Gas detection method and device based on onebox hydraulic braking system

Abstract

The disclosure provides a gas detection method and device based on a Onebox hydraulic braking system, and relates to the technical field of braking system detection. The method comprises the following steps: in response to the fact that a target vehicle meets a gas detection condition, building pressure on an electric cylinder after exhausting the electric cylinder circuit, so as to obtain a detection deviation value; building pressure on the electric cylinder after supplementing liquid to the electric cylinder circuit, so as to obtain an initial gas content; and determining the gas content of the electric cylinder circuit according to the detection deviation value and the initial gas content. The disclosure calculates the detection deviation value by pushing the piston to exhaust the brake fluid gas from the detection circuit based on the error of the indirect detection method itself, and then detects the gas content of the braking system, so that the accuracy and reliability of the detected gas content can be improved, and the safety of the vehicle can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of braking system testing technology, and in particular to a gas detection method and device based on the Onebox hydraulic braking system. Background Technology

[0002] In automotive hydraulic braking systems, air intrusion or gases generated by high-temperature brake fluid can increase brake pedal travel, weaken vehicle braking force, and pose a safety hazard. Current gas detection methods have limitations on vehicle testing conditions and do not account for methodological errors, leading to inaccurate gas content readings.

[0003] In automotive hydraulic braking systems, the presence of air or gases produced by high-temperature vaporization in the brake fluid can significantly increase brake pedal travel and weaken braking force, posing a serious safety hazard. Most gas detection methods in related technologies rely on indirect measurement, estimating gas content from other parameters of the braking system. This indirect detection method is inherently flawed, leading to insufficient accuracy and low reliability in gas content detection. Summary of the Invention

[0004] This disclosure aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, the first aspect of this disclosure proposes a gas detection method based on a Onebox hydraulic braking system. The electric cylinder unit in the Onebox hydraulic braking system is connected to the reservoir and the inlet and return valves of the wheel via an electric cylinder isolation valve. The electric cylinder unit includes an electric cylinder, a motor, and a piston. A pressure-boosting solenoid valve and a pressure-reducing solenoid valve are respectively installed on the inlet and return valves. The method includes the following steps:

[0006] In response to the target vehicle meeting the gas detection conditions, exhaust is performed on the electric cylinder circuit, which is the passage between the electric cylinder and the electric cylinder isolation valve;

[0007] The electric cylinder is pressurized for the first time according to the preset pressure. The first actual brake fluid volume pushed by the piston and the first calibrated brake fluid volume are determined during the first pressurization process. The difference between the first actual brake fluid volume and the first calibrated brake fluid volume is used as the detection deviation value.

[0008] The electric cylinder is replenished with fluid;

[0009] After replenishing the fluid, the electric cylinder is pressurized a second time according to the preset pressure. The second actual brake fluid volume pushed by the piston and the second standard brake fluid volume are determined during the second pressurization process. The difference between the second actual brake fluid volume and the second standard brake fluid volume is used as the initial gas content of the electric cylinder circuit.

[0010] The gas content of the electric cylinder circuit is determined based on the initial gas content and the detection deviation value.

[0011] In some embodiments of this disclosure, determining the first actual brake fluid volume and the first calibrated brake fluid volume pushed by the piston during the first pressure build-up process includes: determining the first initial position of the piston; pushing the piston until the pressure of the electric cylinder reaches the preset pressure and stops pushing, and determining the first stop position of the piston; determining the first actual brake fluid volume pushed by the piston based on the piston stroke difference between the first initial position and the first stop position and the piston area; and obtaining the first calibrated brake fluid volume pushed by the piston based on the preset pressure and a preset PV curve, wherein the PV curve is used to describe the mapping relationship between cylinder pressure and brake fluid volume.

[0012] In some embodiments of this disclosure, the preset pressure is determined by: determining the minimum brake fluid discharge amount that can vent the gas in the electric cylinder circuit; determining the remaining brake fluid amount in the electric cylinder based on the minimum brake fluid discharge amount; determining the maximum build-up pressure value of the remaining brake fluid amount; determining the minimum pressure value in the linear region of the PV curve; and determining the preset pressure within the range between the maximum build-up pressure value and the minimum pressure value.

