Vehicle, control method and device thereof, storage medium and computer program product

Abstract

The application discloses a vehicle and a control method, device and storage medium thereof and a computer program product, and relates to the technical field of vehicles. The control method of the vehicle comprises the following steps: correcting ideal yaw angular velocity according to expected steering characteristic information; obtaining an additional yaw moment according to an ideal center of mass side slip angle, the corrected ideal yaw angular velocity, an actual center of mass side slip angle and an actual yaw angular velocity of the vehicle; and performing torque distribution based on the additional yaw moment. According to the method, the ideal yaw angular velocity is corrected according to the expected steering characteristic information, and then, the variable steering characteristic of the vehicle is realized through torque control based on the ideal center of mass side slip angle, the corrected ideal yaw angular velocity, the actual center of mass side slip angle and the actual yaw angular velocity of the vehicle, so that the vehicle can obtain higher steering sensitivity.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a vehicle and its control method, device, storage medium, and computer program product. Background Technology

[0002] In related technologies, track mode primarily aims to enhance vehicle performance. For example, when track mode is detected, the drive motor is controlled to output maximum torque, and the battery management system outputs maximum power. While this technology can maximize vehicle performance, it lacks control over steering characteristics, thus limiting the ability of skilled drivers to utilize their abilities and resulting in a lack of driving pleasure. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the object of this invention is to provide a vehicle and its control method, apparatus, storage medium, and computer program product, so that the vehicle can achieve higher steering sensitivity.

[0004] In a first aspect, the present invention proposes a vehicle control method, comprising: correcting the ideal yaw rate based on desired steering characteristic information; obtaining an additional yaw moment based on the ideal center of gravity sideslip angle, the corrected ideal yaw rate, and the vehicle's actual center of gravity sideslip angle and actual yaw rate; and distributing torque based on the additional yaw moment.

[0005] In some embodiments of the present invention, the step of correcting the ideal yaw rate based on the desired steering characteristic information includes: obtaining a variable steering characteristic coefficient based on the desired steering characteristic information; and correcting the ideal yaw rate based on the variable steering characteristic coefficient.

[0006] In some embodiments of the present invention, the desired steering characteristic information includes a desired steering characteristic value θ; obtaining the variable steering characteristic coefficient based on the desired steering characteristic information includes:

[0007] When θ is greater than 0, the variable steering characteristic coefficient is obtained as θ*K;

[0008] When θ equals 0, the variable steering characteristic coefficient is 0;

[0009] When θ is less than 0, the variable steering characteristic coefficient is obtained as follows:

[0010] Where K is the stability factor, τ is the preset safety factor, and u cr The critical speed at which the vehicle experiences a sharp turn under excessive steering conditions.

[0011] In some embodiments of the present invention, before correcting the ideal yaw rate according to the variable steering characteristic coefficient, the method further includes limiting the variable steering characteristic coefficient in the following manner:

[0012] The variable steering characteristic coefficient is respectively compared with Compare with K;

[0013] If the variable steering characteristic coefficient is less than Then the variable steering characteristic coefficient is limited to

[0014] If the variable steering characteristic coefficient is greater than K, then the variable steering characteristic coefficient is limited to K;

[0015] If the variable steering characteristic coefficient is greater than or equal to If the value is less than or equal to K, then the variable steering characteristic coefficient remains unchanged.

[0016] In some embodiments of the present invention, the step of correcting the ideal yaw rate according to the variable steering characteristic coefficient includes: replacing the stability factor used to calculate the ideal yaw rate with the variable steering characteristic coefficient to achieve the correction of the ideal yaw rate.

[0017] In some embodiments of the present invention, obtaining the additional yaw moment based on the ideal sideslip angle, the corrected ideal yaw rate, and the vehicle's actual sideslip angle and actual yaw rate includes: limiting the ideal sideslip angle and the corrected ideal yaw rate using the road adhesion coefficient of the road surface where the vehicle is located, respectively, to obtain a reference sideslip angle and a reference yaw rate; and obtaining the additional yaw moment based on the reference sideslip angle, the reference yaw rate, and the actual sideslip angle and the actual yaw rate.

[0018] In some embodiments of the present invention, the reference yaw rate is obtained by limiting the ideal yaw rate using the road surface adhesion coefficient, including: determining the maximum yaw rate based on the road surface adhesion coefficient; comparing the ideal yaw rate with the maximum yaw rate; if the ideal yaw rate is greater than the maximum yaw rate, then the maximum yaw rate is used as the reference yaw rate; if the ideal yaw rate is less than or equal to the maximum yaw rate, then the ideal yaw rate is used as the reference yaw rate.

[0019] In some embodiments of the present invention, the ideal centroid sideslip angle is corrected using the road surface adhesion coefficient to obtain the reference centroid sideslip angle, including: determining the maximum centroid sideslip angle based on the road surface adhesion coefficient; comparing the ideal centroid sideslip angle with the maximum centroid sideslip angle; if the ideal centroid sideslip angle is greater than the maximum centroid sideslip angle, then the maximum centroid sideslip angle is used as the reference centroid sideslip angle; if the ideal centroid sideslip angle is less than or equal to the maximum centroid sideslip angle, then the ideal centroid sideslip angle is used as the reference centroid sideslip angle.

