and the automatic driving controller through signal wires;

the redundant brake controller receives pressure sensor signals in the proportional brake valve assembly through a signal wire, and simultaneously controls the current of each electric control proportional valve through the signal wire and a power wire to adjust the redundant brake output pressure.

Further, the proportional brake valve assembly consists of an electric control proportional valve I, an electric control proportional valve II, a shuttle valve I, a shuttle valve II, a pressure sensor I, a pressure sensor II, air inlets P11 and P21, air outlets P14 and P24, foot valve front communication ports P12 and P22, foot valve rear communication ports P13 and P23 and a valve body;

the air inlet P11 is in air pressure communication with the middle and rear axle air cylinders and is in air pressure communication with the foot valve front communication port P12 and the input end of the electric control proportional valve I; the foot valve rear communication port P13 and the output end of the electric control proportional valve I are respectively in air pressure communication with the two input ends of the shuttle valve I, the output end of the shuttle valve I is in air pressure communication with the air outlet P14, and the air outlet P14 is connected with the dual-channel module of the EBS through an air pressure pipeline;

the air inlet P21 is in air pressure communication with the front axle air storage cylinder and is in air pressure communication with the foot valve front communication port P22 and the input end of the electric control proportional valve II; the foot valve rear communication port P23 and the output end of the electric control proportional valve II are respectively in air pressure communication with the two input ends of the shuttle valve II, the output end of the shuttle valve II is in air pressure communication with the air outlet P24, and the air outlet P24 is connected with the single-channel module of the EBS through an air pressure pipeline;

the first pressure sensor is in air pressure communication with the output end of the first shuttle valve and the air outlet P14, and the second pressure sensor is in air pressure communication with the output end of the second shuttle valve and the air outlet P24.

Further, a foot valve front communication port P12 of the proportional brake valve assembly is in pneumatic communication with a first brake foot valve air inlet P15, and a foot valve rear communication port P13 is in pneumatic communication with a first brake foot valve air outlet P16; the foot valve front communication port P22 of the proportional brake valve assembly is in pneumatic communication with the second brake foot valve air inlet P25, and the foot valve rear communication port P23 is in pneumatic communication with the second brake foot valve air outlet P26.

Further, the redundant brake controller is communicated with the automatic driving controller, the EBS and the EPB through a CAN bus;

the redundant brake controller monitors the heartbeat of the automatic driving controller and reports the self state, fault condition and current value of the pressure sensor of the vehicle drive-by-wire redundant brake unit to the automatic driving controller; the automatic driving controller sends the current speed and heartbeat and a redundant braking control instruction to the redundant braking controller;

when redundant braking is required to be implemented, the pressure air in the air reservoir is conveyed to the front axle, the middle axle and the rear axle braking air chambers through the air pressure channels in the single-channel module and the double-channel module of the EBS;

when the conventional or redundant electronic parking brake is required to be implemented, an automatic driving controller and a redundant braking controller respectively send a parking braking request to the EPB, and the pressure air in the air reservoir is conveyed to a rear axle braking air chamber through an air pressure channel of the EPB.

The application also provides a control method for the line-controlled redundant brake of the commercial vehicle, which is controlled by the line-controlled redundant brake unit of the commercial vehicle and comprises the following steps:

when the vehicle is electrified, the wire control redundant braking unit performs self-checking, and then reports a self-checking result to the automatic driving controller; if the self-checking result is abnormal, a wire control redundant fault lamp is lightened, fault information is sent to an automatic driving controller, and then the wire control redundant braking unit exits; if the self-checking result is normal, judging whether the vehicle is in an automatic driving mode, if so, enabling the wire control redundant brake unit to enter a working state, otherwise, returning to the previous step to continuously judge whether the vehicle is in the automatic driving mode;

after the wire control redundant brake unit enters a working state, firstly judging whether the heartbeat of the automatic driving controller is normal; if the heartbeat of the automatic driving controller is abnormal, executing full-force braking to enable the vehicle to quickly slow down; when the vehicle speed is lower than 5km/h, the wire control redundant brake unit controls the EPB module to implement parking brake, the wire control redundant brake unit releases the redundant brake after the vehicle is completely stationary, and then the wire control redundant brake unit enters a dormant state; if the heartbeat of the automatic driving controller is normal, judging whether a braking instruction of the automatic driving controller is received, and if the braking instruction is not received, returning to continuously judge whether the automatic driving mode is adopted; if a braking instruction is received, controlling the opening of the two electric control proportional valves to execute redundant braking according to the required braking intensity until the braking instruction of the automatic driving controller is received, and then releasing the redundant braking;

then judging whether the vehicle is powered down, if not, returning to continuously judging whether the vehicle is in an automatic driving mode; if the power-down self-checking is normal, the wire control redundant braking unit enters a dormant state, if the power-down self-checking is normal, the fault information is stored and sent to the automatic driving controller, and then the wire control redundant braking unit enters the dormant state.

