Vehicle braking pitching control method, controller, vehicle and storage medium

Abstract

The invention discloses a vehicle braking pitching control method, a controller, a vehicle and a storage medium, and belongs to the technical field of automobiles. The method comprises the following steps: acquiring braking data of a target vehicle; under the condition that it is determined that the braking pitching event occurs, a target braking pitching control mode is determined based on the braking data; generating a target pitching control parameter based on the target braking pitching control mode; the target pitching control parameters comprise target suspension damping, target suspension rigidity, target impact degree, target total braking force, target front axle braking force and target rear axle braking force; and controlling the braking process of the target vehicle based on the target pitching control parameter. According to the vehicle braking pitching control method disclosed by the invention, the control effect of the vehicle braking pitching phenomenon is improved.

Description

Technical Field

[0001] This application belongs to the field of automotive technology, and in particular relates to a vehicle braking pitch control method, controller, vehicle, and storage medium. Background Technology

[0002] When a vehicle brakes, the ground force that changes the vehicle's motion acts on the vehicle's center of gravity in a rectangular pattern, causing the vehicle to pitch (nod). When the vehicle speed drops to zero, the longitudinal ground force decreases rapidly, and the vehicle body quickly returns to its original position. This causes the occupants to initially lean forward and then quickly return to their original position, impacting their seats and causing discomfort. Typically, adjusting a parameter during braking (such as the damping of the vehicle's suspension) can reduce the pitching phenomenon caused by braking.

[0003] However, due to multiple factors such as vehicle speed, driver's intention to decelerate, and road conditions, relying solely on adjusting a single parameter to improve vehicle braking pitch is difficult to apply to complex vehicle braking situations, resulting in unsatisfactory vehicle braking pitch control. Summary of the Invention

[0004] This application aims to at least solve one of the technical problems existing in the prior art. To this end, this application proposes a vehicle braking pitch control method, a controller, a vehicle, and a storage medium to improve the control effect of vehicle braking pitch phenomenon.

[0005] In a first aspect, this application provides a vehicle braking pitch control method, the method comprising:

[0006] Obtain braking data of the target vehicle;

[0007] In the event that a braking pitch event has occurred, the target braking pitch control mode is determined based on the braking data.

[0008] Based on the target braking pitch control mode, determine the target pitch control parameters;

[0009] The braking process of the target vehicle is controlled based on the target pitch control parameters.

[0010] According to the vehicle braking pitch control method of this application, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; target pitch control parameters are generated based on the target braking pitch control mode; and the braking process of the target vehicle is controlled based on the target pitch control parameters. The braking process of the target vehicle is comprehensively controlled through the target pitch control parameters, so that the actual pitch of the target vehicle matches the braking pitch target, thereby improving the control effect of vehicle braking pitch phenomenon.

[0011] According to one embodiment of this application, the braking data includes brake pedal state and brake master cylinder pressure; after acquiring the braking data of the target vehicle, the method includes:

[0012] A brake pitch event is determined to have occurred when the brake pedal is in the first state or the brake master cylinder pressure is greater than or equal to the first threshold. The brake pedal being in the first state indicates that the brake pedal of the target vehicle has been depressed.

[0013] or

[0014] If the brake pedal is in the second state and the brake master cylinder pressure is less than the first threshold, it is determined that no brake pitch event has occurred; the brake pedal being in the second state indicates that the brake pedal of the target vehicle has not been depressed.

[0015] According to one embodiment of this application, the braking data includes at least one of target pitch angle, target pitch rate, real-time pitch angle, real-time pitch rate, braking deceleration, and target deceleration; in the event that a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data, including:

[0016] If a braking pitch event is determined to have occurred, and the braking pitch target can be achieved through the first braking pitch control mode, the first braking pitch control mode is determined as the target braking pitch control mode; the first braking pitch control mode performs braking pitch control based on relevant parameters of the braking system.

[0017] or

[0018] If a braking pitch event is determined to have occurred, and the braking pitch target cannot be achieved through the first braking pitch control mode, the second braking pitch control mode is determined as the target braking pitch control mode; the second braking pitch control mode performs braking pitch control based on relevant parameters of the braking system and relevant parameters of the suspension system.

[0019] Among them, the braking pitch target includes targets whose real-time pitch angle is less than or equal to the target pitch angle and whose real-time pitch angular velocity is less than or equal to the target pitch angular velocity.

[0020] According to one embodiment of this application, the target pitch control parameters are determined based on the target braking pitch control mode, including:

[0021] When the target braking pitch control mode is the first braking pitch control mode, relevant braking system parameters are generated; the relevant braking system parameters include at least one of the target impact intensity, target total braking force, target front axle braking force, and target rear axle braking force.

[0022] When the target braking pitch control mode is the second braking pitch control mode, relevant parameters of the braking system and relevant parameters of the suspension system are generated; the relevant parameters of the suspension system include the target suspension damping and / or the target suspension stiffness.

[0023] According to one embodiment of this application, generating braking system related parameters includes:

[0024] If the braking data meets the braking pressure relief control conditions, the target impact intensity and total braking force are determined based on the braking data.

[0025] According to one embodiment of this application, the braking data includes at least one of brake master cylinder pressure, braking deceleration, vehicle speed, and road gradient; before determining the target impact and target total braking force based on the braking data, provided that the braking data meets the brake pressure relief control conditions, the method includes:

[0026] When the brake master cylinder pressure is within the brake force relief control range, the brake deceleration is within the preset relief control deceleration range, the absolute value of the road slope is less than the slope threshold, and the vehicle speed is greater than the first vehicle speed, the braking data is determined to meet the brake relief control conditions.

[0027] According to one embodiment of this application, generating braking system related parameters includes:

[0028] If the braking data meets the conditions for front and rear axle braking force distribution, the target front axle braking force and the target rear axle braking force are obtained based on the braking data.

[0029] According to one embodiment of this application, the braking data includes steering wheel angle and lateral acceleration; before obtaining the target front axle braking force and the target rear axle braking force based on the braking data, provided that the braking data satisfies the front and rear axle braking force distribution conditions, the method includes:

[0030] When the steering wheel angle is less than or equal to the steering wheel angle threshold, the lateral acceleration is less than or equal to the lateral acceleration threshold, and the braking deceleration is less than or equal to the braking deceleration threshold, the braking data is determined to meet the front and rear axle braking force distribution conditions.

[0031] According to one embodiment of this application, when the braking data satisfies the front and rear axle braking force distribution conditions, obtaining the target front axle braking force and the target rear axle braking force based on the braking data includes:

[0032] Based on braking data, the upper limit of front axle braking force and the upper limit of rear axle braking force are obtained, and the product of the upper limit of rear axle braking force and the pre-set safety distribution coefficient is obtained as the maximum value of rear axle braking force.

[0033] The product of the target total braking force and the target rear axle braking force distribution ratio is determined as the expected rear axle braking force;

[0034] The minimum value between the expected rear axle braking force and the maximum value of the rear axle braking force is determined as the target rear axle braking force, and the difference between the target total braking force and the target rear axle braking force is determined as the target front axle braking force.

[0035] According to one embodiment of this application, generating suspension system-related parameters includes:

[0036] Based on braking data, relevant parameters of the suspension system are obtained for each control stage in several control phases.

[0037] According to one embodiment of this application, the number of control stages is four; based on braking data, suspension system-related parameters for each control stage are obtained, including:

[0038] The product of the real-time pitch angular velocity and the preset gain coefficient is determined as the target suspension damping for the first control stage, and / or the first stiffness is determined as the target suspension stiffness for the first control stage.

[0039] The minimum value between the expected damping and the preset lower limit of damping is determined as the target suspension damping for the second control stage, and / or the second stiffness is determined as the target suspension stiffness for the second control stage; the second stiffness is less than the first stiffness.

[0040] The maximum value of the preset damping range is determined as the target suspension damping of the third control stage, and / or the first stiffness is determined as the target suspension stiffness of the third control stage.

[0041] The minimum value of the preset damping range is determined as the target suspension damping for the fourth control stage, and / or the second stiffness is determined as the target suspension stiffness for the fourth control stage.

[0042] According to one embodiment of this application, controlling the braking process of a target vehicle based on target pitch control parameters includes:

[0043] The target vehicle is controlled to enter the first braking stage. During the first braking stage, the damping of the target vehicle's suspension is controlled to be the target suspension damping of the first control stage, and / or the stiffness of the target vehicle is controlled to be the first stiffness.

[0044] If the braking execution time is greater than or equal to the target braking time, the target vehicle is controlled to enter the second braking stage. In the second braking stage, the damping of the target vehicle's suspension is controlled to be the target suspension damping of the second control stage, and / or the stiffness of the target vehicle is controlled to be the second stiffness.

[0045] When the vehicle speed is less than or equal to the second vehicle speed, the target vehicle is controlled to enter the third braking stage. In the third braking stage, the damping of the target vehicle's suspension is controlled to be the target suspension damping of the third control stage, and / or the stiffness of the target vehicle is controlled to be the first stiffness.

[0046] If the vehicle speed is less than or equal to the third vehicle speed, and the time for executing the third control phase is greater than or equal to the target time, the target vehicle is controlled to enter the fourth braking phase. In the fourth braking phase, the damping of the target vehicle's suspension is controlled to be the target suspension damping of the fourth control phase, and / or the stiffness of the target vehicle is controlled to be the second stiffness; the third vehicle speed is less than the second vehicle speed.

[0047] Secondly, this application provides a controller, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the vehicle braking pitch control method described in the first aspect.

[0048] Thirdly, this application provides a vehicle that includes a braking system and a controller for the second aspect.

[0049] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the steps of the vehicle braking pitch control method of the first aspect described above.

[0050] Fifthly, this application provides a computer program product, including a computer program that is executed by a processor to implement the steps of the vehicle braking pitch control method described in the first aspect.

