A brake-by-wire apparatus for manned unmanned selectable lines

Abstract

The present application belongs to the technical field of vehicle control and steering, and particularly relates to a line control brake device for manned and unmanned selection, which comprises a brake pedal, a rotation angle sensor, a hydraulic pressure reducing valve, an electro-hydraulic proportional pressure reducing valve and a hydraulic control directional valve, can simultaneously meet the requirements of electric control and manual mechanical operation, and has a calibration method which can minimize the oil filling time while making the brake valve have a fault recognition capability according to the flow characteristics of the hydraulic pressure reducing valve and the electro-hydraulic proportional pressure reducing valve. The line control brake device and the calibration method can improve the brake response time on the basis of ensuring the safety of the line control, and have a fault recognition function.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vehicle control and steering, and particularly relates to a line control brake device for manned and unmanned optional vehicles. BACKGROUND

[0002] Most tracked vehicles use mechanical hydraulic brake valves, which cannot meet the needs of unmanned and manned unmanned optional vehicle control. In addition, the valve opening and pressure difference flow characteristics of the mechanical valve determine that the output flow of the mechanical valve increases with the increase of the pedal opening, resulting in the problem of long oil filling time of the system under small pedal opening. The line control steering of the brake can be realized by relying on the electromagnetic pressure reducing valve, but there is a safety risk caused by the failure of the electric control system and other factors. Therefore, it is urgent to carry out research on high safety line control brake devices. SUMMARY

[0003] (I) Technical problem to be solved

[0004] The technical problem to be solved by the present application is how to develop a line control redundancy brake scheme to ensure the reliability of the brake function on the basis of realizing the line control brake of the tracked vehicle, and to shorten the brake system response time and improve the control quality according to the flow characteristics difference of the mechanical valve and the electro-hydraulic proportional pressure reducing valve through the proposed calibration method.

[0005] (II) Technical scheme

[0006] To solve the above technical problems, the present application provides a line control brake device for manned and unmanned optional vehicles, which comprises a mechanical pressure reducing valve (1), an electro-hydraulic proportional pressure reducing valve (2), a hydraulic control directional valve (3), a pressure sensor (4), a brake pedal (5), and a rotation angle sensor (6).

[0007] The mechanical pressure reducing valve (1) is a three-way pressure reducing valve, comprising a first oil supply port, a first oil discharge port and a first output oil port. The valve core of the mechanical pressure reducing valve (1) is connected with the brake pedal (5) and the rotation angle sensor (6) respectively.

[0008] The electro-hydraulic proportional pressure reducing valve (2) is a three-way electro-hydraulic proportional pressure reducing valve, comprising a second oil supply port, a second oil discharge port and a second output oil port.

[0009] The hydraulic control directional valve (3) is a hydraulic control two-position three-way valve, comprising two oil supply ports, a sensitive cavity and a third output oil port. The two oil supply ports are connected with the first output oil port of the mechanical pressure reducing valve (1) and the second output oil port of the electro-hydraulic proportional pressure reducing valve (2) respectively, the sensitive cavity is connected with the second output oil port of the electro-hydraulic proportional pressure reducing valve (2), and the third output oil port is connected with the output port of the brake device and the pressure sensor (4).

[0010] The pressure sensor (4) is configured to measure the output pressure of the brake system.

[0011] The brake device is provided with a housing, and the housing is provided with an externally connected oil supply port and an externally connected oil discharge port.

[0012] The first oil supply port is connected to the externally connected oil supply port of the brake device, and the first oil discharge port is connected to the externally connected oil discharge port of the brake device.

[0013] The second oil supply port is connected to the externally connected oil supply port of the brake device, and the second oil discharge port is connected to the externally connected oil discharge port of the brake device.

[0014] During the operation of the brake device, a calibration process is included, and the calibration process includes the following steps:

[0015] Step 1: Test the differential pressure flow characteristics of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2); according to the differential pressure flow characteristics of the electro-hydraulic proportional pressure reducing valve (2) and the mechanical pressure reducing valve (1), find the output pressure P a corresponding to the output flow characteristic coincidence point of the electro-hydraulic proportional pressure reducing valve (2) and the mechanical pressure reducing valve (1) under different pressures.

[0016] Step 2: Test the pedal opening-output pressure characteristics of the mechanical pressure reducing valve (1); according to the pedal opening-output pressure characteristics of the mechanical pressure reducing valve (1), find the rotation angle position α of the brake pedal (5) corresponding to the output pressure P a of the mechanical pressure reducing valve (1); define this rotation angle position α as a critical point.

