Power-on self-test method and vehicle

Abstract

An embodiment of the present invention provides a power-on self-check method and a vehicle, which relate to the field of vehicle braking. The method includes: when a wake-up signal is received, obtaining the power-off state of the last power-off, when the power-off state of the last power-off is abnormal, controlling the piston to return to the zero position, determining the first stepping state of the brake pedal, and when the first stepping state indicates that the brake pedal is in a stepped state and after the piston returns to the zero position, judging whether the brake pedal is released, and when the brake pedal is not released, braking is performed based on mechanical backup assistance, and when the first stepping state indicates that the brake pedal is not in a stepped state, after the piston returns to the zero position, entering the running state, so as to ensure that power-on self-check can be implemented for different states of the driver's power-on of the vehicle to ensure driving safety.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle braking, and in particular to a power-on self-test method and a vehicle. Background Art

[0002] The integrated electronic hydraulic braking system includes the functions of three major braking products: EHB (Electronic Hydraulic Brake), EPB (Electronic Park Brake), and ESC (Electronic Stability Control). It can achieve high-quality basic braking, wire-controlled braking, wire-controlled parking, stability control and other functions, and can serve as a chassis domain controller to fully take over the wire-controlled chassis.

[0003] However, since multiple braking functions of the integrated electronic hydraulic brake system share one controller, the redundancy is low. When some functions fail, braking can only rely on mechanical backup. In order to reduce the probability of failure of the integrated electronic hydraulic brake system, power-on self-test is required.

[0004] However, during the power-on self-test, during the actual power-on process, the driver has multiple states of control over the vehicle. The current power-on self-test method only sets a self-test under one specific state. When the driver misoperates the vehicle, the vehicle cannot perform self-test, and driving safety cannot be ensured. Summary of the invention

[0005] The object of the present invention is to provide a power-on self-checking method and a vehicle, which can perform power-on self-checking on an electronic hydraulic brake system to ensure driving safety.

[0006] In order to achieve the above purpose, the technical solution adopted by the embodiment of the present invention is as follows:

[0007] In a first aspect, an embodiment of the present invention provides a power-on self-test method, which is applied to a vehicle controller, wherein the vehicle controller is communicatively connected to an electronic hydraulic brake system, and the method comprises:

[0008] When receiving the wake-up signal, the power-off status of the last power-off is obtained;

[0009] When the power-off state of the last power-off is abnormal, the control piston returns to the zero position;

[0010] Determining a first stepping state of the brake pedal, and determining whether the brake pedal is released after the first stepping state indicates that the brake pedal is in a stepped state and the piston returns to a zero position;

[0011] When the brake pedal is not released, assisting based on mechanical backup assistance;

[0012] When the first stepping state indicates that the brake pedal is not stepped on, the running state is entered after the piston returns to the zero position.

[0013] Optionally, the method further comprises:

[0014] The operating status indicates: power is supplied to the SSV valve, PSV1 valve, PSV2 valve, CSV1 valve and CSV2 valve to make them in an operating state, wherein the vehicle controller is communicatively connected with the SSV valve, PSV1 valve, PSV2 valve, CSV1 valve and CSV2 valve.

[0015] Optionally, when the brake pedal is not released, the step of providing assistance based on mechanical backup assistance includes:

[0016] When the brake pedal is not released, the SSV valve, PSV1 valve, PSV2 valve, CSV1 valve and CSV2 valve are powered off so that the pressure of the master cylinder is pushed to the wheel end through the CSV1 valve and the CSV2 valve for braking, wherein the electronic hydraulic brake system includes a master cylinder, which is mechanically connected to the brake pedal, and the master cylinder is pressurized when the brake pedal is stepped on.

[0017] Optionally, the method further comprises:

[0018] When the power-off state of the last power-off is normal, determining a second stepping state of the brake pedal;

[0019] When the second stepping state indicates that the brake pedal is in a stepped state, detecting the effectiveness of the mechanical backup;

[0020] When the second depression state indicates that the brake pedal is not depressed, the control piston retreats to the zero position.

[0021] Optionally, the method further comprises:

[0022] In the process of controlling the piston to return to the zero position, when a stepping operation on the brake pedal is detected, the motor is controlled to stop working, wherein the vehicle controller is in communication connection with the motor, and the motor is used to control the displacement of the piston;

[0023] The effectiveness of the mechanical backup is tested.

[0024] Optionally, when the second stepping state indicates that the brake pedal is in a stepped state, the step of detecting the effectiveness of the mechanical backup comprises:

[0025] Control the CSV1 valve and the CSV2 valve to be in a closed state, and control the PSV1 valve, the PSV2 valve, and the SSV valve to be in an open state, determine the first hydraulic pressure of the master cylinder and determine the first hydraulic pressure curve in the process of establishing the first hydraulic pressure based on the stepping operation of the brake pedal, wherein the electronic hydraulic brake system further includes a master cylinder, a CSV1 valve, a CSV2 valve, a PSV1 valve, a PSV2 valve, and an SSV valve, the vehicle controller is respectively connected to the CSV1 valve, the CSV2 valve, the PSV1 valve, the PSV2 valve, and the SSV valve for communication, the brake pedal is mechanically connected to the master cylinder, and the first hydraulic pressure curve indicates the relationship between the piston displacement and the first hydraulic pressure;

