Parking brake control method and device, vehicle, and storage medium

Abstract

The present invention relates to the technical field of vehicles, and disclosed are a parking brake control method and device, a vehicle, and a storage medium. The parking brake control method comprises the steps of: acquiring the gradient of a hill where a vehicle is located, and determining whether the gradient satisfies a preset gradient range; when the gradient is within the preset gradient range, determining the relationship between the traveling direction of the vehicle and the hill; when the traveling direction is uphill, acquiring a brake pressure of the vehicle, and determining the relationship between the brake pressure and a preset pressure; and when the brake pressure is greater than or equal to the preset pressure, controlling an EPB to switch to a first operating mode, and controlling the vehicle to trigger an HHC. According to the parking brake control method, the operating modes of the EPB and the HHC are determined by means of information about the hill where the vehicle is located and the brake pressure of the vehicle, so that two functions can cooperate with each other, thereby ensuring the smoothness of the vehicle during a hill start, and avoiding the problem that the whole vehicle slides on the hill.

Description

Parking brake control method, control device, vehicle and storage medium TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a parking brake control method, a control device, a vehicle and a storage medium. BACKGROUND

[0002] The electronic parking brake system (EPB), also known as the electronic hand brake, the EPB function has been a common configuration on passenger cars. In order to increase the convenience of the user during use, the EPB develops a driving release function, that is, according to the driver's throttle opening degree and the actual driving torque of the vehicle, the EPB is automatically released when the vehicle does not occur hill start, but due to the limitation of the mechanical structure of the EPB, the EPB release time is about 1s, but the response time of the powertrain of the vehicle (fuel vehicle) is less than 100ms (the response time of the powertrain of the electric vehicle is faster), so there will be a process close to the driving torque during the EPB release process, resulting in uneven starting of the vehicle.

[0003] In order to improve the above situation, in the related art, the EPB develops a P-gear release logic, that is, the EPB starts to release when the driver steps on the brake pedal to shift gears, and the EPB is basically released when the driver's foot moves from the brake pedal to the throttle pedal to start, so that the vehicle can start smoothly.

[0004] The above-mentioned P-gear release logic of the EPB is suitable for the starting of the vehicle on a flat road, and can solve the smoothness of the starting on the flat road. However, when the vehicle is on a slope, the driver steps on the brake pedal to shift gears, at this time, the vehicle has no driving force or only a small driving force when stepping on the brake pedal; After the driver releases the brake pedal, there is a time gap before stepping on the throttle pedal, and during this time gap, since the EPB has been released after the brake pedal is released and the vehicle has no braking force, the driving force has not been established, which will cause the vehicle to slide on the slope.

[0005] SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a parking brake control method, which can ensure the smoothness of the vehicle starting on a slope and avoid the problem of the vehicle sliding on the slope.

[0007] The present application also provides a control device, a vehicle and a storage medium for executing the above-mentioned parking brake control method.

[0008] According to the parking brake control method of the first aspect of the embodiment of the present application, applied to a vehicle having an electronic parking brake system and a hill start assist system, comprising the steps of:

[0009] obtaining a slope of a slope on which the vehicle is located, and determining whether the slope is in a preset slope range, the preset slope range being a slope range in which the vehicle has a risk of rolling down the slope and in which the slope start assist system is triggered to enable the vehicle to stop on the slope;

[0010] when the slope is in the preset slope range, determining a relationship between a driving direction of the vehicle and the slope according to the driving direction;

[0011] when the driving direction is uphill, obtaining a brake pressure of the vehicle, and determining a size relationship between the brake pressure and a preset pressure according to the brake pressure, the preset pressure being a brake force with which the vehicle is able to stop on the slope without a risk of rolling down the slope;

[0012] when the brake pressure is greater than or equal to the preset pressure, controlling the electronic parking brake system to switch to a first working mode, and triggering the slope start assist system according to a signal that the electronic parking brake system is released, the first working mode being a working mode in which the electronic parking brake system is released according to an action of the driver stepping on a brake pedal.

[0013] The parking brake control method according to the embodiment of the application has at least the following beneficial effects: when the vehicle is parked on a slope, the electronic parking brake system is triggered to brake the vehicle; when the vehicle needs to start on the slope, the driver steps on the brake pedal to shift gears, in this process, the slope of the slope on which the vehicle is located is obtained, and it is determined whether the slope is in a preset slope range; when the slope is in the preset slope range, i.e., the slope is in a slope range in which the vehicle has a risk of rolling down the slope and in which the slope start assist system is triggered to enable the vehicle to stop on the slope, the relationship between the driving direction of the vehicle and the slope is determined according to the driving direction; when the driving direction is uphill, the brake pressure of the vehicle is obtained, and the size relationship between the brake pressure and the preset pressure is determined according to the brake pressure, the preset pressure being a brake force with which the vehicle is able to stop on the slope without a risk of rolling down the slope; when the brake pressure is greater than or equal to the preset pressure, the electronic parking brake system is controlled to switch to a first working mode, and the vehicle triggers the slope start assist system, the first working mode being a working mode in which the electronic parking brake system is released from the P gear (i.e., in the process in which the driver steps on the brake pedal to shift gears, the electronic parking brake system starts to be released, and when the driver completes the gear shifting and steps on the accelerator pedal, the electronic parking brake system is completely released), and the vehicle is assisted to start on the slope by the slope start assist system; through the above parking brake control method, the smoothness of the vehicle when starting on the slope can be ensured, and the problem of the vehicle rolling down the slope does not occur.