[0017] Step 3: Calibrate the corresponding relationship between the output pressure of the electro-hydraulic proportional pressure reducing valve (2) and the rotation angle of the brake pedal (5) in the control tool, so that in the interval where the rotation angle of the brake pedal (5) is less than the critical point α, the output pressure of the electro-hydraulic proportional pressure reducing valve (2) is slightly greater than the output pressure of the mechanical pressure reducing valve (1), and at this time, through the switching of the hydraulic control directional valve (3), the brake device outputs the brake pressure by the electro-hydraulic proportional pressure reducing valve (2); in the interval where the rotation angle of the brake pedal (5) is greater than the critical point α, the output pressure of the electro-hydraulic proportional pressure reducing valve (2) is less than the output pressure of the mechanical pressure reducing valve (1), then at this time, through the switching of the hydraulic control directional valve (3), the brake device outputs the brake pressure by the mechanical pressure reducing valve (1).

[0018] In the manned mode, the brake device can have a larger output flow at a small opening, thereby shortening the system oil charging time.

[0019] During the operation of the brake device, a fault identification process is also included, and the fault identification process includes:

[0020] the fault identification process in the manned mode, and the fault identification process in the unmanned mode.

[0021] The fault identification process in the manned mode is as follows:

[0022] Step B1: In manned mode, the angle sensor (6) collects the angle of the brake pedal (5) and the output pressure of the braking device, and verifies whether the actual output pressure is consistent with the output pressure value under the corresponding brake pedal (5) angle in the preset strategy.

[0023] Step B2: If the difference is less than the given value (e.g., within 0.1 MPa), the braking device is considered to be fault-free;

[0024] Step B3: If the difference is greater than the given value, it is considered that there is a fault in the drive-by-wire circuit of the braking device, and the fault information is uploaded.

[0025] The fault identification process in the unmanned mode is as follows:

[0026] Step C1: Collect braking commands from the upper-level controller and set time boundary conditions (e.g., 0.2s) based on the response time of the braking device under normal operating conditions;

[0027] Step C2: If the braking device has no output oil pressure within a given time, or the difference between the output oil pressure and the preset oil pressure is too large (e.g., more than 0.3MPa), it is considered that there is a fault in the drive-by-wire circuit of the braking device, and the occupants are reminded to use the mechanical brake.

[0028] (III) Beneficial Effects

[0029] Compared with existing technologies, the drive-by-wire redundant braking scheme provided by this invention can improve the response time of the braking system in manned mode while realizing drive-by-wire braking control in unmanned mode of tracked vehicles. At the same time, it can ensure that the driver can brake mechanically in the event of a drive-by-wire branch failure, thus ensuring the braking safety of the vehicle.

[0030] The technical solution of this invention can be used in manned and unmanned vehicles. Based on the safety requirements of brake-by-wire, a mechanical pressure reducing valve is used to back up the electro-hydraulic proportional pressure reducing valve. The proposed calibration method increases the output flow of the device under small pedal opening conditions, shortening the oil filling time. The proposed fault identification method identifies faults in the brake-by-wire circuit within the system in both unmanned and manned control modes, which has a positive effect on improving the safety of brake-by-wire. Attached Figure Description

[0031] Figure 1 This is a schematic diagram illustrating the working principle of a wire-controlled redundant braking device according to the present invention. The components include: 1. Mechanical pressure reducing valve; 2. Electro-hydraulic proportional pressure reducing valve; 3. Hydraulic directional valve; 4. Pressure sensor; 5. Brake pedal; 6. Steering angle sensor.

[0032] Figure 2 Pressure differential-flow characteristic map for mechanical pressure reducing valve and proportional pressure reducing valve.

[0033] Figure 3 Pedal rotation angle-output pressure calibration method map for mechanical pressure reducing valve and proportional pressure reducing valve.

[0034] Figure 4 Calibration strategy of the present application and mechanical valve output flow characteristic comparison map.

[0035] Figure 5 Brake device fault identification method map in manned mode.

[0036] Figure 6 Brake device fault identification method map in unmanned mode. DETAILED DESCRIPTION

[0037] In order to make the purpose, content and advantages of the present application clearer, the specific embodiments of the present application are described in further detail below in combination with the drawings and examples.

[0038] To solve the above technical problems, the present application provides a manned and unmanned optional line control brake device, which comprises a mechanical pressure reducing valve (1), an electro-hydraulic proportional pressure reducing valve (2), a hydraulic control directional valve (3), a pressure sensor (4), a brake pedal (5), and a rotation angle sensor (6).

[0039] The mechanical pressure reducing valve (1) is a three-way pressure reducing valve, comprising a first oil supply port, a first oil discharge port, and a first output oil port.

[0040] The electro-hydraulic proportional pressure reducing valve (2) is a three-way electro-hydraulic proportional pressure reducing valve, comprising a second oil supply port, a second oil discharge port, and a second output oil port.

