Calibration and fault identification methods for manned / unmanned selectable wire-controlled braking devices

Abstract

This invention belongs to the field of vehicle operation and control technology, specifically relating to a calibration and fault identification method for a manned / unmanned selectable brake-by-wire device. The brake-by-wire device includes a brake pedal, a steering angle sensor, a hydraulic pressure reducing valve, an electro-hydraulic proportional pressure reducing valve, and a hydraulic directional valve, capable of simultaneously meeting the needs of both electronic control and manual mechanical operation. The calibration method, based on the flow characteristics of the hydraulic and electro-hydraulic proportional pressure reducing valves, minimizes the filling time while enabling the brake valves to have fault identification capabilities. This brake-by-wire device and calibration method can improve braking response time while ensuring brake-by-wire safety and providing fault identification functionality.

Description

Technical Field

[0001] This invention belongs to the field of vehicle operation and control technology, specifically relating to a calibration and fault identification method for manned and unmanned selectable drive-by-wire braking devices. Background Technology

[0002] Existing tracked vehicles mostly use mechanical-hydraulic brake valves, which cannot meet the needs of unmanned and manned / unmanned vehicle control. Furthermore, the valve opening and differential pressure flow characteristics of mechanical valves mean that the output flow rate increases with the pedal opening, resulting in a longer system filling time when the pedal opening is small. While electromagnetic pressure reducing valves can achieve brake-by-wire control, there are safety risks due to factors such as electronic control system failures. Therefore, research on highly safe brake-by-wire devices is urgently needed. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] The technical problem to be solved by this invention is: how to develop a calibration and fault identification method for a wire-controlled redundant braking device, which ensures the reliability of the braking function through mechanical backup on the basis of realizing wire-controlled braking of tracked vehicles, and shortens the response time of the braking system and improves the handling quality by taking into account the differences in flow characteristics between mechanical valves and electro-hydraulic proportional pressure reducing valves through the proposed calibration method.

[0005] (II) Technical Solution

[0006] To solve the above-mentioned technical problems, the present invention provides a calibration method for a manned / unmanned selectable brake line device, wherein the manned / unmanned selectable brake line device includes: a mechanical pressure reducing valve (1), an electro-hydraulic proportional pressure reducing valve (2), a hydraulic directional valve (3), a pressure sensor (4), a brake pedal (5), and a rotation angle sensor (6); wherein the mechanical pressure reducing valve (1) is a three-way pressure reducing valve, including a first oil supply port, a first oil drain port, and a first oil output port; the valve core of the mechanical pressure reducing valve (1) is respectively connected to the brake pedal (5) and the rotation angle sensor (6). The electro-hydraulic proportional pressure reducing valve (2) is a three-way electro-hydraulic proportional pressure reducing valve, including a second oil supply port, a second oil drain port, and a second oil output port; the hydraulic directional valve (3) is a hydraulic two-position three-way valve, including two oil supply ports, a sensitive chamber, and a third oil output port; wherein the two oil supply ports are respectively connected to the first oil output port and the second oil output port of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2), the sensitive chamber is connected to the second oil output port of the electro-hydraulic proportional pressure reducing valve (2), and the third oil output port is connected to the output port of the braking device and the pressure sensor (4);

[0007] The calibration method includes the following steps:

[0008] 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 ;

[0009] 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;

[0010] 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).

[0011] The pressure sensor (4) is used to measure the output pressure of the braking system.

[0012] The braking device is provided with a housing, which has an external oil supply port and an external oil drain port.

[0013] The first oil supply port is connected to the external oil supply port of the braking device, and the first oil drain port is connected to the external oil drain port of the braking device.

[0014] 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.

[0015] In manned mode, the braking device can have a large output flow at a small opening, thereby shortening the system filling time.