[0014] According to some embodiments of the present application, the parking brake control method further comprises the step of: when the driving direction is downhill, controlling the electronic parking brake system to switch to the first working mode.

[0015] According to some embodiments of the present application, the step of controlling the electronic parking brake system to switch to the first working mode and triggering the hill start assist system according to the signal of the electronic parking brake system completing release comprises the steps of: obtaining a signal of a gear shifting action of the driver on the vehicle, and determining whether the gear shifting action is completed according to the signal of the gear shifting action; when the gear shifting action is completed, controlling the electronic parking brake system to release the braking output on the vehicle, activating the hill start assist system and controlling the vehicle to keep the braking output in response to the brake pedal; obtaining a signal of a pedal stepping action of the driver on the accelerator pedal, and determining whether the pedal stepping action is started according to the signal of the pedal stepping action; when the pedal stepping action is started and the driving force output in response to the accelerator pedal meets the hill start requirement, releasing the control of the hill start assist system on the vehicle and releasing the braking output of the vehicle in response to the brake pedal.

[0016] According to some embodiments of the present application, the step of activating the hill start assist system and controlling the vehicle to keep the braking output in response to the brake pedal further comprises the steps of: controlling the vehicle to keep the braking output in response to the brake pedal for a preset time; when the preset time is exceeded or the driving force meets the hill start requirement, releasing the control of the hill start assist system on the vehicle and releasing the braking output of the vehicle in response to the brake pedal.

[0017] According to some embodiments of the present application, the parking brake control method further comprises the steps of: when the slope is smaller than the preset slope range, controlling the electronic parking brake system to switch to the first working mode; obtaining a signal of a gear shifting action of the driver on the vehicle, and determining whether the gear shifting action is completed according to the signal of the gear shifting action; when the gear shifting action is completed, releasing the braking output of the electronic parking brake system on the vehicle.

[0018] According to some embodiments of the present application, the parking brake control method further comprises the steps of: when the slope is greater than the preset slope range, determining the relationship between the driving direction of the vehicle and the slope; when the driving direction is uphill, controlling the electronic parking brake system to switch to the second working mode, wherein the second working mode is a working mode in which the electronic parking brake system releases in response to the driving force output in response to the accelerator pedal.

[0019] According to some embodiments of the present application, the controlling the electronic parking brake system to switch to the second working mode comprises the steps of: controlling the electronic parking brake system to keep braking output to the vehicle; acquiring a signal of a driver's pedal action on an accelerator pedal, judging a size of driving force output by the accelerator pedal in response to the vehicle according to the signal of the pedal action; and when the driving force is greater than a preset driving force, releasing the braking output of the electronic parking brake system to the vehicle, the preset driving force being a driving force required for the vehicle to meet a hill start requirement.

[0020] The control device for the parking brake according to the second aspect of the embodiments of the present application is used to execute the parking brake control method according to the first aspect of the embodiments described above, and the control device comprises:

[0021] The acquiring module is configured to acquire a slope of a hill where the vehicle is located, and acquire a braking pressure of the vehicle;

[0022] The first determining module is configured to judge whether the slope is in a preset slope range according to the slope, when the slope is in the preset slope range, judge a relationship between a driving direction of the vehicle and the hill according to the driving direction, and the preset slope range is a slope range in which the vehicle has a risk of rolling down the hill and a hill start assist system can be triggered to enable the vehicle to stop on the hill;

[0023] The second determining module is configured to, when the driving direction is uphill, judge a size relationship between the braking pressure and a preset pressure according to the braking pressure, and the preset pressure is a braking force required for the vehicle to stop on the hill without the risk of rolling down the hill;

[0024] The executing module is configured to, when the braking pressure is greater than or equal to the preset pressure, control the electronic parking brake system to switch to the first working mode, and control the vehicle to trigger the hill start assist system according to a signal of completion of release of the electronic parking brake system.

[0025] The control device of the parking brake according to the embodiment of the present application has at least the following beneficial effects: when the vehicle needs to start on a slope, the driver steps on the brake pedal to shift gears, during the process, the obtaining module obtains the slope of the slope where the vehicle is located, the first determining module determines whether the slope meets a preset slope range, when the first determining module determines that the slope is in the preset slope range, the first determining module determines the relationship between the driving direction of the vehicle and the slope, when the first determining module determines that the driving direction of the vehicle is uphill, the obtaining module obtains the brake pressure of the vehicle, the second determining module determines the size relationship between the brake pressure and the preset pressure according to the brake pressure, when the second determining module determines that the brake pressure is greater than or equal to the preset pressure, the executing module controls the electronic parking brake system to switch to the first working mode, and controls the vehicle to trigger the hill start assist system, and the vehicle is assisted to start by the hill start assist system, through the control device to execute the parking brake control method, the smoothness of the vehicle starting on the slope can be ensured, and the problem of the whole vehicle sliding on the slope will not occur.