Compared with the prior art, the application has the following beneficial effects:

compared with the scheme I, the wire control redundant braking device can generate the same maximum braking force as the conventional braking device, and the braking pressure of two braking loops can be independently adjusted; compared with the scheme II, the wire control redundant braking device disclosed by the application controls the current of the electromagnetic coil according to the feedback of the pressure sensor so as to achieve the purpose of adjusting the opening of the valve, and the redundant braking pressure is adjustable and controllable. In addition, the control and actuating mechanism of the wire control redundant braking device has the advantages of less parts, simple and compact structure, flexible control and high reliability, and the power requirement of the electromagnetic coil driving is much lower than that of the scheme II motor driving.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute a limitation on the application. In the drawings:

FIG. 1 is a schematic diagram of a proportional brake valve assembly of the present application.

Fig. 2 is a schematic structural view of the RBU of the present application and its connection relationship with a brake foot valve of a vehicle.

Fig. 3 is a control architecture diagram of an RBU and associated control system of the present application.

Fig. 4 is a flowchart of RBU operation of the present application.

Detailed Description

In order to make the technical solutions and advantages of the embodiments of the present application more apparent, the following detailed description of exemplary embodiments of the present application is given with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of a proportional brake valve assembly according to the present application, where the proportional brake valve assembly is composed of an electrically controlled proportional valve one, an electrically controlled proportional valve two, a shuttle valve one, a shuttle valve two, a pressure sensor one, a pressure sensor two, air inlets P11 and P21, air outlets P14 and P24, foot valve front communication ports P12 and P22, foot valve rear communication ports P13 and P23, and a valve body. The air inlet P11 is in air pressure communication with an air reservoir (not shown in the figure) of the middle and rear axles and is in air pressure communication with a foot valve front communication port P12 and an input end of the first electric control proportional valve; the foot valve rear communication port P13 and the output end of the first electric control proportional valve are respectively in air pressure communication with the two input ends of the first shuttle valve, the output end of the first shuttle valve is in air pressure communication with the air outlet P14, and the air outlet P14 is connected into a two-channel module (not shown in the figure) through an air pressure pipeline. The air inlet P21 is in air pressure communication with the front axle air storage cylinder and is in air pressure communication with the foot valve front communication port P22 and the input end of the electric control proportional valve II; the foot valve rear communication port P23 and the output end of the electric control proportional valve II are respectively in air pressure communication with the two input ends of the shuttle valve II, the output end of the shuttle valve II is in air pressure communication with the air outlet P24, and the air outlet P24 is connected into the single-channel module through an air pressure pipeline. The first pressure sensor is in pneumatic communication with the output end of the first shuttle valve and the air outlet P14, and the second pressure sensor is in pneumatic communication with the output end of the second shuttle valve and the air outlet P24.

Fig. 2 is a schematic structural diagram of a brake-by-wire unit (RBU) of the present application and its connection relationship with a brake foot valve of a vehicle, the RBU being composed of a proportional brake valve assembly, a redundant brake controller, an independent power supply, a brake-by-wire fault lamp, etc. The redundant brake controller is powered by an independent power supply, controls the wire control redundant fault lamp to be turned on or off, and is communicated with the EBS, the EPB and the automatic driving controller through signal wires; the redundant brake controller is also provided with a circuit for measuring the working current of an electromagnetic coil of the electric control proportional valve in the proportional brake valve assembly, receives a pressure sensor signal in the proportional brake valve assembly through a signal wire, and simultaneously controls the electric control proportional valve in the proportional brake valve assembly to work through the signal wire and a power wire so as to regulate the pressure output of the electric control proportional valve. The foot valve front communication port P12 of the proportional brake valve assembly is in pneumatic communication with the first brake foot valve air inlet P15, and the foot valve rear communication port P13 is in pneumatic communication with the first brake foot valve air outlet P16. And the foot valve front communication port P22 of the proportional brake valve assembly is in pneumatic communication with the second brake foot valve air inlet P25, and the foot valve rear communication port P23 is in pneumatic communication with the second brake foot valve air outlet P26.