[0013] In some embodiments of this disclosure, determining the preset pressure within the range of the maximum pressure build-up value and the minimum pressure value includes: taking the midpoint between the maximum pressure build-up value and the minimum pressure value as the preset pressure.

[0014] In some embodiments of this disclosure, the gas detection conditions include the target vehicle being in a vehicle power-on self-test state or a stable driving state; wherein, the vehicle power-on self-test state includes ignition cycle start-up, no braking, and the vehicle being stationary; the stable driving state includes the target vehicle speed being within a preset threshold range, the vehicle speed change rate being less than a preset change threshold, and the boost solenoid valve and the depressurization solenoid valve being in a closed state.

[0015] In some embodiments of this disclosure, the method further includes: comparing the gas content with a set gas content exceeding threshold; when the gas content is greater than or equal to the gas content exceeding threshold, determining that the gas content of the Onebox hydraulic braking system exceeds the limit, and generating a gas content exceeding alarm message.

[0016] In some embodiments of this disclosure, the method further includes: after determining the gas content of the electric cylinder circuit, controlling the electric cylinder to depressurize, and the piston to return to its original position.

[0017] A second aspect of this disclosure provides a gas detection device based on a Onebox hydraulic braking system. The electric cylinder unit in the Onebox hydraulic braking system is connected to a reservoir and the inlet and return valves of the wheel via an electric cylinder isolation valve. The electric cylinder unit includes an electric cylinder, a motor, and a piston. A pressure-boosting solenoid valve and a pressure-reducing solenoid valve are respectively installed on the inlet and return valves. The device includes:

[0018] An exhaust module is used to exhaust gas from the electric cylinder circuit in response to the target vehicle meeting the gas detection conditions. The electric cylinder circuit is the passage between the electric cylinder and the electric cylinder isolation valve.

[0019] The first pressure building module is used to build up the pressure of the electric cylinder for the first time according to the preset pressure, determine the first actual brake fluid volume pushed by the piston and the first standard brake fluid volume during the first pressure building process, and use the difference between the first actual brake fluid volume and the first standard brake fluid volume as the detection deviation value.

[0020] A fluid replenishment module is used to replenish fluid to the electric cylinder;

[0021] The second pressure-building module is used to build up the pressure of the electric cylinder a second time according to the preset pressure after replenishment, determine the second actual brake fluid volume pushed by the piston and the second standard brake fluid volume during the second pressure-building process, and use the difference between the second actual brake fluid volume and the second standard brake fluid volume as the initial gas content of the electric cylinder circuit.

[0022] The detection module is used to determine the gas content of the electric cylinder circuit based on the initial gas content and the detection deviation value.

[0023] A third aspect of this disclosure provides an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0024] The memory stores computer-executed instructions;

[0025] The processor executes computer execution instructions stored in the memory to implement the method described in the first aspect above.

[0026] A fourth aspect of this disclosure provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, are used to implement the method described in the first aspect above.

[0027] The gas detection method based on the Onebox hydraulic braking system disclosed herein takes into account the inherent error of indirect detection methods. By pushing the piston to discharge brake fluid gas from the detection circuit, the detection deviation value is calculated, and then the gas content of the braking system is detected. This method can improve the accuracy and reliability of gas content detection and enhance vehicle safety.

[0028] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0029] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 A schematic flowchart of a gas detection method based on a Onebox hydraulic braking system provided in this embodiment of the present disclosure;

[0031] Figure 2 A schematic diagram of a Onebox hydraulic braking system provided in an embodiment of this disclosure;

[0032] Figure 3 This is a schematic diagram of a gas detection device based on a Onebox hydraulic braking system, provided as an embodiment of the present disclosure. Detailed Implementation

[0033] Embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0034] Specifically, the following describes a gas detection method and apparatus based on the Onebox hydraulic braking system according to embodiments of the present disclosure with reference to the accompanying drawings.

[0035] Figure 1 This is a schematic flowchart illustrating a gas detection method based on a Onebox hydraulic braking system, provided in an embodiment of this disclosure. Figure 2 This is a schematic diagram of a Onebox hydraulic braking system provided in an embodiment of this disclosure.