[0051] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0052] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0053] Figure 1 This is one of the schematic flowcharts of the vehicle braking pitch control method provided in the embodiments of this application;

[0054] Figure 2 This is the second schematic flowchart of the vehicle braking pitch control method provided in the embodiments of this application;

[0055] Figure 3 This is a schematic diagram of the vehicle braking pitch control system provided in the embodiments of this application;

[0056] Figure 4This is a schematic diagram of the simulation results of the fusion multi-factor braking pitch control provided in the embodiments of this application;

[0057] Figure 5 This is a schematic diagram of the vehicle braking pitch control device provided in the embodiments of this application;

[0058] Figure 6 This is a schematic diagram of the controller provided in the embodiments of this application. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0060] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0061] The vehicle braking pitch control method, controller, vehicle, and storage medium provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0062] Among them, the vehicle braking pitch control method can be applied to the terminal, and can be executed by the hardware or software in the terminal.

[0063] The terminal includes, but is not limited to, portable communication devices such as mobile phones or tablets with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads). It should also be understood that, in some embodiments, the terminal may not be a portable communication device, but rather a desktop computer with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads).

[0064] The following embodiments describe a terminal including a display and a touch-sensitive surface. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, mouse, and joystick.

[0065] The vehicle braking pitch control method provided in this application embodiment can be executed by an electronic device or a functional module or entity in an electronic device that can implement the vehicle braking pitch control method. The electronic devices mentioned in this application embodiment include, but are not limited to, mobile phones, tablets, computers, cameras, and wearable devices. The vehicle braking pitch control method provided in this application embodiment is described below using an electronic device as the execution subject.

[0066] like Figure 1 As shown, the vehicle braking pitch control method includes steps 110, 120, 130 and 140.

[0067] Step 110: Obtain the braking data of the target vehicle.

[0068] In actual execution, the target vehicle can be any type of vehicle.

[0069] In some embodiments, braking data such as brake pedal status, brake master cylinder pressure, real-time pitch angle, real-time pitch angular velocity, braking deceleration, steering wheel angle, and lateral acceleration can be acquired through internal sensors of the target vehicle (e.g., pressure sensors or any other theoretically feasible sensors).

[0070] In some embodiments, braking data such as road surface slope, road surface bumpiness, and road surface adhesion coefficient can be acquired through a target vehicle's target observation system. The target observation system can be a pre-aiming system.

[0071] In some embodiments, the braking data may also include preset data such as target pitch angle, target pitch rate, and target deceleration.

[0072] In some embodiments, after acquiring the braking data of the target vehicle, it can be determined whether the target vehicle has experienced a braking pitch event. A braking pitch event is a phenomenon in which the vehicle body nods due to braking, such that in the side view, the lateral coordinate axis with the center of gravity of the vehicle body as the origin of the two-dimensional coordinate axis forms an angle with the horizontal line of the ground, and this angle is the pitch angle.

[0073] Step 120: If a braking pitch event is determined, determine the target braking pitch control mode based on the braking data.

[0074] In some embodiments, when a braking pitch event is determined to have occurred, a target braking pitch control mode can be determined from a first braking pitch control mode and a second braking pitch control mode. The first braking pitch control mode performs braking pitch control based on braking system-related parameters, while the second braking pitch control mode performs braking pitch control based on both braking system-related parameters and suspension system-related parameters.

[0075] In some embodiments, if, based on braking data, it is determined that braking pitch control based solely on braking system parameters can achieve the control target, then the first braking pitch control mode is determined as the target braking pitch control mode, i.e., braking pitch control is performed solely based on braking system parameters. Conversely, if braking pitch control based solely on braking system parameters cannot achieve the control target, then the second braking pitch control mode is determined as the target braking pitch control mode, i.e., braking pitch control is performed jointly based on both braking system parameters and suspension system parameters.

[0076] Step 130: Determine the target pitch control parameters based on the target braking pitch control mode.

[0077] In some embodiments, the target pitch control parameters include target suspension damping, target suspension stiffness, target impact, target total braking force, target front axle braking force, and target rear axle braking force.

[0078] In some embodiments, after determining the target braking pitch control mode, target pitch control parameters corresponding to the target braking pitch control mode can be generated based on braking data.

[0079] In some embodiments, when the target braking pitch control mode is the first braking pitch control mode, braking system-related parameters can be generated as target pitch control parameters, such as target impact, target total braking force, target front axle braking force, and target rear axle braking force. When the target braking pitch control mode is the second braking pitch control mode, suspension system-related parameters can be generated as target pitch control parameters, such as target suspension damping, target suspension stiffness, target impact, target total braking force, target front axle braking force, and target rear axle braking force.

[0080] In some embodiments, when the target braking pitch control mode is the first braking pitch control mode, braking system related parameters can be generated as target pitch control parameters, and the target vehicle can maintain its current suspension damping and suspension stiffness.

[0081] Step 140: Control the braking process of the target vehicle based on the target pitch control parameters.

[0082] In some embodiments, after obtaining target pitch control parameters such as target suspension damping, target suspension stiffness, target impact, target total braking force, target front axle braking force, and target rear axle braking force, the braking process of the target vehicle can be controlled based on the target pitch control parameters until the real-time pitch angle of the target vehicle returns to zero, i.e., the braking pitch phenomenon ends.

[0083] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; target pitch control parameters are generated based on the target braking pitch control mode; and the braking process of the target vehicle is controlled based on the target pitch control parameters, so as to comprehensively control the braking process of the target vehicle through the target pitch control parameters, so that the actual pitch of the target vehicle matches the braking pitch target, thereby improving the control effect of vehicle braking pitch phenomenon.

[0084] In some embodiments, after acquiring the braking data of the target vehicle, it can be determined whether a braking pitch event has occurred based on the braking data.

[0085] In some embodiments, it can be determined whether a brake pitch event has occurred based on braking data such as brake pedal status and brake master cylinder pressure.

[0086] In some embodiments, adjustment control of the braking process of the target vehicle is not triggered in the absence of a braking pitch event.

[0087] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; based on the braking data, it is determined whether a braking pitch event has occurred; if a braking pitch event has occurred, a target braking pitch control mode is determined based on the braking data; target pitch control parameters are generated based on the target braking pitch control mode; the target pitch control parameters include target suspension damping, target suspension stiffness, target impact, target total braking force, target front axle braking force, and target rear axle braking force; the braking process of the target vehicle is controlled based on the target pitch control parameters, so as to comprehensively control the braking process of the target vehicle through the target pitch control parameters such as target suspension damping, target suspension stiffness, target impact, target total braking force, target front axle braking force, and target rear axle braking force, so that the actual pitch of the target vehicle conforms to the braking pitch target, thereby improving the control effect of vehicle braking pitch phenomenon.

[0088] In some embodiments, a brake pitch event is determined to have occurred when the brake pedal is in a first state or the brake master cylinder pressure is greater than or equal to a first threshold.

[0089] or

[0090] If the brake pedal is in the second state and the brake master cylinder pressure is less than the first threshold, it is determined that no brake pitch event has occurred.

[0091] In actual operation, the brake pedal status can include the magnitude of the brake pedal force and whether the brake pedal is pressed. The brake pedal status can reflect the driver's driving intention, namely the magnitude of the braking deceleration and the acceleration of the deceleration.

[0092] In actual execution, both the first threshold and the first threshold can be preset values. The first threshold can be a threshold preset based on the brake pedal state. The first threshold can be a threshold preset based on the brake master cylinder pressure.

[0093] In some embodiments, a brake pitch event is determined to have occurred when the brake pedal is in a first state, i.e., the brake pedal of the target vehicle is depressed. In some embodiments, a brake pitch event is determined to have occurred when the brake master cylinder pressure is greater than or equal to a first threshold. For example, if the first threshold is 10%, a brake pitch event is determined to have occurred when the brake master cylinder pressure is 15%.

[0094] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; a braking pitch event is determined to have occurred when the brake pedal is depressed or the brake master cylinder pressure is greater than or equal to a first threshold; or no braking pitch event is determined to have occurred when the brake pedal is not depressed and the brake master cylinder pressure is less than the first threshold. If a braking pitch event is determined to have occurred, a target braking pitch control mode is determined based on the braking data; target pitch control parameters are generated based on the target braking pitch control mode; the target pitch control parameters include target suspension damping, target suspension stiffness, target impact, target total braking force, target front axle braking force, and target rear axle braking force; the braking process of the target vehicle is controlled based on the target pitch control parameters, so as to comprehensively control the braking process of the target vehicle through the target suspension damping, target suspension stiffness, target impact, target total braking force, target front axle braking force, and target rear axle braking force, so that the actual pitch of the target vehicle conforms to the braking pitch target, thereby improving the control effect of vehicle braking pitch phenomenon.

[0095] In some embodiments, the braking data includes at least one of target pitch angle, target pitch rate, real-time pitch angle, real-time pitch rate, braking deceleration, and target deceleration; when a braking pitch event is determined to have occurred, and the braking pitch target can be achieved through a first braking pitch control mode, the first braking pitch control mode is determined as the target braking pitch control mode; the first braking pitch control mode performs braking pitch control based on braking system-related parameters; or when a braking pitch event is determined to have occurred, and the braking pitch target cannot be achieved through the first braking pitch control mode, a second braking pitch control mode is determined as the target braking pitch control mode; the second braking pitch control mode performs braking pitch control based on braking system-related parameters and suspension system-related parameters; wherein, the braking pitch target includes a real-time pitch angle less than or equal to the target pitch angle, and a real-time pitch rate less than or equal to the target pitch rate.

[0096] In actual operation, the target pitch angle is a pre-set pitch angle, that is, a pitch angle that does not affect the passenger comfort during braking. The target pitch angular velocity is a pre-set pitch angular velocity, that is, a pitch angular velocity that does not affect the passenger comfort during braking.

