Hill-hold control function pressure maintaining pressure control method, device and vehicle

Abstract

The application discloses a method and device for controlling pressure maintaining pressure of a hill hold control function and a vehicle, comprising obtaining a real-time state of a brake pedal; determining that a driver steps on the brake pedal when the real-time state meets a preset state; obtaining a real-time activation state of the hill hold control function; determining that an initial threshold of activation of the hill hold control function is reached when the real-time activation state meets a preset activation state; obtaining a real-time slope where the vehicle is located, and calculating a basic pressure maintaining pressure value; correcting the basic pressure maintaining pressure value according to a driving style of the driver, a rate at which the driver steps on the brake pedal and a rate at which the driver steps on an accelerator pedal, so as to obtain a real-time pressure maintaining pressure value; and braking on a hill according to the real-time pressure maintaining pressure value. The real-time pressure maintaining pressure value of the hill hold control function can be adaptively changed according to a driving mode of the vehicle and a driving style of the driver, so as to meet diversified requirements.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, specifically to a pressure control method, device, and vehicle for hill-holding control. Background Technology

[0002] Currently, new energy vehicles are increasingly equipped with Integrated Brake Control (IBC). As an integrated and intelligent electronic braking system, it combines basic brake assist and single-wheel pressure regulation functions, resulting in a compact design, stronger braking performance, and the ability to achieve more braking control functions. Hill Hold Control (HHC) is an additional function of IBC, also commonly known as hill start assist (hereinafter referred to as HHC). Its basic working principle is that during the period from parking on a slope to starting the vehicle, as the driver moves their foot from the brake pedal to the accelerator pedal, a certain braking pressure is maintained in the four brake wheel cylinders to prevent the vehicle from rolling backward and ensure a smooth start. The current industry standard of slope holding control functions with fixed pressure cannot meet the diverse needs of drivers. For example, younger drivers with more aggressive driving habits prefer a lower pressure for smoother starts on slopes, while older drivers with more stable driving habits prefer a higher pressure because they press the accelerator pedal at a relatively slower rate, and a higher pressure helps the vehicle start smoothly on slopes. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention provides a method, device, and vehicle for controlling the pressure holding function of hill-holding control, so that the pressure holding function of hill-holding control can adapt to changes in vehicle driving mode, driver driving style, etc., to meet diverse needs.

[0004] According to a first aspect of the present invention, a pressure holding control method for a ramp holding control function includes: Obtain the real-time status of the brake pedal; When the real-time state meets the preset state, it is determined that the driver has pressed the brake pedal; Obtain the real-time activation status of the ramp holding control function; When the real-time activation state meets the preset activation state, it is determined that the initial activation threshold of the ramp holding control function has been reached. The real-time slope of the vehicle is obtained, and the basic pressure holding value is calculated. The baseline holding pressure value is corrected based on the driver's driving style, the rate at which the driver depresses the brake pedal, and the rate at which the driver depresses the accelerator pedal to obtain the real-time holding pressure value. Apply ramp braking according to the real-time pressure holding value.

[0005] The pressure holding control method according to embodiments of the present invention has at least the following beneficial effects: After the initial threshold for hill-holding control activation is reached, the real-time slope of the vehicle is obtained to calculate the base holding pressure value. Then, the base holding pressure value is corrected according to the driver's driving style, the rate at which the driver depresses the brake pedal, and the rate at which the driver depresses the accelerator pedal to set the real-time holding pressure value. This allows the real-time holding pressure value of the hill-holding control function to adapt to changes in the vehicle's driving mode and the driver's driving style, meeting diverse needs.

[0006] According to some embodiments of the present invention, the step of correcting the baseline holding pressure value based on the driver's driving style, the driver's braking pedal depressing rate, and the driver's accelerator pedal depressing rate to obtain the real-time holding pressure value includes: The real-time pressure holding value p is calculated using the formula p=p0*f1*f2*f3, where p0 is the basic pressure holding value, f1 is a correction coefficient related to the driver's driving style, f2 is a correction coefficient related to the rate at which the driver depresses the brake pedal, and f3 is a correction coefficient related to the rate at which the driver depresses the accelerator pedal.