[0026] The vehicle according to the third aspect of the embodiment of the present application comprises a memory, a processor and a program stored in the memory and executable on the processor, and the program is executed by the processor to implement the parking brake control method according to the first aspect of the embodiment.

[0027] The computer readable storage medium according to the fourth aspect of the embodiment of the present application stores computer executable instructions, and the computer executable instructions are used to make the computer execute the parking brake control method according to the first aspect of the embodiment.

[0028] Since the vehicle and the computer readable storage medium are used to execute the parking brake control method according to the first aspect of the embodiment, at least all the beneficial effects brought by the technical solutions of the embodiment are achieved, which will not be described herein.

[0029] Other features and advantages of the present application will be described in the following description, and some will become apparent from the description, or will be understood by those skilled in the art through implementation of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0030] Fig. 1 is a flow chart of the parking brake control method according to an embodiment of the present application;

[0031] Fig. 2 is a specific step flow chart of the first case of step S200 shown in Fig. 1;

[0032] Fig. 3 is a specific step flow chart of step S400 shown in Fig. 1;

[0033] Fig. 4 is a specific step flow chart of step S4002 shown in Fig. 3;

[0034] Fig. 5 is a detailed step flowchart of a second case of the step S200 shown in Fig. 1;

[0035] Fig. 6 is a detailed step flowchart of a third case of the step S200 shown in Fig. 1;

[0036] Fig. 7 is a detailed step flowchart of the step S250 shown in Fig. 6;

[0037] Fig. 8 is a module diagram of the control device of the parking brake according to an embodiment of the present application;

[0038] Fig. 9 is a program block diagram of a specific example of the parking brake control method according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] Embodiments of the present application will be described in detail below with reference to the drawings, in which like or similar components that have the same or similar functions are designated by like reference numerals throughout the several views. The embodiments described below are merely exemplary for explaining the present application, and should not be construed as limiting the present application.

[0040] In the description of the present application, it should be understood that the positional or locational relationship indicated by terms such as up, down, etc. is based on the positional or locational relationship shown in the drawings, and is merely for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application.

[0041] In the description of the present application, the meaning of a plurality is two or more, greater than, less than, more than, etc. is understood as not including the number itself, above, below, etc. is understood as including the number itself. If it is described as first, second, etc. is only for the purpose of distinguishing technical features, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated.

[0042] In the description of the present application, it should be noted that the words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0043] The technical solutions of the present application will be described below in conjunction with the drawings. Obviously, the following described embodiments are only part of the embodiments of the present application, not all embodiments.

[0044] Electronic parking brake system (EPB) has been a common configuration on passenger cars, in order to increase the convenience of the user during use, EPB develops the drive-off release function, that is, according to the driver's throttle opening and the actual driving torque of the vehicle, when the vehicle does not occur when the vehicle is not on the slope, the EPB is automatically released, but limited to the mechanical structure of the EPB, the EPB release time is about 1s, but for a fuel car, the response time of the vehicle powertrain is less than 100ms, and this response time is only smaller for an electric vehicle, so there is a process close to the driving torque during the EPB release process, resulting in uneven starting of the vehicle.

[0045] In order to improve the above situation, in the related art, the EPB develops the P-gear release logic, that is, when the brake pedal is stepped on for gear shifting, the EPB starts to release, and when the driver's foot moves from the brake pedal to the throttle pedal for starting, the EPB has been basically released, so that the vehicle can start smoothly.

[0046] The above-mentioned EPB P-gear release logic is applicable to the starting of the vehicle on a flat road, and can solve the smoothness of the starting on the flat road. However, when the vehicle is on a slope, the driver steps on the brake pedal for gear shifting, at this time, the vehicle has no driving force or only a small driving force when the brake pedal is stepped on; after the driver releases the brake pedal, there is a time gap before the throttle pedal is stepped on, and in this time gap, since the EPB has been released after the brake pedal is released and the vehicle has no braking force after the brake pedal is released, the driving force is not established, which will cause the vehicle to slide on the slope.

[0047] In view of the above problems, the present application provides a parking brake control method, a control device, a vehicle and a storage medium, which judges whether the EPB is released or not through the conditions of the slope and the driver's brake pressure, and realizes the smooth starting of the vehicle on the slope by cooperating with the hill hold control (HHC).

[0048] The parking brake control method and the control device according to the embodiments of the present application are described with reference to FIGS. 1 to 9, and the following specific embodiments are described.