[0097] In some embodiments, a predictive model can be used to predict the pitch angle to be achieved after using a first braking pitch control mode, based on braking data and the vehicle's real-time braking state. The braking data includes target deceleration and target impact, and the real-time braking state includes real-time pitch angle, real-time pitch acceleration, and real-time deceleration. Based on the predicted pitch angle and the target pitch angle, it can be determined whether the braking pitch target can be achieved using the first braking pitch control mode. For example, if the predicted pitch angle is less than or equal to the target pitch angle, it is determined that the braking pitch target can be achieved using the first braking pitch control mode; if the predicted pitch angle is greater than the target pitch angle, it is determined that the braking pitch target cannot be achieved using the first braking pitch control mode.

[0098] In some embodiments, a predictive model can be used to predict the pitch rate to be reached after using the first braking pitch control mode, based on the real-time pitch rate in the braking data. Then, based on the predicted pitch rate and the target pitch rate, it can be determined whether the braking pitch target can be achieved using the first braking pitch control mode. For example, if the predicted pitch rate is less than the target pitch rate, it is determined that the braking pitch target can be achieved using the first braking pitch control mode; if the predicted pitch rate is greater than or equal to the target pitch rate, it is determined that the braking pitch target cannot be achieved using the first braking pitch control mode.

[0099] According to the vehicle brake pitch control method of this application embodiment, braking data of the target vehicle is acquired; a brake pitch event is determined to have occurred when the brake pedal is in a first state or the brake master cylinder pressure is greater than or equal to a first threshold; or no brake pitch event is determined to have occurred when the brake pedal is in a second state and the brake master cylinder pressure is less than the first threshold. If a brake pitch event is determined to have occurred, a target brake pitch control mode is determined based on the braking data; and target pitch control parameters are generated based on the target brake pitch control mode. The target pitch control parameters include target suspension damping and target suspension stiffness. The system measures the target impact, total braking force, front axle braking force, and rear axle braking force. Based on the target pitch control parameters, the braking process of the target vehicle is controlled. Considering the influence of the suspension system on the braking force distribution control range, the pitch suppression performance of the combined suspension system and braking system is fully explored. The system couples relevant parameters of the suspension system, such as target suspension damping and target suspension stiffness, with relevant parameters of the braking system, such as target impact, total braking force, front axle braking force, and rear axle braking force, to comprehensively control the braking process of the target vehicle, so that the actual pitch of the target vehicle matches the braking pitch target, thereby improving the vehicle's braking pitch suppression performance.

[0100] In some embodiments, when the target braking pitch control mode is a first braking pitch control mode, braking system related parameters are generated; the braking system related parameters include at least one of target impact, target total braking force, target front axle braking force, and target rear axle braking force; when the target braking pitch control mode is a second braking pitch control mode, braking system related parameters are generated, and suspension system related parameters are generated; the suspension system related parameters include target suspension damping and / or target suspension stiffness.

[0101] In some embodiments, when the target braking pitch control mode is the first braking pitch control mode, that is, when braking pitch control is performed only based on braking system-related parameters, braking system-related parameters such as target impact, target total braking force, target front axle braking force, and target rear axle braking force are generated.

[0102] In actual execution, the target impact force represents the acceleration of the target vehicle's deceleration.

[0103] In some embodiments, braking system-related parameters such as target impact, target total braking force, target front axle braking force, and target rear axle braking force can be generated based on braking force generation strategy and front and rear axle braking force distribution strategy.

[0104] In some embodiments, when the target braking pitch control mode is the second braking pitch control mode, that is, when braking pitch control is performed jointly based on braking system related parameters and suspension system related parameters, braking system related parameters such as target impact, target total braking force, target front axle braking force, and target rear axle braking force, and suspension system related parameters such as target suspension damping and target suspension stiffness are generated.

[0105] In some embodiments, when the target brake pitch control mode is the second brake pitch control mode, the second brake pitch control mode may include at least one stage of suspension system control strategy.

[0106] According to the vehicle brake pitch control method of this application embodiment, braking data of the target vehicle is acquired; a brake pitch event is determined to have occurred when the brake pedal is in a first state or the brake master cylinder pressure is greater than or equal to a first threshold; or no brake pitch event is determined to have occurred when the brake pedal is in a second state and the brake master cylinder pressure is less than the first threshold. If a brake pitch event is determined to have occurred, a target brake pitch control mode is determined based on the braking data; if the target brake pitch control mode is a first brake pitch control mode, relevant braking system parameters are generated; these parameters include target impact force, target total braking force, target front axle braking force, and target rear axle braking force; and the target brake pitch... When the control mode is the second braking pitch control mode, relevant parameters of the braking system and relevant parameters of the suspension system are generated. The relevant parameters of the suspension system include the target suspension damping and the target suspension stiffness. Based on the target pitch control parameters, the braking process of the target vehicle is controlled. Considering the influence of the suspension system on the braking force distribution control range, the pitch suppression performance of the combined suspension system and braking system control is fully explored. The braking process of the target vehicle is comprehensively controlled by coupling relevant parameters of the suspension system such as the target suspension damping and the target suspension stiffness with relevant parameters of the braking system such as the target impact, the target total braking force, the target front axle braking force and the target rear axle braking force, so that the actual pitch of the target vehicle fits the braking pitch target, thereby improving the vehicle's braking pitch suppression performance.

[0107] In some embodiments, it is determined whether the braking data meets the braking pressure relief control conditions; if the braking data meets the braking pressure relief control conditions, the target impact intensity and the target total braking force are obtained based on the braking data.

[0108] In actual execution, the target total braking force is the total braking force after depressurization.

[0109] In some embodiments, braking data such as master cylinder pressure, braking deceleration, vehicle speed, and road slope can be used to determine whether the brake pressure relief control conditions are met.

[0110] In some embodiments, a table relating brake pedal force, impact, and total braking force can be pre-constructed. When brake pressure relief control conditions are met, based on the brake pedal force, the table can be used to find the target impact corresponding to the brake pedal force and the target total braking force.

[0111] In some embodiments, the target total braking force, target impact force, and deceleration are positively correlated, and this relationship is obtained through calibration tests. The greater the deceleration, the greater the target total braking force and the greater the target impact force. This correlation is obtained through calibration tests to ensure that appropriate braking pressure is provided under different braking requirements, thereby achieving a more comfortable and safer braking effect.

[0112] In some embodiments, if the brake pressure relief control conditions are not met, the target impact magnitude is the current impact magnitude of the target vehicle, and the target total braking force is the current total braking force of the target vehicle.

[0113] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; if the target braking pitch control mode is a first braking pitch control mode, it is determined based on the braking data whether the braking pressure relief control condition is met; if the braking pressure relief control condition is met, the target impact and target total braking force are acquired based on the braking data, so that the target impact and target total braking force are generated when the target vehicle meets the braking pressure relief control condition, which is more suitable for the actual pressure relief braking situation of the target vehicle and improves the pitch suppression effect.

[0114] In some embodiments, the braking data includes at least one of brake master cylinder pressure, braking deceleration, vehicle speed, and road slope; when the brake master cylinder pressure is within the braking force relief control range, the braking deceleration is within the preset relief control deceleration range, the absolute value of the road slope is less than the slope threshold, and the vehicle speed is greater than the first vehicle speed, it is determined that the braking data meets the braking relief control conditions.

[0115] In actual implementation, the braking force relief control range is a preset range, which can be a range pre-set for the braking force. The preset deceleration control range is also a preset range, which can be a range pre-set for deceleration. The slope threshold can be a preset value, which can be a value pre-set for the road surface slope. The first vehicle speed can be a set value, which can be a set value pre-set based on the vehicle speed.

[0116] In some embodiments, the brake master cylinder pressure can be within the brake force relief control range (e.g., the brake master cylinder pressure falls within the brake force relief control range (P)). L ,P H )), the braking deceleration is within the preset pressure relief control deceleration range (for example, the braking deceleration is within the preset pressure relief control deceleration range (a xL ,a xH If the absolute value of the road slope is less than the slope threshold and the vehicle speed is greater than the first vehicle speed, then the brake pressure relief control conditions are met.

[0117] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; when the target braking pitch control mode is a first braking pitch control mode, the braking pressure relief control conditions are determined to be met when the master cylinder pressure is within the braking force relief control range, the braking deceleration is within the preset pressure relief control deceleration range, the absolute value of the road slope is less than the slope threshold, and the vehicle speed is greater than a first vehicle speed; when the braking pressure relief control conditions are met, the target impact and target total braking force are acquired based on the braking data, so that the target impact and target total braking force are generated when the target vehicle meets the braking pressure relief control conditions, which is more suitable for the actual pressure relief braking situation of the target vehicle and improves the pitch suppression effect. In some embodiments, the braking data includes brake master cylinder pressure, braking deceleration, vehicle speed, and road slope; when the brake master cylinder pressure is within the braking force relief control range, the braking deceleration is within the preset relief control deceleration range, the absolute value of the road slope is less than the slope threshold, and the vehicle speed is greater than the first vehicle speed, it is determined that the braking pressure relief control conditions are met.

[0118] In some embodiments, based on braking data, it is determined whether the braking data meets the front and rear axle braking force distribution conditions; if the front and rear axle braking force distribution conditions are met, the target front axle braking force and the target rear axle braking force are obtained based on the braking data.

[0119] In some embodiments, braking data such as steering wheel angle and lateral acceleration can be used to determine whether the front and rear axle braking force distribution conditions are met.

[0120] In some embodiments, if the front and rear axle braking force distribution conditions are not met, the current front axle braking force of the target vehicle can be used as the target front axle braking force, and the current rear axle braking force of the target vehicle can be used as the target rear axle braking force.

[0121] In some embodiments, if the front and rear axle braking force distribution conditions are met, the target total braking force can be divided based on braking data to obtain the target front axle braking force and the target rear axle braking force.