[0007] According to some embodiments of the present invention, the correction coefficient f1 is obtained through a limited number of real vehicle calibration tests. The correction coefficient f1 is obtained by calibrating different parameter values ​​under different vehicle driving modes and correcting the parameters according to the driver's driving habits within a set period.

[0008] According to some embodiments of the present invention, a correction coefficient f2 is obtained through a limited number of real vehicle calibration tests, wherein, after the rate at which the driver depresses the brake pedal exceeds a first preset threshold, the pressure holding value is reduced according to the first preset value while ensuring that the vehicle does not roll backward.

[0009] According to some embodiments of the present invention, the correction coefficient f3 is obtained through a finite number of real vehicle calibration tests, wherein, If the driver depresses the accelerator pedal at a rate exceeding the second preset threshold, and the proportion of the driver depressing the accelerator pedal at a rate exceeding the second preset threshold exceeds the first preset proportion within the current driving cycle, the pressure holding value is reduced according to the second preset value while ensuring that the vehicle does not roll backward. When the driver depresses the accelerator pedal at a rate lower than the third preset threshold, and the proportion of the driver depressing the accelerator pedal at a rate exceeding the third preset threshold exceeds the second preset proportion within the current driving cycle, the pressure holding value is increased according to the third preset value.

[0010] According to some embodiments of the present invention, obtaining the real-time slope of the vehicle and calculating the basic pressure holding value includes: Under different slopes, the component of the vehicle's weight in the slope direction is obtained through mechanical analysis and calculation to determine the braking force required for the vehicle to maintain its position on the slope. Based on the braking force, the basic pressure holding value is calculated.

[0011] According to some embodiments of the present invention, obtaining the real-time state of the brake pedal includes: The travel distance of the pedal push rod is collected by a travel sensor.

[0012] The step of determining that the driver has pressed the brake pedal when the real-time state meets the preset state includes: When the pedal push rod travels more than a preset travel, remains for more than a first preset time, and the brake light switch signal is on, it is determined that the driver has pressed the brake pedal.

[0013] According to some embodiments of the present invention, the acquisition of the real-time activation state of the ramp holding control function includes: It acquires the vehicle's current slope, the braking pressure requested by the driver when pressing the brake pedal, fault signals from the integrated braking control system, and the vehicle's current gear. The initial threshold for determining whether the ramp holding control function is activated when the real-time activation state meets the preset activation state includes: When the absolute value of the slope the vehicle is currently on is greater than the fourth preset value, the braking pressure value requested by the driver when pressing the brake pedal exceeds the fifth preset value and exceeds the second preset time, the integrated braking control system has no fault signal, and the vehicle's current gear is not P or N, the initial threshold for activating the hill hold control function is determined to have been reached.

[0014] According to a second aspect of the present invention, a pressure holding control device with a ramp holding control function includes: The data acquisition and calculation module is used to acquire the real-time status of the brake pedal; acquire the real-time activation status of the hill hold control function; acquire the real-time slope of the vehicle; and calculate the basic pressure holding value. The judgment module is used to determine that the driver has pressed the brake pedal when the real-time state meets the preset state; and to determine that the initial threshold for the hill hold control function has been reached when the real-time activation state meets the preset activation state. The correction module is used to correct the basic holding pressure value according to the driver's driving style, the rate at which the driver depresses the brake pedal and the rate at which the driver depresses the accelerator pedal, so as to obtain the real-time holding pressure value. The execution control module is used to perform ramp braking according to the real-time pressure holding value.

[0015] According to a third aspect of the present invention, a vehicle includes the aforementioned pressure holding control device.