[0026] Establishing a second hydraulic pressure for the electric cylinder and determining a second hydraulic pressure curve in the process of establishing the second hydraulic pressure for the electric cylinder, wherein the electronic hydraulic brake system further includes an electric cylinder, the vehicle controller is in communication connection with the electric cylinder, the second hydraulic pressure curve indicates a relationship between the second hydraulic pressure and time, and the second hydraulic pressure is greater than the first hydraulic pressure;

[0027] Based on the first hydraulic pressure curve and the second hydraulic pressure curve, determining whether the electric cylinder and the master cylinder can build pressure normally;

[0028] When the master cylinder and the electric cylinder can build pressure normally, the SSV valve is powered on, the CSV1 valve is powered off, and a first change curve of the hydraulic pressure at the electric cylinder within a preset time period and a first change rate of the first change curve are determined;

[0029] De-energizing the CSV2 valve, and determining a second change curve of the hydraulic pressure at the electric cylinder within the preset time period and a second change rate of the second change curve;

[0030] The PSV1 valve, the PSV2 valve, the CSV1 valve, and the CSV2 valve are detected based on the first change rate and the second change rate.

[0031] Optionally, the step of determining whether the electric cylinder and the master cylinder can build pressure normally based on the first hydraulic pressure curve and the second hydraulic pressure curve includes:

[0032] comparing the first hydraulic pressure curve with a first preset hydraulic pressure curve;

[0033] When the first hydraulic pressure curve is consistent with the first preset hydraulic pressure curve, it is determined that the master cylinder can build pressure normally and that the power-on state of the SSV valve is normal;

[0034] comparing the second hydraulic pressure curve with a second preset hydraulic pressure curve;

[0035] When the second hydraulic pressure curve is consistent with the second preset hydraulic pressure curve, it is determined that the electric cylinder can build pressure normally.

[0036] Optionally, the step of detecting the PSV1 valve, the PSV2 valve, the CSV1 valve, and the CSV2 valve based on the first change rate and the second change rate includes:

[0037] comparing the first rate of change with the second rate of change;

[0038] When the second change rate is greater than the first change rate, it is determined that the de-energized states of the CSV1 valve and the CSV2 valve are normal, and it is determined that the energized states of the PSV1 valve and the PSV2 valve are normal.

[0039] Optionally, the step of controlling the piston to return to the zero position when the power-off state of the last power-off is abnormal includes:

[0040] Controlling the motor of the electric cylinder to rotate in the reverse direction for a preset time period so that the piston returns to the mechanical zero position;

[0041] The motor is controlled to rotate forward by a preset distance so that the piston returns to the software zero position.

[0042] In a second aspect, an embodiment of the present invention provides a vehicle, including a processor and a memory, wherein the memory stores a computer program that can be executed by the processor, and the processor can execute the computer program to implement the power-on self-test method.

[0043] The present invention has the following beneficial effects:

[0044] The present invention obtains the power-off state of the last power-off when receiving a wake-up signal, controls the piston to return to the zero position when the power-off state of the last power-off is abnormal, determines the first stepped state of the brake pedal, and determines whether the brake pedal is released when the first stepped state indicates that the brake pedal is in a stepped state and after the piston returns to the zero position. When the brake pedal is not released, braking is performed based on mechanical backup assistance, and enters the operating state after the piston returns to the zero position when the first stepped state indicates that the brake pedal is not stepped on, so as to ensure that power-on self-check can be implemented according to different states of the driver's power-on of the vehicle to ensure driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0046] Figure 1A schematic diagram of an electronic hydraulic brake system provided by an embodiment of the present invention;

[0047] Figure 2 A block diagram of a vehicle controller provided by an embodiment of the present invention;

[0048] Figure 3 One of the flowcharts of a power-on self-test method provided by an embodiment of the present invention;

[0049] Figure 4 A second flowchart of a power-on self-test method provided by an embodiment of the present invention;

[0050] Figure 5 A third flowchart of a power-on self-test method provided by an embodiment of the present invention;

[0051] Figure 6 A fourth flowchart of a power-on self-test method provided by an embodiment of the present invention;

[0052] Figure 7 A fifth flowchart of a power-on self-test method provided by an embodiment of the present invention;

[0053] Figure 8 A sixth flowchart of a power-on self-test method provided by an embodiment of the present invention;

[0054] Fig. 9 A seventh flowchart of a power-on self-test method provided by an embodiment of the present invention;

[0055] Fig.10 A structural diagram of a power-on self-test device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0057] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0059] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0060] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0061] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] The integrated electronic hydraulic braking system includes the functions of three major braking products: EHB (Electronic Hydraulic Brake), EPB (Electronic Park Brake), and ESC (Electronic Stability Control). It can achieve high-quality basic braking, wire-controlled braking, wire-controlled parking, stability control and other functions, and can serve as a chassis domain controller to fully take over the wire-controlled chassis.