[0020] In some embodiments of the present invention, the maximum yaw rate is Where μ is the road surface adhesion coefficient, g is the gravitational acceleration, u is the vehicle speed, and η is the preset safety factor.

[0021] In some embodiments of the present invention, the maximum centroid sideslip angle is tan -1 0.02μg, where μ is the road surface adhesion coefficient and g is the gravitational acceleration.

[0022] In some embodiments of the present invention, obtaining the additional yaw moment based on the reference centroid sideslip angle, the reference yaw rate, the actual centroid sideslip angle, and the actual yaw rate includes: calculating a first difference between the reference yaw rate and the actual yaw rate, and calculating a second difference between the reference centroid sideslip angle and the actual centroid sideslip angle; and obtaining the additional yaw moment using a preset closed-loop control algorithm based on the first difference and the second difference.

[0023] In some embodiments of the present invention, the vehicle is a distributed drive vehicle; the torque distribution based on the additional yaw moment includes:

[0024] Torque distribution is performed using the following formula:

[0025]

[0026] In the formula, T reqL and T reqR T represents the torque distribution to the left drive motor and the torque distribution to the right drive motor of the vehicle, respectively. reqAXLE R is the total driving torque of the drive shaft. w Let B be the wheel rolling radius, B be the drive axle track width, and i be the wheel rolling radius. L and i R M represents the reduction ratio of the left drive motor and the reduction ratio of the right drive motor, respectively. z，req The additional yaw moment.

[0027] Secondly, embodiments of the present invention provide a vehicle control device, comprising: a correction module for correcting the ideal yaw rate based on desired steering characteristic information; a processing module for obtaining an additional yaw torque based on the ideal center of gravity sideslip angle, the corrected ideal yaw rate, and the vehicle's actual center of gravity sideslip angle and actual yaw rate; and a distribution module for distributing torque based on the additional yaw torque.

[0028] Thirdly, embodiments of the present invention provide a vehicle, including: the vehicle control device described in the second aspect above.

[0029] Thirdly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the method described in the first aspect above.

[0030] Fourthly, embodiments of the present invention provide a computer program product, including a computer program, which, when executed by a processor, implements the method described in the first aspect above.

[0031] The vehicle and its control method, device, storage medium, and computer program product of the present invention correct the ideal yaw rate according to the desired steering characteristic information, and then, based on the ideal center of gravity sideslip angle, the corrected ideal yaw rate, and the vehicle's actual center of gravity sideslip angle and actual yaw rate, realize the vehicle's variable steering characteristics through torque control, so that the vehicle can obtain higher steering sensitivity. Attached Figure Description

[0032] Figure 1 This is a curve showing the relationship between steady-state yaw rate gain and vehicle speed in one embodiment;

[0033] Figure 2 This is a flowchart of a vehicle control method according to an embodiment of the present invention;

[0034] Figure 3 This is a flowchart of step S21 of an embodiment of the present invention;

[0035] Figure 4 This is a flowchart of step S22 of an embodiment of the present invention;

[0036] Figure 5 This is a flowchart of a vehicle control method according to a specific embodiment of the present invention;

[0037] Figure 6 This is a flowchart of step S53 of an embodiment of the present invention;

[0038] Figure 7 This is a structural block diagram of the vehicle control device according to an embodiment of the present invention;

[0039] Figure 8 This is a structural block diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0040] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0041] The foundation of vehicle torque distribution is vehicle handling stability control, which first requires determining a suitable ideal reference model that represents the driver's driving intentions and the vehicle's ideal response characteristics. Currently, common vehicle models include two-degree-of-freedom, three-degree-of-freedom, and seven-degree-of-freedom models. Among them, the linear two-degree-of-freedom model mainly targets the vehicle's handling stability response characteristics within a linear range. These characteristics are predictable and familiar to the driver, thus the linear two-degree-of-freedom model can represent the driver's driving intentions to a large extent.

[0042] The yaw rate of the ideal vehicle can be obtained from the linear two-degree-of-freedom model as follows:

[0043]

[0044] Where u is the vehicle speed, L is the vehicle wheelbase, δ is the front wheel Ackerman angle (the angle between the two front steering wheels when the vehicle is turning, which is related to the steering wheel angle), and K is the stability factor, an important parameter characterizing the vehicle's steering characteristics. It is only related to the vehicle's mass, longitudinal position of the center of gravity, and tire lateral stiffness, and is an inherent property of the vehicle structure.

[0045] The stability factor K can be calculated using the following formula:

[0046]

[0047] Where m is the vehicle mass, a is the distance from the vehicle's center of gravity to the front axle, b is the distance from the vehicle's center of gravity to the rear axle, k is the front wheel lateral stiffness (a negative value), and k' is the rear wheel lateral stiffness (a negative value). It should be noted that the formula for calculating K above is derived from a linear two-degree-of-freedom model. This model simplifies the vehicle to the greatest extent possible, considering only the yaw and lateral motion caused by the wheel's lateral force, omitting many factors such as wheel camber, wheel toe-in, and wheel load variations.