[0016] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a flowchart of the pressure holding control method of the present invention; Figure 2 This is a schematic diagram of the pressure holding control device of the present invention; Figure 3 This is a flowchart of the vehicle executing the pressure holding control method of the present invention. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0020] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0021] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0023] The current Hill Hold Control (IBC) function works as follows: When the activation conditions for Hill Hold Control are met, the IBC system maintains a certain braking pressure in the four brake wheel cylinders of the vehicle when the driver releases the brake pedal. This specific braking pressure value is generally obtained by the OEM or parts supplier through parameter calibration during the vehicle development stage. The holding pressure value usually varies with the slope. However, a single, fixed holding pressure cannot meet the diverse needs of drivers. For example, younger drivers with more aggressive driving habits prefer a lower holding pressure for smoother starts on slopes; older drivers with more stable driving habits prefer a higher holding pressure because they press the accelerator pedal at a relatively slower rate, and a higher holding pressure helps the vehicle start smoothly on slopes. To address the aforementioned issues, this invention proposes a pressure holding control method for hill-holding control function. After detecting that the initial activation threshold of hill-holding control function has been reached, the real-time pressure holding is set by comprehensively considering factors such as real-time slope, driver's driving style, and braking and accelerator pedal operation. This allows the pressure holding of hill-holding control function to adapt to changes in vehicle driving mode, driver's driving style, etc.

[0024] like Figure 1 As shown, the pressure holding control method of the present invention includes the following steps: Step S100: Obtain the real-time status of the brake pedal; Step S200: When the real-time status meets the preset status, it is determined that the driver has pressed the brake pedal; Step S300: Obtain the real-time activation status of the ramp holding control function; Step S400: When the real-time activation state meets the preset activation state, it is determined that the initial activation threshold of the ramp holding control function has been reached. Step S500: Obtain the real-time slope of the vehicle and calculate the basic pressure holding value; Step S600: Based on the driver's driving style, the rate at which the driver depresses the brake pedal, and the rate at which the driver depresses the accelerator pedal, the base pressure holding value is corrected to obtain the real-time pressure holding value. Step S700: Apply ramp braking according to the real-time pressure holding value.

[0025] After the initial threshold for hill-holding control activation is reached, the real-time slope of the vehicle is obtained to calculate the base holding pressure value. Then, the base holding pressure value is corrected according to the driver's driving style, the rate at which the driver depresses the brake pedal, and the rate at which the driver depresses the accelerator pedal. The real-time holding pressure value is then set so that the real-time holding pressure value of the hill-holding control function can adapt to changes in the vehicle's driving mode and the driver's driving style to meet diverse needs.

[0026] In step S100, the real-time status of the driver's operation of the brake pedal is mainly acquired. In this embodiment, the real-time status of the brake pedal is fed back through the pedal push rod travel. Therefore, step S100 also includes step S110: acquiring the pedal push rod travel through a travel sensor. Specifically, the pedal push rod travel inside the IBC is acquired by the travel sensor inside the IBC, parsed by the IBC's own controller, and then sent out, which can be directly read by the controller.

[0027] In step S200, the main step is to determine whether the driver has pressed the brake pedal. This is because when the vehicle is on a slope, the brake pedal is typically pressed to apply pressure, and then the accelerator pedal is pressed to initiate the hill start assist function. Therefore, it's necessary to first determine whether the driver has pressed the brake pedal. This invention verifies the real-time state of the brake pedal against a preset state to determine if the driver has pressed the brake pedal. Step S200 also includes step S210: when the pedal push rod travel is greater than a preset travel, remains for more than a first preset time, and the brake light switch signal is on, it is determined that the driver has pressed the brake pedal. The preset travel and first preset time are calibrated and confirmed based on the actual vehicle model. In this embodiment, the preset travel is set to 0.5 mm, and the first preset time is 0.01 seconds. Therefore, the method of this invention to determine whether the driver has pressed the brake pedal is that the pedal push rod travel inside the IBC is greater than 0.5 mm, remains for more than 0.01 seconds, and the brake light switch signal is 1.