[0049] With reference to FIG. 1, the parking brake control method of the first aspect of the embodiments of the present application includes but is not limited to the following steps:

[0050] In step S100, the slope of the slope where the vehicle is located is obtained, and it is judged whether the slope is in a preset slope range or not, the preset slope range is the slope range where the vehicle has a risk of sliding on the slope and the HHC can make the vehicle stop on the slope;

[0051] In step S200, when the slope is in the preset slope range, the relationship between the driving direction and the slope is judged according to the driving direction of the vehicle;

[0052] Step S300, when the driving direction is uphill, the brake pressure of the vehicle is obtained, and the brake pressure is compared with a preset pressure to determine the relationship between the brake pressure and the preset pressure, the preset pressure being a brake force for stopping the vehicle on the slope without the risk of rolling back;

[0053] Step S400, when the brake pressure is greater than or equal to the preset pressure, the EPB is controlled to switch to a first working mode, and the vehicle is controlled to trigger the HHC according to a signal of completion of release of the EPB, the first working mode being a working mode in which the EPB is released according to the action of the driver stepping on the brake pedal.

[0054] It can be understood that the vehicle for executing the above control method needs to be provided with the EPB and the HHC. By the conditions of the slope and the brake pressure of the vehicle, it is determined whether the EPB is released and whether the HHC is triggered. The control method cooperates the EPB and the HHC to make the vehicle more smooth when starting on the slope under the premise of ensuring no rolling back. When the driver steps on the accelerator after completing the shifting action, the driving force of the vehicle and the brake output of the EPB to the vehicle do not exist a relatively strong process, thereby avoiding the shaking of the vehicle when starting, and the smoothness of the vehicle when starting is good.

[0055] It should be noted that the EPB has two working modes, namely a first working mode and a second working mode. The first working mode is a P-out release mode of the EPB, and the second working mode is an automatic release mode (also referred to as a driving-off release mode) of the EPB.

[0056] It can be understood that for the first working mode of the EPB, the working process is as follows: during the process of the driver stepping on the brake pedal for shifting, i.e., during the process of switching from the parking gear to the forward gear or the reverse gear, the EPB starts to release and gradually releases the brake output to the vehicle; after the driver completes the shifting action, the EPB is completely released and releases the brake output to the vehicle. For the second working mode of the EPB, the working process is as follows: during the process of the driver stepping on the brake pedal for shifting, the EPB does not release and maintains the brake output to the vehicle; after the driver completes the shifting action, the EPB continues to maintain the brake output to the vehicle; the driver steps on the accelerator pedal to make the vehicle respond to the driving force output of the accelerator pedal, and when the driving force reaches a certain value, the EPB is released to release the brake output to the vehicle. During this process, the driving force needs to reach a value that can prevent the vehicle from rolling back.

[0057] It should be noted that the working process of the HHC is as follows: during the process of the driver stepping on the brake pedal for shifting, the HHC does not trigger, and after the driver releases the brake pedal, the HHC triggers and controls the vehicle to maintain the brake output of the vehicle when the driver steps on the brake pedal, and after maintaining the brake output of the vehicle for a certain period of time, the HHC is released. During the period from the release of the brake pedal to the stepping on of the accelerator pedal by the driver, the brake output maintained by the vehicle can prevent the vehicle from rolling back.

[0058] Referring to FIG. 1, in step S100, the vehicle can estimate the slope of the slope on which the vehicle is located by using various sensors and algorithms, for example, using an inertial measurement unit (IMU). It can be understood that the IMU on the vehicle can measure acceleration, including longitudinal acceleration due to slope; by measuring the acceleration (a) of the vehicle in the horizontal plane, and taking into account the acceleration of gravity (g), the sine value of the slope angle can be calculated; since there is a relationship between the slope angle (θ) and the slope percentage (P): sin(θ) = vertical height change / horizontal distance change, the slope angle can be estimated by the longitudinal acceleration (a) measured by the IMU sensor: sin(θ) = a / g, and then the sine value is converted to an angle, and the slope percentage is calculated: P = sin(θ) x 100%.

[0059] It can be understood that after obtaining the slope on which the vehicle is located, it is necessary to determine the size of the slope, that is, to compare it with the preset slope range. The preset slope range is the slope range on which the vehicle has a risk of rolling down and triggering HHC can make the vehicle stop. This parameter is calibrated according to the actual vehicle model, for example, a slope with a slope less than 2% is defined as a slope without a risk of rolling down, a slope with a slope between 2% and 8% is defined as a slope with a risk of rolling down, and triggering HHC can make the vehicle stop on the slope, and a slope with a slope greater than 8% is defined as a slope with a risk of rolling down, and triggering HHC cannot make the vehicle stop on the slope. Among them, 2% slope is understood as the vertical height change of the slope is 2 units per 100 units of horizontal distance, and the rest of the percentage slope is the same, which will not be repeated here.

[0060] It can be understood that there is no risk of rolling down, which means that the vehicle does not need to apply additional braking force and will not roll down; there is a risk of rolling down, and triggering HHC can make the vehicle stop on the slope, which means that the vehicle does not need to apply additional braking force, and the HHC controlled vehicle will not roll down due to the original braking output in response to the brake pedal.