[0048] The stability factor K is an important parameter characterizing vehicle steering characteristics. Based on its sign, steering characteristics can be divided into three categories (e.g., stability factor K). Figure 1 As shown):

[0049] When K=0, the vehicle is in a neutral steering state. See [link / reference]. Figure 1 Under this steering condition, the steady-state yaw rate is linearly related to the vehicle speed;

[0050] When K > 0, the vehicle is in an understeering state. See [reference needed]. Figure 1 In this steering state, the curve relating vehicle speed to steady-state yaw rate gain bends downwards, and the steady-state yaw rate gain reaches its maximum at the characteristic vehicle speed u. ch Take the maximum value at that point;

[0051] When K < 0, the vehicle is in an oversteering state. See [reference needed]. Figure 1 In this steering state, the curve relating vehicle speed to steady-state yaw rate gain bends upwards, and the steady-state yaw rate gain reaches the critical vehicle speed u. cr When the radius becomes infinitely large, even a small angle of rotation of the front wheels can cause the vehicle to spin violently (spinning wildly), which can easily lead to skidding or even rollover, making it extremely dangerous.

[0052] Ideally, a vehicle should have a perfectly linear response, meaning it operates in a neutral steering state to satisfy the driver's intentions. However, in practice, to prevent severe spin when the vehicle is oversteered, vehicles are generally designed with a slight understeer characteristic.

[0053] As the above analysis shows, vehicle stability design comes at the cost of handling. Therefore, in racing car design that emphasizes vehicle performance, vehicles are often designed with slight oversteer characteristics to meet the driver's requirements for high steering sensitivity and improve vehicle handling.

[0054] As vehicles increasingly emphasize personalization and driving pleasure, and while track modes in related technologies primarily aim to enhance vehicle power, this invention proposes a vehicle control method. This method corrects the ideal yaw rate based on desired steering characteristic information, and then achieves variable steering characteristics through torque control. This allows the vehicle to achieve higher steering sensitivity, tending towards oversteer, which helps skilled drivers achieve fast cornering, while novice drivers can easily experience the driving pleasure of "fishtailing" and "understeer." Simultaneously, based on this vehicle control method, a vehicle control device, a vehicle, a storage medium, and a computer program product are also proposed.

[0055] The following description, with reference to the accompanying drawings, describes a vehicle and its control method, apparatus, storage medium, and computer program product according to embodiments of the present invention.

[0056] Figure 2This is a flowchart of a vehicle control method according to an embodiment of the present invention. The control method can be executed by an electronic device, which can be a vehicle controller or a device independent of the vehicle controller used to implement vehicle dynamics control.

[0057] like Figure 2 As shown, the vehicle control methods include:

[0058] S21, the ideal yaw rate is corrected based on the desired steering characteristic information.

[0059] The desired steering characteristic information can be a value within a preset range (such as [-100%, 100%], [-1, 1], etc.), and can be defined as the desired steering characteristic value. For ease of description, the desired steering characteristic value can be represented by the symbol θ, i.e., θ∈[-100%, 100%], θ∈[-1, 1], etc. When the sign of θ is positive, it indicates that the desired driving characteristic is understeer; the larger the absolute value, the greater the understeer. When the sign of θ is negative, the desired driving characteristic is oversteer; the larger the absolute value, the greater the oversteer.

[0060] In one implementation, the desired steering characteristic information is set by the driver, such as through an HMI (Human Machine Interface). For example, a track mode activation button can be installed in the vehicle. By pressing this button, the driver can activate the track mode. At this time, the in-vehicle terminal can display a track mode page through the HMI interface. This page includes input controls for desired steering characteristic information, which the driver can input.

[0061] As another implementation method, the desired steering characteristic information is set by default. For example, if the driver activates track mode and does not set the desired steering characteristic information, the desired steering characteristic information θ can be set to 100% by default, meaning that the vehicle's steering characteristics remain unchanged and it is still understeer.

[0062] Optionally, before step S21, the process may include: determining that the vehicle has activated track mode.

[0063] In this embodiment, the ideal yaw rate can be obtained through the aforementioned degree-of-freedom model. Taking a linear two-degree-of-freedom model as an example, the ideal yaw rate... As one implementation method, a correspondence between desired steering characteristic information and K can be pre-established (stored in the form of tables, curves, functions, etc.). This correspondence can be obtained experimentally, with the goal of improving vehicle steering agility. In practical use, this correspondence can be looked up based on the desired steering characteristic information to obtain the corresponding K value, which can then be used to replace... The K value is used to correct the ideal yaw rate.

[0064] It should be noted that the vehicle speed u and the front wheel Ackerman angle δ used to calculate the ideal yaw rate can both be obtained through corresponding sensors. For example, the vehicle speed u can be obtained directly through the vehicle speed sensor, or it can be calculated from the wheel speed sensed by the wheel speed sensor; the front wheel Ackerman angle δ can be calculated from the steering wheel angle sensed by the steering wheel sensor.

[0065] S22. Based on the ideal sideslip angle, the corrected ideal yaw rate, and the vehicle's actual sideslip angle and actual yaw rate, the additional yaw moment is obtained.

[0066] In this embodiment, the ideal centroid sideslip angle can also be obtained through the aforementioned degree-of-freedom model. Taking a linear two-degree-of-freedom model as an example, the ideal centroid sideslip angle... Where u is the vehicle speed, L is the vehicle wheelbase, δ is the front wheel Ackerman angle, m is the vehicle mass, a is the distance from the vehicle's center of gravity to the front axle, b is the distance from the vehicle's center of gravity to the rear axle, k1 is the front wheel lateral stiffness (a negative value), and k2 is the rear wheel lateral stiffness (a negative value).