[0063] like Figure 1As shown, it is a schematic diagram of an electronic hydraulic brake system, which includes an oil pot module 10, a wheel end module 20, a main brake circuit 30 and a mechanical brake circuit 40. The oil pot module includes a small oil pot 11 and a large oil pot 12. The main brake circuit 30 includes an electric cylinder 31 and a PSV1 valve and a PSV2 valve. The pressure buildup of the electric cylinder 31 is achieved by the piston movement in the electric cylinder driven by the motor. The wheel end module 20 includes an IV1 valve, an IV2 valve, an IV3 valve, an IV4 valve, an OV1 valve, an OV2 valve, an OV3 valve and an OV4 valve. The IV1 valve is connected to the OV1 valve, the OV1 valve is connected to the first wheel end, the IV2 valve is connected to the OV2 valve, and the OV2 valve is connected to the second wheel end. The IV3 valve is connected to the OV3 valve, the OV3 valve is connected to the third wheel end, the IV4 valve is connected to the OV4 valve, and the OV4 valve is connected to the fourth wheel end. The PSV1 valve of the main brake circuit 30 is connected to the IV1 valve and the IV2 valve through an oil circuit, and the PSV2 valve of the main brake circuit 30 is connected to the IV3 valve and the IV4 valve through an oil circuit. When the solenoid valve in the mechanical brake circuit 40 is in a closed state and the PSV1 valve and the PSV2 valve are in an open state, the electric cylinder 31 provides hydraulic pressure to the IV1 valve, the IV2 valve, the IV3 valve and the IV4 valve.

[0064] The mechanical brake circuit 40 includes a master cylinder 41, a CSV1 valve, a CSV2 valve, an SSV valve and a TSV valve. The CSV1 valve, the CSV2 valve, the SSV valve and the TSV valve are respectively connected to the master cylinder. The SSV valve is connected to the simulation chamber 42. The simulation chamber 42 is connected to the oil pot module 10 through an oil circuit. The other end of the TSV valve is connected to the oil pot module 10. The CSV1 valve is connected to the IV1 valve and the IV2 valve through an oil circuit. The CSV2 valve is connected to the IV3 valve and the IV4 valve through an oil circuit. When the CSV1 valve and the CSV2 valve are in an open state, that is, the CSV1 valve and the CSV2 valve allow flow to pass through, and the PSV1 valve and the PSV2 valve are in a closed state, that is, the PSV1 valve and the PSV2 valve do not allow flow to pass through, the master cylinder 41 provides hydraulic pressure to the IV1 valve, the IV2 valve, the IV3 valve and the IV4 valve. The master cylinder 41 is connected to the brake pedal 43, and pressure is built up for the master cylinder 41 by stepping on the brake pedal 43.

[0065] It should be noted that the CSV1 valve, CSV2 valve, IV1 valve, IV2 valve, IV3 valve and IV4 valve are normally open valves, that is, when the CSV1 valve, CSV2 valve, IV1 valve, IV2 valve, IV3 valve and IV4 valve are powered on, the CSV1 valve, CSV2 valve, IV1 valve, IV2 valve, IV3 valve and IV4 valve are in a closed state, that is, a state in which flow is not allowed to pass, and when the CSV1 valve, CSV2 valve, IV1 valve, IV2 valve, IV3 valve and IV4 valve are powered off, the CSV1 valve, CSV2 valve, IV1 valve, IV2 valve, IV3 valve and IV4 valve are in an open state, that is, a state in which flow is allowed to pass. In the electronic hydraulic brake system, other solenoid valves except the above-mentioned CSV1 valve, CSV2 valve, IV1 valve, IV2 valve, IV3 valve and IV4 valve are normally closed valves.

[0066] Since the driver may have multiple control states of the vehicle during the actual power-on process, the current power-on self-check method only sets a self-check under one specific state. When the driver misoperates the vehicle, the vehicle cannot perform self-check, and thus driving safety cannot be ensured. Therefore, it is urgent to provide a power-on self-check method that can realize power-on self-check for vehicles in different states to ensure driving safety.

[0067] In view of the discovery of the above problems, the present embodiment provides a power-on self-check method and a vehicle, which can obtain the power-off state of the last power-off when receiving a wake-up signal. When the power-off state of the last power-off is abnormal, the piston is controlled to return to the zero position, and the first stepping state of the brake pedal is determined. When the first stepping state indicates that the brake pedal is in a stepped state and after the piston returns to the zero position, it is determined whether the brake pedal is released. When the brake pedal is not released, braking is performed based on mechanical backup assistance. When the first stepping state indicates that the brake pedal is not stepped on, after the piston returns to the zero position, the running state is entered to ensure that power-on self-check can be implemented for different states of the driver's power-on of the vehicle to ensure driving safety. The solution provided in the present embodiment is elaborated in detail below.

[0068] This embodiment provides a vehicle controller that can perform power-on self-test on an electronic hydraulic brake system. In a possible implementation, the vehicle controller can be, but is not limited to, a driving computer, a server, a smart phone, a personal computer (PC), a tablet computer, a personal digital assistant (PDA), a mobile Internet device (MID), etc.

[0069] Please refer to Figure 2 , Figure 2FIG. 1 is a schematic diagram of the structure of a vehicle controller 100 provided in an embodiment of the present invention. The vehicle controller 100 may also include Figure 2 More or fewer components as shown, or with Figure 2 Different configurations shown. Figure 2 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0070] The vehicle controller 100 includes a power-on self-test device 110 , a memory 120 and a processor 130 .

