Method and device for determining side slip angle of vehicle and vehicle

Abstract

The invention provides a method and device for determining a vehicle side slip angle and a vehicle. The method comprises the steps that target parameters of the vehicle are obtained; wherein the target parameters comprise the transverse adhesive force and the longitudinal adhesive force of each wheel in the vehicle and the longitudinal vehicle speed of the vehicle; based on the transverse adhesive force and the longitudinal adhesive force, a predicted value of the transverse acceleration of the vehicle is obtained; obtaining a target transverse speed of the vehicle based on the predicted value of the transverse acceleration; and obtaining a side slip angle of the vehicle based on the target transverse vehicle speed and the longitudinal vehicle speed. According to the method, the more accurate target transverse vehicle speed can be obtained, so that the accuracy of the vehicle side slip angle and the calculation precision of the vehicle side slip angle are improved.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to a method, a device and a vehicle for determining a vehicle sideslip angle in the field of vehicles. Background Art

[0002] The vehicle's side slip angle and its changes are one of the important indicators of vehicle stability and an important reference value for vehicle stability control. However, due to the limitations of the test level and test cost of vehicle-mounted sensors, it is difficult to directly measure the vehicle's side slip angle. If the lateral and longitudinal speeds of the vehicle are directly determined by acceleration to determine the vehicle's side slip angle, the error of the vehicle's side slip angle will be large.

[0003] Therefore, how to improve the calculation accuracy of the vehicle sideslip angle is a technical problem that needs to be solved at present. Summary of the invention

[0004] The present application provides a method, device and vehicle for determining a vehicle sideslip angle. The method determines a target lateral speed of the vehicle according to a predicted value of the vehicle's lateral acceleration; and obtains the vehicle's sideslip angle according to the target lateral speed and the longitudinal speed, thereby improving the calculation accuracy of the vehicle's sideslip angle.

[0005] In a first aspect, a method for determining a sideslip angle of a vehicle is provided, the method comprising:

[0006] Obtaining target parameters of the vehicle; wherein the target parameters include lateral adhesion, longitudinal adhesion and longitudinal speed of the vehicle;

[0007] Based on the lateral adhesion and the longitudinal adhesion, a predicted value of the lateral acceleration of the vehicle is obtained;

[0008] Based on the predicted value of the lateral acceleration, a target lateral speed of the vehicle is obtained;

[0009] Based on the target lateral and longitudinal vehicle speeds, the vehicle's sideslip angle is obtained.

[0010] In the embodiment of the present application, the predicted value of lateral acceleration is determined according to the lateral adhesion and longitudinal adhesion of the vehicle; the target lateral speed of the vehicle is determined according to the predicted value of lateral acceleration of the vehicle; and the sideslip angle of the vehicle is obtained according to the target lateral speed and longitudinal speed. Since the predicted value of lateral acceleration is determined according to the lateral adhesion and longitudinal adhesion of the vehicle; therefore, compared with the directly measured lateral acceleration, it is not easily affected by interference factors in the measurement process (for example, interference of yaw motion on the measurement process, interference of uneven road surface on the measurement process, etc.); therefore, determining the target lateral speed according to the predicted value of lateral acceleration can obtain a more accurate target lateral speed; thereby ensuring that a more accurate sideslip angle can be determined according to the longitudinal speed and the more accurate target lateral speed; improving the accuracy of the vehicle sideslip angle and the calculation accuracy of the vehicle sideslip angle.

[0011] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes:

[0012] Obtaining a measurement of the lateral acceleration of the vehicle;

[0013] Based on the predicted value of the lateral acceleration, the target lateral speed of the vehicle is obtained, including:

[0014] A target lateral acceleration is obtained based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration;

[0015] Based on the target lateral acceleration, a target lateral speed of the vehicle is obtained.

[0016] In an embodiment of the present application, a target lateral acceleration is determined based on a measured value of the lateral acceleration and a predicted value of the lateral acceleration; and a target lateral vehicle speed is determined based on the target lateral acceleration; since the predicted value of the lateral acceleration is an acceleration value determined based on an acquired target parameter; if the acquired target parameter is inaccurate, a large error may occur in the predicted value of the lateral acceleration; therefore, the target lateral acceleration is comprehensively determined based on the predicted value of the lateral acceleration and the measured value of the lateral acceleration; ensuring that the obtained target lateral acceleration has a higher accuracy; and further ensuring that a target lateral vehicle speed with a higher accuracy can be obtained based on the target lateral acceleration with a higher accuracy, thereby improving the calculation accuracy of the vehicle sideslip angle.

[0017] In combination with the first aspect and the above implementations, in some implementations of the first aspect, obtaining the target lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration includes:

[0018] Obtaining a first lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration;

[0019] A target lateral acceleration is obtained based on the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed.

[0020] In the embodiment of the present application, the target lateral acceleration is determined according to the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed. When the vehicle is in yaw motion (i.e., rotating around a vertical axis), a lateral vehicle speed component at the center of mass of the vehicle will be caused, i.e., the yaw motion of the vehicle will cause the lateral acceleration of the vehicle to change; therefore, the target lateral acceleration is determined according to the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed, ensuring that the influence of the vehicle's yaw motion on the lateral acceleration is taken into account, thereby ensuring that a more accurate target lateral acceleration is obtained.

[0021] In combination with the first aspect and the above implementations, in some implementations of the first aspect, obtaining the first lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration includes:

[0022] If the acceleration direction indicated by the predicted value of the lateral acceleration is the same as the acceleration direction indicated by the measured value of the lateral acceleration, the lateral acceleration with the smaller absolute value between the predicted value of the lateral acceleration and the measured value of the lateral acceleration is determined as the first lateral acceleration;

[0023] If the acceleration direction indicated by the predicted value of the lateral acceleration is different from the acceleration direction indicated by the measured value of the lateral acceleration, the preset target value is determined as the first lateral acceleration.

[0024] In the embodiments of the present application, since there are certain drift and noise problems when obtaining the measured value of the lateral acceleration, and there is an instantaneous overshoot phenomenon in the measuring device, the measured value may be too large, that is, the measured value of the lateral acceleration is higher than the actual value; therefore, if the predicted value of the lateral acceleration is the same as the acceleration direction indicated by the measured value (for example, the predicted value of the lateral acceleration and the measured value both point to the left side of the vehicle, or both point to the right side of the vehicle), it means that the direction of the lateral acceleration indicated by the predicted value of the lateral acceleration and the measured value is relatively accurate; and the error between the lateral acceleration with a smaller absolute value in the predicted value of the lateral acceleration and the actual lateral acceleration of the vehicle is small; at this time, the lateral acceleration with a smaller absolute value in the predicted value of the lateral acceleration and the measured value is determined as the first lateral acceleration, ensuring that the direction of the obtained first lateral acceleration is the same as the direction of the actual lateral acceleration of the vehicle, and the error of the numerical value of the first lateral acceleration is small. If the directions of the lateral acceleration indicated by the predicted value of the lateral acceleration and the measured value are different, it means that there are large errors between the predicted value and the measured value of the current lateral acceleration. Therefore, the preset target value is determined as the first lateral acceleration. Through the above scheme, it is ensured that the influence of the error (including the measurement error and the calculation error) on the lateral acceleration can be taken into account, and the value with the smaller error between the predicted value and the measured value of the lateral acceleration is selected as the first lateral acceleration, thereby improving the accuracy of the first lateral acceleration.

[0025] In combination with the first aspect and the above implementations, in some implementations of the first aspect, the following further includes:

[0026] Get the wheel angle of each wheel in the vehicle;

[0027] Based on the lateral adhesion and the longitudinal adhesion, the predicted value of the vehicle's lateral acceleration is obtained, including:

[0028] Determine the lateral force of the target axle in the vehicle based on the wheel angle, lateral adhesion and longitudinal adhesion of each wheel;

[0029] Based on the lateral force on the target axis and the mass of the vehicle, the predicted value of the lateral acceleration is determined.

[0030] In the embodiment of the present application, the lateral force of the target axis is determined according to the wheel angle, lateral adhesion and longitudinal adhesion of the vehicle; the lateral force generated by the lateral adhesion and longitudinal adhesion acting on the target axis of the vehicle causes the vehicle to have lateral acceleration. Therefore, the lateral force of the target axis is determined according to the lateral adhesion and longitudinal adhesion and each wheel angle, ensuring that the predicted value of the lateral acceleration can be determined according to the lateral force and the mass of the vehicle.