[0061] Referring to FIG. 1, in step S200, when it is determined that the slope of the slope is in the preset slope range, that is, in the range of 2% to 8% slope, it is necessary to determine the driving direction of the vehicle and judge the relationship between the driving direction and the slope, that is, to judge whether the driving direction is uphill or downhill. When the driving direction of the vehicle is uphill, the problem of rolling down when the vehicle starts needs to be considered; when the driving direction of the vehicle is downhill, the problem of rolling down when the vehicle starts does not need to be considered.

[0062] Referring to FIG. 2, step S300 further includes but is not limited to the following steps:

[0063] Step S310, when the driving direction is downhill, control the EPB to switch to the first working mode.

[0064] It can be understood that when the vehicle stops on the slope, the vehicle head can be oriented to the uphill direction, or the vehicle tail can be oriented to the uphill direction, and meanwhile, the vehicle can move forward in the head direction or move backward in the tail direction. When the vehicle head is oriented to the uphill direction, the vehicle switches to the forward gear to move forward, and at this time, the driving direction of the vehicle is uphill. When the vehicle head is oriented to the uphill direction, the vehicle switches to the reverse gear to move backward, and at this time, the driving direction of the vehicle is downhill. When the vehicle tail is oriented to the uphill direction, the vehicle switches to the forward gear to move forward, and at this time, the driving direction of the vehicle is downhill. When the vehicle tail is oriented to the uphill direction, the vehicle switches to the reverse gear to move backward, and at this time, the driving direction of the vehicle is uphill. When the driving direction of the vehicle is downhill, the EPB can be released according to the action of the driver stepping on the brake pedal, and the starting speed of the vehicle is faster.

[0065] Referring to FIG. 1, in step S300, when it is determined that the driving direction of the vehicle is uphill, the brake pressure of the vehicle is obtained, and the brake pressure and the preset pressure are compared. The preset pressure is the brake force that makes the vehicle stop on the slope without the risk of rolling down the slope. This parameter is calibrated according to the actual vehicle model, for example, the preset pressure is calibrated as 120% of the brake pressure that makes the vehicle stop on the slope. Since the HHC only maintains the brake output of the vehicle in response to the original brake pedal of the driver, if the brake pressure of the vehicle is less than the preset pressure, the maintained brake output cannot guarantee that the vehicle will not roll down the slope after the HHC is triggered, and there is a risk of rolling down the slope. Therefore, before the EPB is controlled to switch the working mode and the HHC is triggered, it is necessary to determine the size of the brake pressure of the vehicle at this time.

[0066] Referring to FIG. 1, in step S400, when it is determined that the brake pressure of the vehicle is greater than or equal to the preset pressure, the EPB is controlled to switch to the first working mode, and after the EPB is released, the HHC is triggered and assists the vehicle to start on the slope, so that the vehicle starts smoothly on the slope.

[0067] Referring to FIG. 3, step S400 further includes but is not limited to the following steps:

[0068] Step S410, obtaining a shift action signal of the driver to the vehicle, and determining whether the shift action is completed according to the shift action signal;

[0069] Step S420, when the shift action is completed, controlling the EPB to release the brake output of the vehicle, activating the HHC, and controlling the vehicle to maintain the brake output in response to the brake pedal;

[0070] Step S430, obtaining a pedal action signal of the driver to the accelerator pedal, and determining whether the pedal action is started according to the pedal action signal;

[0071] Step S440, when the stepping action starts, and the driving force output by the vehicle in response to the accelerator pedal meets the hill start requirement, the control of the vehicle by the HHC is released, and the braking output of the vehicle in response to the brake pedal is released;

[0072] It can be understood that, in the first working mode of the EPB, after the gear of the vehicle is switched from the parking gear to the forward gear or the reverse gear, that is, after the parking gear, the EPB is controlled to release and release the braking output of the vehicle, and the HHC is activated; after the HHC is activated, the driver has not released the brake pedal, the HHC keeps the braking output of the vehicle in response to the brake pedal of the driver at this moment, and lasts for a certain time, for example, 1.5S, to give the driver enough time to step on the accelerator pedal to avoid rolling on the slope; after the driver steps on the accelerator pedal, the vehicle outputs the driving force, and when the driving force meets the hill start requirement, the HHC is controlled to release the control of the vehicle, and the vehicle is controlled to release the braking output in response to the brake pedal, to realize smooth starting. The EPB cooperates with the HHC to ensure that the vehicle starts smoothly and does not roll on the slope.

[0073] Referring to FIG. 4, step S420 further includes but is not limited to the following steps:

[0074] Step S421, the vehicle keeps the braking output in response to the brake pedal within a preset time;

[0075] Step S422, when the preset time is exceeded or the driving force meets the hill start requirement, the HHC releases the control of the vehicle, and the vehicle releases the braking output in response to the brake pedal.

[0076] It can be understood that, when the HHC is triggered, the vehicle will also keep stationary on the slope within 1.5S to avoid rolling on the slope after the EPB is released and the driver releases the brake pedal. From the time when the EPB is released and the driver releases the brake pedal to the time when the driver steps on the accelerator pedal, it is a vacuum period, and the HHC needs to keep the braking effect of the vehicle. When the preset time is exceeded or the driving force meets the hill start requirement, the HHC is released, and the vehicle starts normally, and in this process, the vehicle does not have the braking force competing with the driving force of the vehicle, and starts smoothly.