[0036] like Figure 2As shown, in some embodiments of this disclosure, the Onebox hydraulic braking system may include an electric cylinder unit 201, an electric cylinder isolation valve PSV 202, a reservoir 203, and inlet and return valve lines 204 for the wheels. The electric cylinder unit 201 includes an electric cylinder 205, a motor 206, and a piston 207. The inlet and return valve lines 204 are respectively equipped with a pressure boosting solenoid valve ISO 208 and a pressure reducing solenoid valve Dump 209. The electric cylinder unit 201 is connected to the reservoir 203 and the inlet and return valve lines 204 through the electric cylinder isolation valve PSV 202. Figure 2 Other components include: brake pedal 210, test valve TSV211, manual cylinder isolation valve CSV212, and simulation valve SSV.

[0037] like Figure 1 As shown, the gas detection method based on the Onebox hydraulic braking system provided in this disclosure embodiment may include the following steps:

[0038] Step 101: In response to the target vehicle meeting the gas detection conditions, exhaust gas is vented from the electric cylinder circuit.

[0039] Among them, the electric cylinder circuit is the passage between the electric cylinder and the electric cylinder isolation valve.

[0040] In some embodiments of this disclosure, the gas detection conditions may include the target vehicle being in a vehicle power-on self-test state or a stable driving state.

[0041] The vehicle's power-on self-test state includes ignition cycle starting, no braking, and the vehicle being stationary. The stable driving state includes the target vehicle's speed being within a preset threshold range, the rate of speed change being less than a preset threshold, and the booster and depressurization solenoid valves being closed. In other words, the stable driving state limits vehicle speed and speed changes, avoiding potential braking situations or excessive speed, and preventing the risk of insufficient braking force due to interruption or delay in the detection process. When the target vehicle is determined to be in a driving state, all booster and depressurization solenoid valves on the inlet and return valve lines must be closed. Therefore, the gas detection method provided in this embodiment can perform detection not only when the vehicle is stationary but also while the vehicle is in motion, expanding the application scope of gas detection.

[0042] Blowing air from the electric cylinder circuit can include:

[0043] S1, Open the electric cylinder isolation valve PSV202;

[0044] S2, push the piston forward to build pressure, and the brake fluid is pushed to the circuit of test valve TSV211, manual cylinder isolation valve CSV212, and electric cylinder isolation valve PSV202, which will discharge the brake fluid gas that was originally in the electric cylinder circuit until the piston reaches the preset stroke and stops.

[0045] S3, close the electric cylinder isolation valve PSV202, and retain a small amount of brake fluid in the electric cylinder circuit.

[0046] Step 102: Perform the first pressure build-up on the electric cylinder according to the preset pressure, determine the first actual brake fluid volume pushed by the piston and the first standard brake fluid volume during the first pressure build-up process, and take the difference between the first actual brake fluid volume and the first standard brake fluid volume as the detection deviation value.

[0047] In one implementation, during the initial pressure build-up process, the first initial position of the piston can be determined; the piston is pushed until the pressure in the electric cylinder reaches a preset pressure, at which point the first stopping position of the piston is determined; based on the piston stroke difference between the first initial position and the first stopping position and the piston area, the first actual brake fluid volume pushed by the piston is determined; and based on the preset pressure and a preset PV curve, the first standardized brake fluid volume pushed by the piston is obtained. The PV curve describes the mapping relationship between cylinder pressure and the pushed brake fluid volume.

[0048] The difference between the first actual brake fluid volume and the first calibrated brake fluid volume is the current gas content volume of the braking system. This gas content is used as the error of the detection method itself, i.e., the detection deviation value. .

[0049] Optionally, the preset pressure can be determined in the following ways:

[0050] S1, determine the minimum amount of brake fluid that can be discharged to vent the gas in the electric cylinder circuit;

[0051] S2, determine the remaining brake fluid volume of the electric cylinder based on the minimum brake fluid discharge volume;

[0052] S3, determine the maximum pressure build-up value that can be achieved by the remaining brake fluid in the electric cylinder;

[0053] S4, determine the minimum pressure value in the linear region of the PV curve;

[0054] This example ensures measurement accuracy by utilizing the linear region of the PV curve.

[0055] S5, determine the preset pressure within the range of the maximum pressure build-up value and the minimum pressure value.

