Method and equipment for controlling main power of suspension under steering working condition and medium

Abstract

The invention provides a suspension active force control method and device under a steering working condition and a medium, and the method comprises the steps: determining an expected roll angle according to a current lateral acceleration and roll angle planning scheme, and determining an expected pitch angle according to the expected roll angle, a steering direction and a pitch angle planning scheme; determining an active roll control moment according to the current roll angle, the current lateral acceleration and the expected roll angle, and determining an active pitch control moment according to the current pitch angle and the expected pitch angle; and according to the active roll control moment, the active pitch control moment and a preset cost function, solving to obtain a control active force corresponding to each suspension. According to the technical scheme, active planning and control over the posture of the vehicle body under the steering working condition are achieved, and the driving safety effect is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, specifically to a method, device, and medium for controlling the active force of a suspension under steering conditions. Background Technology

[0002] When a vehicle turns, it will generate a large body roll angle. Conventional active suspension control strategies in cornering conditions often only consider suppressing body roll. However, in order to ensure the driver has a better driving view and to ensure driving safety, the front of the vehicle needs to be depressed to a certain extent when cornering, that is, the vehicle needs to maintain a certain pitch angle.

[0003] Currently, traditional semi-active suspensions, due to the characteristics of semi-active shock absorbers and the limited range of damping force adjustment, cannot control vehicle roll while simultaneously planning and tracking front-end sag during cornering, nor do they consider the need for planning and controlling vehicle pitch angle during steering. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, this application aims to provide a method, device and medium for active suspension force control under steering conditions, so as to realize active planning and control of the vehicle body attitude under steering conditions and improve driving safety.

[0005] This application provides a method for controlling the active force of a suspension under steering conditions, the method comprising: Based on the current lateral acceleration and roll angle planning scheme, determine the desired roll angle, and based on the desired roll angle, steering direction, and pitch angle planning scheme, determine the desired pitch angle. The active roll control torque is determined based on the current roll angle, the current lateral acceleration, and the desired roll angle; and the active pitch control torque is determined based on the current pitch angle and the desired pitch angle. Based on the active roll control torque, the active pitch control torque, and the preset cost function, the control active force corresponding to each suspension is obtained; The preset cost function is a function with the objective of minimizing the value, constructed based on the first relationship between the active roll control torque and the control active force corresponding to each suspension, and the second relationship between the active pitch control torque and the control active force corresponding to each suspension.

[0006] According to the technical solution provided in the embodiments of this application, optionally, determining the desired roll angle based on the current lateral acceleration and roll angle planning scheme includes: In response to the current lateral acceleration being less than the lateral acceleration threshold, the desired roll angle is determined to be 0; In response to the current lateral acceleration being greater than or equal to the lateral acceleration threshold, the desired roll angle corresponding to the current lateral acceleration is determined based on the current lateral acceleration, the lateral acceleration threshold, and the control roll gradient. Wherein, the controlled roll gradient is less than the passive roll gradient, and the passive roll gradient is the ratio of the uncontrolled roll angle corresponding to the lateral acceleration threshold to the lateral acceleration threshold.

[0007] According to the technical solution provided in the embodiments of this application, optionally, determining the desired pitch angle based on the desired roll angle, steering direction, and pitch angle planning scheme includes: In response to the steering direction being a left turn, the pitch angle to be limited is determined based on the first slope under the left turn condition and the desired roll angle; In response to the steering direction being a right turn, the pitch angle to be limited is determined based on the second slope under the right turn condition and the desired roll angle; The desired pitch angle is determined based on the preset maximum pitch angle and the pitch angle to be limited.

[0008] According to the technical solution provided in the embodiments of this application, optionally, determining the active roll control torque based on the current roll angle, the current lateral acceleration, and the desired roll angle includes: The desired lateral acceleration is determined based on the desired roll angle and the passive roll gradient. The feedforward active roll control torque is determined based on the desired lateral acceleration, the current lateral acceleration, the vehicle mass, and the vehicle roll radius. Based on the current roll angle and the desired roll angle, determine the roll angle difference, and based on the roll angle difference and the first proportional-integral-derivative controller, determine the feedback active roll control torque; The sum of the feedforward active roll control torque and the feedback active roll control torque is taken as the active roll control torque; The passive roll gradient is the ratio of the uncontrolled roll angle to the corresponding lateral acceleration when no active suspension control is applied.

[0009] According to the technical solution provided in the embodiments of this application, optionally, determining the feedforward active roll control torque based on the desired lateral acceleration, the current lateral acceleration, the vehicle mass, and the vehicle roll radius includes: The feedforward active roll control torque is determined using the following formula:

[0010] in, It is the feedforward active roll control torque. It's the car body quality. It is the vehicle's roll radius. It is the current lateral acceleration. It is the desired lateral acceleration.

[0011] According to the technical solution provided in the embodiments of this application, optionally, determining the active pitch control torque based on the current pitch angle and the desired pitch angle includes: The desired longitudinal acceleration is determined based on the desired pitch angle and the passive pitch gradient. The feedforward active pitch control torque is determined based on the desired longitudinal acceleration, vehicle mass, and vehicle pitch radius. Based on the current pitch angle and the desired pitch angle, determine the pitch angle difference, and based on the pitch angle difference and the second proportional-integral-derivative controller, determine the feedback active pitch control torque; The sum of the feedforward active pitch control torque and the feedback active pitch control torque is taken as the active pitch control torque; The passive pitch gradient is the ratio of the uncontrolled pitch angle to the corresponding longitudinal acceleration when no active suspension control is applied.