[0067] The actual center-of-gravity sideslip angle β refers to the angle between the direction of the vehicle's center-of-gravity velocity and the direction the vehicle's nose points. It can be determined by electronic equipment or the vehicle controller using the following formula based on the lateral velocity u of the center of gravity. x and longitudinal velocity of the center of mass u y The result is:

[0068] β=arctan(u y / u x )

[0069] The actual yaw rate can be sensed by a yaw rate sensor installed on the vehicle and sent to electronic equipment.

[0070] In one implementation, after obtaining the ideal sideslip angle, the corrected ideal yaw rate, the actual sideslip angle, and the actual yaw rate, the difference between the ideal sideslip angle and the actual sideslip angle can be calculated, as well as the difference between the corrected ideal yaw rate and the actual yaw rate. These two differences are used as closed-loop feedback and input to a preset controller (such as a PID controller, fuzzy controller, or fuzzy PID controller) to output an additional yaw torque. Alternatively, the two differences can be input to two preset controllers, each outputting its own additional yaw torque. These two additional yaw torques are then weighted to obtain the final additional yaw torque for subsequent torque distribution. The two differences can also be used as input to a single preset controller, which outputs an additional yaw torque for subsequent torque distribution.

[0071] S23, torque distribution based on additional yaw moment.

[0072] Specifically, the vehicle can be a distributed drive vehicle, utilizing a torque distribution controller to optimize torque distribution based on additional yaw moment, with the goal of minimizing the sum of the squares of all tire load rates. Here, tire load rate refers to the ratio between the actual load on a tire and its rated load. This ratio reflects the relationship between the load conditions of the tire in actual use and the maximum load capacity specified in the tire's design. For example, if the rated load of a tire is 1000 kg, and the actual load it bears is 800 kg, then the tire load rate is 80%.

[0073] As one implementation method, the distributed torque of each wheel can be obtained using a dynamic load distribution algorithm through the following formula:

[0074]

[0075] Among them, T req，f1 T req，fr T req，rl T req，rr The torque distribution F represents the torque allocated to the left front-wheel drive motor, right front-wheel drive motor, left rear-wheel drive motor, and right rear-wheel drive motor, respectively. fl F fr F rl F rr These represent the vertical loads on the left front wheel, right front wheel, left rear wheel, and right rear wheel, respectively. These loads can be calculated using vehicle speed, longitudinal acceleration, etc. d represents the wheelbase, and M represents the distance between the wheels. z，req To add yaw moment, R w This is the rolling radius of the wheel.

[0076] As another implementation method, torque can be distributed based on the total drive torque of the drive shaft using the following formula:

[0077]

[0078] In the formula, T reqL and T reqR These represent the torque distribution to the left-side drive motor and the torque distribution to the right-side drive motor, respectively. reqAxLE R is the total drive torque of the drive shaft (which can be obtained based on the vehicle's accelerator pedal opening). w Let B be the wheel rolling radius, B be the drive axle track width, and i be the wheel rolling radius. L and i R These are the reduction ratios of the left and right drive motors, respectively, M. z，req To add yaw moment.

[0079] The vehicle's control method corrects the ideal yaw rate based on the desired steering characteristic information. Then, based on the ideal center of gravity sideslip angle, the corrected ideal yaw rate, and the vehicle's actual center of gravity sideslip angle and actual yaw rate, torque control is used to achieve the vehicle's variable steering characteristics. This allows the vehicle to obtain higher steering sensitivity, that is, tends to oversteer, which helps skilled drivers to achieve fast cornering, and allows novice drivers to easily experience the driving pleasure of "fishtailing" and "understeer".

[0080] In some embodiments of the present invention, such as Figure 3 As shown, the ideal yaw rate is corrected based on the desired steering characteristic information, including:

[0081] S211, Calculate the variable steering characteristic coefficient based on the desired steering characteristic information.

[0082] Specifically, a correspondence between desired steering characteristic information and variable steering characteristic coefficients can be established in advance (which can be stored in the form of tables, curves, functions, etc.). In actual use, the variable steering characteristic coefficients can be obtained by looking up the correspondence based on the desired steering characteristic information.

[0083] In some examples, the desired steering characteristic information includes the desired steering characteristic value θ; the variable steering characteristic coefficients are obtained from the desired steering characteristic information, including:

[0084] When θ is greater than 0, the variable steering characteristic coefficient is obtained as θ*K;

[0085] When θ equals 0, the variable steering characteristic coefficient is 0;

[0086] When θ is less than 0, the variable steering characteristic coefficient is obtained as follows:

[0087] Where K is the stability factor, τ is the preset safety factor, and u cr The critical speed at which a vehicle experiences a sharp turn when it is under excessive steering.

[0088] In this example, the desired steering characteristic information θ and the variable steering characteristic coefficient The correspondence between them can be represented by the following function:

[0089]

[0090] It should be noted that K in the above function is a fixed value and is greater than 0, which corresponds to the aforementioned vehicle design with slight understeer characteristics, in order to ensure the vehicle's stability to the greatest extent in non-track mode.

[0091] S212, corrects the ideal yaw rate based on the variable steering characteristic coefficient.