[0122] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; when the target braking pitch control mode is a first braking pitch control mode, it is determined based on the braking data whether the front and rear axle braking force distribution conditions are met; when the front and rear axle braking force distribution conditions are met, the target front axle braking force and target rear axle braking force are acquired based on the braking data, so that the target front axle braking force and target rear axle braking force are generated when the target vehicle meets the front and rear axle braking force distribution conditions, which is more suitable for the actual front and rear axle braking force situation of the target vehicle and improves the pitch suppression effect.

[0123] In some embodiments, braking data includes steering wheel angle and lateral acceleration; if the steering wheel angle is less than or equal to a steering wheel angle threshold, the lateral acceleration is less than or equal to a lateral acceleration threshold, and the braking deceleration is less than or equal to a braking deceleration threshold, the braking data is determined to satisfy the front and rear axle braking force distribution conditions.

[0124] In actual execution, lateral acceleration refers to the acceleration of the target vehicle due to centripetal force during a turn.

[0125] In actual operation, the steering wheel angle threshold, lateral acceleration threshold, and braking deceleration threshold are all preset values.

[0126] In some embodiments, braking data includes steering wheel angle and lateral acceleration; if the steering wheel angle is less than or equal to a steering wheel angle threshold, the lateral acceleration is less than or equal to a lateral acceleration threshold, and the braking deceleration is less than or equal to a braking deceleration threshold, it is determined that the front and rear axle braking force distribution conditions are met, and the process of dividing the target total braking force based on the braking data to obtain the target front axle braking force and the target rear axle braking force is triggered.

[0127] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; when the target braking pitch control mode is a first braking pitch control mode, if the steering wheel angle is less than or equal to a steering wheel angle threshold, the lateral acceleration is less than or equal to a lateral acceleration threshold, and the braking deceleration is less than or equal to a braking deceleration threshold, it is determined that the front and rear axle braking force distribution conditions are met; when the front and rear axle braking force distribution conditions are met, the target front axle braking force and the target rear axle braking force are acquired based on the braking data, so that the target front axle braking force and the target rear axle braking force are generated when the target vehicle meets the front and rear axle braking force distribution conditions, which is more suitable for the actual front and rear axle braking force situation of the target vehicle and improves the pitch suppression effect.

[0128] In some embodiments, when the braking data satisfies the front and rear axle braking force distribution conditions, the upper limit of the front axle braking force and the upper limit of the rear axle braking force are obtained based on the braking data; the target front axle braking force and the target rear axle braking force are obtained based on the braking data, the upper limit of the front axle braking force, and the upper limit of the rear axle braking force.

[0129] In some embodiments, when the braking data meets the front and rear axle braking force distribution conditions, the upper limit of the front axle braking force and the upper limit of the rear axle braking force are obtained based on the braking data, and the product of the upper limit of the rear axle braking force and the preset safety distribution coefficient is obtained as the maximum value of the rear axle braking force; the product between the target total braking force and the target rear axle braking force distribution ratio is determined as the expected rear axle braking force; the minimum value between the expected rear axle braking force and the maximum value of the rear axle braking force is determined as the target rear axle braking force, and the difference between the target total braking force and the target rear axle braking force is determined as the target front axle braking force.

[0130] In some embodiments, the upper limits of the front axle braking force and the rear axle braking force can be obtained respectively using the following formulas:

[0131]

[0132] Among them, F xf F represents the upper limit of front axle braking force. xr Indicated as the upper limit of rear axle braking force, μ f Represents the front wheel ground adhesion coefficient, μ r The coefficient of friction for the rear wheels is represented by l, where l represents the wheelbase of the target vehicle. f The length l represents the distance from the center of gravity of the target vehicle to the front axle. r Let m represent the length from the target vehicle's center of mass to its rear axle, m represent the target vehicle's mass, and g represent the acceleration due to gravity. uf The unsprung mass of the front axle is represented by m. ur The unsprung mass of the rear axle, z uf z represents the unsprung mass displacement at the front axle. ur f represents the unsprung mass displacement at the rear axle. f f represents the suspension force acting on the front axle. r f represents the suspension force acting on the rear axle. f and f r The results can be calculated using the following formulas:

[0133] f f =-k sf (z sf -z uf )-c sf (z sf -z uf )+f af ;

[0134] f r =-k sr (z sr -z ur )-c sf (z sf -z uf )+f ar ;

[0135] Where, k sf k represents the stiffness coefficient of the front suspension. sr z represents the stiffness coefficient of the rear suspension. sf The displacement z represents the sprung mass at the front axle. sr This indicates the displacement at the rear axle due to the sprung mass; z uf The displacement at the front axle represents the unsprung mass, z. ur f represents the displacement at the rear axle of the unsprung mass. af f represents the active force on the front axle of the active suspension. ar This indicates the active force of the rear axle in the active suspension system.

[0136] In some embodiments, after obtaining the upper limits of the front axle braking force and the rear axle braking force, the upper limit of the rear axle braking force can be multiplied by a safety distribution coefficient to obtain the maximum value of the rear axle braking force, and the upper limit of the front axle braking force can be multiplied by a safety distribution coefficient to obtain the maximum value of the front axle braking force. The target total braking force and target rear axle braking force distribution ratio R is then applied. r Multiply the values ​​to obtain the expected rear axle braking force. Compare the expected rear axle braking force with the maximum value of the rear axle braking force, and take the smaller of the two as the target rear axle braking force (for example, if the expected rear axle braking force is less than the maximum value, the expected rear axle braking force is determined as the target rear axle braking force; if the expected rear axle braking force is greater than the maximum value, the maximum value of the rear axle braking force is determined as the target rear axle braking force). The difference between the target total braking force and the target rear axle braking force is determined as the target front axle braking force. The target rear axle braking force distribution ratio is obtained through simulation or real vehicle calibration testing.

[0137] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; when the target braking pitch control mode is a first braking pitch control mode, and the front and rear axle braking force distribution conditions are met when the steering wheel angle is less than or equal to a steering wheel angle threshold, the lateral acceleration is less than or equal to a lateral acceleration threshold, and the braking deceleration is less than or equal to a braking deceleration threshold; when the front and rear axle braking force distribution conditions are met, the upper limit of the front axle braking force and the upper limit of the rear axle braking force are acquired based on the braking data; and the target front axle braking force and the target rear axle braking force are acquired based on the braking data, the upper limit of the front axle braking force, and the upper limit of the rear axle braking force, so that the target front axle braking force and the target rear axle braking force are generated when the target vehicle meets the front and rear axle braking force distribution conditions, which is more suitable for the actual front and rear axle braking force situation of the target vehicle and improves the pitch suppression effect.

[0138] In some embodiments, suspension system parameters for each control phase are obtained based on braking data.

[0139] In some embodiments, the process of braking pitch control based on suspension system parameters can be divided into at least two control stages based on braking data such as brake pedal state, brake master cylinder pressure, braking time, and target vehicle speed, and suspension system parameters for each stage can be obtained.

[0140] In actual execution, the number of control phases can be any value greater than 1.

[0141] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; when the target braking pitch control mode is the second braking pitch control mode, the target suspension damping and target suspension stiffness of each control stage in several control stages are acquired based on the braking data, so as to combine the pitch performance of the target vehicle in different braking stages to perform segmented feedforward control, so that the control of each control stage is more in line with the actual working conditions of the target vehicle in each braking stage, the control is more precise, the response is faster, and the pitch suppression effect is better.

[0142] In some embodiments, the number of control stages is four; the product of the real-time pitch angular velocity and a preset gain coefficient is determined as the target suspension damping of the first control stage, and / or a first stiffness is determined as the target suspension stiffness of the first control stage; the minimum value between the expected damping and a preset lower limit value is determined as the target suspension damping of the second control stage, and / or a second stiffness is determined as the target suspension stiffness of the second control stage; the second stiffness is less than the first stiffness; the maximum value of a preset damping range is determined as the target suspension damping of the third control stage, and / or the first stiffness is determined as the target suspension stiffness of the third control stage; the minimum value of a preset damping range is determined as the target suspension damping of the fourth control stage, and / or the second stiffness is determined as the target suspension stiffness of the fourth control stage.

[0143] In some embodiments, during the first control phase of braking pitch control based on relevant parameters of the suspension system, the product of the real-time pitch angular velocity and a preset gain coefficient is determined as the target suspension damping for the first control phase, and a first stiffness is determined as the target suspension stiffness for the first control phase. The preset gain coefficient is a pre-set value, and the first stiffness is a pre-set value obtained through simulation or real vehicle calibration testing.

[0144] In actual implementation, a damping adjustment coefficient table and a damping lower limit table are preset. The damping adjustment coefficient table stores the correspondence between longitudinal acceleration and preset damping adjustment coefficients, and the damping lower limit table stores the correspondence between longitudinal acceleration and preset damping lower limit values.

[0145] In some embodiments, during the second control stage of braking pitch control based on relevant parameters of the suspension system, a preset damping adjustment coefficient corresponding to the longitudinal acceleration can be found in the damping adjustment coefficient table, and a preset damping lower limit value corresponding to the longitudinal acceleration can be found in the damping lower limit value table.

[0146] In some embodiments, during the second control stage of braking pitch control based on suspension system parameters, the product of the real-time pitch angular velocity and the preset damping adjustment coefficient is obtained as the expected damping. The minimum value between the expected damping and the preset lower limit is determined as the target suspension damping for the second control stage (e.g., if the expected damping is less than the preset lower limit, the expected damping is determined as the target suspension damping for the second control stage; if the expected damping is greater than the preset lower limit, the preset lower limit is determined as the target suspension damping for the second control stage). A second stiffness is also determined as the target suspension stiffness for the second control stage. Both the preset damping adjustment coefficient and the preset lower limit can be set values ​​obtained through simulation or real-vehicle calibration tests. The second stiffness is a preset stiffness value obtained through simulation or real-vehicle calibration tests, and the second stiffness is less than the first stiffness.