[0031] In combination with the first aspect and the above implementations, in some implementations of the first aspect, the following further includes:

[0032] Obtain the vehicle speed, the wheel speed of each wheel, the lateral stiffness coefficient and the longitudinal stiffness coefficient;

[0033] Get the target parameters of the vehicle, including:

[0034] Determine the lateral adhesion coefficient and the longitudinal adhesion coefficient of each wheel based on the vehicle speed, wheel speed, lateral stiffness coefficient and longitudinal stiffness coefficient;

[0035] The lateral adhesion and longitudinal adhesion of each wheel are determined based on the lateral adhesion coefficient and the longitudinal adhesion coefficient.

[0036] In the embodiment of the present application, since the adhesion coefficient of each wheel in the vehicle (including the lateral adhesion coefficient and the longitudinal adhesion coefficient) is related to the stiffness coefficient of the wheel (including the lateral stiffness coefficient and the longitudinal stiffness coefficient), that is, when the stiffness coefficient of the vehicle is different, the adhesion coefficient of each wheel is also different. Therefore, according to the vehicle speed, wheel speed, lateral stiffness coefficient and longitudinal stiffness coefficient, the lateral adhesion coefficient and longitudinal adhesion coefficient of each wheel are determined to ensure that the lateral adhesion coefficient and the longitudinal adhesion coefficient can be calculated; and then according to the lateral adhesion coefficient and the longitudinal adhesion coefficient, the lateral adhesion force and the longitudinal adhesion force are obtained.

[0037] In combination with the first aspect and the above implementations, in some implementations of the first aspect, determining the lateral adhesion coefficient and the longitudinal adhesion coefficient of each wheel based on the vehicle speed, the wheel speed, the lateral stiffness coefficient and the longitudinal stiffness coefficient includes:

[0038] Based on the vehicle speed and wheel speed, determine the lateral slip rate and longitudinal slip rate of each wheel;

[0039] Based on the longitudinal slip rate and the longitudinal stiffness coefficient, the longitudinal adhesion coefficient is determined;

[0040] The lateral adhesion coefficient is determined based on the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient.

[0041] In the embodiment of the present application, since the longitudinal adhesion coefficient of the vehicle is related to the longitudinal slip rate and the longitudinal stiffness coefficient of the vehicle, the longitudinal adhesion coefficient is determined according to the longitudinal slip rate and the longitudinal stiffness coefficient to ensure that the longitudinal adhesion coefficient can be obtained. In addition to being related to the lateral slip rate and the lateral stiffness coefficient of the vehicle, the lateral adhesion coefficient of the vehicle is also affected by the longitudinal adhesion coefficient; therefore, the lateral adhesion coefficient is determined according to the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient to ensure that the obtained lateral adhesion coefficient is more accurate.

[0042] In combination with the first aspect and the above implementations, in some implementations of the first aspect, determining the lateral adhesion coefficient based on the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient includes:

[0043] determining a first adhesion coefficient based on the longitudinal adhesion coefficient;

[0044] Determining a second adhesion coefficient based on the lateral slip rate and the lateral stiffness coefficient;

[0045] The smaller value between the first adhesion coefficient and the second adhesion coefficient is determined as the lateral adhesion coefficient.

[0046] In an embodiment of the present application, the second adhesion coefficient is determined according to the lateral slip rate, and the smaller value of the first adhesion coefficient and the second adhesion coefficient corresponding to the longitudinal adhesion coefficient is determined as the lateral adhesion coefficient; ensuring that when determining the lateral adhesion coefficient, the influence of the longitudinal adhesion coefficient on the lateral adhesion coefficient is taken into account.

[0047] In a second aspect, a device for determining a side slip angle of a vehicle is provided, the device comprising:

[0048] An acquisition module, used for acquiring target parameters of the vehicle; wherein the target parameters include the lateral adhesion, longitudinal adhesion and longitudinal speed of the vehicle;

[0049] The processing module is used to obtain a predicted value of a lateral acceleration of the vehicle based on the lateral adhesion and the longitudinal adhesion; obtain a target lateral speed of the vehicle based on the predicted value of the lateral acceleration; and obtain a sideslip angle of the vehicle based on the target lateral speed and the longitudinal speed.

[0050] In combination with the second aspect, in certain implementations of the second aspect, the acquisition module is also used to: obtain a measured value of the vehicle's lateral acceleration; the processing module is specifically used to: obtain a target lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration; and obtain a target lateral speed of the vehicle based on the target lateral acceleration.

[0051] In combination with the second aspect and the above-mentioned implementation methods, in some implementation methods of the second aspect, the processing module is specifically used to: obtain a first lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration; and obtain a target lateral acceleration based on the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed.

[0052] In combination with the second aspect and the above-mentioned implementation methods, in certain implementation methods of the second aspect, the processing module is specifically used to: if the acceleration direction indicated by the predicted value of the lateral acceleration is the same as the acceleration direction indicated by the measured value of the lateral acceleration, determine the lateral acceleration with the smaller absolute value between the predicted value of the lateral acceleration and the measured value of the lateral acceleration as the first lateral acceleration; if the acceleration direction indicated by the predicted value of the lateral acceleration is different from the acceleration direction indicated by the measured value of the lateral acceleration, determine the preset target value as the first lateral acceleration.

[0053] In combination with the second aspect and the above-mentioned implementation methods, in some implementation methods of the second aspect, the acquisition module is also used to: obtain the wheel angle of each wheel in the vehicle; the processing module is specifically used to: determine the lateral force of the target axis in the vehicle based on the wheel angle, lateral adhesion and longitudinal adhesion of each wheel; determine the predicted value of the lateral acceleration based on the lateral force of the target axis and the mass of the vehicle.

[0054] In combination with the second aspect and the above-mentioned implementation methods, in some implementation methods of the second aspect, the acquisition module is also used to: obtain the vehicle speed, the wheel speed of each wheel, the lateral stiffness coefficient and the longitudinal stiffness coefficient; the processing module is specifically used to: determine the lateral adhesion coefficient and the longitudinal adhesion coefficient of each wheel based on the vehicle speed, wheel speed, the lateral stiffness coefficient and the longitudinal stiffness coefficient; determine the lateral adhesion force and the longitudinal adhesion force of each wheel based on the lateral adhesion coefficient and the longitudinal adhesion coefficient.

[0055] In combination with the second aspect and the above-mentioned implementation methods, in some implementation methods of the second aspect, the processing module is specifically used to: determine the lateral slip rate and longitudinal slip rate of each wheel based on the vehicle speed and the wheel speed; determine the longitudinal adhesion coefficient based on the longitudinal slip rate and the longitudinal stiffness coefficient; determine the lateral adhesion coefficient based on the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient.

[0056] In combination with the second aspect and the above-mentioned implementation methods, in some implementation methods of the second aspect, the processing module is specifically used to: determine the first adhesion coefficient based on the longitudinal adhesion coefficient; determine the second adhesion coefficient based on the lateral slip rate and the lateral stiffness coefficient; and determine the smaller value between the first adhesion coefficient and the second adhesion coefficient as the lateral adhesion coefficient.

[0057] In a third aspect, a vehicle is provided, comprising a memory and a processor, wherein the memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the vehicle executes the method in the above-mentioned first aspect or any possible implementation of the first aspect.

[0058] In a fourth aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0059] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed, the method in the above-mentioned first aspect or any possible implementation manner of the first aspect is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a schematic diagram of a kinetic model provided in an embodiment of the present application;

[0061] Figure 2 is a schematic flow chart of a method for determining a vehicle sideslip angle provided in an embodiment of the present application;

[0062] Figure 3 is a schematic flow chart of another method for determining a vehicle sideslip angle provided in an embodiment of the present application;

[0063] Figure 4 is a schematic structural diagram of a device for determining a vehicle sideslip angle provided in an embodiment of the present application;

[0064] Figure 5 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0065] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0066] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0067] Figure 1 It is a schematic diagram of a kinetic model provided in an embodiment of the present application.

[0068] like Figure 1 Schematic diagram of the vehicle dynamics model shown in FIG. 1 ; wherein 110 is the front wheel of the vehicle, 120 is the rear wheel of the vehicle, 130 is the center of mass of the vehicle, and F y_R Indicates the lateral force on the rear axle of the vehicle, F y_F represents the lateral force on the front axle of the vehicle, α r represents the rear wheel turning angle, α f Represents the front wheel turning angle, V y Indicates the lateral speed of the vehicle, V x represents the longitudinal speed of the vehicle, V represents the total speed of the vehicle, β is the side slip angle of the vehicle, and L r Indicates the distance from the rear axle of the vehicle to the center of mass of the vehicle, L f is the distance from the front axle of the vehicle to the center of mass of the vehicle.