[0056] Optionally, the midpoint between the maximum build-up pressure and the minimum pressure can be used as the preset pressure.

[0057] Step 103: Add fluid to the electric cylinder.

[0058] This means that the electric cylinder depressurizes, the piston retracts, and the fluid replenishment begins, drawing brake fluid (which may contain air) from the brake lines into the electric cylinder until the replenishment is complete.

[0059] Step 104: After replenishing the fluid, the electric cylinder is pressurized a second time according to the preset pressure. The actual brake fluid volume pushed by the piston during the second pressurization process is determined, and the difference between the actual brake fluid volume and the standard brake fluid volume is used as the initial gas content of the electric cylinder circuit.

[0060] It should be noted that the second pressure build-up process can refer to the first pressure build-up process in step 102, using the same method to obtain the second actual brake fluid volume and the second calibrated brake fluid volume. The only difference is that the first pressure build-up is performed after bleeding the electric cylinder circuit, while the second pressure build-up is performed after adding fluid to the electric cylinder. Therefore, the second pressure build-up process will not be described in detail here.

[0061] The difference between the second actual brake fluid volume and the second calibrated brake fluid volume during the second pressure build-up process is the current gas content volume of the braking system. This gas content is taken as the gas content containing error, i.e., the initial gas content. .

[0062] Step 105: Determine the gas content of the electric cylinder circuit based on the initial gas content and the detection deviation value.

[0063] In some embodiments of this disclosure, due to the initial gas content Since the gas content contains errors, the difference between the initial gas content and the detection deviation value can be calculated to obtain the gas content of the electric cylinder circuit. .

[0064] In some embodiments of this disclosure, the gas content may also be... The gas content is compared with the set threshold for exceeding the gas content limit; when the gas content is greater than or equal to the threshold for exceeding the gas content limit, it is determined that the gas content of the Onebox hydraulic braking system exceeds the limit, and a gas content exceeding the limit alarm message is generated.

[0065] In some embodiments of this disclosure, after determining the gas content in the electric cylinder circuit, the braking system can be reset to control the depressurization of the electric cylinder and the piston return to its original position. If the target vehicle is in a stable driving state, all booster solenoid valves and depressurizer solenoid valves on the inlet and return valve lines also need to be opened.

[0066] By implementing the embodiments of this disclosure, the inherent errors of the indirect detection method are taken into account. By pushing the piston to discharge brake fluid gas from the detection circuit, the detection deviation value is calculated, and the gas content of the braking system is detected. This improves the accuracy and reliability of gas content detection and enhances vehicle safety.

[0067] Figure 3This is a schematic diagram of a gas detection device based on a Onebox hydraulic braking system, provided as an embodiment of this disclosure. Figure 3 As shown, the gas detection device based on the Onebox hydraulic braking system may include: an exhaust module 301, a first pressure building module 302, a fluid replenishment module 303, a second pressure building module 304, and a detection module 305.

[0068] The exhaust module 301 is used to exhaust the electric cylinder circuit in response to the target vehicle meeting the gas detection conditions. The electric cylinder circuit is the passage between the electric cylinder and the electric cylinder isolation valve.

[0069] Gas detection conditions include the target vehicle being in either a power-on self-test state or a stable driving state. The power-on self-test state includes ignition cycle starting, no braking, and the vehicle being stationary. The stable driving state includes the target vehicle's speed being within a preset threshold range, the rate of speed change being less than a preset threshold, and both the boost and depressurization solenoid valves being closed.

[0070] The first pressure-building module 302 is used to build up the pressure of the electric cylinder for the first time according to the preset pressure, determine the first actual brake fluid volume pushed by the piston and the first standard brake fluid volume during the first pressure-building process, and use the difference between the first actual brake fluid volume and the first standard brake fluid volume as the detection deviation value.

[0071] In some embodiments of this disclosure, the first pressure-building module 302 is specifically used for: determining the first initial position of the piston; pushing the piston and stopping pushing when the pressure of the electric cylinder reaches a preset pressure, and determining the first stop position of the piston; determining the first actual brake fluid volume pushed by the piston based on the piston stroke difference between the first initial position and the first stop position and the piston area; and obtaining the first standardized brake fluid volume pushed by the piston based on the preset pressure and the preset PV curve, wherein the PV curve is used to describe the mapping relationship between the cylinder pressure and the brake fluid volume.