[0071] The memory 120 and the processor 130 are electrically connected to each other directly or indirectly to achieve data transmission or interaction. For example, these elements can be electrically connected to each other through one or more communication buses or signal lines. The power-on self-test device 110 includes at least one software function module that can be stored in the memory 120 in the form of software or firmware or solidified in the operating system (OS) of the vehicle controller 100. The processor 130 is used to execute the executable modules stored in the memory 120, such as the software function modules and computer programs included in the power-on self-test device 110.

[0072] The memory 120 may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), etc. The memory 120 is used to store a program, and the processor 130 executes the program after receiving an execution instruction.

[0073] Please refer to Figure 3 , Figure 3 For application Figure 2 A flow chart of a power-on self-test method of a vehicle controller 100 is shown, and the method including each step is described in detail below.

[0074] S201: When a wake-up signal is received, a power-off state of the last power-off is obtained.

[0075] S202: When the power-off state of the last power-off is abnormal, the control piston returns to the zero position.

[0076] S203: Determine a first stepping state of the brake pedal, and determine whether the brake pedal is released after the first stepping state indicates that the brake pedal is in a stepped state and the piston returns to a zero position.

[0077] S204: When the brake pedal is not released, assisting the vehicle based on the mechanical backup assist.

[0078] S205: When the first stepping state indicates that the brake pedal is not stepped on, the running state is entered after the piston returns to the zero position.

[0079] It should be noted that the vehicle can be powered on by a Bluetooth key, that is, the vehicle is powered on when a wake-up signal sent by the Bluetooth key is received. The vehicle can be powered on by ignition after the brake pedal is stepped on, that is, when the brake pedal is stepped on and the ignition operation is received, it is determined that the wake-up signal is received to power on.

[0080] The wake-up signal may include a CAN network wake-up signal, a KL15 hard-line wake-up signal, and an EPB switch wake-up signal.

[0081] There are multiple implementations for obtaining the power-off status of the last power-off. In one implementation, the power-off information of the last power-off may be obtained, and whether the last power-off is abnormal may be determined based on the power-off information of the last power-off.

[0082] When the power-off state of the last power-off is abnormal, it means that the last power-off state is abnormal due to a power failure of the vehicle or a system failure of the vehicle at the time of the last power-off.

[0083] When the last power-off state is detected to be abnormal, only mechanical backup assistance is provided. Figure 1 , when the power-off state of the last power-off was abnormal, the PSV1 valve and PSV2 valve corresponding to the electric cylinder were in a power-off state, the motor of the electric cylinder was in a power-off state, the control SSV valve, CSV1 valve and CSV2 valve were in an open state, and the IV1 valve, IV2 valve, IV3 valve and IV4 valve were all in a power-off state, that is, the IV1 valve, IV2 valve, IV3 valve and IV4 valve were in an open state. At this time, the only way to provide braking force for the vehicle is to control the master cylinder to build pressure through the brake pedal. The hydraulic pressure built by the master cylinder is pushed to the wheel end through the CSV1 valve, CSV2 valve, IV1 valve, IV2 valve, IV3 valve and IV4 valve, pushing the caliper to clamp the brake disc to achieve braking.

[0084] When the vehicle controller receives a wake-up signal and determines that the last power-off state is abnormal, the control piston returns to the zero position, and the electronic hydraulic brake system is powered on based on the first pedaling state of the brake pedal in the electronic hydraulic brake system and the different pedaling states of the brake pedal.

[0085] When the power-off state of the last power-off is abnormal, the control piston returns to the zero position to avoid residual hydraulic pressure in the electronic hydraulic brake system due to the last power-off abnormality. After the control piston returns to the zero position, the electronic hydraulic brake system can be depressurized, that is, the residual pressure in the electronic hydraulic brake system is released and the piston in the electric cylinder is calibrated back to zero, thereby avoiding failure of the electronic hydraulic brake system during vehicle driving and facilitating the normal pressure buildup of the electric cylinder during subsequent vehicle operation, to ensure the normal operation of the electronic hydraulic brake system and thus ensure driving safety.

[0086] After the first stepping state of the brake pedal indicates that the brake pedal is in a stepped state and the control piston returns to the zero position, the state of the brake pedal is detected. When the brake pedal is not released, assistance is provided based on mechanical backup, that is, CSV1 valve and CSV2 valve are not energized, CSV1 valve and CSV2 valve are in an open state, PSV1 valve and PSV2 valve are not energized and are in a closed state, IV1 valve, IV2 valve, IV3 valve and IV4 valve are not energized, and are all in an open state. At this time, the brake pedal is not released, and the master cylinder establishes hydraulic pressure based on the stepping of the brake pedal. The hydraulic pressure established by the master cylinder pushes the hydraulic pressure to the corresponding wheel end through the CSV1 valve, CSV2 valve, IV1 valve, IV2 valve, IV3 valve and IV4 valve, that is, the vehicle is assisted based on the hydraulic pressure of the master cylinder.