[0069] For example, Figure 1 As shown, the side slip angle of the vehicle indicates the longitudinal speed V of the vehicle. x The angle between the vehicle's total velocity V and the side slip angle can be calculated using the following formula:

[0070]

[0071] Since V x Usually a known quantity, a more reliable V can be obtained through sensors and motion dynamics algorithms x Therefore, it is necessary to calculate V y , and according to V y With V x The vehicle's sideslip angle β is calculated using formula 1.

[0072] For example, due to the limitations of the test level and test cost of vehicle-mounted sensors, it is difficult to directly measure the vehicle's side slip angle. If the lateral speed of the vehicle is directly measured and the vehicle side slip angle is determined based on the measured lateral speed and longitudinal speed, the error of the vehicle side slip angle is relatively large.

[0073] For example, if the lateral acceleration of a vehicle is measured by an acceleration sensor, the lateral speed of the vehicle is determined by the lateral acceleration of the vehicle. Since the acceleration sensor is usually installed at a fixed point of the vehicle (such as the bottom of the vehicle body) rather than the position of the center of mass of the vehicle; the vehicle will produce rotational motion (yaw) when turning, and the lateral speed at different positions is not the same. The lateral speed at the location of the acceleration sensor may be amplified or reduced due to the yaw motion, resulting in inaccurate measurement.

[0074] In addition, when the vehicle is turning, the lateral speed changes rapidly. The sensor needs to have a high sampling rate and fast response time to capture these transient changes. If the dynamic response of the sensor is not fast enough, important transient information may be missed, resulting in measurement errors. If the vehicle is driving on an uneven road (for example, potholes, cracks, etc.), it may have a significant impact on the sensor readings, causing the measured lateral speed to contain additional noise. This noise will make the measurement of the lateral speed unstable and difficult to accurately reflect the actual sideslip angle, resulting in a low accuracy of the obtained vehicle sideslip angle.

[0075] Therefore, how to improve the calculation accuracy of the vehicle sideslip angle is a technical problem that needs to be solved at present.

[0076] In view of this, the present application provides a method, device and vehicle for determining the sideslip angle of a vehicle; through the embodiments of the present application, the target lateral speed of the vehicle is determined according to the predicted value of the lateral acceleration of the vehicle; and the sideslip angle of the vehicle is obtained according to the target lateral speed and the longitudinal speed, which can improve the calculation accuracy of the sideslip angle of the vehicle.

[0077] Figure 2 It is a schematic flowchart of a method for determining a vehicle sideslip angle provided in an embodiment of the present application.

[0078] For example, Figure 2 The illustrated method 200 may be performed by a vehicle; or may be performed by a processor or chip in a vehicle.

[0079] like Figure 2 As shown, the method 200 for determining the vehicle sideslip angle includes S210 to S240 , which will be described in detail below.

[0080] S210, obtaining target parameters of the vehicle.

[0081] Among them, the target parameters include the lateral adhesion, longitudinal adhesion and longitudinal speed of each wheel of the vehicle.

[0082] For example, lateral adhesion is used to indicate the friction between each wheel of the vehicle and the road surface in the lateral direction (sideways); lateral adhesion is related to the lateral adhesion coefficient. Longitudinal adhesion refers to the friction between each wheel of the vehicle and the road surface in the longitudinal direction (forward or backward direction); longitudinal adhesion is related to the longitudinal adhesion coefficient of the wheel. The method for determining the lateral adhesion and longitudinal adhesion in the target parameters is described in detail below.

[0083] In one implementation, the vehicle speed, the wheel speed of each wheel, the lateral stiffness coefficient and the longitudinal stiffness coefficient are obtained; based on the vehicle speed, wheel speed, lateral stiffness coefficient and longitudinal stiffness coefficient, the lateral adhesion coefficient and the longitudinal adhesion coefficient of each wheel are determined; based on the lateral adhesion coefficient and the longitudinal adhesion coefficient, the lateral adhesion force and the longitudinal adhesion force of each wheel are determined.

[0084] For example, if the lateral adhesion coefficient of the wheel is Muy and the longitudinal adhesion coefficient is Mux, then when determining the lateral adhesion and longitudinal adhesion of each wheel, the lateral adhesion F of the wheel can be determined by using Formula 2: 车轮-y , and use Formula 3 to determine the longitudinal adhesion F of the wheel 车轮-x .

[0085] F 车轮-y =Muy 车轮 ×F z ; (Formula 2)

[0086] F 车轮-x =Mux 车轮 ×F z ; (Formula 3)

[0087] Among them, F 车轮-y Indicates the lateral adhesion of the wheel, F 车轮-x Indicates longitudinal adhesion, Muy 车轮 Represents the lateral adhesion coefficient of the wheel, Mux 车轮 Indicates the longitudinal adhesion coefficient of the wheel, F z Represents the vertical force of the vehicle.

[0088] It should be noted that F z is a known quantity, Muy 车轮 With Mux 车轮 It is a value calculated based on the vehicle speed, the wheel speed of each wheel, the lateral stiffness coefficient and the longitudinal stiffness coefficient.

[0089] Optionally, since the lateral adhesion coefficients and longitudinal adhesions of different wheels in the vehicle may be different, the lateral adhesion and longitudinal adhesion of each wheel are determined according to the lateral adhesion coefficients and longitudinal adhesion coefficients of each wheel.

[0090] For example, taking the right front wheel FR as an example, the lateral adhesion of the right front wheel of the vehicle is F FR-y , the longitudinal adhesion of the right front wheel F FR-x , if the lateral adhesion coefficient of the right front wheel of the vehicle is Muy FR ; According to Formula 2, F FR-y =Muy FR ×F z ; If the longitudinal adhesion coefficient of the right front wheel of the vehicle is Mux FR ; According to Formula 3, the longitudinal adhesion of the right front wheel of the vehicle is F FR-x =Mux FR ×F z .

[0091] It should be noted that the lateral adhesion F of each wheel in the vehicle (including the left front wheel FL of the vehicle, the right rear wheel RR of the vehicle, and the left rear wheel RL of the vehicle) is 车轮-y With longitudinal adhesion F 车轮-x The calculation is similar to that of the right front wheel FR and will not be repeated here.

[0092] In the embodiment of the present application, since the adhesion coefficient of each wheel in the vehicle (including the lateral adhesion coefficient and the longitudinal adhesion coefficient) is related to the stiffness coefficient of the wheel (including the lateral stiffness coefficient and the longitudinal stiffness coefficient), that is, when the stiffness coefficient of the vehicle is different, the adhesion coefficient of each wheel is also different. Therefore, according to the vehicle speed, wheel speed, lateral stiffness coefficient and longitudinal stiffness coefficient, the lateral adhesion coefficient and longitudinal adhesion coefficient of each wheel are determined to ensure that the lateral adhesion coefficient and the longitudinal adhesion coefficient can be calculated; and then according to the lateral adhesion coefficient and the longitudinal adhesion coefficient, the lateral adhesion force and the longitudinal adhesion force are obtained.

[0093] The method for determining the lateral adhesion coefficient and the longitudinal adhesion coefficient is further explained below.

[0094] In one implementation, the lateral adhesion coefficient and the longitudinal adhesion coefficient of each wheel are determined based on the vehicle speed, the wheel speed, the lateral stiffness coefficient and the longitudinal stiffness coefficient, including:

[0095] Based on the vehicle speed and wheel speed, the lateral slip rate and longitudinal slip rate of each wheel are determined; based on the longitudinal slip rate and the longitudinal stiffness coefficient, the longitudinal adhesion coefficient is determined; based on the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient, the lateral adhesion coefficient is determined.

[0096] Exemplarily, when determining the longitudinal slip rate and the lateral slip rate, the lateral vehicle speed of each wheel and the longitudinal vehicle speed of the wheel are determined, and the longitudinal wheel speed of the wheel is determined based on the lateral vehicle speed of the wheel and the longitudinal vehicle speed of the wheel; and the longitudinal slip rate of the vehicle is determined based on the longitudinal vehicle speed of the wheel and the vehicle speed; the lateral slip rate is determined based on the lateral vehicle speed of the wheel and the longitudinal vehicle speed of the wheel.

[0097] Specifically, the lateral speed of each wheel is calculated using the following formula 4, and the longitudinal speed of each wheel is calculated using formula 5:

[0098] V 车轮-y _=V yK1 +YawRate×L; (Formula 4)

[0099] V 车轮-x =V x +YawRate×B; (Formula 5)

[0100] Among them, V 车轮-y is the lateral speed of each wheel, V yK1 The vehicle's lateral speed calculated in the previous cycle, YawRate is the vehicle's yaw rate, L is the wheelbase from the vehicle's center of mass to the target axis (the vehicle's front or rear axle), V 车轮-x is the longitudinal speed of each wheel, V x is the longitudinal speed of the vehicle, and B is half of the vehicle's wheelbase.