[0077] Referring to FIG. 5, the parking brake control method of the first aspect of the embodiment of the application further includes but is not limited to the following steps:

[0078] Step S210, when the slope is less than a preset slope range, the EPB is controlled to switch to the first working mode;

[0079] Step S220, a gear shifting action signal of the driver to the vehicle is acquired, and whether the gear shifting action is completed is judged according to the gear shifting action signal;

[0080] When the shifting action is completed, the EPB is controlled to release the brake output to the vehicle in step S230.

[0081] It can be understood that when the slope is less than the preset slope range, the vehicle does not have the risk of rolling down the slope, and thus the EPB can be directly controlled to switch to the first working mode to start the vehicle by releasing the P position of the EPB. The slope less than the preset slope range can be understood as that the vehicle is on a flat ground or a slight slope.

[0082] Referring to FIG. 6, the parking brake control method of the first aspect of the embodiment of the present application further includes but is not limited to the following steps:

[0083] When the slope is greater than the preset slope range, the relationship between the driving direction of the vehicle and the slope is determined in step S240.

[0084] When the driving direction is uphill, the EPB is controlled to switch to the second working mode in step S250, and the second working mode is a working mode in which the EPB is released according to the driving force of the vehicle in response to the output of the accelerator pedal.

[0085] It can be understood that when the slope is greater than the preset slope range, the vehicle has the risk of rolling down the slope, and triggering the HHC cannot make the vehicle stop on the slope. If the EPB is controlled to switch to the first working mode and the HHC is triggered, the brake output of the vehicle maintained by the HHC control cannot guarantee the safe starting of the vehicle, that is, the vehicle may slip under the action of gravity, and thus the EPB needs to be controlled to switch to the second working mode. Only when the driving force is large enough, the EPB is released, thereby avoiding the situation of the vehicle slipping and rolling down the slope. The slope greater than the preset slope range indicates that the vehicle is on a steep slope.

[0086] Referring to FIG. 7, step S250 further includes but is not limited to the following steps:

[0087] The EPB is controlled to maintain the brake output to the vehicle in step S251.

[0088] The driver's pedal action signal to the accelerator pedal is obtained in step S252, and the size of the driving force of the vehicle in response to the pedal action is determined according to the pedal action signal.

[0089] When the driving force is greater than a preset driving force, the EPB is controlled to release the brake output to the vehicle in step S253, and the preset driving force is a driving force required for the vehicle to meet the requirements of starting on the slope.

[0090] It can be understood that when the EPB is controlled to switch to the second working mode, the safety of the vehicle is given priority, and the smoothness is given secondary consideration, and thus after the driver releases the brake pedal, the EPB still needs to maintain the brake output to the vehicle, instead of the HHC maintaining the brake output of the vehicle in response to the brake pedal. When the driving force of the vehicle reaches a certain value, the EPB is released.

[0091] Referring to FIG. 8, the control device of the parking brake according to the second aspect of the embodiments of the present application comprises an obtaining module, a first determining module, a second determining module and an executing module. The obtaining module is configured to obtain the slope of the slope on which the vehicle is located, and obtain the brake pressure of the vehicle. The first determining module is configured to determine whether the slope is in a preset slope range according to the slope, and determine the relationship between the driving direction of the vehicle and the slope according to the driving direction of the vehicle when the slope is in the preset slope range. The preset slope range is the slope range in which the vehicle has a risk of rolling down the slope and the HHC can be triggered to stop the vehicle on the slope. The second determining module is configured to determine the size relationship between the brake pressure and a preset pressure according to the brake pressure when the driving direction is uphill. The preset pressure is the brake force that can stop the vehicle on the slope without the risk of rolling down the slope. The executing module is configured to control the EPB to switch to the first working mode when the brake pressure is greater than or equal to the preset pressure, and control the vehicle to trigger the HHC according to the signal that the EPB is released.

[0092] It can be understood that when the vehicle needs to start on the slope, the driver steps on the brake pedal to shift gears. During this process, the obtaining module obtains the slope of the slope on which the vehicle is located, and the first determining module determines the size of the slope. When the first determining module determines that the slope is in the preset slope range, i.e., the slope is in the slope range in which the vehicle has a risk of rolling down the slope and the HHC can be triggered to stop the vehicle on the slope, the first determining module determines the relationship between the driving direction of the vehicle and the slope. When the first determining module determines that the driving direction of the vehicle is uphill, the obtaining module obtains the brake pressure of the vehicle, and the second determining module determines the size relationship between the brake pressure and a preset pressure according to the brake pressure. The preset pressure is the brake force that can stop the vehicle on the slope without the risk of rolling down the slope. When the second determining module determines that the brake pressure is greater than or equal to the preset pressure, the executing module controls the EPB to switch to the first working mode, and controls the vehicle to trigger the HHC. The first working mode is the working mode in which the EPB releases the P gear, i.e., during the process in which the driver steps on the brake pedal to shift gears, the EPB starts to release, and when the driver completes the gear shifting and steps on the accelerator pedal, the EPB completely releases. After the HHC is triggered, the vehicle starts by the assistance of the HHC. By executing the parking brake control method by the control device, the smoothness of the vehicle starting on the slope can be ensured, and the problem of the whole vehicle rolling down the slope can be avoided.