[0087] When the brake pedal is released and the piston returns to the zero position, the electronic hydraulic brake system is controlled to enter the operating state, that is, the SSV valve, PSV1 valve, PSV2 valve, CSV1 valve and CSV2 valve are energized, the SSV valve, PSV1 valve and PSV2 valve are in the open state, and the CSV1 valve and CSV2 valve are in the closed state. At this time, the braking of the vehicle is achieved by the electric cylinder and the PSV1 valve and PSV2 valve corresponding to the electric cylinder. When the electric cylinder builds pressure, the hydraulic pressure is pushed to the corresponding wheel end through the PSV1 valve and PSV2 valve to assist the vehicle.

[0088] When the vehicle is powered on in a way that requires stepping on the brake pedal, then when the brake pedal is in the stepped state, it is obtained whether the power-off state of the last power-off is abnormal. When the power-off state of the last power-off is abnormal, the control piston is returned to the zero position, and it is determined whether the brake pedal is released. If the brake pedal is not released, there is a need for assistance, and assistance is provided based on the mechanical backup assistance. When it is detected that the brake pedal is released, the piston returns to the zero position and enters the running state. When the brake pedal is stepped on during the period when the control piston returns to the zero position, the control motor stops working and the piston remains in the current position.

[0089] When the wake-up signal is received, the power-off state of the last power-off is obtained. When the power-off state of the last power-off is normal, there are multiple implementation methods for performing power-on self-test on the electronic hydraulic brake system. In one implementation method, for example Figure 4 As shown, the following steps are included:

[0090] S301: When the power-off state of the last power-off is normal, determine a second stepping state of the brake pedal.

[0091] S302: When the second stepping state indicates that the brake pedal is in a stepped state, the effectiveness of the mechanical backup is detected.

[0092] S303: When the second stepping state indicates that the brake pedal is not stepped on, the control piston returns to the zero position.

[0093] When the power-off state of the last power-off is normal, a power-on self-check is performed on the electronic hydraulic brake system based on the second stepping state of the brake pedal.

[0094] Specifically, when the second stepping state of the brake pedal is the stepped state, Figure 1 The CSV1 valve, CSV2 valve, SSV valve, PSV1 valve and PSV2 valve are powered on for detection.

[0095] The master cylinder and the electric cylinder are controlled separately to build up pressure. When the master cylinder and the electric cylinder are pressured separately, the PSV1 valve, PSV2 valve, CSV1 valve, CSV2 valve and SSV valve are controlled to be opened and closed. Based on the changes in the pressure of the master cylinder and the electric cylinder, the PSV1 valve, PSV2 valve, CSV1 valve, CSV2 valve and SSV valve are tested to determine whether the PSV1 valve, PSV2 valve, CSV1 valve, CSV2 valve and SSV valve are controlled normally.

[0096] When the brake pedal is in the second pedaling state and is not pedaled, the control piston returns to the zero position to release the residual pressure in the electronic hydraulic brake system and calibrate the piston in the electric cylinder back to zero, thereby avoiding failure of the electronic hydraulic brake system during vehicle driving and facilitating the normal pressure buildup in the electric cylinder during subsequent vehicle operation, to ensure the normal operation of the electronic hydraulic brake system and driving safety.

[0097] When the wake-up signal is received, the power-off state of the last power-off is obtained, and when the power-off state of the last power-off is normal, another implementation method of performing a power-on self-test on the electronic hydraulic brake system is as follows: Figure 5 As shown, the following steps are included:

[0098] S304: When the control piston is returning to the zero position and a stepping operation on the brake pedal is detected, the control motor stops working.

[0099] The vehicle controller is connected to the motor for communication, and the motor is used to control the displacement of the piston.

[0100] S305: Check the effectiveness of the mechanical backup.

[0101] When the power-off state of the last power-off is normal and the second stepping state indicates that the brake pedal is not stepped on, the control piston returns to zero position. During the process of the control piston returning to zero position, if the brake pedal is detected to be stepped on, the current operation of returning the control piston to zero position is exited, and the operation of returning the control piston to zero position is no longer performed during the current power-on to the current power-off. The master cylinder and the electric cylinder are controlled to build pressure respectively. When the master cylinder and the electric cylinder are respectively built up, the PSV1 valve, PSV2 valve, CSV1 valve, CSV2 valve and SSV valve are controlled to be opened and closed, and the PSV1 valve, PSV2 valve, CSV1 valve, CSV2 valve and SSV valve are tested based on the changes in the pressure of the master cylinder and the electric cylinder to achieve self-checking of the effectiveness of mechanical backup.

[0102] There are many ways to detect the effectiveness of mechanical backup. In one implementation, for example, Figure 6 As shown, the following steps are included:

[0103] S401: Control the CSV1 valve and the CSV2 valve to be in the closed state, control the PSV1 valve, the PSV2 valve and the SSV valve to be in the open state, and determine the first hydraulic pressure of the master cylinder and the first hydraulic pressure curve in the process of establishing the first hydraulic pressure based on the stepping operation of the brake pedal.

[0104] Among them, the electronic hydraulic braking system also includes a master cylinder, a CSV1 valve, a CSV2 valve, a PSV1 valve, a PSV2 valve and an SSV valve. The vehicle controller is communicated with the CSV1 valve, the CSV2 valve, the PSV1 valve, the PSV2 valve and the SSV valve respectively. The brake pedal is mechanically connected to the master cylinder. The first hydraulic curve indicates the relationship between the piston displacement and the first hydraulic pressure.