[0101] Exemplarily, when the target axis is the front axis, L is Figure 1 L shown f ; When the target axis is the rear axis, L is Figure 1 L shown r .

[0102] For example, after obtaining the lateral speed V of each wheel 车轮-y The longitudinal speed V of each wheel 车轮-x After that, V 车轮-y With V 车轮-x Substituting into formula 6, the longitudinal wheel speed of each wheel is calculated:

[0103] V 车轮轮速-x =V 车轮-x ×cosα 车轮 -V 车轮-y ×sinα 车轮 ; (Formula 6)

[0104] Among them, V 车轮轮速-x Indicates the longitudinal wheel speed of each wheel, V 车轮-x represents the longitudinal speed of each wheel, α 车轮 represents the wheel angle of each wheel, cosα 车轮 Represents the cosine value of the wheel angle, sinα车轮 Represents the sine of the wheel angle.

[0105] Exemplarily, the longitudinal wheel speed of the wheel and the vehicle speed obtained from Formula 6 are substituted into Formula 7 to calculate the longitudinal slip rate of the vehicle:

[0106]

[0107] Among them, η X Indicates the longitudinal slip rate of the wheel, V 车轮轮速-x represents the longitudinal wheel speed of each wheel, and V represents the vehicle speed (actual vehicle speed).

[0108] Exemplarily, the lateral speed of each wheel obtained according to Formula 4 and the longitudinal speed of each wheel obtained according to Formula 5 are substituted into Formula 8 to obtain the lateral slip rate of the vehicle:

[0109] η y =V 车轮-y ÷V 车轮-x ; (Formula 8)

[0110] Among them, ηy represents the lateral slip rate of the wheel, V 车轮-y Indicates the lateral speed of each wheel of the vehicle, V 车轮-x Indicates the longitudinal speed of each wheel of the vehicle.

[0111] Exemplarily, after the lateral slip rate and the longitudinal slip rate of the wheel are obtained, the longitudinal adhesion coefficient is determined according to the longitudinal slip rate and the longitudinal stiffness coefficient, and the lateral adhesion coefficient is determined according to the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient.

[0112] Specifically, according to the longitudinal slip rate and the longitudinal stiffness coefficient, the longitudinal adhesion coefficient of the wheel is determined using Formula 9:

[0113] Mux 车轮 =η X ×C x ; (Formula 9)

[0114] Among them, Mux 车轮 is the longitudinal adhesion coefficient of the wheel, η X is the longitudinal slip rate of the wheel, C x is the longitudinal stiffness coefficient of the wheel.

[0115] Exemplarily, when determining the lateral adhesion coefficient, the lateral adhesion coefficient of the wheel is comprehensively determined based on the longitudinal adhesion coefficient, lateral slip rate and lateral stiffness coefficient of the wheel.

[0116] It should be noted that since the friction between the tire and the ground has a limit value, beyond which the tire will begin to slide, the lateral adhesion coefficient of the vehicle is related to the longitudinal adhesion coefficient of the vehicle and the lateral friction and longitudinal friction; therefore, there is the following relationship between the lateral adhesion coefficient and the longitudinal adhesion coefficient (Mux 车轮 ) 2 +(Muy 车轮 ) 2 ≤TBD value; where TBD value is the value obtained in advance testing.

[0117] In the embodiment of the present application, since the longitudinal adhesion coefficient of the vehicle is related to the longitudinal slip rate and the longitudinal stiffness coefficient of the vehicle, the longitudinal adhesion coefficient is determined according to the longitudinal slip rate and the longitudinal stiffness coefficient to ensure that the longitudinal adhesion coefficient can be obtained. In addition to being related to the lateral slip rate and the lateral stiffness coefficient of the vehicle, the lateral adhesion coefficient of the vehicle is also affected by the longitudinal adhesion coefficient; therefore, the lateral adhesion coefficient is determined according to the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient to ensure that the obtained lateral adhesion coefficient is more accurate.

[0118] Exemplarily, when determining the lateral adhesion coefficient, a first adhesion coefficient is determined based on the longitudinal adhesion coefficient; a second adhesion coefficient is determined based on the lateral slip rate and the lateral stiffness coefficient; and a smaller value between the first adhesion coefficient and the second adhesion coefficient is determined as the lateral adhesion coefficient.

[0119] Exemplarily, the first adhesion coefficient is obtained according to the longitudinal adhesion coefficient and the relationship between the lateral adhesion coefficient and the longitudinal adhesion coefficient; the first adhesion coefficient represents the maximum value Muy of the lateral adhesion coefficient. 车轮 max; According to the lateral slip rate and the lateral stiffness coefficient, the second adhesion coefficient is calculated using formula 10:

[0120] muy 车轮 =η y ×C y ; (Formula 10)

[0121] Among them, muy 车轮 is the second adhesion coefficient of each wheel, η y is the lateral slip rate of the wheel, C y is the lateral stiffness coefficient of the wheel.

[0122] If the second adhesion coefficient is less than the first adhesion coefficient, the second adhesion coefficient muy 车轮 Determined as the lateral adhesion coefficient Muy 车轮 If the second adhesion coefficient is greater than the first adhesion coefficient, then the first adhesion coefficient Muy 车轮max Determined as the lateral adhesion coefficient Muy 车轮 .

[0123] In an embodiment of the present application, the second adhesion coefficient is determined according to the lateral slip rate, and the smaller value of the first adhesion coefficient and the second adhesion coefficient corresponding to the longitudinal adhesion coefficient is determined as the lateral adhesion coefficient; ensuring that when determining the lateral adhesion coefficient, the influence of the longitudinal adhesion coefficient on the lateral adhesion coefficient is taken into account.

[0124] S220: Obtain a predicted value of the lateral acceleration of the vehicle based on the lateral adhesion and the longitudinal adhesion.

[0125] Exemplarily, the lateral adhesion is calculated according to Formula 2, and the longitudinal adhesion is calculated according to Formula 3; the lateral force of the target axis of the vehicle is calculated according to the lateral adhesion and the longitudinal adhesion, and the predicted value of the lateral acceleration is determined according to the lateral force. The method for determining the predicted value of the lateral acceleration is described in detail below.

[0126] In one implementation, the wheel angle of each wheel in the vehicle is obtained; based on the wheel angle, lateral adhesion and longitudinal adhesion of each wheel, the lateral force of a target axis in the vehicle is determined; based on the lateral force of the target axis and the mass of the vehicle, a predicted value of the lateral acceleration is determined.

[0127] The target axis is the driven axis of the vehicle. If the vehicle is a rear-wheel drive vehicle, the driven axis of the vehicle is the front axis of the vehicle, and the front axis is the target axis. If the vehicle is a front-wheel drive vehicle, the driven axis of the vehicle is the rear axis of the vehicle, and the rear axis is the target axis.

[0128] It should be noted that since the driving shaft is mainly responsible for providing driving force, the driven shaft of the vehicle is less affected by interference factors than the driving shaft. The driven shaft is determined as the target shaft, and the predicted value of the vehicle's lateral acceleration is determined based on the lateral force of the driven shaft to ensure that the predicted value of the lateral acceleration is less affected by interference factors, that is, to ensure that a more accurate predicted value of the lateral acceleration is obtained.

[0129] Exemplarily, the wheel angle, lateral adhesion and longitudinal adhesion of each wheel are obtained. If the target axis is the front axle, the lateral force of the front axle of the vehicle is calculated using formula 11:

[0130] F 前轴-y =F 前轮-x ×sinα 前轮 +F 前轮-y ×cosα 前轮 ; (Formula 11)

[0131] Among them, F 前轴-y is the lateral force on the front axle of the vehicle, F 前轮-x is the longitudinal adhesion of the vehicle's front wheels, including the left front wheel FL and the right front wheel FR; α 前轮 is the turning angle of the front wheels of the vehicle, F前轮-y represents the lateral adhesion of the front wheel, sinα 前轮 Represents the sine value of the front wheel steering angle, cosα 前轮 Represents the cosine of the front wheel steering angle.

[0132] In a possible implementation, if the longitudinal adhesion of the left front wheel of the vehicle is F FL-x , the lateral adhesion of the left front wheel of the vehicle is F FL-y , the turning angle of the left front wheel of the vehicle is α FL ; The longitudinal adhesion of the right front wheel is F FR-x , the lateral adhesion of the right front wheel of the vehicle is F FR-y , the turning angle of the right front wheel of the vehicle is α FR ; Then the lateral force F on the front axle of the vehicle 前轴-y =F FL-x ×sinα FL +F FL-y ×cosα FL +F FR-x ×sinα FR +F FR-y ×cosα FR .