[0072] The fluid replenishment module 303 is used to replenish fluid to the electric cylinder.

[0073] The second pressure-building module 304 is used to build up the pressure of the electric cylinder a second time according to the preset pressure after replenishment. It determines the second actual brake fluid volume pushed by the piston and the second standard brake fluid volume during the second pressure-building process, and uses the difference between the second actual brake fluid volume and the second standard brake fluid volume as the initial gas content of the electric cylinder circuit.

[0074] The detection module 305 is used to determine the gas content of the electric cylinder circuit based on the initial gas content and the detection deviation value.

[0075] In some embodiments of this disclosure, such as Figure 3Based on the illustrated embodiment, the gas detection device based on the Onebox hydraulic braking system may further include a determination module. The determination module is used to: determine the minimum brake fluid discharge amount required to vent gas from the electric cylinder circuit; determine the remaining brake fluid volume in the electric cylinder based on the minimum brake fluid discharge amount; determine the maximum pressure build-up value of the remaining brake fluid volume; determine the minimum pressure value in the linear region of the PV curve; and determine a preset pressure within the range between the maximum pressure build-up value and the minimum pressure value.

[0076] In some embodiments of this disclosure, the median of the maximum pressure build-up and the minimum pressure is used as the preset pressure.

[0077] In some embodiments of this disclosure, such as Figure 3 Based on the illustrated embodiment, the gas detection device for the Onebox hydraulic braking system may further include an alarm module. The alarm module is used to: compare the gas content with a set gas content exceeding a threshold; when the gas content is greater than or equal to the gas content exceeding the threshold, determine that the gas content of the Onebox hydraulic braking system exceeds the limit, and generate a gas content exceeding alarm message.

[0078] In some embodiments of this disclosure, such as Figure 3 Based on the illustrated embodiment, the gas detection device based on the Onebox hydraulic braking system may further include a reset module. The reset module is used to: after determining the gas content in the electric cylinder circuit, control the electric cylinder to depressurize and return the piston to its original position.

[0079] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0080] To implement the above embodiments, this disclosure also proposes an electronic device, including: a processor and a memory communicatively connected to the processor; the memory stores computer execution instructions; the processor executes the computer execution instructions stored in the memory to implement the method provided in the foregoing embodiments.

[0081] To implement the above embodiments, this disclosure also proposes a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the methods provided in the foregoing embodiments.

[0082] To implement the above embodiments, this disclosure also proposes a computer program product, including a computer program that, when executed by a processor, implements the methods provided in the foregoing embodiments.

[0083] In the foregoing descriptions of the embodiments, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0084] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0085] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of this disclosure includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of this disclosure pertain.

[0086] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0087] It should be understood that various parts of this disclosure can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0088] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0089] Furthermore, the functional units in the various embodiments of this disclosure can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0090] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A gas detection method based on a Onebox hydraulic braking system, an electric cylinder unit in the Onebox hydraulic braking system is connected with a liquid storage tank and a wheel inlet and return liquid valve path through an electric cylinder isolation valve respectively, the electric cylinder unit comprises an electric cylinder, a motor and a piston, and a pressure increasing electromagnetic valve and a pressure reducing electromagnetic valve are arranged on the inlet and return liquid valve path respectively; characterized in that, The method comprises the following steps: In response to the target vehicle meeting a gas detection condition, the electric cylinder circuit is vented, the electric cylinder circuit being a passage between the electric cylinder and the electric cylinder isolation valve; A first actual brake fluid volume pushed by the piston is determined according to a preset pressure, and a first calibration brake fluid volume is determined, and a difference between the first actual brake fluid volume and the first calibration brake fluid volume is taken as a detection deviation value; The electric cylinder is supplemented with liquid; After the liquid is supplemented, a second calibration brake fluid volume is determined according to a second time of building pressure of the electric cylinder according to the preset pressure, and a second actual brake fluid volume pushed by the piston in the second time of building pressure is determined, and a difference between the second actual brake fluid volume and the second calibration brake fluid volume is taken as an initial gas content of the electric cylinder circuit; The gas content of the electric cylinder circuit is determined according to the initial gas content and the detection deviation value.