[0028] When the vehicle requires hill-keeping control to intervene, it is also necessary to determine whether the initial activation threshold of the hill-keeping control function has been reached. In step S300, the real-time activation status of the hill-keeping control function is obtained. In this embodiment, the real-time activation status includes the slope, the braking pressure requested by the driver when pressing the brake pedal, whether the integrated braking control system is operating normally, and the vehicle's gear position. For the slope, the hill-keeping control function is activated only after the slope reaches a set value. If the slope is too small, the hill-keeping control function does not need to intervene. When the vehicle stops on a slope, the driver will press the brake pedal deeply to increase the braking force on the vehicle and stop it steadily on the slope. At this time, the hill-keeping control function is activated only after the braking pressure requested by the driver when pressing the brake pedal reaches a set value. At the same time, the integrated braking control system needs to ensure that the hill-keeping control function is operating normally before it is activated, ensuring that the hill-keeping control function is operating normally. In addition, the vehicle's gear position also needs to be in a set position. If the vehicle is parked on a slope or needs to be pushed due to other emergencies, the hill-keeping control function does not need to be activated.

[0029] In step S400, when the real-time activation state meets the preset activation state, it is determined that the initial activation threshold of the ramp holding control function has been reached, and the ramp holding control function is activated at this time.

[0030] Step S300 in this embodiment further includes step S310: obtaining the current slope of the vehicle, the braking pressure requested by the driver when pressing the brake pedal, the fault signal of the integrated braking control system, and the current gear of the vehicle.

[0031] Specifically, the vehicle's current slope can be detected by an angle sensor to determine the vehicle's tilt; the braking pressure requested by the driver when pressing the brake pedal is detected by a pressure sensor to determine the hydraulic pressure in the braking system; and the vehicle's current gear and fault signals of the integrated braking control system are detected by the vehicle controller.

[0032] In this embodiment, the vehicle's current slope signal and the braking pressure value requested by the driver when pressing the brake pedal are obtained by reading the internal signal of the IBC, and the vehicle's current gear signal is read through the CAN bus.

[0033] In this embodiment, step S400 further includes step S410: when the absolute value of the current slope of the vehicle is greater than the fourth preset value, the braking pressure value requested by the driver when pressing the brake pedal exceeds the fifth preset value and exceeds the second preset time, the integrated braking control system has no fault signal, and the current gear of the vehicle is not P or N, it is determined that the initial threshold for activating the hill-holding control function has been reached.

[0034] The fourth preset value, the fifth preset value, and the second preset time are calibrated and confirmed based on the actual vehicle effect of the specific vehicle model. In this embodiment, the fourth preset value is set to 4%, the fifth preset value is 5 bar, and the second preset time is 0.05 seconds.

[0035] The present invention sets the activation initial threshold for hill hold control function as follows: the following factors are met simultaneously: ① the absolute value of the current slope of the vehicle is greater than 4%; ② the braking pressure requested by the driver when pressing the brake pedal exceeds 5 bar and lasts for more than 0.05 seconds; ③ the IBC system is fault-free; ④ the current gear of the vehicle is not P or N.

[0036] In step S500, the basic pressure holding value is the pressure required to keep the vehicle stationary on the slope and prevent it from rolling backward. The basic pressure holding value is determined by the slope gradient of the vehicle. A suitable pressure holding value can be calculated through simple mechanical analysis, that is, the component of the vehicle's weight in the slope direction and the braking force are balanced. Furthermore, step S500 of this embodiment also includes step S510: under different slopes where the vehicle is located, the component of the vehicle's weight in the slope direction is calculated through mechanical analysis to obtain the braking force required for the vehicle to maintain its position on the slope, and the basic pressure holding value is calculated based on the braking force. This is a common method in the current industry and is not the focus of this application, so it will not be elaborated upon.