[0016] Furthermore, the present invention also provides a fault identification method for a manned / unmanned selectable wire-controlled braking device, the manned / unmanned selectable wire-controlled braking device comprising: a mechanical pressure reducing valve (1), an electro-hydraulic proportional pressure reducing valve (2), a hydraulic directional valve (3), a pressure sensor (4), a brake pedal (5), and a rotation angle sensor (6); wherein, the mechanical pressure reducing valve (1) is a three-way pressure reducing valve, comprising a first oil supply port, a first oil drain port, and a first oil output port; the valve core of the mechanical pressure reducing valve (1) is connected to the brake pedal (5) and the rotation angle 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 supply port, a second oil drain port, and a second oil output port; the hydraulic directional valve (3) is a hydraulic two-position three-way valve, including two oil supply ports, a sensitive chamber, and a third oil output port; wherein the two oil supply ports are respectively connected to the first oil output port and the second oil output port of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2), the sensitive chamber is connected to the second oil output port of the electro-hydraulic proportional pressure reducing valve (2), and the third oil output port is connected to the output port of the braking device and the pressure sensor (4);

[0017] The fault identification method includes:

[0018] The fault identification process in manned mode and the fault identification process in unmanned mode.

[0019] The fault identification process in the manned mode is as follows:

[0020] 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.

[0021] Step B2: If the difference is less than the given value, the braking device is considered to be fault-free;

[0022] 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.

[0023] The fault identification process in the unmanned mode is as follows:

[0024] Step C1: Collect braking commands from the upper-level controller and set time boundary conditions based on the response time of the braking device under normal operating conditions;

[0025] 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, 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.

[0026] In step B2, the given value is 0.1 MPa;

[0027] In step C1, the time boundary condition is 0.2s;

[0028] In step C2, the difference between the output oil pressure and the preset oil pressure is greater than 0.3 MPa.

[0029] (III) Beneficial Effects

[0030] Compared with the prior art, the calibration and fault identification method of the wire-controlled redundant braking device provided by the present invention can improve the response time of the braking system in manned mode while realizing wire-controlled braking in unmanned mode of tracked vehicles. At the same time, it can ensure that the driver can brake mechanically in the event of a fault in the wire-controlled branch, thus ensuring the braking safety of the vehicle.

[0031] 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

[0032] 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.

[0033] Figure 2 This is a diagram showing the differential pressure-flow characteristics of a mechanical pressure reducing valve and a proportional pressure reducing valve.

[0034] Figure 3 Diagram showing the method for calibrating the pedal angle and output pressure of mechanical pressure reducing valves and proportional pressure reducing valves.

[0035] Figure 4 This is a comparison chart of the calibration strategy of this invention and the output flow characteristics of a mechanical valve.

[0036] Figure 5 A diagram illustrating the method for identifying brake device faults in manned mode.

[0037] Figure 6 This diagram illustrates a method for identifying brake device faults in unmanned mode. Detailed Implementation

[0038] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0039] To solve the above-mentioned technical problems, the present invention provides a calibration method for a manned / unmanned selectable brake line device, wherein the manned / unmanned selectable brake line device includes: a mechanical pressure reducing valve (1), an electro-hydraulic proportional pressure reducing valve (2), a hydraulic directional valve (3), a pressure sensor (4), a brake pedal (5), and a rotation angle sensor (6); wherein the mechanical pressure reducing valve (1) is a three-way pressure reducing valve, including a first oil supply port, a first oil drain port, and a first oil output port; the valve core of the mechanical pressure reducing valve (1) is respectively connected to the brake pedal (5) and the rotation angle sensor (6). The electro-hydraulic proportional pressure reducing valve (2) is a three-way electro-hydraulic proportional pressure reducing valve, including a second oil supply port, a second oil drain port, and a second oil output port; the hydraulic directional valve (3) is a hydraulic two-position three-way valve, including two oil supply ports, a sensitive chamber, and a third oil output port; wherein the two oil supply ports are respectively connected to the first oil output port and the second oil output port of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2), the sensitive chamber is connected to the second oil output port of the electro-hydraulic proportional pressure reducing valve (2), and the third oil output port is connected to the output port of the braking device and the pressure sensor (4);

[0040] The calibration method includes the following steps:

[0041] 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 ;

[0042] 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;

[0043] 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).

[0044] The pressure sensor (4) is used to measure the output pressure of the braking system.

[0045] The braking device is provided with a housing, which has an external oil supply port and an external oil drain port.

[0046] The first oil supply port is connected to the external oil supply port of the braking device, and the first oil drain port is connected to the external oil drain port of the braking device.

[0047] 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.

[0048] In manned mode, the braking device can have a large output flow at a small opening, thereby shortening the system filling time.