[0147] In actual implementation, the preset damping range is a preset range for damping obtained through simulation or real vehicle calibration tests.

[0148] In some embodiments, during the third control stage of braking pitch control based on relevant parameters of the suspension system, the maximum value of the preset damping range is determined as the target suspension damping of the third control stage, and the first stiffness is determined as the target suspension stiffness of the third control stage.

[0149] In some embodiments, during the fourth control stage of braking pitch control based on suspension system parameters, the minimum value of the preset damping range is determined as the target suspension damping of the fourth control stage, and the second stiffness is determined as the target suspension stiffness of the fourth control stage. The third vehicle speed is a vehicle speed value preset based on the vehicle speed, and the third vehicle speed is less than the second vehicle speed.

[0150] In some embodiments, the target vehicle is controlled to enter a first braking phase, during which the damping of the target vehicle's suspension is controlled to be the target suspension damping of the first control phase, and / or the stiffness of the target vehicle is controlled to be a first stiffness; if the braking execution time is greater than or equal to the target braking time, the target vehicle is controlled to enter a second braking phase, during which the damping of the target vehicle's suspension is controlled to be the target suspension damping of the second control phase, and / or the stiffness of the target vehicle is controlled to be a second stiffness; if the vehicle speed is less than or equal to the second vehicle speed, the target vehicle is controlled to enter a third braking phase, during which the damping of the target vehicle's suspension is controlled to be the target suspension damping of the third control phase, and / or the stiffness of the target vehicle is controlled to be a first stiffness; if the vehicle speed is less than or equal to the third vehicle speed, and the execution time of the third control phase is greater than or equal to the target time, the target vehicle is controlled to enter a fourth braking phase, during which the damping of the target vehicle's suspension is controlled to be the target suspension damping of the fourth control phase, and / or the stiffness of the target vehicle is controlled to be a second stiffness; the third vehicle speed is less than the second vehicle speed.

[0151] In some embodiments, when the target brake pitch control mode is determined to be the second brake pitch control mode, a first control phase based on suspension system parameters for brake pitch control is triggered.

[0152] In some embodiments, during the first control phase of braking pitch control based on relevant parameters of the suspension system, the product of the real-time pitch angular velocity and a preset gain coefficient is determined as the target suspension damping for the first control phase, and a first stiffness is determined as the target suspension stiffness for the first control phase. The preset gain coefficient is a pre-set value, and the first stiffness is a pre-set value obtained through simulation or real vehicle calibration testing.

[0153] In some embodiments, if the braking execution time is greater than or equal to the target braking time (e.g., the brake pedal trigger signal or force signal is continuously detected during the target braking time), a second control phase based on suspension system parameters for braking pitch control is triggered.

[0154] In actual implementation, a damping adjustment coefficient table and a damping lower limit table are preset. The damping adjustment coefficient table stores the correspondence between longitudinal acceleration and preset damping adjustment coefficients, and the damping lower limit table stores the correspondence between longitudinal acceleration and preset damping lower limit values.

[0155] In some embodiments, during the second control stage of braking pitch control based on relevant parameters of the suspension system, a preset damping adjustment coefficient corresponding to the longitudinal acceleration can be found in the damping adjustment coefficient table, and a preset damping lower limit value corresponding to the longitudinal acceleration can be found in the damping lower limit value table.

[0156] In some embodiments, during the second control stage of braking pitch control based on suspension system parameters, the product of the real-time pitch angular velocity and the preset damping adjustment coefficient is obtained as the expected damping. The minimum value between the expected damping and the preset lower limit is determined as the target suspension damping for the second control stage (e.g., if the expected damping is less than the preset lower limit, the expected damping is determined as the target suspension damping for the second control stage; if the expected damping is greater than the preset lower limit, the preset lower limit is determined as the target suspension damping for the second control stage). A second stiffness is also determined as the target suspension stiffness for the second control stage. Both the preset damping adjustment coefficient and the preset lower limit can be set values ​​obtained through simulation or real-vehicle calibration tests. The second stiffness is a preset stiffness value obtained through simulation or real-vehicle calibration tests, and the second stiffness is less than the first stiffness.

[0157] In some embodiments, when the vehicle speed is less than or equal to the second vehicle speed, a third control phase is triggered to perform brake pitch control based on relevant parameters of the suspension system.

[0158] In actual implementation, the preset damping range is a preset range for damping obtained through simulation or real vehicle calibration tests.

[0159] In some embodiments, during the third control stage of braking pitch control based on relevant parameters of the suspension system, the maximum value of the preset damping range is determined as the target suspension damping of the third control stage, and the first stiffness is determined as the target suspension stiffness of the third control stage.

[0160] In some embodiments, when the vehicle speed is less than or equal to the third vehicle speed and the time for executing the third control phase is greater than or equal to the target time, a fourth control phase based on suspension system parameters for braking pitch control is triggered.

[0161] In some embodiments, during the fourth control stage of braking pitch control based on suspension system parameters, the minimum value of the preset damping range is determined as the target suspension damping of the fourth control stage, and the second stiffness is determined as the target suspension stiffness of the fourth control stage. The third vehicle speed is a vehicle speed value preset based on the vehicle speed, and the third vehicle speed is less than the second vehicle speed.

[0162] According to the vehicle braking pitch control method of this application embodiment, braking data of the target vehicle is acquired; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; when the target braking pitch control mode is the second braking pitch control mode, the target suspension damping and target suspension stiffness of each control stage in several control stages are acquired based on the braking data, so as to combine the pitch performance of the target vehicle in different braking stages to perform segmented feedforward control, so that the control of each control stage is more in line with the actual working conditions of the target vehicle in each braking stage, the control is more precise, the response is faster, and the pitch suppression effect is better.

[0163] To better understand the vehicle braking pitch control method provided in the embodiments of this application, further explanation is provided below. It should be understood that the following discussion is merely exemplary.

[0164] This application provides a vehicle braking pitch control method, the specific steps of which are as follows: Figure 2 As shown:

[0165] Step 210: Obtain the braking data of the target vehicle.

[0166] In actual execution, the target vehicle can be any type of vehicle.

[0167] In some embodiments, such as Figure 3 As shown, braking data such as brake pedal status, brake master cylinder pressure, real-time pitch angle, real-time pitch angular velocity, braking deceleration, steering wheel angle, and lateral acceleration can be obtained through the target vehicle's internal sensors (such as pressure sensors or any other theoretically feasible sensors).

[0168] In some embodiments, the braking data may also include preset data such as target pitch angle, target pitch rate, and target deceleration.

[0169] In some embodiments, braking data such as road surface slope, road surface bumpiness, and road surface adhesion coefficient can be acquired through a target vehicle's target observation system. The target observation system can be a pre-aiming system.

[0170] In some embodiments, after acquiring the braking data of the target vehicle, it can be determined whether the target vehicle has experienced a braking pitch event. A braking pitch event is a phenomenon in which the vehicle body nods due to braking, such that in the side view, the lateral coordinate axis with the center of gravity of the vehicle body as the origin of the two-dimensional coordinate axis forms an angle with the horizontal line of the ground, and this angle is the pitch angle.

[0171] Step 220: Based on the braking data, determine whether a braking pitch event has occurred.

[0172] In some embodiments, it can be determined whether a brake pitch event has occurred based on braking data such as brake pedal status and brake master cylinder pressure.

[0173] In some embodiments, adjustment control of the braking process of the target vehicle is not triggered in the absence of a braking pitch event.

[0174] In some embodiments, a brake pitch event is determined to have occurred when the brake pedal is in a first state or the brake master cylinder pressure is greater than or equal to a first threshold.

[0175] or

[0176] If the brake pedal is in the second state and the brake master cylinder pressure is less than the first threshold, it is determined that no brake pitch event has occurred.

[0177] In actual operation, the brake pedal status can include the magnitude of the brake pedal force and whether the brake pedal of the target vehicle is pressed. The brake pedal status can reflect the driver's driving intention, namely the magnitude of the braking deceleration and the acceleration of the deceleration.

[0178] In actual execution, the first threshold can be a set value. The first threshold can be a threshold preset based on the brake master cylinder pressure.

[0179] In some embodiments, a brake pitch event is determined to have occurred when the brake master cylinder pressure is greater than or equal to a first threshold. For example, if the first threshold is x0 (bar), a brake pitch event is determined to have occurred when the brake master cylinder pressure is x1 (bar) and x1 > x0.

[0180] Step 230: If a braking pitch event is determined to have occurred, and the braking pitch target can be achieved through the first braking pitch control mode, the first braking pitch control mode is determined as the target braking pitch control mode; the first braking pitch control mode performs braking pitch control based on relevant parameters of the braking system.

[0181] In actual execution, the braking pitch target includes the real-time pitch angle reaching the target pitch angle and the real-time pitch angular velocity reaching the target pitch angular velocity.

[0182] In actual operation, the target pitch angle is a pre-set pitch angle, that is, a pitch angle that does not affect the passenger experience during braking. The target pitch angular velocity is a pre-set pitch angular velocity, that is, a pitch angular velocity that does not affect the passenger experience during braking.

[0183] In some embodiments, a predictive model can be used to predict the pitch angle to be reached after using the first braking pitch control mode, based on the real-time pitch angle in the braking data. Based on the predicted pitch angle and the target pitch angle, it can be determined whether the braking pitch target can be achieved using the first braking pitch control mode. For example, if the predicted pitch angle is less than the target pitch angle, it is determined that the braking pitch target can be achieved using the first braking pitch control mode; if the predicted pitch angle is greater than or equal to the target pitch angle, it is determined that the braking pitch target cannot be achieved using the first braking pitch control mode.