[0037] In step S600, the present invention reduces or increases the pressure based on the basic pressure holding value according to the driver's driving style, the driver's braking pedal rate and the driver's accelerator pedal rate, in order to obtain a real-time pressure holding value.

[0038] Specifically, step S600 of this embodiment further includes step S610: calculating the real-time pressure holding value p according to the formula p=p0*f1*f2*f3; where p0 is the basic pressure holding value, f1 is the correction coefficient related to the driver's driving style, f2 is the correction coefficient related to the driver's braking pedal rate, and f3 is the correction coefficient related to the driver's accelerator pedal rate.

[0039] For F1, it refers to the driver's driving style determined based on vehicle data when the vehicle is in different driving modes or within a certain driving cycle.

[0040] In step S610 of this embodiment, f1, f2 and f3 also need to be obtained. The correction coefficients f1, f2 and f3 are obtained by a limited number of real vehicle calibration tests.

[0041] Furthermore, step S610 of this embodiment also includes the following steps: Step S611: By calibrating different parameter values ​​under different vehicle driving modes and adjusting the parameters according to the driver's driving habits within a set period, a correction coefficient f1 is obtained. Therefore, f1 is a coefficient that can be dynamically adjusted according to the vehicle driving mode and the driver's driving habits within a certain period.

[0042] Step S612: After the driver depresses the brake pedal at a rate exceeding the first preset threshold, the pressure holding value is reduced according to the first preset value, ensuring that the vehicle does not roll backward.

[0043] Step S613: After the driver depresses the accelerator pedal at a rate exceeding the second preset threshold, and the proportion of the driver depressing the accelerator pedal at a rate exceeding the second preset threshold in the current driving cycle exceeds the first preset proportion, the pressure holding value is reduced according to the second preset value while ensuring that the vehicle does not roll backward. At the same time, when the driver depresses the accelerator pedal at a rate lower than the third preset threshold, and the proportion of the driver depressing the accelerator pedal at a rate exceeding the third preset threshold in the current driving cycle exceeds the second preset proportion, the pressure holding value is increased according to the third preset value.

[0044] In step S612, this embodiment sets the first preset threshold value to 100mm / s. This value needs to be calibrated and confirmed based on the actual effect of a specific vehicle model. At this time, when the driver depresses the brake pedal at a rate exceeding 100mm / s, the first preset value is used to appropriately reduce the pressure holding value while ensuring that the vehicle does not roll backward, thereby adapting to the actual needs of drivers with a more aggressive driving style. The first preset value is calibrated and confirmed based on the actual effect of a specific vehicle model to obtain f2.

[0045] In step S613, this embodiment sets the second preset threshold value to 80mm / s, the third preset threshold value to 20mm / s, the first preset ratio value to 50%, and the second preset ratio value to 60%. The above data are calibrated and confirmed based on the actual vehicle effect of a specific model. It can be understood that when the driver depresses the accelerator pedal at a rate exceeding 80mm / s, and the proportion of the accelerator pedal depressing rate exceeding the threshold value exceeds 50% in the current driving cycle, the holding pressure value is appropriately reduced according to the second preset value while ensuring that the vehicle does not roll backward. At the same time, when the driver depresses the accelerator pedal at a rate below 20mm / s, and the proportion of the accelerator pedal depressing rate exceeding the threshold value exceeds 60% in the current driving cycle, the holding pressure value is appropriately increased according to the third preset value to obtain f3.

[0046] In step S700, after calculating the real-time pressure holding value, the HHC function is activated, and the IBC performs the pressure holding action, thereby maintaining the braking pressure in the brake cylinders of the four wheels, so that the vehicle remains stationary on the slope.

[0047] like Figure 2 As shown, this embodiment of the invention also provides a pressure holding control device, which is suitable for the integrated braking control system of a vehicle. The pressure holding control device specifically includes: a data acquisition and calculation module, a judgment module, a correction module, and an execution control module.

[0048] The acquisition and calculation module can also perform steps such as acquiring various signals and parameters and calculating the basic holding pressure value, specifically as described above in steps S100, S300, S500, S310, S110 and S510.