[0133] For example, if the vehicle is a front-wheel drive vehicle and the target axis is the rear axle, the lateral force on the rear axle of the vehicle is calculated using Formula 12:

[0134] F 后轴-y =F 后轮-x ×sinα 后轮 +F 后轮-y ×cosα 后轮 ; (Formula 12)

[0135] Among them, F 后轴-y is the lateral force on the rear axle of the vehicle, F 后轮-x is the longitudinal adhesion of the rear wheels of the vehicle, including the left rear wheel RL and the right front wheel RR; α 后轮 is the turning angle of the rear wheels of the vehicle, F 后轮-y Represents the lateral adhesion of the rear wheel, sinα 后轮 Represents the sine value of the rear wheel steering angle, cosα 后轮 Represents the cosine of the rear wheel steering angle.

[0136] In a possible implementation, if the longitudinal adhesion of the left rear wheel of the vehicle is F RL-x , the lateral adhesion of the left rear wheel of the vehicle is F RL-y , the turning angle of the left rear wheel of the vehicle is α RL ; The longitudinal adhesion of the right rear wheel is F RR-x , the lateral adhesion of the right rear wheel of the vehicle is F RR-y , the turning angle of the right rear wheel of the vehicle is α RR; Then the lateral force F on the rear axle of the vehicle 后轴-y =F RL-x ×sinα RL +F RL-y ×cosα RL +F RR-x ×sinα RR +F RR-y ×cosα RR .

[0137] In one possible implementation, the turning angles of the front wheels of the vehicle (including the left front wheel and the right front wheel) remain consistent; the turning angles of the rear wheels of the vehicle (including the left rear wheel and the right rear wheel) remain consistent. In this case, α FL With α FR correspond Figure 1 The front wheel turning angle α f ; α RL With α RR correspond Figure 1 The rear wheel turning angle α r .

[0138] It should be noted that the turning angle of each wheel in the vehicle is directly measured, and the lateral adhesion and longitudinal adhesion of each wheel of the vehicle are calculated by the relevant formula in S210. The turning angle of each wheel and the lateral adhesion and longitudinal adhesion of each wheel are substituted into the above formula 11 or formula 12 to calculate the lateral force of the target axis.

[0139] Optionally, the lateral force of the target axis and the mass of the vehicle are determined; if the target axis is the front axis, the predicted value of the lateral acceleration of the vehicle is determined using Formula 13. If the target axis is the rear axis, the predicted value of the lateral acceleration of the vehicle is determined using Formula 14:

[0140] a y =F 前轴-y ÷M 车辆 ; (Formula 13)

[0141] a y =F 后轴-y ÷M 车辆 ; (Formula 14)

[0142] Where, ay is the predicted value of lateral acceleration, F 前轴-y is the lateral force on the front axle of the vehicle, F 后轴-y is the lateral force on the rear axle of the vehicle, M 车辆 The quality of the vehicle.

[0143] In the embodiment of the present application, the lateral force of the target axis is determined according to the wheel angle, lateral adhesion and longitudinal adhesion of the vehicle; the lateral force generated by the lateral adhesion and longitudinal adhesion acting on the target axis of the vehicle causes the vehicle to have lateral acceleration. Therefore, the lateral force of the target axis is determined according to the lateral adhesion and longitudinal adhesion and each wheel angle, ensuring that the predicted value of the lateral acceleration can be determined according to the lateral force and the mass of the vehicle.

[0144] S230: Obtain a target lateral speed of the vehicle based on the predicted value of the lateral acceleration.

[0145] Exemplarily, a target lateral acceleration is determined according to the predicted value of the lateral acceleration, and an integration operation is performed on the target lateral acceleration to obtain a target lateral vehicle speed of the vehicle.

[0146] In one implementation, a measured value of a lateral acceleration of the vehicle is obtained; a target lateral acceleration is obtained based on the measured value of the lateral acceleration and a predicted value of the lateral acceleration; and a target lateral speed of the vehicle is obtained based on the target lateral acceleration.

[0147] For example, the measured value of the lateral acceleration may be obtained by an acceleration sensor installed in the vehicle.

[0148] Exemplarily, a target lateral acceleration is determined based on a measured value of the lateral acceleration and a predicted value of the lateral acceleration; and a target lateral vehicle speed is determined based on the target lateral acceleration; since the predicted value of the lateral acceleration is an acceleration value determined based on an acquired target parameter; if the acquired target parameter is inaccurate, a large error may occur in the predicted value of the lateral acceleration; therefore, the target lateral acceleration is comprehensively determined based on the predicted value of the lateral acceleration and the measured value of the lateral acceleration; ensuring that the obtained target lateral acceleration has a higher accuracy; and further ensuring that a target lateral vehicle speed with a higher accuracy can be obtained based on the target lateral acceleration with a higher accuracy, thereby improving the calculation accuracy of the vehicle sideslip angle.

[0149] In the embodiment of the present application, the measured value of the lateral acceleration obtained by the acceleration sensor and the predicted value of the lateral acceleration obtained by calculation are obtained; the target lateral acceleration of the vehicle is comprehensively determined based on the measured value and the predicted value. Since the measured value and the predicted value are integrated and restricted to a certain extent, when the signs are the same, the error of the lateral acceleration corresponding to the smaller value is smaller; therefore, the smaller value is determined as the target lateral acceleration. It is ensured that when there are errors in both the predicted value and the measured value, the target lateral acceleration with a smaller error can be determined, thereby improving the robustness and accuracy of the sideslip angle calculation.

[0150] In one implementation, the target lateral acceleration is obtained based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration, including: obtaining the first lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration; obtaining the target lateral acceleration based on the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed.

[0151] Exemplarily, if the acceleration direction indicated by the predicted value of the lateral acceleration is the same as the acceleration direction indicated by the measured value of the lateral acceleration, the lateral acceleration with the smaller absolute value between the predicted value of the lateral acceleration and the measured value of the lateral acceleration is determined as the first lateral acceleration; if the acceleration direction indicated by the predicted value of the lateral acceleration is different from the acceleration direction indicated by the measured value of the lateral acceleration, the preset target value is determined as the first lateral acceleration.

[0152] For example, lateral acceleration refers to the acceleration component perpendicular to the driving direction generated by the vehicle during a turn, which is used to measure the lateral force or steering performance of the vehicle, and the direction of the lateral acceleration is usually the same as the direction of the lateral force when the vehicle turns. For example, if the vehicle turns right, the lateral acceleration points to the left side of the vehicle; if the vehicle turns left, the lateral acceleration points to the right side of the vehicle.

[0153] Optionally, the direction of the lateral acceleration can be indicated by the positive or negative value of the lateral acceleration; for example, if the right side of the vehicle is positive; when the vehicle turns right, the lateral acceleration points to the left side of the vehicle, then the lateral acceleration is negative; when the vehicle turns left, the lateral acceleration points to the right side of the vehicle, then the lateral acceleration is positive.

[0154] It should be noted that since the sensor is easily affected by interference factors when measuring the lateral acceleration of the vehicle, the measured value of the vehicle's lateral acceleration is usually greater than the actual lateral acceleration. For example, when the vehicle turns, it will produce rotational motion (yaw), and the lateral acceleration at different positions is not the same. As a result, the lateral acceleration at the location of the sensor may be amplified due to the yaw motion, that is, the measured value is greater than the actual lateral acceleration. The acceleration sensor may have certain drift and noise problems, and the noise and drift will cause the sensor reading to be higher than the actual lateral acceleration. Under rapidly changing dynamic conditions (such as emergency avoidance or sharp steering), the dynamic response characteristics of the sensor may cause instantaneous overshoot, that is, the measured value is temporarily higher than the actual value. When the vehicle yaws and accelerates laterally at the same time, the sensor may capture additional acceleration components, resulting in a higher measured value. If the vehicle vibrates due to uneven road surface, the vibration may be superimposed on the sensor reading, causing the measured value to be higher.

[0155] For example, when obtaining the measured value of the lateral acceleration, there are certain drift and noise problems, and the measuring device has an instantaneous overshoot phenomenon, which may cause the measured value to be too large, that is, the measured value of the lateral acceleration is higher than the actual value; therefore, when the direction of the lateral acceleration indicated by the predicted value of the lateral acceleration is the same as that indicated by the measured value (for example, the lateral accelerations both point to the left side of the vehicle, or the lateral accelerations both point to the right side of the vehicle), it means that the direction of the lateral acceleration indicated by the predicted value of the lateral acceleration and the measured value is relatively accurate; and the error between the lateral acceleration with a smaller absolute value in the predicted value of the lateral acceleration and the actual lateral acceleration of the vehicle is small; at this time, the lateral acceleration with a smaller absolute value in the predicted value of the lateral acceleration and the measured value is determined as the first lateral acceleration, ensuring that the direction of the obtained first lateral acceleration is the same as the direction of the actual lateral acceleration of the vehicle, and the error of the numerical value of the first lateral acceleration is small.