[0093] It should be noted that in some embodiments, when the first determining module determines that the slope is less than the preset slope range, the executing module controls the EPB to switch to the first working mode. When the first determining module determines that the slope is greater than the preset slope range, the executing module controls the EPB to switch to the second working mode. The second working mode is the working mode in which the EPB is automatically released, which responds to the driving force of the vehicle. When the driving force is large enough, the EPB releases. In the second working mode of the EPB, the safety of the vehicle is given priority.

[0094] With reference to FIG. 9, a specific example of the control method according to the first aspect of the embodiment of the application is described, and one case is listed as follows:

[0095] The vehicle stops on a slope, the EPB is in the clamping state, the obtaining module obtains the slope size, the first determining module determines whether the slope is within 2% of the slope, when the first determining module determines that the slope is not within 2% of the slope, the obtaining module obtains the gear shifting action information of the driver, the first determining module determines the driving state of the vehicle according to the gear shifting action information, when the first determining module determines that the vehicle is in the reverse gear and is on a downhill, the first determining module determines whether the slope is within the slope range of 2% to 8%, when the first determining module determines that the slope is within the slope range of 2% to 8%, the obtaining module obtains the brake pressure of the vehicle, the second determining module determines the size of the brake pressure, when the second determining module determines that the brake pressure is greater than 120% of the brake force required for the vehicle to stop on the current slope, the executing module controls the EPB to release and controls the HHC to trigger, when the second determining module determines that the torque generated by the driving force of the vehicle can make the vehicle start on the slope, the HHC releases.

[0096] It should be noted that when the first determining module determines that the driving state of the vehicle is on an uphill and determines that the slope is greater than 8%, the obtaining module can first obtain the brake pressure of the vehicle, when the second determining module determines that the brake pressure is greater than 120% of the brake force required for the vehicle to stop on the current slope, the executing module controls the EPB to release and controls the HHC to trigger, that is, after determining that the driving state of the vehicle is on an uphill and the slope is greater than 8%, the control method has two control routes to choose from, that is, the first route is to control the EPB to switch to the second working mode, and the second route is to determine the brake pressure, and then determine whether the working mode of the EPB is the first working mode or the second working mode according to the brake pressure, when the brake pressure is greater than 120% of the brake force required for the vehicle, the EPB is controlled to switch to the first working state and the HHC is triggered, and when the brake pressure is less than 120% of the brake force required for the vehicle, the EPB is controlled to switch to the second working state.

[0097] That is, in general, when the slope is greater than 8%, safety is given priority, and therefore the EPB is directly controlled to switch to the second working mode. However, for the case where the slope is greater than 8%, the EPB does not have to be directly switched to the second working mode, and the working mode of the EPB can be determined after the brake pressure of the vehicle is determined.

[0098] The vehicle of the third aspect of the embodiment of the application comprises a memory, a processor and a program stored in the memory and executable on the processor, and the program is executed by the processor to implement the parking brake control method described above. Taking the processor and the memory in the vehicle controller as an example, the processor and the memory can be connected by a bus. The memory as a non-transitory computer readable storage medium can be used to store non-transitory software programs and non-transitory computer executable programs. In addition, the memory can include a high-speed random access memory and can also include a non-transitory memory, such as at least one disk memory, a flash memory device, or other non-transitory solid-state memory device. In some embodiments, the memory can optionally include a memory remotely arranged relative to the control processor, and these remote memories can be connected to the controller through a network.

[0099] The non-transitory software programs and instructions required to implement the control method of the above-described embodiments are stored in the memory, and when executed by the processor, the control method in the above-described embodiments is executed. For example, the method steps S100 to S400 in FIG. 1, the method step S310 in FIG. 2, etc. are executed.

[0100] The device embodiments described above are only schematic, and the units described as separate components can or can not be physically separate, i.e., can be located in one place or can be distributed to multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0101] It should be noted that the vehicle can be a private car, such as a sedan, an SUV, an MPV, or a pickup truck, etc. The vehicle can also be an operating vehicle, such as a van, a bus, a small truck, or a large trailer, etc. The vehicle needs to have an electric motor that can output power or store mechanical energy as a generator. When the vehicle is a new energy vehicle, it can be a hybrid vehicle or a pure electric vehicle.

[0102] The vehicle adopts the control device to execute the parking brake control method described above, which can ensure smooth starting and no hill rolling of the vehicle on a slope.

[0103] The computer readable storage medium of the fourth aspect of the embodiment of the application stores computer executable instructions, and the computer executable instructions are used to make the computer execute the parking brake control method described above. Since the computer readable storage medium can execute all the technical solutions of the control method described above, it at least has all the beneficial effects brought by the technical solutions of the above-described embodiments, which will not be described here.