2. The method of claim 1, wherein, The first actual brake fluid volume pushed by the piston and the first calibration brake fluid volume in the first time of building pressure are determined, comprising: A first initial position of the piston is determined; The piston is pushed, and the piston is stopped from being pushed when the pressure of the electric cylinder reaches the preset pressure, and a first stop position of the piston is determined; The first actual brake fluid volume pushed by the piston is determined according to a piston stroke difference between the first initial position and the first stop position and a piston area; The first calibration brake fluid volume pushed by the piston is obtained according to the preset pressure and a preset P-V curve, and the P-V curve is used to describe a mapping relationship between cylinder pressure and brake fluid volume.

3. The method of claim 2, wherein, The preset pressure is determined by the following method: A minimum brake fluid discharge amount capable of emptying the gas in the electric cylinder circuit is determined; The remaining brake fluid amount of the electric cylinder is determined based on the minimum brake fluid discharge amount; A maximum building pressure value of the remaining brake fluid amount is determined; A minimum pressure value in a linear region of the P-V curve is determined; The preset pressure is determined within an interval range of the maximum building pressure value and the minimum pressure value.

4. The method of claim 3, wherein, The preset pressure is determined within the interval range of the maximum building pressure value and the minimum pressure value, comprising: The median value of the maximum building pressure value and the minimum pressure value is taken as the preset pressure.

5. The method of claim 1, wherein, The gas detection condition comprises that the target vehicle is in a vehicle power-on self-checking state or a stable driving state; The vehicle power-on self-checking state comprises that the ignition cycle is started, and there is no braking, and the vehicle is stationary; The stable driving state comprises that the speed of the target vehicle is in a preset threshold interval, and the speed variation rate is less than a preset variation threshold, and the pressure increasing electromagnetic valve and the pressure reducing electromagnetic valve are in a closed state.

6. The method of claim 1, wherein, The method further comprises: The gas content is compared with a set gas content over-standard threshold value; When the gas content is greater than or equal to the gas content over-standard threshold value, it is determined that the gas content of the Onebox hydraulic brake system is over-standard, and gas content over-standard alarm information is generated.

7. The method according to any one of claims 1 to 6, characterized in that, The method further comprises: After the gas content of the electric cylinder circuit is determined, the electric cylinder is controlled to be depressurized, and the piston is returned.

8. A gas detection device based on a Onebox hydraulic braking system, wherein an electric cylinder unit in the Onebox hydraulic braking system is connected with a liquid storage tank and a wheel inlet and return liquid valve path through an electric cylinder isolation valve respectively, the electric cylinder unit comprises an electric cylinder, a motor and a piston, and a pressure increasing electromagnetic valve and a pressure reducing electromagnetic valve are arranged on the inlet and return liquid valve path respectively; characterized in that, The device comprises: An exhaust module is configured to exhaust the electric cylinder circuit in response to the target vehicle satisfying a gas detection condition, the electric cylinder circuit being a passage between the electric cylinder and the electric cylinder isolation valve; A first pressure building module is configured to build pressure in the electric cylinder for a first time according to a preset pressure, to determine a first actual brake fluid volume pushed by the piston in the first pressure building process and a first calibration brake fluid volume, and to take a difference between the first actual brake fluid volume and the first calibration brake fluid volume as a detection deviation value; A liquid supplementing module is configured to supplement the electric cylinder with liquid; A second pressure building module is configured to build pressure in the electric cylinder for a second time according to the preset pressure after the liquid supplementing, to determine a second actual brake fluid volume pushed by the piston in the second pressure building process and a second calibration brake fluid volume, and to take a difference between the second actual brake fluid volume and the second calibration brake fluid volume as an initial gas content of the electric cylinder circuit; A detection module is configured to determine a gas content of the electric cylinder circuit according to the initial gas content and the detection deviation value.

9. An electronic device, comprising: Comprise: a processor, and a memory connected to the processor in communication; the memory stores computer execution instructions; the processor executes the computer execution instructions stored in the memory to implement the method of any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer execution instructions, and the computer execution instructions are executed by the processor to implement the method of any one of claims 1-7.

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