[0156] It should be noted that interference factors may cause errors between the measured value or predicted value and the true value. If the predicted value of the lateral acceleration is different from the direction of the lateral acceleration indicated by the measured value, it means that there are large errors between the predicted value and the measured value of the current lateral acceleration. Therefore, the preset target value is determined as the first lateral acceleration; the target value can be a zero value, which ensures that when there are large errors between the predicted value and the measured value of the lateral acceleration, the value with a large error can be avoided from being determined as the first lateral acceleration.

[0157] For example, if the measured lateral acceleration has the same acceleration direction as the predicted value (both pointing to the left side of the vehicle), and the measured lateral acceleration is 30 km / s 2 , the predicted value of lateral acceleration is 20km / s 2 , the predicted value is less than the measured value, indicating that the predicted value is more accurate; therefore, the predicted value is used as the first lateral acceleration, and the target lateral acceleration is determined based on the first lateral acceleration. If the measured value of the lateral acceleration is 30km / s 2 , the predicted value of lateral acceleration is 40km / s 2 ; Since the predicted value is greater than the measured value, and the actual lateral acceleration of the vehicle is usually less than the measured value, the error between the current predicted value result and the actual lateral acceleration is too large, and the error is greater than the error between the measured value and the actual lateral acceleration; therefore, the measured value with a smaller error is determined as the first lateral acceleration, and the target lateral acceleration is determined based on the first lateral acceleration.

[0158] It should be noted that the above are examples of measured values ​​and predicted values ​​of lateral acceleration, and the present application does not limit the specific values.

[0159] In the embodiment of the present application, the target lateral acceleration is determined according to the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed. When the vehicle is in yaw motion (i.e., rotating around a vertical axis), a lateral vehicle speed component at the center of mass of the vehicle will be caused, i.e., the yaw motion of the vehicle will cause the lateral acceleration of the vehicle to change; therefore, the target lateral acceleration is determined according to the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed, ensuring that the influence of the vehicle's yaw motion on the lateral acceleration is taken into account; thereby improving the accuracy of the obtained target lateral acceleration.

[0160] For example, after the first lateral acceleration is obtained, the target lateral acceleration is determined according to the yaw rate, the longitudinal vehicle speed and the first lateral acceleration. The target lateral acceleration can be calculated using the following formula 15:

[0161] dV y =a y '+YawRate*V x ; (Formula 15)

[0162] Among them, dV y V y The differential of the target lateral acceleration; a y ' is the first lateral acceleration of the vehicle, YawRate is the vehicle yaw rate, V x is the longitudinal speed of the vehicle.

[0163] For example, for dV y The target lateral speed of the vehicle is obtained by integrating the values ​​over time.

[0164] S240: Obtain a sideslip angle of the vehicle based on the target lateral vehicle speed and the target longitudinal vehicle speed.

[0165] Exemplarily, the target lateral speed and longitudinal speed of the vehicle are determined, and substituted into Formula 1 to calculate the sideslip angle of the vehicle.

[0166] Optionally, after the target lateral speed of the vehicle is calculated, the target lateral speed is stored so that in the next calculation cycle, the stored target lateral speed is substituted into Formula 4 to calculate the lateral speed of each wheel in the next cycle.

[0167] In the above embodiment, the predicted value of lateral acceleration is determined according to the lateral adhesion and longitudinal adhesion of the vehicle; the target lateral speed of the vehicle is determined according to the predicted value of lateral acceleration of the vehicle; and the sideslip angle of the vehicle is obtained according to the target lateral speed and longitudinal speed. Since the predicted value of lateral acceleration is determined according to the lateral adhesion and longitudinal adhesion of the vehicle; therefore, compared with the directly measured lateral acceleration, it is not easily affected by interference factors in the measurement process (for example, interference of yaw motion on the measurement process, interference of uneven road surface on the measurement process, etc.); therefore, determining the target lateral speed according to the predicted value of lateral acceleration can obtain a more accurate target lateral speed; thereby ensuring that a more accurate sideslip angle can be determined according to the longitudinal speed and the more accurate target lateral speed; improving the accuracy of the vehicle sideslip angle and the calculation precision of the vehicle sideslip angle.

[0168] Figure 3 It is a schematic flowchart of another method for determining the sideslip angle of a vehicle provided in an embodiment of the present application.

[0169] Figure 3 The illustrated method 300 may be performed by a vehicle; or may be performed by a processor or chip in a vehicle.

[0170] like Figure 3 The method 300 for determining the vehicle sideslip angle includes S301 to S313 , which are described in detail below.

[0171] S301, obtaining the vehicle speed, the wheel speed of each wheel, the lateral stiffness coefficient and the longitudinal stiffness coefficient.

[0172] Exemplarily, the vehicle speed is obtained according to the vehicle speed sensor, which is the actual speed of the vehicle when traveling; the wheel speed of each wheel is obtained according to the wheel speed sensor installed at each wheel; and the lateral stiffness coefficient and the longitudinal stiffness coefficient of each wheel are obtained.

[0173] Exemplarily, the lateral stiffness coefficient and longitudinal stiffness coefficient of a wheel are parameters that describe the deformation characteristics of a tire when subjected to lateral force and longitudinal force; wherein the lateral stiffness coefficient refers to the stiffness characteristic of a tire when subjected to lateral force (lateral force), and indicates the amount of lateral deformation of the tire caused by a unit lateral force. It reflects the tire's ability to resist deformation under the action of lateral force. The longitudinal stiffness coefficient of a wheel refers to the stiffness characteristic of a tire when subjected to longitudinal force (such as driving force or braking force), and indicates the amount of longitudinal deformation of the tire caused by a unit longitudinal force, and reflects the tire's ability to resist deformation under the action of longitudinal force.

[0174] It should be noted that the lateral stiffness coefficient and the longitudinal stiffness coefficient of the wheel are properties of the wheel and can be measured in advance and stored in the vehicle.

[0175] S302, determining the lateral adhesion coefficient and the longitudinal adhesion coefficient of the vehicle according to the vehicle speed, the wheel speed, the lateral stiffness coefficient and the longitudinal stiffness coefficient.

[0176] Exemplarily, the lateral slip rate and longitudinal slip rate of the wheel are determined according to the vehicle speed and the wheel speed; the longitudinal adhesion coefficient is determined according to the longitudinal slip rate and the longitudinal stiffness coefficient; and the lateral adhesion coefficient is determined according to the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient.

[0177] Optionally, the implementation of S302 can refer to Figure 2 The relevant description of determining the lateral adhesion coefficient and the longitudinal adhesion coefficient is not repeated here.

[0178] S303: Determine the lateral adhesion and longitudinal adhesion of each wheel according to the lateral adhesion coefficient and the longitudinal adhesion coefficient.

[0179] Exemplarily, the lateral adhesion of the vehicle is determined according to the lateral adhesion coefficient and the vertical force of the vehicle; and the longitudinal adhesion of the vehicle is determined according to the longitudinal adhesion coefficient and the vertical force of the wheels.

[0180] Optionally, the vertical force is usually a known quantity, and may also be calculated based on the lateral acceleration and longitudinal acceleration of the vehicle.

[0181] For example, for the lateral acceleration a y With longitudinal acceleration a x Decompose in the vertical direction to obtain a vertical increment; obtain the first vertical force corresponding to the vertical increment based on the product of the vertical increment and the vehicle's mass; sum the first vertical force and the pressure of the vehicle on the wheel (obtained by detecting a pressure sensor) to determine the wheel vertical force.

[0182] Optionally, the implementation of S301 to S303 can refer to Figure 2 The relevant description of S210 is not repeated here.

[0183] S304: Obtain the wheel angle of each wheel in the vehicle.

[0184] Exemplarily, the wheel angle of a vehicle is the rotation angle of each wheel in the vehicle relative to the longitudinal axis of the vehicle. The wheel angle is one of the key parameters of the vehicle steering system and directly affects the steering performance and handling stability of the vehicle.

[0185] For example, the vehicle may measure the wheel angle by installing a wheel angle sensor on the vehicle's steering system.

[0186] Optionally, the vehicle can calculate the wheel turning angle by measuring the angle of the steering wheel and the transmission ratio of the steering system, that is, wheel turning angle = steering wheel angle ÷ transmission ratio of the steering system.

[0187] Among them, the total transmission ratio of the steering system represents the ratio of the corresponding angle rotated by the wheel when the steering wheel is turned by a certain angle, which can usually be directly obtained; the steering wheel angle can be measured by a steering wheel angle sensor or encoder.

[0188] S305: Determine the lateral force of the target axis of the vehicle according to the wheel angle, the lateral adhesion and the longitudinal adhesion.