[0049] Furthermore, the present invention also provides a fault identification method for a manned / unmanned selectable wire-controlled braking device, the manned / unmanned selectable wire-controlled braking device comprising: a mechanical pressure reducing valve (1), an electro-hydraulic proportional pressure reducing valve (2), a hydraulic directional valve (3), a pressure sensor (4), a brake pedal (5), and a rotation angle sensor (6); wherein, the mechanical pressure reducing valve (1) is a three-way pressure reducing valve, comprising a first oil supply port, a first oil drain port, and a first oil output port; the valve core of the mechanical pressure reducing valve (1) is connected to the brake pedal (5) and the rotation angle 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 supply port, a second oil drain port, and a second oil output port; the hydraulic directional valve (3) is a hydraulic two-position three-way valve, including two oil supply ports, a sensitive chamber, and a third oil output port; wherein the two oil supply ports are respectively connected to the first oil output port and the second oil output port of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2), the sensitive chamber is connected to the second oil output port of the electro-hydraulic proportional pressure reducing valve (2), and the third oil output port is connected to the output port of the braking device and the pressure sensor (4);

[0050] The fault identification method includes:

[0051] The fault identification process in manned mode and the fault identification process in unmanned mode.

[0052] The fault identification process in the manned mode is as follows:

[0053] 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.

[0054] 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;

[0055] 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.

[0056] The fault identification process in the unmanned mode is as follows:

[0057] 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;

[0058] 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.

[0059] In step B2, the given value is 0.1 MPa;

[0060] In step C1, the time boundary condition is 0.2s;

[0061] In step C2, the difference between the output oil pressure and the preset oil pressure is greater than 0.3 MPa.

[0062] In summary, the drive-by-wire braking device provided by this invention includes a brake pedal, a steering angle sensor, a hydraulic pressure reducing valve, an electro-hydraulic proportional pressure reducing valve, and a hydraulic directional valve. It can simultaneously meet the needs of both electronic control and manual mechanical operation. The calibration method, based on the flow characteristics of the hydraulic and electro-hydraulic proportional pressure reducing valves, minimizes the oil filling time while enabling the brake valves to have fault identification capabilities. This braking device and calibration method can improve braking response time while ensuring drive-by-wire safety and provide fault identification functionality.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A calibration method for a manned / unmanned selectable brake-by-wire device, characterized in that, The manned / unmanned selectable line-controlled braking device includes: a mechanical pressure reducing valve (1), an electro-hydraulic proportional pressure reducing valve (2), a hydraulic directional valve (3), a pressure sensor (4), a brake pedal (5), and a rotation angle sensor (6); wherein, the mechanical pressure reducing valve (1) is a three-way pressure reducing valve, including a first oil supply port, a first oil drain port, and a first oil output port; the valve core of the mechanical pressure reducing valve (1) is connected to the brake pedal (5) and the rotation angle 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 supply port, a second oil drain port, and a second oil output port; the hydraulic directional valve (3) is a hydraulic two-position three-way valve, including two oil supply ports, a sensitive chamber, and a third oil output port; wherein the two oil supply ports are connected to the first and second oil output ports of the mechanical pressure reducing valve (1) and the electro-hydraulic proportional pressure reducing valve (2) respectively, the sensitive chamber is connected to the second oil output port of the electro-hydraulic proportional pressure reducing valve (2), and the third oil output port is connected to the output port of the braking device and the pressure sensor (4); The calibration method 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); 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 overlap 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); 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 angle position α of the brake pedal (5); define the angle position α as the critical point; 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).

2. The calibration method for a manned / unmanned selectable line-of-sight braking device as described in claim 1, characterized in that, The pressure sensor (4) is used to measure the output pressure of the braking system.

3. The calibration method for a manned / unmanned selectable wire-controlled braking device as described in claim 1, characterized in that, The braking device is provided with a housing, and the housing is provided with an external oil supply port and an external oil drain port.

4. The calibration method for a manned / unmanned selectable line-of-sight braking device as described in claim 3, characterized in that, The first oil supply port is connected to the external oil supply port of the braking device, and the first oil drain port is connected to the external oil drain port of the braking device.

5. The calibration method for a manned / unmanned selectable line-of-sight braking device as described in claim 3, characterized in that, 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.

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