As shown in FIG. 3, the redundant brake controllers within the RBU communicate with the autopilot controller, the EBS, and the EPB via CAN buses (CAN-H and CAN-L in the figure). The redundant brake controller can receive a redundant brake control instruction of the automatic driving controller, monitor heartbeats of the automatic driving controller (in the monitoring of industrial equipment, the equipment periodically sends information to judge the health condition of the equipment, judge whether the other party survives or not) and report the state of the RBU, the fault condition, the current value of the pressure sensor and the like to the redundant brake controller; the automatic driving controller sends information such as the current speed and heartbeat to the redundant brake controller. When redundant braking is needed, the RBU transmits the pressure air in the air reservoir to the front axle, the middle axle and the rear axle braking air chambers through the air pressure channels in the EBS single-channel module and the double-channel module. The electrical and pneumatic connection of the EPB to other components is also shown in fig. 3, i.e. when a conventional or redundant electronic parking brake is to be applied, a parking brake request is issued by the autopilot controller and the redundant brake controller, respectively, to the EPB, which delivers the pressurized air in the reservoir to the rear axle brake chamber via the pneumatic channel therein.

As shown in fig. 4, the working process: when the vehicle is electrified, the RBU performs self-checking, and then reports a self-checking result to the automatic driving controller. And if the self-checking result is abnormal, the drive-by-wire redundant fault lamp is lightened, fault information is sent to the automatic driving controller, and then the RBU exits. If the self-checking result is normal, judging whether the vehicle is in an automatic driving mode, if so, the RBU enters a working state, otherwise, returning to the previous step to continuously judge whether the vehicle is in the automatic driving mode. After the RBU enters a working state, whether the heartbeat of the automatic driving controller is normal is judged first. If the heartbeat of the automatic driving controller is abnormal, executing full-force braking to enable the vehicle to quickly slow down; when the vehicle speed is lower than 5km/h, the RBU controls the EPB module to apply parking braking, the RBU releases redundant braking after the vehicle is completely stationary, and then the RBU enters a dormant state. If the heartbeat of the automatic driving controller is normal, judging whether a braking instruction of the automatic driving controller is received, and if the braking instruction is not received, returning to continuously judge whether the automatic driving mode is adopted; and if a braking instruction is received, controlling the opening degrees of the 2 electric control proportional valves to execute redundant braking according to the required braking intensity until the braking instruction of the automatic driving controller is received, and releasing the redundant braking. Then judging whether the vehicle is powered down, if not, returning to continuously judging whether the vehicle is in an automatic driving mode; if the power-down self-checking is normal, the power-down self-checking enters a dormant state, if the power-down self-checking is normal, fault information is stored and sent to the automatic driving controller, and then the power-down self-checking enters the dormant state.

Claims (5)

1. The line-control redundant braking unit for the commercial vehicle is characterized by comprising a proportional braking valve assembly, a redundant braking controller, a line-control redundant fault lamp and an independent power supply;

the proportional brake valve assembly comprises two electric control proportional valves and two shuttle valves, wherein the two electric control proportional valves are connected with the brake foot valves in parallel through brake pneumatic pipelines and the shuttle valves, and respectively control a front axle brake loop, a middle axle brake loop and a rear axle brake loop to implement redundant braking;

the redundant brake controller is powered by an independent power supply, controls the wire control redundant fault lamp to be turned on or off, and is communicated with the EBS, the EPB and the automatic driving controller through signal wires;

the redundant brake controller receives pressure sensor signals in the proportional brake valve assembly through a signal wire, and simultaneously controls the current of each electric control proportional valve through the signal wire and a power wire to adjust the redundant brake output pressure.