[0092] Specifically, the stability factor K in the ideal reference model used for torque distribution in distributed drive vehicles can be replaced by a variable steering characteristic coefficient to correct the ideal yaw rate. Taking the ideal yaw rate obtained from a two-degree-of-freedom model as an example, the corrected ideal yaw rate is: Where φ is the variable steering characteristic coefficient, ω rd This is the corrected ideal yaw rate.

[0093] By introducing a variable steering characteristic coefficient to correct the ideal yaw rate, the steering sensitivity of the vehicle can be effectively improved and the steering characteristics can be changed.

[0094] In some embodiments of the present invention, before correcting the ideal yaw rate based on the variable steering characteristic coefficient, the method further includes limiting the variable steering characteristic coefficient in the following manner:

[0095] The variable steering characteristic coefficient is respectively compared with Compare with K;

[0096] If the variable steering characteristic coefficient is less than The variable steering characteristic coefficient is then limited to...

[0097] If the variable steering characteristic coefficient is greater than K, then the variable steering characteristic coefficient is limited to K;

[0098] If the variable steering characteristic coefficient is greater than or equal to If the value is less than or equal to K, then the variable steering characteristic coefficient remains unchanged.

[0099] Specifically, in track mode, the vehicle needs to possess basic stability to avoid dangerous situations such as excessive steering at high speeds caused by understeer. To this end, this invention proposes limiting the variable steering characteristic coefficient φ and using the critical vehicle speed u at which excessive steering leads to dangerous steering. cr As a constraint, the critical vehicle speed u is used. cr The steering characteristic coefficient when the vehicle experiences a sharp turn is derived and used as the maximum oversteer limit for the variable steering characteristic coefficient φ. A safety factor τ is also designed to provide a certain safety margin. The maximum understeer limit for the variable steering characteristic coefficient φ is the steering characteristic coefficient when the original vehicle has no active control. Therefore, the constraints on the variable steering characteristic coefficient φ are as follows:

[0100]

[0101] By limiting the variable steering characteristic coefficient, it is possible to improve vehicle steering sensitivity while maintaining stability.

[0102] In some embodiments of the present invention, such as Figure 4 As shown, based on the ideal sideslip angle, the corrected ideal yaw rate, and the vehicle's actual sideslip angle and actual yaw rate, the additional yaw moment is obtained, including:

[0103] S221, by using the road surface adhesion coefficient of the road surface where the vehicle is located, the ideal centroid sideslip angle and the corrected ideal yaw rate are limited respectively, so as to obtain the reference centroid sideslip angle and the reference yaw rate.

[0104] The road surface adhesion coefficient can be estimated by the vehicle controller and obtained by the electronic equipment from the vehicle controller; or the road surface adhesion coefficient can be estimated by the electronic equipment itself.

[0105] S222, based on the reference center of mass sideslip angle, the reference yaw rate, and the actual center of mass sideslip angle and the actual yaw rate, the additional yaw torque is obtained.

[0106] In this embodiment, the additional yaw moment is obtained based on the reference centroid sideslip angle, the reference yaw rate, the actual centroid sideslip angle, and the actual yaw rate. This includes: calculating a first difference between the reference yaw rate and the actual yaw rate, and calculating a second difference between the reference centroid sideslip angle and the actual centroid sideslip angle; and using a preset closed-loop control algorithm (e.g., PID control algorithm, fuzzy control algorithm, fuzzy PID control algorithm, etc.) to obtain the additional yaw moment based on the first and second differences.

[0107] For example, the first difference and the second difference can be input to two corresponding controllers, and the two controllers output their respective additional yaw torques. The two additional yaw torques are then weighted to obtain the final additional yaw torque for subsequent torque distribution. Alternatively, the first difference and the second difference can be used as inputs to a controller, which outputs an additional yaw torque for subsequent torque distribution.

[0108] In some examples, the ideal yaw rate is limited by the road surface adhesion coefficient to obtain a reference yaw rate, including: determining the maximum yaw rate based on the road surface adhesion coefficient; comparing the ideal yaw rate with the maximum yaw rate; if the ideal yaw rate is greater than the maximum yaw rate, then the maximum yaw rate is used as the reference yaw rate; if the ideal yaw rate is less than or equal to the maximum yaw rate, then the ideal yaw rate is used as the reference yaw rate.

[0109] The maximum yaw rate can be: Where μ is the road surface adhesion coefficient, g is the gravitational acceleration, u is the vehicle speed, and η is the preset safety factor. The value of η can be set as needed, and the value range can be [0.8, 1].

[0110] Similarly, the ideal centroid sideslip angle is corrected using the road surface adhesion coefficient to obtain the reference centroid sideslip angle, including: determining the maximum centroid sideslip angle based on the road surface adhesion coefficient; comparing the ideal centroid sideslip angle with the maximum centroid sideslip angle; if the ideal centroid sideslip angle is greater than the maximum centroid sideslip angle, then the maximum centroid sideslip angle is used as the reference centroid sideslip angle; if the ideal centroid sideslip angle is less than or equal to the maximum centroid sideslip angle, then the ideal centroid sideslip angle is used as the reference centroid sideslip angle.

[0111] The maximum centroid sideslip angle is tan -1 0.02μg, where μ is the road surface adhesion coefficient and g is the gravitational acceleration.