[0189] Exemplarily, the wheel angle, lateral adhesion and longitudinal adhesion are substituted into Formula 11 or Formula 12 to calculate the lateral force on the target axis of the vehicle.

[0190] Specifically, if the target axis is the front axle of the vehicle, the wheel angle, lateral adhesion and longitudinal adhesion are substituted into formula 11 to calculate the lateral force on the front axle; if the target axis is the rear axle of the vehicle, the wheel angle, lateral adhesion and longitudinal adhesion are substituted into formula 12 to calculate the lateral force on the rear axle.

[0191] S306: Determine a predicted value of the lateral acceleration of the vehicle according to the lateral force and the mass of the vehicle.

[0192] Exemplarily, the lateral force and the mass of the vehicle are substituted into Formula 13 or Formula 14 to obtain a predicted value of the lateral acceleration of the vehicle.

[0193] Specifically, if the target axis is the front axis, substitute it into Formula 13 to calculate the predicted value of the lateral acceleration of the vehicle. If the target axis is the rear axis, substitute it into Formula 14 to calculate the predicted value of the lateral acceleration of the vehicle.

[0194] Optionally, the implementation of S304 and S306 can refer to Figure 2 The implementation method of S220 in FIG. 1 is not described in detail here.

[0195] S307, obtaining a measured value of the lateral acceleration.

[0196] For example, the vehicle may obtain a measurement value of the lateral acceleration through an acceleration sensor.

[0197] S308, determine whether the acceleration direction indicated by the measured value is the same as the acceleration direction indicated by the predicted value; if so, execute S309; ​​if not, execute S310.

[0198] Exemplarily, determine whether the acceleration direction indicated by the measured value of the vehicle's lateral acceleration is the same as the acceleration direction indicated by the predicted value of the lateral acceleration; if the directions are the same; determine the lateral acceleration with the smaller absolute value between the measured value and the predicted value as the first lateral acceleration; if the directions are different, determine a preset target value as the first lateral acceleration.

[0199] S309: Determine the lateral acceleration with a smaller absolute value between the measured value and the predicted value as the first lateral acceleration.

[0200] For example, since the measured value of the lateral acceleration of the vehicle is usually greater than the actual lateral acceleration, when the acceleration direction indicated by the predicted value of the lateral acceleration of the vehicle is the same as the acceleration direction indicated by the measured value, it means that the directions of the lateral acceleration indicated by the predicted value of the lateral acceleration and the measured value are more accurate, and the error between the lateral acceleration with a smaller absolute value between the predicted value of the lateral acceleration and the measured value of the lateral acceleration and the actual lateral acceleration is smaller. Therefore, the lateral acceleration with a smaller absolute value between the measured value and the predicted value is determined as the first lateral acceleration.

[0201] S310: Determine the target value as the first lateral acceleration.

[0202] Exemplarily, interference factors may cause an error between the measured value or predicted value and the true value. When the directions of the lateral acceleration indicated by the predicted value of the lateral acceleration and the measured value are different, it means that there are large errors between the predicted value and the measured value of the current lateral acceleration. Therefore, the preset target value is determined as the first lateral acceleration; therefore, the target value is determined as the first lateral acceleration; avoid determining a predicted value or measured value with a large error as the first lateral acceleration; wherein the target value may be a zero value.

[0203] S311, determining a target lateral acceleration according to the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed.

[0204] Exemplarily, the first lateral acceleration, the yaw angular velocity, and the longitudinal vehicle speed are substituted into Formula 15 to obtain the target lateral acceleration.

[0205] S312: Determine a target lateral vehicle speed according to the target lateral acceleration.

[0206] For example, the target lateral acceleration is integrated to obtain the target lateral vehicle speed

[0207] Optionally, the implementation of S307 to S312 can refer to Figure 2 The relevant description of S230 is not repeated here.

[0208] S313: Determine the sideslip angle of the vehicle according to the target lateral vehicle speed and the longitudinal vehicle speed of the vehicle.

[0209] Exemplarily, the target lateral speed and longitudinal speed of the vehicle are determined, and substituted into Formula 1 to calculate the sideslip angle of the vehicle.

[0210] Optionally, the implementation of S313 can refer to Figure 2 The relevant description of S240 is not repeated here.

[0211] In the embodiment of the present application, due to the lateral force generated by the lateral adhesion and the longitudinal adhesion acting on the target axis of the vehicle, the lateral force causes the vehicle to have lateral acceleration. Therefore, the lateral force of the target axis is determined according to the lateral adhesion and the longitudinal adhesion and the turning angle of each wheel, ensuring that the predicted value of the lateral acceleration can be determined according to the lateral force and the mass of the vehicle. According to the predicted value of the lateral acceleration and the measured value of the lateral acceleration, the target lateral acceleration of the vehicle is comprehensively determined to ensure that the error of the obtained target lateral acceleration is small, thereby obtaining a more accurate target lateral acceleration. According to the more accurate target lateral acceleration, a more accurate target lateral vehicle speed is calculated to ensure that when the sideslip angle of the vehicle is determined according to the target lateral vehicle speed and the longitudinal vehicle speed, the accuracy of the obtained sideslip angle is high.

[0212] Combination of the above Figures 1 to 3 The method for determining the vehicle side slip angle provided by the embodiment of the present application is described in detail; Figure 4 and Figure 5 The device embodiments of the present application are described in detail. It should be understood that the device in the embodiments of the present application can execute the various methods of the aforementioned embodiments of the present application, that is, the specific working processes of the following various products can refer to the corresponding processes in the aforementioned method embodiments.

[0213] Figure 4 It is a structural schematic diagram of a device for determining a vehicle sideslip angle provided in an embodiment of the present application.

[0214] For example, Figure 4 As shown, the device 400 for determining the vehicle side slip angle includes:

[0215] The acquisition module 410 is used to acquire target parameters of the vehicle; wherein the target parameters include lateral adhesion, longitudinal adhesion and longitudinal vehicle speed of the vehicle;

[0216] The processing module 420 is used to obtain a predicted value of the lateral acceleration of the vehicle based on the lateral adhesion and the longitudinal adhesion; obtain a target lateral speed of the vehicle based on the predicted value of the lateral acceleration; and obtain a sideslip angle of the vehicle based on the target lateral speed and the longitudinal speed.

[0217] Optionally, as an embodiment, the acquisition module 410 is also used to: obtain the measured value of the vehicle's lateral acceleration; the processing module 420 is specifically used to: obtain the target lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration; and obtain the target lateral speed of the vehicle based on the target lateral acceleration.

[0218] Optionally, as an embodiment, the processing module 420 is specifically used to: obtain a first lateral acceleration based on a measured value of the lateral acceleration and a predicted value of the lateral acceleration; and obtain a target lateral acceleration based on the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed.

[0219] Optionally, as an embodiment, the processing module 420 is specifically used to: if the acceleration direction indicated by the predicted value of the lateral acceleration is the same as the acceleration direction indicated by the measured value of the lateral acceleration, use the lateral acceleration with the smaller absolute value between the predicted value of the lateral acceleration and the measured value of the lateral acceleration as the first lateral acceleration; if the acceleration direction indicated by the predicted value of the lateral acceleration is different from the acceleration direction indicated by the measured value of the lateral acceleration, determine the preset target value as the first lateral acceleration.

[0220] Optionally, as an embodiment, the acquisition module 410 is also used to: obtain the wheel angle of each wheel in the vehicle; the processing module 420 is specifically used to: determine the lateral force of the target axis in the vehicle based on the wheel angle, lateral adhesion and longitudinal adhesion of each wheel; determine the predicted value of the lateral acceleration based on the lateral force of the target axis and the mass of the vehicle.

[0221] Optionally, as an embodiment, the acquisition module 410 is also used to: acquire the vehicle speed, the wheel speed of each wheel, the lateral stiffness coefficient and the longitudinal stiffness coefficient; the processing module 420 is specifically used to: determine the lateral adhesion coefficient and the longitudinal adhesion coefficient of each wheel based on the vehicle speed, wheel speed, the lateral stiffness coefficient and the longitudinal stiffness coefficient; determine the lateral adhesion force and the longitudinal adhesion force of each wheel based on the lateral adhesion coefficient and the longitudinal adhesion coefficient.

[0222] Optionally, as an embodiment, the processing module 420 is specifically used to: determine the lateral slip rate and longitudinal slip rate of each wheel based on the vehicle speed and the wheel speed; determine the longitudinal adhesion coefficient based on the longitudinal slip rate and the longitudinal stiffness coefficient; determine the lateral adhesion coefficient based on the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient.