[0184] In some embodiments, a predictive model can be used to predict the pitch rate to be reached after using the first braking pitch control mode, based on the real-time pitch rate in the braking data. Then, based on the predicted pitch rate and the target pitch rate, it can be determined whether the braking pitch target can be achieved using the first braking pitch control mode. For example, if the predicted pitch rate is less than the target pitch rate, it is determined that the braking pitch target can be achieved using the first braking pitch control mode; if the predicted pitch rate is greater than or equal to the target pitch rate, it is determined that the braking pitch target cannot be achieved using the first braking pitch control mode.

[0185] Step 240: If a braking pitch event is determined to have occurred, and the braking pitch target cannot be achieved through the first braking pitch control mode, the second braking pitch control mode is determined as the target braking pitch control mode; the second braking pitch control mode performs braking pitch control based on relevant parameters of the braking system and relevant parameters of the suspension system.

[0186] Step 250: Based on the braking data, determine whether the braking pressure relief control conditions are met; if the braking pressure relief control conditions are met, obtain the target impact intensity and the target total braking force based on the braking data.

[0187] In actual execution, the target total braking force is the total braking force after depressurization.

[0188] In some embodiments, braking data such as master cylinder pressure, braking deceleration, vehicle speed, and road slope can be used to determine whether the brake pressure relief control conditions are met.

[0189] In some embodiments, a table relating brake pedal force, impact, and total braking force can be pre-constructed. When brake pressure relief control conditions are met, based on the brake pedal force, the table can be used to find the target impact corresponding to the brake pedal force and the target total braking force.

[0190] In some embodiments, the target total braking force, target impact force, and deceleration are positively correlated, and this relationship is obtained through calibration tests. The greater the deceleration, the greater the target total braking force and the greater the target impact force. This correlation is obtained through calibration tests to ensure that appropriate braking pressure is provided under different braking requirements, thereby achieving a more comfortable and safer braking effect.

[0191] In some embodiments, when the brake pressure relief control conditions are met, the target impact magnitude is the current impact magnitude of the target vehicle, and the target total braking force is the current total braking force of the target vehicle.

[0192] In some embodiments, the braking data includes brake master cylinder pressure, braking deceleration, vehicle speed, and road slope; when the brake master cylinder pressure is within the braking force relief control range, the braking deceleration is within the preset relief control deceleration range, the absolute value of the road slope is less than the slope threshold, and the vehicle speed is greater than the first vehicle speed, it is determined that the braking pressure relief control conditions are met.

[0193] In actual implementation, the braking force relief control range is a preset range, which can be a range pre-set for the braking force. The preset deceleration control range is also a preset range, which can be a range pre-set for deceleration. The slope threshold can be a preset value, which can be a value pre-set for the road surface slope. The first vehicle speed can be a set value, which can be a set value pre-set based on the vehicle speed.

[0194] In some embodiments, the brake master cylinder pressure can be within the brake force relief control range (e.g., the brake master cylinder pressure falls within the brake force relief control range (P)). L ,P H )), the braking deceleration is within the preset pressure relief control deceleration range (e.g., the braking deceleration is within the preset pressure relief control deceleration range (ax) L ,ax H If the absolute value of the road slope is less than the slope threshold and the vehicle speed is greater than the first vehicle speed, then the brake pressure relief control conditions are met.

[0195] Step 260: Based on the braking data, determine whether the front and rear axle braking force distribution conditions are met; if the front and rear axle braking force distribution conditions are met, obtain the target front axle braking force and the target rear axle braking force based on the braking data.

[0196] In some embodiments, braking data such as steering wheel angle and lateral acceleration can be used to determine whether the front and rear axle braking force distribution conditions are met.

[0197] In some embodiments, if the front and rear axle braking force distribution conditions are not met, the current front axle braking force of the target vehicle can be used as the target front axle braking force, and the current rear axle braking force of the target vehicle can be used as the target rear axle braking force.

[0198] In some embodiments, if the front and rear axle braking force distribution conditions are met, the target total braking force can be divided based on braking data to obtain the target front axle braking force and the target rear axle braking force.

[0199] In some embodiments, braking data includes steering wheel angle and lateral acceleration; if the steering wheel angle is less than or equal to a steering wheel angle threshold, the lateral acceleration is less than or equal to a lateral acceleration threshold, and the braking deceleration is less than or equal to a braking deceleration threshold, it is determined that the front and rear axle braking force distribution conditions are met.

[0200] In actual execution, lateral acceleration refers to the acceleration of the target vehicle due to centripetal force during a turn.

[0201] In actual operation, the steering wheel angle threshold, lateral acceleration threshold, and braking deceleration threshold are all preset values.

[0202] In some embodiments, braking data includes steering wheel angle and lateral acceleration; if the steering wheel angle is less than or equal to a steering wheel angle threshold, the lateral acceleration is less than or equal to a lateral acceleration threshold, and the braking deceleration is less than or equal to a braking deceleration threshold, it is determined that the front and rear axle braking force distribution conditions are met, and the process of dividing the target total braking force based on the braking data to obtain the target front axle braking force and the target rear axle braking force is triggered.

[0203] In some embodiments, when the front and rear axle braking force distribution conditions are met, the upper limit of the front axle braking force and the upper limit of the rear axle braking force are obtained based on braking data; and the target front axle braking force and the target rear axle braking force are obtained based on braking data, the upper limit of the front axle braking force, and the upper limit of the rear axle braking force.

[0204] In some embodiments, the upper limits of the front axle braking force and the rear axle braking force can be obtained respectively using the following formulas:

[0205]

[0206] Among them, F xf F represents the upper limit of front axle braking force. xr Indicated as the upper limit of rear axle braking force, μ f Represents the front wheel ground adhesion coefficient, μ r The coefficient of friction for the rear wheels is represented by l, where l represents the wheelbase of the target vehicle. f The length l represents the distance from the center of gravity of the target vehicle to the front axle. r Let m represent the length from the target vehicle's center of mass to its rear axle, m represent the target vehicle's mass, and g represent the acceleration due to gravity. uf The unsprung mass of the front axle is represented by m. ur The unsprung mass of the rear axle, z uf z represents the unsprung mass displacement at the front axle. ur f represents the unsprung mass displacement at the rear axle. f f represents the suspension force acting on the front axle. r f represents the suspension force acting on the rear axle. f and f r The results can be calculated using the following formulas:

[0207] f f =-k sf (z sf -z uf )-c sf (z sf -z uf )+f af ;

[0208] f r =-k sr (z sr -z ur )-c sf (z sf -z uf )+f ar ;

[0209] Where, k sf k represents the stiffness coefficient of the front suspension. sr z represents the stiffness coefficient of the rear suspension. sf The displacement z represents the sprung mass at the front axle. sr This indicates the displacement at the rear axle due to the sprung mass; z uf The displacement at the front axle represents the unsprung mass, z. ur f represents the displacement at the rear axle of the unsprung mass. af f represents the active force on the front axle of the active suspension. ar This indicates the active force of the rear axle in the active suspension system.

[0210] In some embodiments, after obtaining the upper limits of the front axle braking force and the rear axle braking force, the upper limit of the rear axle braking force can be multiplied by a safety distribution coefficient to obtain the maximum value of the rear axle braking force, and the upper limit of the front axle braking force can be multiplied by the safety distribution coefficient to obtain the maximum value of the front axle braking force. The target total braking force is multiplied by the target rear axle braking force distribution ratio Rr to obtain the expected rear axle braking force. The expected rear axle braking force is compared with the maximum value of the rear axle braking force, and the smaller of the two is taken as the target rear axle braking force (for example, if the expected rear axle braking force is less than the maximum value of the rear axle braking force, the expected rear axle braking force is determined as the target rear axle braking force; if the expected rear axle braking force is greater than the maximum value of the rear axle braking force, the maximum value of the rear axle braking force is determined as the target rear axle braking force). The difference between the target total braking force and the target rear axle braking force is determined as the target front axle braking force. The target rear axle braking force distribution ratio is obtained through simulation or real vehicle calibration testing.

[0211] Step 270: Based on braking data, obtain the target suspension damping and target suspension stiffness for each control stage in several control stages.

[0212] In some embodiments, the process of braking pitch control based on suspension system parameters can be divided into at least two control stages based on braking data such as brake pedal state, brake master cylinder pressure, braking time, and target vehicle speed, and the target suspension damping and target suspension stiffness can be obtained for each stage.

[0213] In actual execution, the number of control phases can be any value greater than 1.

[0214] In some embodiments, the number of control stages is four; based on real-time pitch angular velocity and a preset gain coefficient, the target suspension damping of the first control stage is obtained, and the first stiffness is determined as the target suspension stiffness of the first control stage; when the braking execution time is greater than or equal to the target braking time, based on real-time pitch angular velocity, longitudinal acceleration, a preset damping adjustment coefficient, and a preset damping lower limit, the target suspension damping of the second control stage is obtained, and the second stiffness is determined as the target suspension stiffness of the second control stage; the second stiffness is less than the first stiffness; when the vehicle speed is less than or equal to the second vehicle speed, the maximum value of the preset damping range is determined as the target suspension damping of the third control stage, and the first stiffness is determined as the target suspension stiffness of the third control stage; when the vehicle speed is less than or equal to the third vehicle speed, and the execution time of the third control stage is greater than or equal to the target time, the minimum value of the preset damping range is determined as the target suspension damping of the fourth control stage, and the second stiffness is determined as the target suspension stiffness of the fourth control stage; the third vehicle speed is less than the second vehicle speed.

[0215] In some embodiments, when the target brake pitch control mode is determined to be the second brake pitch control mode, a first control phase based on suspension system parameters for brake pitch control is triggered.