[0049] The judgment module can also perform steps such as judging whether the driver has pressed the brake pedal and judging whether the initial threshold for HHC function activation has been reached, specifically as described in steps S200, S400, S210, and S410 above.

[0050] The correction module can also perform steps to correct the basic holding pressure value, specifically as described in steps S600, S610, S611, S612, and S613 above.

[0051] The execution control module can also perform pressure holding action steps, as described in step S700 above.

[0052] This invention also provides a vehicle that includes the aforementioned pressure holding control device.

[0053] The vehicle can be a private car, such as a sedan, SUV, MPV, or pickup truck. It can also be a commercial vehicle, such as a van, bus, small truck, or large semi-trailer. The vehicle must have an electric motor capable of outputting power or acting as a generator to store mechanical energy. When the vehicle is a new energy vehicle, it can be a hybrid or a pure electric vehicle.

[0054] Since the vehicle applies all the technical solutions of the pressure holding control device described above, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0055] like Figure 3 As shown, the specific steps of the vehicle of the present invention in performing the above-described pressure holding control method are as follows: Step S1: Power on the vehicle, initialize the IBC system, and read various signals and parameters. In this embodiment, the vehicle is in normal condition, and the IBC system and all signals are normal.

[0056] Step S2: Determine whether the driver has pressed the brake pedal. In this embodiment, the following conditions must be met simultaneously: the pedal push rod inside the IBC has a travel greater than 0.5 mm, is held for more than 0.01 seconds, and the brake light switch signal is 1. Proceed to step S3. If these conditions are not met, return to step S1.

[0057] Step S3: Determine whether the initial threshold for HHC function activation has been reached. In this embodiment, the following factors must be met simultaneously: ① The absolute value of the current slope of the vehicle is greater than 4%; ② The maximum pressure value requested by the driver when pressing the brake pedal exceeds 5 bar and exceeds 0.1 seconds; ③ The IBC system is fault-free; ④ The current gear of the vehicle is not P or N. Proceed to step S4. If the conditions are not met, return to step S1.

[0058] Step S4: Calculate the pressure holding pressure by considering the current slope of the vehicle, the driver's driving style, and the braking and accelerator pedal input. In this embodiment, a suitable pressure holding pressure is calculated by considering all factors.

[0059] Step S5: HHC function activated, IBC pressure maintained. In this embodiment, after obtaining the pressure holding value, the IBC performs the pressure holding action, thereby maintaining the braking pressure in the brake cylinders of the four wheels, so that the vehicle remains stationary on the slope.

[0060] Furthermore, one embodiment of the present invention provides a computer-readable storage medium storing computer-executable instructions for performing the above-described pressure holding control method.

[0061] It is worth noting that, since the computer-readable storage medium of the present invention is capable of executing the pressure holding control method of any of the above embodiments, the specific implementation and technical effects of the computer-readable storage medium of the present invention can be referred to the specific implementation and technical effects of the pressure holding control method of any of the above embodiments.

[0062] Furthermore, one embodiment of the present invention provides a computer program product, including a computer program or computer instructions, which are stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium and executes the computer program or computer instructions, causing the computer device to perform the aforementioned pressure holding control method.

[0063] It is worth noting that, since the computer program product of this embodiment can execute the pressure holding control method of any of the above embodiments, the specific implementation method and technical effect of the computer program product of this embodiment can be referred to the specific implementation method and technical effect of the pressure holding control method of any of the above embodiments.

[0064] The computer-readable storage medium of this invention can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this invention, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0065] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0066] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0067] It should be understood that various parts of the present invention 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.

[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. 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.