[0105] The electronic hydraulic brake system also includes a first pressure sensor and a first displacement sensor, which are respectively connected to the master cylinder. The first pressure sensor is used to detect the hydraulic pressure of the master cylinder, and the first displacement sensor is used to detect the displacement of the piston in the master cylinder.

[0106] In the process of establishing the first hydraulic pressure in the master cylinder, the first pressure sensor detects the hydraulic pressure of the master cylinder, and the first displacement sensor detects the displacement of the piston of the master cylinder. The detected hydraulic pressure of the master cylinder is fitted with the displacement of the piston of the master cylinder to obtain the first hydraulic pressure curve in the process of establishing the first hydraulic pressure.

[0107] S402: Establishing a second hydraulic pressure for the electric cylinder and determining a second hydraulic pressure curve in the process of establishing the second hydraulic pressure for the electric cylinder.

[0108] Among them, the electronic hydraulic braking system also includes an electric cylinder, the vehicle controller is communicatively connected with the electric cylinder, the second hydraulic curve indicates the relationship between the second hydraulic pressure and time, and the second hydraulic pressure is greater than the first hydraulic pressure.

[0109] The electronic hydraulic braking system further includes a second pressure sensor, which is connected to the electric cylinder and is used to detect the hydraulic pressure of the electric cylinder.

[0110] In the process of establishing the second hydraulic pressure for the electric cylinder, the hydraulic pressure of the electric cylinder is detected by the second pressure sensor, and based on the hydraulic pressure of the electric cylinder, a second hydraulic pressure curve in the process of establishing the second hydraulic pressure is obtained.

[0111] S403: Based on the first hydraulic pressure curve and the second hydraulic pressure curve, determine whether the electric cylinder and the master cylinder can build up pressure normally.

[0112] When the first hydraulic pressure curve meets the pressure building expectation, it is determined that the master cylinder can build pressure normally and the master cylinder has no leakage. When the second hydraulic pressure curve meets the pressure building expectation, it is determined that the electric cylinder can build pressure normally and the electric cylinder has no leakage.

[0113] When the first hydraulic pressure curve does not meet the pressure building expectation, it is determined that the master cylinder cannot build pressure normally and there is leakage in the master cylinder. When the second hydraulic pressure curve does not meet the pressure building expectation, it is determined that the electric cylinder cannot build pressure normally and there is leakage in the electric cylinder.

[0114] S404: When the master cylinder and the electric cylinder can build up pressure normally, the SSV valve is energized, the CSV1 valve is de-energized, and a first change curve of the hydraulic pressure at the electric cylinder within a preset time and a first change rate of the first change curve are determined.

[0115] When the CSV1 valve is powered off, the CSV1 valve is in an open state, the hydraulic pressure in the master cylinder is released based on the CSV1 valve, and the hydraulic pressure at the electric cylinder is detected based on the second pressure sensor corresponding to the electric cylinder. The moment when the CSV1 valve is opened is used as the initial time, and the first change curve of the hydraulic pressure at the electric cylinder within a preset time after the initial time is determined, as well as the first change rate corresponding to the first change curve at the electric cylinder.

[0116] S405: De-energize the CSV2 valve, and determine a second change curve of the hydraulic pressure at the electric cylinder within a preset time period and a second change rate of the second change curve.

[0117] After the CSV1 valve is powered off, when it is detected that the hydraulic pressure detected at the electric cylinder is less than the second hydraulic pressure, the CSV2 valve is powered off to make the CSV2 valve in an open state. The hydraulic pressure at the electric cylinder is detected based on the second pressure sensor corresponding to the electric cylinder. The moment when the CSV2 valve is opened is used as the initial time, and the second change curve of the hydraulic pressure at the electric cylinder within a preset time after the initial time and the second change rate corresponding to the second change curve at the electric cylinder are determined.

[0118] S406: Detect the PSV1 valve, the PSV2 valve, the CSV1 valve, and the CSV2 valve based on the first change rate and the second change rate.

[0119] There are many ways to determine whether the electric cylinder and the master cylinder can build pressure normally based on the first hydraulic curve and the second hydraulic curve. In one implementation, Figure 7 As shown, the following steps are included:

[0120] S403-1: Compare the first hydraulic pressure curve with the first preset hydraulic pressure curve.

[0121] S403-2: When the first hydraulic pressure curve is consistent with the first preset hydraulic pressure curve, it is determined that the master cylinder can build pressure normally and that the power-on state of the SSV valve is normal.

[0122] S403-3: Compare the second hydraulic pressure curve with the second preset hydraulic pressure curve.

[0123] S403-4: When the second hydraulic pressure curve is consistent with the second preset hydraulic pressure curve, it is determined that the electric cylinder can build pressure normally.