[0112] In this embodiment, after obtaining the ideal centroid sideslip angle and the corrected ideal yaw rate, further corrections based on road conditions are needed, requiring the determination of the vehicle's longitudinal acceleration 'a'. y There is an upper limit, which is less than or equal to the product of the road adhesion coefficient μ and the gravitational acceleration g. Longitudinal acceleration a y This can be expressed by the following formula:

[0113]

[0114] And, satisfying a y ≤μg.

[0115] Because the actual sideslip angle β of the vehicle's center of gravity is relatively small when the vehicle is in motion, The last two values ​​in the formula are relatively small and are ignored for ease of calculation. However, other influencing factors exist during actual driving. Based on design experience, a certain stability margin, such as 10%, can be reserved. Thus, the corrected formula for the ideal yaw rate limit is as follows:

[0116]

[0117] At the same time, a limiting formula for the ideal center of gravity sideslip angle can be obtained based on the vehicle's tire model data and experience: β rd ≤tan -1 0.02μg.

[0118] By limiting the ideal sideslip angle and corrected ideal yaw rate obtained above using the aforementioned limiting formulas, reference sideslip angle and reference yaw rate can be obtained. Then, the deviations between the reference yaw rate and reference sideslip angle and the vehicle's actual yaw rate and sideslip angle are used as inputs to a preset controller (such as a PID controller) to calculate the additional yaw moment M required for the vehicle to follow the reference values. z，req .

[0119] By limiting the ideal center-of-gravity sideslip angle using the road adhesion coefficient and by limiting the corrected ideal yaw rate, the steering sensitivity and stability of the vehicle can be further improved.

[0120] To facilitate understanding, the following will be combined with Figure 5 , Figure 6 The vehicle control method of the present invention is described through a specific embodiment:

[0121] like Figure 5 As shown, the vehicle control methods include:

[0122] S51, confirm that the vehicle has entered track mode.

[0123] S52, obtain the actual yaw rate, and obtain the actual centroid sideslip angle based on the lateral velocity and longitudinal velocity of the centroid.

[0124] S53, based on the ideal reference model, obtains the reference yaw rate and reference centroid sideslip angle according to the desired steering characteristic information, steering wheel angle, vehicle speed, road adhesion coefficient, etc.

[0125] See Figure 5 Steps S52 and S53 can be executed in parallel to reduce control time.

[0126] like Figure 6 As shown, step S53 may include:

[0127] S61, Obtain the variable steering characteristic coefficient based on the desired steering characteristic information;

[0128] S62, limits the variable steering characteristic coefficient;

[0129] S63, the ideal yaw rate obtained from the ideal reference model is corrected based on the limited variable steering characteristic coefficient;

[0130] S64. By using the road surface adhesion coefficient to limit the ideal centroid sideslip angle and the corrected ideal yaw rate obtained from the ideal reference model, the reference centroid sideslip angle and the reference yaw rate are obtained.

[0131] S54, calculate the first difference between the reference yaw rate and the actual yaw rate, and calculate the second difference between the reference center-of-mass sideslip angle and the actual center-of-mass sideslip angle.

[0132] S55 uses a preset PID controller to obtain the additional yaw torque based on the first difference and the second difference.

[0133] S56 utilizes a torque distribution controller to distribute torque among the vehicle's drive motors based on the additional yaw moment.

[0134] The allocation method can adopt the dynamic load allocation algorithm described above, or the allocation method based on the total drive torque of the drive shaft described above.

[0135] The vehicle control method of this invention obtains a variable steering characteristic coefficient based on desired steering characteristic information, and then limits the variable steering characteristic coefficient. The limited variable steering characteristic coefficient is then used to correct the ideal yaw rate. Next, the road adhesion coefficient is used to limit the ideal centroid sideslip angle obtained from the ideal reference model and the corrected ideal yaw rate, respectively, to obtain the reference centroid sideslip angle and reference yaw rate. Finally, torque is distributed based on the reference centroid sideslip angle, reference yaw rate, actual centroid sideslip angle, and actual yaw rate. During torque distribution, the advantage of distributed drive vehicles—which allow for highly flexible control of vehicle motion—is utilized. This allows the vehicle to tend towards slight oversteer, thereby providing the driver with higher steering sensitivity and maneuverability, meeting the driver's higher requirements for vehicle handling performance, while also maintaining stability.

[0136] Figure 7 This is a structural block diagram of the vehicle control device according to an embodiment of the present invention.

[0137] like Figure 7 As shown, the vehicle control device 700 includes: a correction module 710, a processing module 720, and a distribution module 730.

[0138] The correction module 510 is used to correct the ideal yaw rate based on the desired steering characteristic information; the processing module 720 is used to obtain the additional yaw torque based on the ideal center of gravity sideslip angle, the corrected ideal yaw rate, and the vehicle's actual center of gravity sideslip angle and actual yaw rate; and the distribution module 730 is used to distribute torque based on the additional yaw torque.

[0139] In some embodiments of the present invention, the ideal yaw rate is corrected based on the desired steering characteristic information, including: obtaining a variable steering characteristic coefficient based on the desired steering characteristic information; and correcting the ideal yaw rate based on the variable steering characteristic coefficient.

[0140] In some embodiments of the present invention, the desired steering characteristic information includes a desired steering characteristic value θ; obtaining the variable steering characteristic coefficient based on the desired steering characteristic information includes:

[0141] When θ is greater than 0, the variable steering characteristic coefficient is obtained as θ*K;

[0142] When θ equals 0, the variable steering characteristic coefficient is 0;

[0143] When θ is less than 0, the variable steering characteristic coefficient is obtained as follows:

[0144] Where K is the stability factor, τ is the preset safety factor, and u cr The critical speed at which a vehicle experiences a sharp turn when it is under excessive steering.