[0069] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A pressure control method for maintaining a ramp, characterized in that, include: To obtain the real-time status of the brake pedal, specifically by collecting the pedal push rod travel through a travel sensor; When the real-time state meets the preset state, it is determined that the driver has pressed the brake pedal. Specifically, when the pedal push rod travel is greater than the preset travel, is maintained for more than the first preset time, and the brake light switch signal is on, it is determined that the driver has pressed the brake pedal. The real-time activation status of the hill-hold control function is obtained, specifically the current slope of the vehicle, the braking pressure requested by the driver when pressing the brake pedal, the fault signal of the integrated braking control system, and the current gear of the vehicle. When the real-time activation state meets the preset activation state, it is determined that the initial activation threshold of the hill-holding control function has been reached. Specifically, when the absolute value of the current slope of the vehicle is greater than the fourth preset value, the braking pressure value requested by the driver when pressing the brake pedal exceeds the fifth preset value and exceeds the second preset time, the integrated braking control system has no fault signal, and the current gear of the vehicle is not P or N, it is determined that the initial activation threshold of the hill-holding control function has been reached. The real-time slope of the vehicle is obtained, and the basic pressure holding value is calculated. The baseline holding pressure value is corrected based on the driver's driving style, the rate at which the driver depresses the brake pedal, and the rate at which the driver depresses the accelerator pedal to obtain the real-time holding pressure value. Specifically, this is done according to the formula p=p0. f1 f2 f3 is used to calculate the real-time holding pressure value p, where p0 is the basic holding pressure value, f1 is the correction coefficient related to the driver's driving style, f2 is the correction coefficient related to the driver's braking pedal rate, and f3 is the correction coefficient related to the driver's accelerator pedal rate. Correction coefficient f1 was obtained through a limited number of real-vehicle calibration tests. This was achieved by calibrating different parameter values ​​under different vehicle driving modes and adjusting the parameters based on driver habits within a set period. Correction coefficient f2 was also obtained through a limited number of real-vehicle calibration tests. This involved reducing the brake pressure value according to a first preset threshold after the driver depresses the brake pedal at a rate exceeding this threshold, while ensuring the vehicle does not roll backward. Correction coefficient f3 was also obtained through a limited number of real-vehicle calibration tests. If the driver depresses the accelerator pedal at a rate exceeding the second preset threshold, and the proportion of the driver depressing the accelerator pedal at a rate exceeding the second preset threshold exceeds the first preset proportion within the current driving cycle, the pressure holding value is reduced according to the second preset value while ensuring that the vehicle does not roll backward. When the driver depresses the accelerator pedal at a rate lower than the third preset threshold, and the proportion of the driver depressing the accelerator pedal at a rate higher than the third preset threshold in the current driving cycle exceeds the second preset proportion, the holding pressure value is increased according to the third preset value. Apply ramp braking according to the real-time pressure holding value.

2. The pressure holding control method according to claim 1, characterized in that: The process of obtaining the real-time slope of the vehicle and calculating the basic pressure holding value includes: Under different slopes, the component of the vehicle's weight in the slope direction is obtained through mechanical analysis and calculation to determine the braking force required for the vehicle to maintain its position on the slope. Based on the braking force, the basic pressure holding value is calculated.

3. A pressure-holding control device with ramp-keeping control function, characterized in that, The pressure holding control device, applicable to the pressure holding control method as described in any one of claims 1 and 2, comprises: The data acquisition and calculation module is used to acquire the real-time status of the brake pedal; acquire the real-time activation status of the hill hold control function; acquire the real-time slope of the vehicle; and calculate the basic pressure holding value. The judgment module is used to determine that the driver has pressed the brake pedal when the real-time state meets the preset state; and to determine that the initial threshold for the hill hold control function has been reached when the real-time activation state meets the preset activation state. The correction module is used to correct the basic holding pressure value according to the driver's driving style, the rate at which the driver depresses the brake pedal and the rate at which the driver depresses the accelerator pedal, so as to obtain the real-time holding pressure value. The execution control module is used to perform ramp braking according to the real-time pressure holding value.

4. A vehicle, characterized in that, It includes the pressure holding control device as described in claim 3.

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