2. The line-controlled redundant brake unit for a commercial vehicle according to claim 1, wherein the proportional brake valve assembly is composed of an electronically controlled proportional valve one, an electronically controlled proportional valve two, a shuttle valve one, a shuttle valve two, a pressure sensor one, a pressure sensor two, air inlets P11 and P21, air outlets P14 and P24, foot valve front communication ports P12 and P22, foot valve rear communication ports P13 and P23, and a valve body;

the air inlet P11 is in air pressure communication with the middle and rear axle air cylinders and is in air pressure communication with the foot valve front communication port P12 and the input end of the electric control proportional valve I; the foot valve rear communication port P13 and the output end of the electric control proportional valve I are respectively in air pressure communication with the two input ends of the shuttle valve I, the output end of the shuttle valve I is in air pressure communication with the air outlet P14, and the air outlet P14 is connected with the dual-channel module of the EBS through an air pressure pipeline;

the air inlet P21 is in air pressure communication with the front axle air storage cylinder and is in air pressure communication with the foot valve front communication port P22 and the input end of the electric control proportional valve II; the foot valve rear communication port P23 and the output end of the electric control proportional valve II are respectively in air pressure communication with the two input ends of the shuttle valve II, the output end of the shuttle valve II is in air pressure communication with the air outlet P24, and the air outlet P24 is connected with the single-channel module of the EBS through an air pressure pipeline;

the first pressure sensor is in air pressure communication with the output end of the first shuttle valve and the air outlet P14, and the second pressure sensor is in air pressure communication with the output end of the second shuttle valve and the air outlet P24.

3. The line-controlled redundant brake unit for a commercial vehicle according to claim 2, wherein the foot valve front communication port P12 of the proportional brake valve assembly is in pneumatic communication with the brake foot valve air inlet P15, and the foot valve rear communication port P13 is in pneumatic communication with the brake foot valve air outlet P16; the foot valve front communication port P22 of the proportional brake valve assembly is in pneumatic communication with the second brake foot valve air inlet P25, and the foot valve rear communication port P23 is in pneumatic communication with the second brake foot valve air outlet P26.

4. A commercial vehicle brake-by-wire unit according to claim 3, wherein the redundant brake controller communicates with the autopilot controller, EBS, EPB via a CAN bus;

the redundant brake controller monitors the heartbeat of the automatic driving controller and reports the self state, fault condition and current value of the pressure sensor of the vehicle drive-by-wire redundant brake unit to the automatic driving controller; the automatic driving controller sends the current speed and heartbeat and a redundant braking control instruction to the redundant braking controller;

when redundant braking is required to be implemented, the pressure air in the air reservoir is conveyed to the front axle, the middle axle and the rear axle braking air chambers through the air pressure channels in the single-channel module and the double-channel module of the EBS;

when the conventional or redundant electronic parking brake is required to be implemented, an automatic driving controller and a redundant braking controller respectively send a parking braking request to the EPB, and the pressure air in the air reservoir is conveyed to a rear axle braking air chamber through an air pressure channel of the EPB.

5. A method for controlling a commercial vehicle brake-by-wire system, characterized by being controlled by a commercial vehicle brake-by-wire system according to any one of claims 1-4, comprising the steps of:

when the vehicle is electrified, the wire control redundant braking unit performs self-checking, and then reports a self-checking result to the automatic driving controller; if the self-checking result is abnormal, a wire control redundant fault lamp is lightened, fault information is sent to an automatic driving controller, and then the wire control redundant braking unit exits; if the self-checking result is normal, judging whether the vehicle is in an automatic driving mode, if so, enabling the wire control redundant brake unit to enter a working state, otherwise, returning to the previous step to continuously judge whether the vehicle is in the automatic driving mode;

after the wire control redundant brake unit enters a working state, firstly judging whether the heartbeat of the automatic driving controller is normal; if the heartbeat of the automatic driving controller is abnormal, executing full-force braking to enable the vehicle to quickly slow down; when the vehicle speed is lower than 5km/h, the wire control redundant brake unit controls the EPB module to implement parking brake, the wire control redundant brake unit releases the redundant brake after the vehicle is completely stationary, and then the wire control redundant brake unit enters a dormant state; if the heartbeat of the automatic driving controller is normal, judging whether a braking instruction of the automatic driving controller is received, and if the braking instruction is not received, returning to continuously judge whether the automatic driving mode is adopted; if a braking instruction is received, controlling the opening of the two electric control proportional valves to execute redundant braking according to the required braking intensity until the braking instruction of the automatic driving controller is received, and then releasing the redundant braking;

then judging whether the vehicle is powered down, if not, returning to continuously judging whether the vehicle is in an automatic driving mode; if the power-down self-checking is normal, the wire control redundant braking unit enters a dormant state, if the power-down self-checking is normal, the fault information is stored and sent to the automatic driving controller, and then the wire control redundant braking unit enters the dormant state.