[0145] In some embodiments of the present invention, before correcting the ideal yaw rate based on the variable steering characteristic coefficient, the method further includes limiting the variable steering characteristic coefficient in the following manner:

[0146] The variable steering characteristic coefficient is respectively compared with Compare with K;

[0147] If the variable steering characteristic coefficient is less than The variable steering characteristic coefficient is then limited to...

[0148] If the variable steering characteristic coefficient is greater than K, then the variable steering characteristic coefficient is limited to K;

[0149] If the variable steering characteristic coefficient is greater than or equal to If the value is less than or equal to K, then the variable steering characteristic coefficient remains unchanged.

[0150] In some embodiments of the present invention, the ideal yaw rate is corrected according to the variable steering characteristic coefficient, including replacing the stability factor used to calculate the ideal yaw rate with the variable steering characteristic coefficient to achieve the correction of the ideal yaw rate.

[0151] In some embodiments of the present invention, an additional yaw moment is obtained based on the ideal centroid sideslip angle, the corrected ideal yaw rate, and the vehicle's actual centroid sideslip angle and actual yaw rate. This includes: limiting the ideal centroid sideslip angle and the corrected ideal yaw rate using the road adhesion coefficient of the road surface where the vehicle is located, respectively, to obtain a reference centroid sideslip angle and a reference yaw rate; and obtaining the additional yaw moment based on the reference centroid sideslip angle, the reference yaw rate, and the actual centroid sideslip angle and actual yaw rate.

[0152] In some embodiments of the present invention, the ideal yaw rate is limited by the road surface adhesion coefficient to obtain a reference yaw rate, including: determining the maximum yaw rate based on the road surface adhesion coefficient; comparing the ideal yaw rate with the maximum yaw rate; if the ideal yaw rate is greater than the maximum yaw rate, then the maximum yaw rate is used as the reference yaw rate; if the ideal yaw rate is less than or equal to the maximum yaw rate, then the ideal yaw rate is used as the reference yaw rate.

[0153] Among them, the maximum yaw rate is μ is the road surface adhesion coefficient, g is the gravitational acceleration, u is the vehicle speed, and η is the preset safety factor.

[0154] In some embodiments of the present invention, the ideal centroid sideslip angle is corrected using the road surface adhesion coefficient to obtain a reference centroid sideslip angle, including: determining the maximum centroid sideslip angle based on the road surface adhesion coefficient; comparing the ideal centroid sideslip angle with the maximum centroid sideslip angle; if the ideal centroid sideslip angle is greater than the maximum centroid sideslip angle, then the maximum centroid sideslip angle is used as the reference centroid sideslip angle; if the ideal centroid sideslip angle is less than or equal to the maximum centroid sideslip angle, then the ideal centroid sideslip angle is used as the reference centroid sideslip angle.

[0155] The maximum centroid sideslip angle is tan -1 0.02μg, where μ is the road surface adhesion coefficient and g is the gravitational acceleration.

[0156] In some embodiments of the present invention, an additional yaw moment is obtained based on a reference centroid sideslip angle, a reference yaw rate, and an actual centroid sideslip angle and an actual yaw rate. This includes: calculating a first difference between the reference yaw rate and the actual yaw rate, and calculating a second difference between the reference centroid sideslip angle and the actual centroid sideslip angle; and obtaining the additional yaw moment using a preset closed-loop control algorithm based on the first difference and the second difference.

[0157] In some embodiments of the present invention, the vehicle is a distributed drive vehicle; torque distribution based on additional yaw moment includes:

[0158] Torque distribution is performed using the following formula:

[0159]

[0160] In the formula, T reqL and T reqR These represent the torque distribution to the left-side drive motor and the torque distribution to the right-side drive motor, respectively. reqAXLE R is the total driving torque of the drive shaft. w Let B be the wheel rolling radius, B be the drive axle track width, and i be the wheel rolling radius. L and i R These are the reduction ratios of the left and right drive motors, respectively, M. z，req To add yaw moment.

[0161] It should be noted that for other specific embodiments of the vehicle control device of the present invention, please refer to the specific embodiments of the vehicle control method of the above embodiments of the present invention.

[0162] Figure 8 This is a structural block diagram of a vehicle according to an embodiment of the present invention.

[0163] like Figure 8 As shown, the vehicle 800 includes: the vehicle control device 700 of the above embodiment.

[0164] Based on the vehicle control method of the above embodiments, the present invention proposes a computer-readable storage medium.

[0165] In this embodiment, a computer program is stored on a computer-readable storage medium, and when the computer program is executed by a processor, it implements the vehicle control method of the above embodiment.

[0166] Based on the vehicle control method of the above embodiments, the present invention also proposes a computer program product.

[0167] In this embodiment, the computer program product includes a computer program that, when executed by a processor, implements the vehicle control method of the above embodiment.