[0124] The vehicle controller is preset with multiple preset curves, that is, when the master cylinder has no leakage, preset curves corresponding to different hydraulic pressures are preset for the master cylinder. The first preset curve corresponding to the first hydraulic pressure is obtained from the multiple preset curves, and the first preset curve is compared with the first hydraulic pressure curve. When the first preset curve is consistent with the first hydraulic pressure curve, it is determined that the master cylinder has no leakage, pressure can be built normally, and the SSV valve is powered normally. When the first preset curve is inconsistent with the first hydraulic pressure curve, it is determined that the master cylinder is leaking and pressure cannot be built normally or the SSV valve conduction is abnormal.

[0125] The vehicle controller is preset with multiple preset curves, that is, when the electric cylinder has no leakage, preset curves corresponding to different hydraulic pressures are preset for the electric cylinder. A second preset curve corresponding to the second hydraulic pressure is obtained from the multiple preset curves, and the second preset curve is compared with the second hydraulic pressure curve. When the second preset curve is consistent with the second hydraulic pressure curve, it is determined that the electric cylinder has no leakage and can build pressure normally. When the second preset curve is inconsistent with the second hydraulic pressure curve, it is determined that the electric cylinder has leakage and cannot build pressure normally.

[0126] There are many implementations for detecting the PSV1 valve, the PSV2 valve, the CSV1 valve, and the CSV2 valve based on the first change rate and the second change rate. In one implementation, Figure 8 As shown, the following steps are included:

[0127] S406 - 1 : Compare the first change rate with the second change rate.

[0128] S406-2: When the second change rate is greater than the first change rate, determine that the power-off state of the CSV1 valve and the CSV2 valve is normal, and determine that the power-on state of the PSV1 valve and the PSV2 valve is normal.

[0129] When the second change rate is less than or equal to the first change rate, a fault alarm message is generated and the vehicle enters a driving prohibited state.

[0130] When the power-off state of the last power-off is abnormal, there are multiple ways to control the piston to return to the zero position. In one implementation, for example, Fig. 9 As shown, the following steps are included:

[0131] S501: Control the motor of the electric cylinder to rotate in the reverse direction for a preset time, so that the piston returns to the mechanical zero position.

[0132] S502: Control the motor to rotate forward by a preset distance, so that the piston returns to the software zero position.

[0133] The zero position of the piston of the electric cylinder includes the mechanical zero position and the software zero position. The distance between the software zero position and the bottom of the electric cylinder is smaller than the distance between the mechanical zero position and the bottom of the electric cylinder.

[0134] The method of controlling the piston to return to the zero position may be: controlling the motor corresponding to the electric cylinder to rotate in the opposite direction according to the speed change curve and return to the mechanical zero position; wherein the speed of the piston in the speed change curve decreases with the increase of time, and during the period when the piston returns to the mechanical zero position, the piston speed needs to be limited to not exceed the first preset speed, and when it is detected that the piston speed is less than the second preset speed and continues for a preset duration, it is determined that the piston has returned to the mechanical zero position. wherein the first preset speed is greater than the second preset speed.

[0135] It should be noted that the first preset speed can be set to 10 mm / s, the second preset speed can be set to 0.2 mm / s, and the preset duration can be set to 5 ms, which is not specifically limited in the embodiment of the present invention.

[0136] After the piston returns to the mechanical zero position, the control motor rotates forward by a preset distance to make the piston return to the software zero position.

[0137] It should be noted that the preset distance may be set to 0.8 mm, and the embodiment of the present invention does not impose any specific limitation on this.

[0138] Please refer to Fig.10 The embodiment of the present invention also provides a method for applying Figure 2 A power-on self-test device 110 of the vehicle controller 100, the power-on self-test device 110 comprising:

[0139] The acquisition module 111 is used to acquire the power-off state of the last power-off when receiving the wake-up signal;

[0140] The control module 112 is used to control the piston to return to the zero position when the power-off state of the last power-off is abnormal;

[0141] The determining module 113 is configured to determine a first stepped state of the brake pedal, wherein the first stepped state indicates that the brake pedal is in a stepped state.

[0142] and after the piston returns to the zero position, determining whether the brake pedal is released;

[0143] A boost module 114, configured to provide boost based on mechanical backup boost when the brake pedal is not released;

[0144] The control module 112 is further configured to enter a running state after the piston returns to a zero position when the first stepping state indicates that the brake pedal is not stepped on.

[0145] The present invention also provides a vehicle, comprising a processor and a memory, wherein the memory stores a computer program that can be executed by the processor, and the processor can execute the computer program to implement the power-on self-test method.

[0146] In the embodiments provided by the present invention, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0147] In addition, each functional module in each embodiment of the present invention can be integrated together to form an independent part, or each module can exist separately, or two or more modules can be integrated to form an independent part. If the function is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