[0216] In some embodiments, during the first control phase of braking pitch control based on relevant parameters of the suspension system, the product of the real-time pitch angular velocity and a preset gain coefficient is obtained as the target suspension damping for the first control phase, and a first stiffness is determined as the target suspension stiffness for the first control phase. The preset gain coefficient is a pre-set value, and the first stiffness is a pre-set value obtained through simulation or real vehicle calibration testing.

[0217] In some embodiments, if the braking execution time is greater than or equal to the target braking time (e.g., the brake pedal trigger signal or force signal is continuously detected during the target braking time), a second control phase based on suspension system parameters for braking pitch control is triggered.

[0218] In actual implementation, a damping adjustment coefficient table and a damping lower limit table are preset. The damping adjustment coefficient table stores the correspondence between longitudinal acceleration and preset damping adjustment coefficients, and the damping lower limit table stores the correspondence between longitudinal acceleration and preset damping lower limit values.

[0219] In some embodiments, during the second control stage of braking pitch control based on relevant parameters of the suspension system, a preset damping adjustment coefficient corresponding to the longitudinal acceleration can be found in the damping adjustment coefficient table, and a preset damping lower limit value corresponding to the longitudinal acceleration can be found in the damping lower limit value table.

[0220] In some embodiments, during the second control stage of braking pitch control based on suspension system parameters, the product of the real-time pitch angular velocity and a preset damping adjustment coefficient is obtained as the expected damping. The expected damping is compared with a preset lower limit value, and the smaller value between the two is taken as the target suspension damping for the second control stage (for example, if the expected damping is less than the preset lower limit value, the expected damping is determined as the target suspension damping for the second control stage; if the expected damping is greater than the preset lower limit value, the preset lower limit value is determined as the target suspension damping for the second control stage). A second stiffness is then determined as the target suspension stiffness for the second control stage. Both the preset damping adjustment coefficient and the preset lower limit value can be set values ​​obtained through simulation or real-vehicle calibration tests. The second stiffness is a preset stiffness value obtained through simulation or real-vehicle calibration tests, and the second stiffness is less than the first stiffness.

[0221] In some embodiments, when the vehicle speed is less than or equal to the second vehicle speed, a third control phase is triggered to perform brake pitch control based on relevant parameters of the suspension system.

[0222] In actual implementation, the preset damping range is a preset range for damping obtained through simulation or real vehicle calibration tests.

[0223] In some embodiments, during the third control stage of braking pitch control based on relevant parameters of the suspension system, the maximum value of the preset damping range is determined as the target suspension damping of the third control stage, and the first stiffness is determined as the target suspension stiffness of the third control stage.

[0224] In some embodiments, when the vehicle speed is less than or equal to the third vehicle speed and the time for executing the third control phase is greater than or equal to the target time, a fourth control phase based on suspension system parameters for braking pitch control is triggered.

[0225] In some embodiments, during the fourth control stage of braking pitch control based on suspension system parameters, the minimum value of the preset damping range is determined as the target suspension damping for the fourth control stage, and the second stiffness is determined as the target suspension stiffness for the fourth control stage. The third vehicle speed is a preset vehicle speed value, which is less than the second vehicle speed.

[0226] In some embodiments, such as Figure 4 As shown in the simulation test results, the control effect of integrating target suspension damping, target suspension stiffness, target total braking force, target impact, target front axle braking force and target rear axle braking force on braking pitch is significantly better than the control effect of a single influencing factor; the more influencing factors in the optimized control, the better the pitch control effect.

[0227] This application provides a vehicle braking pitch control device.

[0228] like Figure 5 As shown, the vehicle braking pitch control device 500 includes a first acquisition module 510, a first determination module 520, a generation module 530, and a control module 540.

[0229] The first acquisition module 510 is used to acquire the braking data of the target vehicle;

[0230] The first determining module 520 is used to determine the target braking pitch control mode based on braking data when a braking pitch event is determined to have occurred.

[0231] The second determining module 530 is used to determine the target pitch control parameters based on the target braking pitch control mode;

[0232] The control module 540 is used to control the braking process of the target vehicle based on the target pitch control parameters.

[0233] According to the vehicle braking pitch control device of this application embodiment, the device acquires braking data of the target vehicle; when a braking pitch event is determined, a target braking pitch control mode is determined based on the braking data; a target pitch control parameter is generated based on the target braking pitch control mode; and the braking process of the target vehicle is controlled based on the target pitch control parameter. The braking process of the target vehicle is comprehensively controlled through the target pitch control parameter, so that the actual pitch of the target vehicle matches the braking pitch target, thereby improving the control effect of vehicle braking pitch phenomenon.

[0234] In some embodiments, braking data includes brake pedal status and brake master cylinder pressure; the vehicle brake pitch control device 500 further includes a third determining module, used for:

[0235] A brake pitch event is determined to have occurred when the brake pedal is in the first state or the brake master cylinder pressure is greater than or equal to the first threshold. The brake pedal being in the first state indicates that the brake pedal of the target vehicle has been depressed.

[0236] or

[0237] If the brake pedal is in the second state and the brake master cylinder pressure is less than the first threshold, it is determined that no brake pitch event has occurred; the brake pedal being in the second state indicates that the brake pedal of the target vehicle has not been depressed.

[0238] In some embodiments, the braking data includes at least one of target pitch angle, target pitch rate, real-time pitch angle, real-time pitch rate, braking deceleration, and target deceleration; the first determining module 420 includes:

[0239] The first determining unit is used to determine the first braking pitch control mode as the target braking pitch control mode when it is determined that a braking pitch event has occurred and the braking pitch target can be achieved through the first braking pitch control mode; the first braking pitch control mode performs braking pitch control based on relevant parameters of the braking system.

[0240] or

[0241] The second determining unit is used to determine the second braking pitch control mode as the target braking pitch control mode when it is determined that a braking pitch event has occurred and the braking pitch target cannot be achieved through the first braking pitch control mode; the second braking pitch control mode performs braking pitch control based on relevant parameters of the braking system and relevant parameters of the suspension system.

[0242] Among them, the braking pitch target includes targets whose real-time pitch angle is less than or equal to the target pitch angle and whose real-time pitch angular velocity is less than or equal to the target pitch angular velocity.

[0243] In some embodiments, the second determining module 530 includes:

[0244] The first generation unit is used to generate relevant parameters of the braking system when the target braking pitch control mode is the first braking pitch control mode; the relevant parameters of the braking system include the target impact intensity, the total braking force of the target, the front axle braking force of the target, and the rear axle braking force of the target.

[0245] The second generation unit is used to generate relevant parameters of the braking system and relevant parameters of the suspension system when the target braking pitch control mode is the second braking pitch control mode; the relevant parameters of the suspension system include the target suspension damping and the target suspension stiffness.

[0246] In some embodiments, the first generating unit is used for:

[0247] When the braking data meets the braking pressure relief control conditions, the target impact intensity and total braking force are obtained based on the braking data.

[0248] In some embodiments, braking data includes master cylinder pressure, braking deceleration, vehicle speed, and road gradient; the first generation unit is used for:

[0249] When the brake master cylinder pressure is within the brake force relief control range, the brake deceleration is within the preset relief control deceleration range, the absolute value of the road slope is less than the slope threshold, and the vehicle speed is greater than the first vehicle speed, the braking data is determined to meet the brake relief control conditions.

[0250] In some embodiments, the first generating unit is used for:

[0251] If the braking data meets the conditions for front and rear axle braking force distribution, the target front axle braking force and the target rear axle braking force are obtained based on the braking data.

[0252] In some embodiments, braking data includes steering wheel angle and lateral acceleration; the first generation unit is used for:

[0253] When the steering wheel angle is less than or equal to the steering wheel angle threshold, the lateral acceleration is less than or equal to the lateral acceleration threshold, and the braking deceleration is less than or equal to the braking deceleration threshold, the braking data is determined to meet the front and rear axle braking force distribution conditions.

[0254] In some embodiments, the first generating unit is used for:

[0255] Based on braking data, the upper limit of front axle braking force and the upper limit of rear axle braking force are obtained, and the product of the upper limit of rear axle braking force and the safety distribution coefficient is obtained as the maximum value of rear axle braking force.

[0256] The product of the target total braking force and the target rear axle braking force distribution ratio is determined as the expected rear axle braking force;

[0257] The minimum value between the expected rear axle braking force and the maximum value of the rear axle braking force is determined as the target rear axle braking force, and the difference between the target total braking force and the target rear axle braking force is determined as the target front axle braking force.

[0258] According to one embodiment of this application, the second generating unit is used for:

[0259] Based on braking data, the target suspension damping and target suspension stiffness are obtained for each of the several control phases.

[0260] In some embodiments, the number of control stages is four; the second generation unit is used for:

[0261] The product of the real-time pitch angular velocity and the preset gain coefficient is determined as the target suspension damping for the first control stage, and / or the first stiffness is determined as the target suspension stiffness for the first control stage.

[0262] The minimum value between the expected damping and the preset lower limit of damping is determined as the target suspension damping for the second control stage, and / or the second stiffness is determined as the target suspension stiffness for the second control stage; the second stiffness is less than the first stiffness.

[0263] The maximum value of the preset damping range is determined as the target suspension damping of the third control stage, and / or the first stiffness is determined as the target suspension stiffness of the third control stage.

[0264] The minimum value of the preset damping range is determined as the target suspension damping for the fourth control stage, and / or the second stiffness is determined as the target suspension stiffness for the fourth control stage.

[0265] According to one embodiment of this application, the control module 540 is used for:

[0266] The target vehicle is controlled to enter the first braking stage. During the first braking stage, the damping of the target vehicle's suspension is controlled to be the target suspension damping of the first control stage, and / or the stiffness of the target vehicle is controlled to be the first stiffness.

[0267] If the braking execution time is greater than or equal to the target braking time, the target vehicle is controlled to enter the second braking stage. In the second braking stage, the damping of the target vehicle's suspension is controlled to be the target suspension damping of the second control stage, and / or the stiffness of the target vehicle is controlled to be the second stiffness.