[0168] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0169] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0170] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0171] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0172] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0173] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0174] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0175] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for controlling a vehicle, characterized in that, include: The ideal yaw rate is corrected based on the desired steering characteristic information; The additional yaw moment is obtained based on the ideal sideslip angle, the corrected ideal yaw rate, and the vehicle's actual sideslip angle and actual yaw rate. Torque distribution is performed based on the additional yaw moment; The correction of the ideal yaw rate based on the desired steering characteristic information includes: The variable steering characteristic coefficient is obtained based on the desired steering characteristic information; The ideal yaw rate is corrected based on the variable steering characteristic coefficient. The desired steering characteristic information includes the desired steering characteristic value. The process of obtaining the variable steering characteristic coefficient based on the desired steering characteristic information includes: when When the value is greater than 0, the variable steering characteristic coefficient is obtained as follows: ; when When equal to 0, the variable steering characteristic coefficient is obtained as follows: ; when When it is less than 0, the variable steering characteristic coefficient is obtained as follows: ; in, As a stability factor, To preset a safety factor, The critical speed at which the vehicle experiences a sharp turning condition under excessive steering conditions; Before correcting the ideal yaw rate based on the variable steering characteristic coefficient, the method further includes limiting the variable steering characteristic coefficient in the following manner: The variable steering characteristic coefficient is respectively compared with and Compare; If the variable steering characteristic coefficient is less than Then the variable steering characteristic coefficient is limited to ; If the variable steering characteristic coefficient is greater than Then the variable steering characteristic coefficient is limited to ; If the variable steering characteristic coefficient is greater than or equal to and less than or equal to If so, the variable steering characteristic coefficient remains unchanged.

2. The method according to claim 1, characterized in that, The correction of the ideal yaw rate based on the variable steering characteristic coefficient includes: The stability factor used to calculate the ideal yaw rate is replaced with the variable steering characteristic coefficient to correct the ideal yaw rate.

3. The method according to any one of claims 1-2, characterized in that, The process of obtaining the additional yaw moment based on the ideal sideslip angle, the corrected ideal yaw rate, and the vehicle's actual sideslip angle and actual yaw rate includes: By using the road surface adhesion coefficient of the road surface where the vehicle is located to limit the ideal centroid sideslip angle and the corrected ideal yaw rate, a reference centroid sideslip angle and a reference yaw rate are obtained. The additional yaw moment is obtained based on the reference centroid sideslip angle, the reference yaw rate, the actual centroid sideslip angle, and the actual yaw rate.

4. The method according to claim 3, characterized in that, The reference yaw rate is obtained by limiting the ideal yaw rate using the road surface adhesion coefficient, including: The maximum yaw rate is determined based on the road surface adhesion coefficient. Compare the ideal yaw rate with the maximum yaw rate; If the ideal yaw rate is greater than the maximum yaw rate, then the maximum yaw rate is used as the reference yaw rate. If the ideal yaw rate is less than or equal to the maximum yaw rate, then the ideal yaw rate is used as the reference yaw rate.

5. The method according to claim 3 or 4, characterized in that, The ideal centroid sideslip angle is corrected using the road surface adhesion coefficient to obtain the reference centroid sideslip angle, including: The maximum centroid sideslip angle is determined based on the road surface adhesion coefficient. Compare the ideal centroid sideslip angle with the maximum centroid sideslip angle; If the ideal centroid sideslip angle is greater than the maximum centroid sideslip angle, then the maximum centroid sideslip angle is taken as the reference centroid sideslip angle. If the ideal centroid sideslip angle is less than or equal to the maximum centroid sideslip angle, then the ideal centroid sideslip angle is used as the reference centroid sideslip angle.

6. The method according to claim 4, characterized in that, The maximum yaw rate is ,in, The road surface adhesion coefficient is... It is the acceleration due to gravity. Let η be the vehicle speed, and η be a preset safety factor.

7. The method according to claim 5, characterized in that, The maximum centroid sideslip angle is ,in, The road surface adhesion coefficient is... This is the acceleration due to gravity.

8. The method according to any one of claims 3-7, characterized in that, The step of obtaining the additional yaw moment based on the reference sideslip angle, the reference yaw rate, the actual sideslip angle, and the actual yaw rate includes: Calculate the first difference between the reference yaw rate and the actual yaw rate, and calculate the second difference between the reference centroid sideslip angle and the actual centroid sideslip angle; The additional yaw moment is obtained by using a preset closed-loop control algorithm based on the first difference and the second difference.

9. The method according to any one of claims 1-8, characterized in that, The vehicle is a distributed drive vehicle; the torque distribution based on the additional yaw moment includes: Torque distribution is performed using the following formula: In the formula, and These are the torque distributions for the left-side drive motor and the right-side drive motor of the vehicle, respectively. This represents the total driving torque of the drive shaft. The radius of the wheel's rolling motion. For the drive axle track, and These are the reduction ratios of the left drive motor and the right drive motor, respectively. The additional yaw moment.

10. A vehicle control device, characterized in that, For implementing the method according to any one of claims 1-9, comprising: The correction module is used to correct the ideal yaw rate based on the desired steering characteristic information; The processing module is used to obtain the additional yaw moment based on the ideal center of gravity sideslip angle, the corrected ideal yaw rate, and the vehicle's actual center of gravity sideslip angle and actual yaw rate. The distribution module is used to distribute torque based on the additional yaw moment.

11. A vehicle, characterized in that, include: The vehicle control device according to claim 10.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method according to any one of claims 1-9.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method according to any one of claims 1-9.

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