[0148] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0149] The above are only various embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A power-on self-test method, applied to a vehicle controller, wherein the vehicle controller is communicatively connected to an electronic hydraulic brake system, characterized in that: The method comprises: When receiving the wake-up signal, the power-off status of the last power-off is obtained; When the power-off state of the last power-off is abnormal, the control piston is returned to the zero position, wherein the piston is the piston in the electric cylinder; determining a first stepping state of the brake pedal, and determining whether the brake pedal is released when the first stepping state indicates that the brake pedal is in a stepped state and after the piston returns to a zero position; When the brake pedal is not released, assisting based on mechanical backup assistance; When the first stepping state indicates that the brake pedal is not stepped on, the running state is entered after the piston returns to the zero position; Wherein, the method further comprises: When the power-off state of the last power-off is normal, determining a second stepping state of the brake pedal; When the second stepping state indicates that the brake pedal is in a stepped state, detecting the effectiveness of the mechanical backup; When the second stepping state indicates that the brake pedal is not stepped on, the control piston returns to the zero position; The step of detecting the effectiveness of the mechanical backup when the second stepping state indicates that the brake pedal is in a stepped state comprises: Control the CSV1 valve and the CSV2 valve to be in a closed state, control the PSV1 valve, the PSV2 valve and the SSV valve to be in an open state, determine the first hydraulic pressure of the master cylinder and determine the first hydraulic pressure curve in the process of establishing the first hydraulic pressure based on the stepping operation of the brake pedal, wherein the electronic hydraulic brake system further includes a master cylinder, a CSV1 valve, a CSV2 valve, a PSV1 valve, a PSV2 valve and an SSV valve, the vehicle controller is respectively connected to the CSV1 valve, the CSV2 valve, the PSV1 valve, the PSV2 valve and the SSV valve for communication, the brake pedal is mechanically connected to the master cylinder, and the first hydraulic pressure curve indicates the relationship between the piston displacement and the first hydraulic pressure; Establishing a second hydraulic pressure for the electric cylinder and determining a second hydraulic pressure curve in the process of establishing the second hydraulic pressure for the electric cylinder, wherein the electronic hydraulic brake system further includes an electric cylinder, the vehicle controller is in communication connection with the electric cylinder, the second hydraulic pressure curve indicates a relationship between the second hydraulic pressure and time, and the second hydraulic pressure is greater than the first hydraulic pressure; Based on the first hydraulic pressure curve and the second hydraulic pressure curve, determining whether the electric cylinder and the master cylinder can build pressure normally; When the master cylinder and the electric cylinder can build pressure normally, the SSV valve is powered on, the CSV1 valve is powered off, and a first change curve of the hydraulic pressure at the electric cylinder within a preset time period and a first change rate of the first change curve are determined; De-energizing the CSV2 valve, and determining a second change curve of the hydraulic pressure at the electric cylinder within the preset time period and a second change rate of the second change curve; The PSV1 valve, the PSV2 valve, the CSV1 valve, and the CSV2 valve are detected based on the first change rate and the second change rate.

2. The method according to claim 1, characterized in that The operating status indicates: power is supplied to the SSV valve, PSV1 valve, PSV2 valve, CSV1 valve and CSV2 valve to make them in an operating state, wherein the vehicle controller is communicatively connected with the SSV valve, PSV1 valve, PSV2 valve, CSV1 valve and CSV2 valve.

3. The method according to claim 1 or 2, characterized in that: The step of providing assistance based on mechanical backup assistance when the brake pedal is not released comprises: When the brake pedal is not released, the SSV valve, PSV1 valve, PSV2 valve, CSV1 valve and CSV2 valve are powered off so that the pressure of the master cylinder is pushed to the wheel end through the CSV1 valve and the CSV2 valve for braking, wherein the electronic hydraulic brake system includes a master cylinder, which is mechanically connected to the brake pedal, and the master cylinder is pressurized when the brake pedal is stepped on.

4. The method according to claim 1, characterized in that: The method further comprises: In the process of controlling the piston to return to the zero position, when a stepping operation on the brake pedal is detected, the motor is controlled to stop working, wherein the vehicle controller is in communication connection with the motor, and the motor is used to control the displacement of the piston; The effectiveness of the mechanical backup is tested.

5. The method according to claim 1, characterized in that The step of determining whether the electric cylinder and the master cylinder can build pressure normally based on the first hydraulic pressure curve and the second hydraulic pressure curve comprises: comparing the first hydraulic pressure curve with a first preset hydraulic pressure curve; When the first hydraulic pressure curve is consistent with the first preset hydraulic pressure curve, it is determined that the master cylinder can build pressure normally and that the power-on state of the SSV valve is normal; comparing the second hydraulic pressure curve with a second preset hydraulic pressure curve; When the second hydraulic pressure curve is consistent with the second preset hydraulic pressure curve, it is determined that the electric cylinder can build pressure normally.

6. The method according to claim 1, characterized in that The step of detecting the PSV1 valve, the PSV2 valve, the CSV1 valve, and the CSV2 valve based on the first change rate and the second change rate includes: comparing the first rate of change with the second rate of change; When the second change rate is greater than the first change rate, it is determined that the de-energized states of the CSV1 valve and the CSV2 valve are normal, and it is determined that the energized states of the PSV1 valve and the PSV2 valve are normal.

7. The method according to claim 1, characterized in that The step of controlling the piston to return to the zero position when the power-off state of the last power-off is abnormal includes: Controlling the motor of the electric cylinder to rotate in the reverse direction for a preset time period so that the piston returns to the mechanical zero position; The motor is controlled to rotate forward by a preset distance so that the piston returns to the software zero position.

8. A vehicle, characterized in that: The invention comprises a processor and a memory, wherein the memory stores a computer program executable by the processor, and the processor can execute the computer program to implement the power-on self-test method according to any one of claims 1 to 7.

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