[0268] When the vehicle speed is less than or equal to the second vehicle speed, the target vehicle is controlled to enter the third braking stage. In the third braking stage, the damping of the target vehicle's suspension is controlled to be the target suspension damping of the third control stage, and / or the stiffness of the target vehicle is controlled to be the first stiffness.

[0269] If the vehicle speed is less than or equal to the third vehicle speed, and the time for executing the third control phase is greater than or equal to the target time, the target vehicle is controlled to enter the fourth braking phase. In the fourth braking phase, the damping of the target vehicle's suspension is controlled to be the target suspension damping of the fourth control phase, and / or the stiffness of the target vehicle is controlled to be the second stiffness; the third vehicle speed is less than the second vehicle speed.

[0270] The vehicle braking pitch control device in this application embodiment can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. The computer can be a terminal or other device besides a terminal. For example, the computer device can be a mobile phone, tablet computer, laptop computer, PDA, in-vehicle electronic device, mobile internet device (MID), augmented reality (AR) / virtual reality (VR) device, robot, wearable device, ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA), etc. It can also be a server, network attached storage (NAS), personal computer (PC), television set (TV), ATM, or self-service machine, etc. This application embodiment does not specifically limit the device.

[0271] The vehicle braking pitch control device in this application embodiment can be a device with an operating system. This operating system can be a Microsoft (Windows) operating system, an Android operating system, an iOS operating system, or other possible operating systems; this application embodiment does not specifically limit it.

[0272] In some embodiments, such as Figure 6 As shown, this application embodiment also provides a controller 600, including a processor 601, a memory 602, and a computer program stored in the memory 602 and executable on the processor 601. When the program is executed by the processor 601, it implements the various processes of the above-described vehicle braking pitch control method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0273] This application provides a vehicle that includes a braking system and the aforementioned controller; to avoid repetition, these will not be described again here.

[0274] It should be noted that the electronic devices in the embodiments of this application include the mobile electronic devices and non-mobile electronic devices described above.

[0275] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described vehicle braking pitch control method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0276] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0277] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described vehicle braking pitch control method.

[0278] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0279] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described vehicle braking pitch control method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0280] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0281] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0282] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0283] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0284] 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 this application. 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.

[0285] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A vehicle braking pitch control method, characterized in that, include: Obtain braking data of the target vehicle; If a braking pitch event is determined to have occurred, a target braking pitch control mode is determined based on the braking data. Based on the target braking pitch control mode, determine the target pitch control parameters; The braking process of the target vehicle is controlled based on the target pitch control parameters.

2. The vehicle braking pitch control method according to claim 1, characterized in that, The braking data includes brake pedal status and brake master cylinder pressure; after acquiring the braking data of the target vehicle, the process includes: A brake pitch event is determined to have occurred when the brake pedal is in the first state or the brake master cylinder pressure is greater than or equal to a first threshold; the brake pedal being in the first state indicates that the brake pedal of the target vehicle is depressed. or If the brake pedal is in the second state and the brake master cylinder pressure is less than the first threshold, it is determined that no brake pitch event has occurred; the brake pedal being in the second state indicates that the brake pedal of the target vehicle has not been depressed.

3. The vehicle braking pitch control method according to claim 1, characterized in that, The braking data includes at least one of the following: target pitch angle, target pitch rate, real-time pitch angle, real-time pitch rate, braking deceleration, and target deceleration. The step of determining a target braking pitch control mode based on the braking data when a braking pitch event is determined to have occurred includes: If a braking pitch event is determined to have occurred, and the braking pitch target can be achieved through the first braking pitch control mode, the first braking pitch control mode is determined as the target braking pitch control mode; the first braking pitch control mode performs braking pitch control based on relevant parameters of the braking system. or If a braking pitch event is determined to have occurred, and the braking pitch target cannot be achieved through the first braking pitch control mode, the second braking pitch control mode is determined as the target braking pitch control mode; the second braking pitch control mode performs braking pitch control based on relevant parameters of the braking system and relevant parameters of the suspension system; The braking pitch target includes targets whose real-time pitch angle is less than or equal to the target pitch angle, and whose real-time pitch angular velocity is less than or equal to the target pitch angular velocity.

4. The vehicle braking pitch control method according to claim 1, characterized in that, The determination of target pitch control parameters based on the target braking pitch control mode includes: When the target braking pitch control mode is the first braking pitch control mode, braking system related parameters are generated; the braking system related parameters include at least one of the target impact force, target total braking force, target front axle braking force and target rear axle braking force. When the target braking pitch control mode is the second braking pitch control mode, the relevant parameters of the braking system are generated, and the relevant parameters of the suspension system are generated; the relevant parameters of the suspension system include the target suspension damping and / or the target suspension stiffness.

5. The vehicle braking pitch control method according to claim 4, characterized in that, The generated braking system parameters include: If the braking data meets the braking pressure relief control conditions, the target impact intensity and the target total braking force are determined based on the braking data.

6. The vehicle braking pitch control method according to claim 5, characterized in that, The braking data includes at least one of the following: master cylinder pressure, braking deceleration, vehicle speed, and road gradient. Before determining the target impact magnitude and the target total braking force based on the braking data, provided that the braking data meets the braking pressure relief control conditions, the method includes: When the brake master cylinder pressure is within the brake force relief control range, the brake deceleration is within the preset relief control deceleration range, the absolute value of the road slope is less than the slope threshold, and the vehicle speed is greater than the first vehicle speed, the braking data is determined to meet the brake relief control conditions.

7. The vehicle braking pitch control method according to claim 4, characterized in that, The generated braking system parameters include: If the braking data satisfies the front and rear axle braking force distribution conditions, the target front axle braking force and the target rear axle braking force are obtained based on the braking data.

8. The vehicle braking pitch control method according to claim 7, characterized in that, The braking data includes steering wheel angle and lateral acceleration; before obtaining the target front axle braking force and the target rear axle braking force based on the braking data, provided that the braking data satisfies the front and rear axle braking force distribution conditions, the method includes: If the steering wheel angle is less than or equal to the steering wheel angle threshold, the lateral acceleration is less than or equal to the lateral acceleration threshold, and the braking deceleration is less than or equal to the braking deceleration threshold, the braking data is determined to meet the front and rear axle braking force distribution conditions.

9. The vehicle braking pitch control method according to claim 7, characterized in that, When the braking data satisfies the front and rear axle braking force distribution conditions, obtaining the target front axle braking force and the target rear axle braking force based on the braking data includes: Based on the braking data, the upper limit of the front axle braking force and the upper limit of the rear axle braking force are obtained, and the product of the upper limit of the rear axle braking force and the preset safety distribution coefficient is obtained as the maximum value of the rear axle braking force. The product of the target total braking force and the target rear axle braking force distribution ratio is determined as the expected rear axle braking force; The minimum value between the expected rear axle braking force and the maximum value of the rear axle braking force is determined as the target rear axle braking force, and the difference between the target total braking force and the target rear axle braking force is determined as the target front axle braking force.

10. The vehicle braking pitch control method according to claim 4, characterized in that, The parameters related to the generated suspension system include: Based on the braking data, the relevant parameters of the suspension system for each of the several control phases are obtained.

11. The vehicle braking pitch control method according to claim 10, characterized in that, The number of control phases is four; based on the braking data, the relevant parameters of the suspension system for each of the several control phases are obtained, including: The product of the real-time pitch angular velocity and the preset gain coefficient is determined as the target suspension damping in the first control stage, and / or the first stiffness is determined as the target suspension stiffness in the first control stage. The product of the real-time pitch angular velocity and the preset damping adjustment coefficient is obtained as the expected damping. The minimum value between the expected damping and the preset damping lower limit is determined as the target suspension damping in the second control stage, and / or the second stiffness is determined as the target suspension stiffness in the second control stage; the second stiffness is less than the first stiffness. The maximum value of the preset damping range is determined as the target suspension damping in the third control stage, and / or the first stiffness is determined as the target suspension stiffness in the third control stage; The minimum value of the preset damping range is determined as the target suspension damping in the fourth control stage, and / or the second stiffness is determined as the target suspension stiffness in the fourth control stage.

12. The vehicle braking pitch control method according to claim 11, characterized in that, The braking process of controlling the target vehicle based on the target pitch control parameters includes: The target vehicle is controlled to enter the first braking stage, and the damping of the target vehicle suspension is controlled to be the target suspension damping of the first control stage during the first braking stage, and / or the stiffness of the target vehicle is controlled to be the first stiffness. If the braking execution time is greater than or equal to the target braking time, the target vehicle is controlled to enter the second braking stage. In the second braking stage, the damping of the target vehicle suspension is controlled to be the target suspension damping of the second control stage, and / or the stiffness of the target vehicle is controlled to be the second stiffness. When the vehicle speed is less than or equal to the second vehicle speed, the target vehicle is controlled to enter the third braking stage. In the third braking stage, the damping of the target vehicle suspension is controlled to be the target suspension damping of the third control stage, and / or the stiffness of the target vehicle is controlled to be the first stiffness. If the vehicle speed is less than or equal to the third vehicle speed, and the time for executing the third control phase is greater than or equal to the target time, the target vehicle is controlled to enter the fourth braking phase. In the fourth braking phase, the damping of the target vehicle suspension is controlled to be the target suspension damping of the fourth control phase, and / or the stiffness of the target vehicle is controlled to be the second stiffness; the third vehicle speed is less than the second vehicle speed.

13. A controller, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the vehicle braking pitch control method according to any one of claims 1-12.

14. A vehicle, characterized in that, The vehicle includes a braking system and a controller as described in claim 13.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the vehicle braking pitch control method according to any one of claims 1-12.

16. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the vehicle braking pitch control method according to any one of claims 1-12.

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