[0104] The embodiments of the application are described in detail above in combination with the drawings, but the application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. A parking brake control method, characterized in that, Applied to vehicles equipped with electronic parking brake systems and hill start assist systems, the parking brake control method includes the following steps: The slope of the ramp where the vehicle is located is obtained, and it is determined whether the slope is within a preset slope range. The preset slope range is the range within which the vehicle is at risk of rolling back and the ramp start assist system can stop the vehicle within the slope range. When the slope is within the preset slope range, the relationship between the driving direction and the slope is determined based on the driving direction of the vehicle. When the driving direction is uphill, the braking pressure of the vehicle is obtained, and the relationship between the braking pressure and the preset pressure is determined based on the braking pressure. The preset pressure is the braking force that stops the vehicle on the slope without the risk of rolling back. When the braking pressure is greater than or equal to the preset pressure, the electronic parking brake system is controlled to switch to the first working mode, and the vehicle is controlled to trigger the hill start assist system according to the signal that the electronic parking brake system has completed the release. The first working mode is the working mode in which the electronic parking brake system releases according to the driver's action of pressing the brake pedal.

2. The parking brake control method according to claim 1, characterized in that, The parking brake control method further includes the following steps: When the driving direction is downhill, the electronic parking brake system is switched to the first working mode.

3. The parking brake control method according to claim 1, characterized in that, The steps of controlling the electronic parking brake system to switch to the first operating mode and the vehicle triggering the hill start assist system based on the signal indicating that the electronic parking brake system has completed releasing include: Acquire the driver's gear shifting action signal for the vehicle, and determine whether the gear shifting action is completed based on the gear shifting action signal; When the gear shifting action is completed, the electronic parking brake system is controlled to release the braking output to the vehicle, the hill start assist system is activated, and the vehicle is controlled to maintain the braking output in response to the brake pedal. Acquire the driver's accelerator pedal depress signal, and determine whether the depressing action has started based on the depressing signal; When the pedal action begins, and the driving force output by the vehicle in response to the accelerator pedal meets the hill start requirements, the hill start assist system releases control of the vehicle and releases the vehicle's braking output in response to the brake pedal.

4. The parking brake control method according to claim 3, characterized in that, Activating the hill start assist system and controlling the vehicle to maintain braking output responsive to the brake pedal further includes the step of: Control the vehicle to maintain braking output in response to the brake pedal for a preset time; When the preset time is exceeded or the driving force meets the hill start requirements, the hill start assist system releases control of the vehicle and releases the vehicle's braking output in response to the brake pedal.

5. The parking brake control method according to claim 1, characterized in that, The parking brake control method further includes the following steps: When the slope is less than the preset slope range, the electronic parking brake system is controlled to switch to the first working mode; Acquire the driver's gear shifting action signal for the vehicle, and determine whether the gear shifting action is completed based on the gear shifting action signal; When the gear shifting action is completed, the electronic parking brake system releases its braking output on the vehicle.

6. The parking brake control method according to claim 1, characterized in that, The parking brake control method further includes the following steps: When the slope is greater than the preset slope range, determine the relationship between the vehicle's driving direction and the slope. When the driving direction is uphill, the electronic parking brake system is switched to the second working mode. The second working mode is the working mode in which the electronic parking brake system releases the brake according to the driving force output by the vehicle in response to the accelerator pedal.

7. The parking brake control method according to claim 6, characterized in that, The step of controlling the electronic parking brake system to switch to the second operating mode includes: Control the electronic parking brake system to maintain braking output on the vehicle; The driver's accelerator pedal depressing signal is acquired, and the magnitude of the driving force output by the vehicle in response to the accelerator pedal is determined based on the depressing signal. When the driving force is greater than the preset driving force, the electronic parking brake system releases its braking output on the vehicle. The preset driving force is the driving force that enables the vehicle to meet the requirements for starting on a slope.

8. A parking brake control device, characterized in that, For performing the parking brake control method as described in any one of claims 1 to 7, the control device comprises: The acquisition module is configured to acquire the slope of the ramp where the vehicle is located, and to acquire the braking pressure of the vehicle. The first determining module is configured to determine whether the slope is within a preset slope range based on the slope. When the slope is within the preset slope range, the module determines the relationship between the driving direction and the slope based on the driving direction of the vehicle. The preset slope range indicates that the vehicle is at risk of rolling back, and triggering the slope start assist system can stop the vehicle within the slope range of the slope. The second determining module is configured to, when the driving direction is uphill, determine the relationship between the braking pressure and a preset pressure based on the braking pressure, wherein the preset pressure is the pressure that stops the vehicle on the slope without risk of rolling back. Braking force; The execution module is configured to control the electronic parking brake system to switch to a first working mode when the braking pressure is greater than or equal to the preset pressure, and to control the vehicle to trigger the hill start assist system according to the signal that the electronic parking brake system has completed release.

9. A vehicle, characterized in that, It includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the parking brake control method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the parking brake control method as described in any one of claims 1 to 7.

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