[0041] The hydraulic control directional valve (3) is a hydraulic control two-position three-way valve, comprising two oil supply ports, a sensitive cavity, and a third output oil port. The two oil supply ports are connected to the first output oil port of the mechanical pressure reducing valve (1) and the second output oil port of the electro-hydraulic proportional pressure reducing valve (2), respectively. The sensitive cavity is connected to the second output oil port of the electro-hydraulic proportional pressure reducing valve (2). The third output oil port is connected to the output port of the brake device and the pressure sensor (4).

[0042] The pressure sensor (4) is used to measure the output pressure of the brake system.

[0043] The brake device is provided with a housing, and the housing is provided with an external oil supply port and an external oil discharge port.

[0044] The first oil supply port is connected to the external oil supply port of the brake device, and the first oil discharge port is connected to the external oil discharge port of the brake device.

[0045] The second oil supply port is connected to the external oil supply port of the braking device, and the second oil drain port is connected to the external oil drain port of the braking device.

[0046] The braking device includes a calibration process during operation, which comprises the following steps:

[0047] Step 1: Test the differential pressure flow characteristics of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2); based on the differential pressure flow characteristics of the electro-hydraulic proportional pressure reducing valve (2) and the mechanical pressure reducing valve (1), find the output pressure P corresponding to the point of coincidence of the output flow characteristics of the electro-hydraulic proportional pressure reducing valve (2) and the mechanical pressure reducing valve (1) under different pressures. a ;

[0048] Step 2: Test the pedal opening-output pressure characteristic of the mechanical pressure reducing valve (1); based on the pedal opening-output pressure characteristic of the mechanical pressure reducing valve (1), find the corresponding output pressure P of the mechanical pressure reducing valve (1). a The angular position α of the brake pedal (5); this angular position α is defined as the critical point;

[0049] Step 3: In the control tool, calibrate the correspondence between the output pressure of the electro-hydraulic proportional pressure reducing valve (2) and the rotation angle of the brake pedal (5). Make the output pressure of the electro-hydraulic proportional pressure reducing valve (2) slightly greater than the output pressure of the mechanical pressure reducing valve (1) in the range where the rotation angle of the brake pedal (5) is less than the critical point α. At this time, by switching the hydraulic directional valve (3), the braking device outputs braking pressure from the electro-hydraulic proportional pressure reducing valve (2). In the range where the rotation angle of the brake pedal (5) is greater than the critical point α, make the output pressure of the electro-hydraulic proportional pressure reducing valve (2) less than the output pressure of the mechanical pressure reducing valve (1). At this time, by switching the hydraulic directional valve (3), the braking device outputs braking pressure from the mechanical pressure reducing valve (1).

[0050] In manned mode, the braking device can have a large output flow at a small opening, thereby shortening the system filling time.

[0051] The braking device also includes a fault identification process during operation, which includes:

[0052] The fault identification process in manned mode and the fault identification process in unmanned mode.

[0053] The fault identification process in the manned mode is as follows:

[0054] Step B1: In manned mode, the angle sensor (6) collects the angle of the brake pedal (5) and the output pressure of the braking device, and verifies whether the actual output pressure is consistent with the output pressure value under the corresponding brake pedal (5) angle in the preset strategy.

[0055] Step B2: If the difference is less than a given value (e.g. within 0.1 MPa), it is considered that the brake device is not faulty;

[0056] Step B3: If the difference is greater than a given value, it is considered that the brake-by-wire loop of the brake device is faulty, and the fault information is uploaded.

[0057] Wherein, the fault identification process in the unmanned mode is as follows:

[0058] Step C1: Collect the brake instruction of the upper controller, and set the time boundary condition (e.g. 0.2 s) according to the response time of the brake device under normal working conditions;

[0059] Step C2: If there is no output oil pressure of the brake device within a given time, or the difference between the output oil pressure and the preset oil pressure is too large (e.g. more than 0.3 MPa), it is considered that the brake-by-wire loop of the brake device is faulty, and the passenger is reminded to operate the mechanical brake.

[0060] In summary, the brake-by-wire device provided by the present application includes a brake pedal, an angle sensor, a hydraulic pressure reducing valve, an electro-hydraulic proportional pressure reducing valve, and a hydraulic control directional valve, which can simultaneously meet the requirements of electric control and manual mechanical operation. The calibration method can minimize the oil filling time while making the brake valve have fault identification capability according to the flow characteristics of the hydraulic pressure reducing valve and the electro-hydraulic proportional pressure reducing valve. The brake valve configuration and calibration method can improve the brake response time while ensuring the safety of the brake-by-wire, and have fault identification function.

[0061] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be considered as the protection scope of the present application.