[0223] Optionally, as an embodiment, the processing module 420 is specifically used to: determine a first adhesion coefficient based on the longitudinal adhesion coefficient; determine a second adhesion coefficient based on the lateral slip rate and the lateral stiffness coefficient; and determine the smaller value between the first adhesion coefficient and the second adhesion coefficient as the lateral adhesion coefficient.

[0224] It should be noted that the above-mentioned device for determining the sideslip angle of a vehicle is embodied in the form of a functional unit. The term "module" here can be implemented in the form of software and / or hardware, and is not specifically limited to this.

[0225] For example, a "module" may be a software program, a hardware circuit, or a combination of the two that implements the above functions. The hardware circuit may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor, or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combined logic circuit, and / or other suitable components that support the described functions.

[0226] Therefore, the units of each example described in the embodiments of the present application can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present application.

[0227] Figure 5 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0228] Exemplarily, vehicle 500 includes: a processor 510 , a memory 520 , and executable program code 530 .

[0229] Exemplarily, the vehicle 500 includes one or more processors 510, which can support the vehicle 500 to implement the method for determining the vehicle side slip angle in the method embodiment. The processor 510 can be a general-purpose processor or a special-purpose processor. For example, the processor 510 can be a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, such as discrete gates, transistor logic devices, or discrete hardware components.

[0230] Exemplarily, the processor 510 may be used to control the vehicle 500, execute software programs, and process data of the software programs. The vehicle 500 may also include a communication unit to implement input (reception) and output (transmission) of signals.

[0231] Exemplarily, the vehicle 500 may include one or more memories 520 on which executable program code 530 is stored. The executable program code 530 can be executed by the processor 510 to generate instructions so that the processor 510 executes the method for determining the vehicle sideslip angle described in the above method embodiment according to the instructions.

[0232] Optionally, data may be stored in the memory 520. Optionally, the processor 510 may read data stored in the memory 520, which may be stored at the same storage address as the executable program code 530, or may be stored at a different storage address from the executable program code 530.

[0233] Exemplarily, the processor 510 and the memory 520 may be provided separately or integrated together, for example, integrated on a system on chip (SOC) of the terminal device.

[0234] Exemplarily, the memory 520 may be used to store relevant programs of the method for determining the sideslip angle of a vehicle provided in an embodiment of the present application, and the processor 520 may be used to call the executable program code 530 stored in the memory 520 when controlling the vehicle, and execute the method for determining the sideslip angle of a vehicle in an embodiment of the present application; for example, obtaining target parameters of the vehicle; wherein the target parameters include the lateral adhesion, longitudinal adhesion, and longitudinal vehicle speed of the vehicle; obtaining a predicted value of the lateral acceleration of the vehicle based on the lateral adhesion and the longitudinal adhesion; obtaining a target lateral vehicle speed of the vehicle based on the predicted value of the lateral acceleration; and obtaining the sideslip angle of the vehicle based on the target lateral vehicle speed and the longitudinal vehicle speed.

[0235] The present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for determining the sideslip angle of a vehicle in any of the aforementioned embodiments.

[0236] Among them, computer-readable storage media may include but are not limited to any type of disk, including floppy disks, optical disks, digital versatile disks (Digital Video Disc, DVD), compact disc read-only memory (Compact Disc Read-Only Memory, CD-ROM), microdrives and magneto-optical disks, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), erasable programmable read-only memory (Erasable Programmable Read-Only Memory, EPROM), electrically erasable programmable read only memory (Electrically Erasable Programmable read only memory, EEPROM), dynamic random access memory (Dynamic Random Access Memory, DRAM), video random access memory (Video Random Access Memory, VRAM), flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0237] The present application also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement a method for determining a vehicle sideslip angle in the above-mentioned embodiment.

[0238] In addition, the vehicle provided in the embodiments of the present application may specifically be a chip, a component or a module, and the vehicle may include a connected processor and a memory; wherein the memory is used to store instructions, and when the vehicle is running, the processor may call and execute the instructions so that the chip executes a method for determining the vehicle sideslip angle in the above-mentioned embodiments.

[0239] Among them, the vehicle, computer-readable storage medium, computer program product or chip provided in the present application are all used to execute the corresponding method for determining the vehicle sideslip angle provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method for determining the vehicle sideslip angle provided above, and will not be repeated here.

[0240] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0241] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0242] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for determining a vehicle sideslip angle, characterized in that: The method comprises: Acquiring target parameters of the vehicle; wherein the target parameters include the lateral adhesion, longitudinal adhesion of each wheel in the vehicle and the longitudinal speed of the vehicle; Obtaining a predicted value of a lateral acceleration of the vehicle based on the lateral adhesion and the longitudinal adhesion; Obtaining a target lateral speed of the vehicle based on the predicted value of the lateral acceleration; A sideslip angle of the vehicle is obtained based on the target lateral vehicle speed and the longitudinal vehicle speed.

2. The method according to claim 1, characterized in that Also includes: obtaining a measurement of the lateral acceleration of the vehicle; The step of obtaining a target lateral speed of the vehicle based on the predicted value of the lateral acceleration includes: Obtaining a target lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration; Based on the target lateral acceleration, a target lateral vehicle speed of the vehicle is obtained.

3. The method according to claim 2, characterized in that The step of obtaining a target lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration comprises: Obtaining a first lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration; The target lateral acceleration is obtained based on the first lateral acceleration, the yaw angular velocity and the longitudinal vehicle speed.

4. The method according to claim 3, characterized in that The obtaining of a first lateral acceleration based on the measured value of the lateral acceleration and the predicted value of the lateral acceleration comprises: If the acceleration direction indicated by the predicted value of the lateral acceleration is the same as the acceleration direction indicated by the measured value of the lateral acceleration, determining the lateral acceleration with the smaller absolute value between the predicted value of the lateral acceleration and the measured value of the lateral acceleration as the first lateral acceleration; If the acceleration direction indicated by the predicted value of the lateral acceleration is different from the acceleration direction indicated by the measured value of the lateral acceleration, a preset target value is determined as the first lateral acceleration.

5. The method according to claim 1, characterized in that Also includes: Obtaining the wheel angle of each wheel in the vehicle; The step of obtaining a predicted value of the lateral acceleration of the vehicle based on the lateral adhesion and the longitudinal adhesion includes: Determining a lateral force on a target axis in the vehicle based on the wheel angles of the wheels, the lateral adhesion and the longitudinal adhesion; The predicted value of the lateral acceleration is determined based on the lateral force of the target axis and the mass of the vehicle.

6. The method according to claim 1, characterized in that Also includes: Obtaining the vehicle speed, the wheel speed of each wheel, the lateral stiffness coefficient and the longitudinal stiffness coefficient of the vehicle; The step of obtaining the target parameters of the vehicle includes: Determining a lateral adhesion coefficient and a longitudinal adhesion coefficient of each wheel based on the vehicle speed, wheel speed, lateral stiffness coefficient and longitudinal stiffness coefficient; Based on the lateral adhesion coefficient and the longitudinal adhesion coefficient, the lateral adhesion and the longitudinal adhesion of each wheel are determined.

7. The method according to claim 6, characterized in that Determining the lateral adhesion coefficient and the longitudinal adhesion coefficient of each wheel based on the vehicle speed, wheel speed, lateral stiffness coefficient and longitudinal stiffness coefficient includes: Determining a lateral slip rate and a longitudinal slip rate of each wheel based on the vehicle speed and the wheel speed; determining the longitudinal adhesion coefficient based on the longitudinal slip rate and the longitudinal stiffness coefficient; The lateral adhesion coefficient is determined based on the longitudinal adhesion coefficient, the lateral slip ratio and the lateral stiffness coefficient.

8. The method according to claim 7, characterized in that The determining the lateral adhesion coefficient based on the longitudinal adhesion coefficient, the lateral slip rate and the lateral stiffness coefficient includes: determining a first adhesion coefficient based on the longitudinal adhesion coefficient; determining a second adhesion coefficient based on the lateral slip rate and the lateral stiffness coefficient; A smaller value between the first adhesion coefficient and the second adhesion coefficient is determined as the lateral adhesion coefficient.

9. A device for determining a vehicle side slip angle, characterized in that: The device comprises: An acquisition module, used for acquiring target parameters of a vehicle; wherein the target parameters include lateral adhesion, longitudinal adhesion and longitudinal speed of the vehicle; A processing module is used to obtain a predicted value of a lateral acceleration of the vehicle based on the lateral adhesion and the longitudinal adhesion; obtain a target lateral speed of the vehicle based on the predicted value of the lateral acceleration; and obtain a sideslip angle of the vehicle based on the target lateral speed and the longitudinal speed.

10. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor is used to call and run the executable program code from the memory so that the vehicle executes the method as claimed in any one of claims 1 to 8.

Images