Claims

1. A brake-by-wire apparatus for manned unmanned optional line control, characterized in that, It includes: Mechanical pressure reducing valve (1), electro-hydraulic proportional pressure reducing valve (2), hydraulic control directional valve (3), pressure sensor (4), brake pedal (5), corner sensor (6); Among them, the mechanical pressure reducing valve (1) is a three-way pressure reducing valve, including a first oil inlet, a first oil outlet and a first output oil port; the valve core of the mechanical pressure reducing valve (1) is connected with the brake pedal (5) and the corner sensor (6) respectively; The electro-hydraulic proportional pressure reducing valve (2) is a three-way electro-hydraulic proportional pressure reducing valve, including a second oil inlet, a second oil outlet and a second output oil port; The hydraulic control directional valve (3) is a hydraulic control two-position three-way valve, including two oil inlets, a sensitive cavity and a third output oil port; wherein the two oil inlets are connected with the first output oil port and the second output oil port of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2) respectively, the sensitive cavity is connected with the second output oil port of the electro-hydraulic proportional pressure reducing valve (2), and the third output oil port is connected with the output port of the brake device and the pressure sensor (4); The working process of the brake device includes a calibration link, and the calibration link includes the following steps: Step 1: test the differential pressure flow characteristics of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2); according to the differential pressure flow characteristics of the electro-hydraulic proportional pressure reducing valve (2) and the mechanical pressure reducing valve (1), find the output pressure P corresponding to the coincidence point of the output flow characteristics of the electro-hydraulic proportional pressure reducing valve (2) and the mechanical pressure reducing valve (1) under different pressures a ; Step 2: Test the pedal opening-output pressure characteristic of the mechanical pressure reducing valve (1); find the corner position a of the brake pedal (5) corresponding to the output pressure P of the mechanical pressure reducing valve (1) according to the pedal opening-output pressure characteristic of the mechanical pressure reducing valve (1); define the corner position a as the critical point. a Step 2: Test the pedal opening-output pressure characteristic of the mechanical pressure reducing valve (1); find the corner position a of the brake pedal (5) corresponding to the output pressure P of the mechanical pressure reducing valve (1) according to the pedal opening-output pressure characteristic of the mechanical pressure reducing valve (1); define the corner position a as the critical point. Step 3: calibrate the corresponding relationship between the output pressure of the electro-hydraulic proportional pressure reducing valve (2) and the corner of the brake pedal (5) in the control tool, so that the output pressure of the electro-hydraulic proportional pressure reducing valve (2) is greater than the output pressure of the mechanical pressure reducing valve (1) in the interval where the corner of the brake pedal (5) is less than the critical point α, at this time, through the switching of the hydraulic control directional valve (3), the brake device outputs the brake pressure by the electro-hydraulic proportional pressure reducing valve (2); in the interval where the corner of the brake pedal (5) is greater than the critical point α, the output pressure of the electro-hydraulic proportional pressure reducing valve (2) is less than the output pressure of the mechanical pressure reducing valve (1), then at this time, through the switching of the hydraulic control directional valve (3), the brake device outputs the brake pressure by the mechanical pressure reducing valve (1).

2. The manned-unmanned optional line control braking apparatus of claim 1, wherein, The pressure sensor (4) is used to measure the output pressure of the brake system.

3. The manned-unmanned optional line control braking apparatus of claim 1, wherein, The brake device is provided with a shell, and the shell is provided with an external oil inlet and an external oil outlet.

4. The manned-unmanned optional line control braking apparatus of claim 3, wherein, The first oil inlet is connected with the external oil inlet of the brake device, and the first oil outlet is connected with the external oil outlet of the brake device.

5. The manned-unmanned optional line control braking apparatus of claim 3, wherein, The second oil inlet is connected with the external oil inlet of the brake device, and the second oil outlet is connected with the external oil outlet of the brake device.

6. The manned-unmanned optional line control braking apparatus of claim 1, wherein, Its characteristics are that The working process of the brake device also includes a fault identification link, and the fault identification link includes: The fault identification process in the manned mode and the fault identification process in the unmanned mode.

7. The manned-unmanned optional line control braking apparatus of claim 6, wherein, The fault identification process in the manned mode is as follows: Step B1: in the manned mode, the corner sensor (6) collects the corner of the brake pedal (5) and the output pressure of the brake device, and checks whether the actual output pressure is consistent with the output pressure value corresponding to the corner of the brake pedal (5) in the preset strategy; Step B2: if the difference is less than the given value, it is considered that the brake device has no fault; Step B3: if the difference is greater than the given value, it is considered that the brake device has a fault in the line control loop, and the fault information is uploaded.

8. The manned-unmanned optional line control braking apparatus of claim 7, wherein, The fault identification process in the unmanned mode is as follows: Step C1: collect the brake instruction of the upper controller, and set the time boundary condition according to the response time of the brake device under normal working condition; Step C2: If there is no output oil pressure of the brake device within a given time, it is considered that the brake-by-wire loop of the brake device has a fault, and the passenger is reminded to operate the mechanical brake.

Images