[0012] According to the technical solution provided in the embodiments of this application, optionally, the first relationship between the active roll control torque and the control active force corresponding to each suspension is:

[0013] The second relationship between the active pitch control torque and the corresponding active control force of each suspension is:

[0014] The preset cost function is:

[0015] in, For active roll control torque, For active pitch control torque, This is the distance from the vehicle's center of gravity to the left wheel. The distance from the vehicle's center of gravity to the right wheel. The distance from the vehicle's center of gravity to the front axle. The distance from the vehicle's center of gravity to the rear axle. It is the control force corresponding to the left front suspension. It is the control force corresponding to the right front suspension. It is the control force corresponding to the left rear suspension. It is the control force corresponding to the right rear suspension. f (·) represents the preset cost function.

[0016] According to the technical solution provided in the embodiments of this application, optionally, the step of obtaining the control active force corresponding to each suspension based on the active roll control torque, the active pitch control torque, and the preset cost function includes: Substitute the active roll control torque and the active pitch control torque into the preset cost function, and calculate the partial derivatives of the active control forces corresponding to each suspension to obtain the partial derivatives of the active forces corresponding to each suspension. With the goal of minimizing the partial derivative of the active force corresponding to each suspension, the search iteratively proceeds in the negative gradient direction to obtain the control active force corresponding to each suspension.

[0017] This application also provides an electronic device, the electronic device comprising: Processor and memory; The processor executes the steps of the suspension active force control method under steering conditions as described in any embodiment by calling the program or instructions stored in the memory.

[0018] This application also provides a computer-readable storage medium storing a program or instructions that cause a computer to perform the steps of the suspension active force control method under steering conditions as described in any embodiment.

[0019] In summary, this application proposes a suspension active force control method under steering conditions. By planning a scheme based on the current lateral acceleration and roll angle, the desired roll angle is determined. Then, based on the desired roll angle, steering direction, and pitch angle, the desired pitch angle is determined. This helps suppress roll angle under steering conditions and provides a certain pitch angle to reduce front-end pressure and improve visibility. Furthermore, based on the current roll angle, current lateral acceleration, and desired roll angle, an active roll control torque is determined. Similarly, based on the current pitch angle and desired pitch angle, an active pitch control torque is determined. Finally, based on the active roll control torque, active pitch control torque, and a preset cost function, the corresponding control active force for each suspension is calculated. This achieves active planning and control of the vehicle's attitude under steering conditions, improving driving safety. Attached Figure Description

[0020] Figure 1 This is a flowchart of a suspension active force control method under steering conditions provided in an embodiment of this application; Figure 2 This is a flowchart of another suspension active force control method under steering conditions provided in the embodiments of this application; Figure 3 This is a schematic diagram illustrating the relationship between uncontrolled roll angle and lateral acceleration, as well as the functional relationship in the roll angle planning scheme, provided in the embodiments of this application. Figure 4 This is a schematic diagram of the functional relationship in the pitch angle planning scheme provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0021] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a flowchart illustrating a suspension active force control method under steering conditions provided in an embodiment of this application. See also... Figure 1 The specific methods for controlling the active force of the suspension under this steering condition include: S110. Based on the current lateral acceleration and roll angle planning scheme, determine the desired roll angle, and based on the desired roll angle, steering direction, and pitch angle planning scheme, determine the desired pitch angle.

[0024] The current lateral acceleration is the vehicle's lateral acceleration measured by an acceleration sensor installed on the vehicle. The roll angle planning scheme is used to determine the desired roll angle corresponding to the current lateral acceleration after applying active suspension control. The desired roll angle is the roll angle corresponding to the current lateral acceleration after applying active suspension control. It can be understood that the roll angle planning scheme is a pre-planned functional relationship between the roll angle and lateral acceleration; the desired roll angle obtained after planning according to this functional relationship is less than the uncontrolled roll angle before planning. The steering direction is the direction corresponding to the current steering condition, including left and right turns. The pitch angle planning scheme is used to determine the desired roll angle and the pitch angle corresponding to the steering direction after applying active suspension control. The desired pitch angle is the pitch angle corresponding to the desired roll angle and the steering direction after applying active suspension control. Understandably, the pitch angle planning scheme is a pre-planned functional relationship between the pitch angle, the desired roll angle, and the steering direction. The desired pitch angle obtained after planning according to the above functional relationship can make the front of the car have a certain degree of downward pressure under steering conditions, ensuring that the driver has a wider field of vision.

[0025] Specifically, by substituting the current lateral acceleration into the roll angle planning scheme, the desired roll angle after applying control can be obtained, i.e., the expected roll angle. Furthermore, by substituting the expected roll angle and steering direction into the pitch angle planning scheme, the desired pitch angle after applying control can be obtained, i.e., the expected pitch angle.

[0026] S120. Determine the active roll control torque based on the current roll angle, current lateral acceleration, and desired roll angle, and determine the active pitch control torque based on the current pitch angle and desired pitch angle.

[0027] Here, the current roll angle is the currently measured roll angle of the vehicle body. The active roll control torque is the suspension torque actively applied based on the analysis of roll conditions. The current pitch angle is the currently measured pitch angle of the vehicle body. The active pitch control torque is the suspension torque actively applied based on the analysis of steering conditions, pressing down on the front of the vehicle.

[0028] Specifically, active roll control torque can be determined through active and / or passive methods. The active method involves determining the lateral acceleration without applied suspension forces based on the desired roll angle, and then using the difference between the determined lateral acceleration and the current lateral acceleration to plan the active roll control torque. The passive method applies the active roll control torque using a feedback iterative approach to bring the current roll angle closer to the desired roll angle. A combined active and passive method involves superimposing the active roll control torques obtained from both methods to obtain a new active roll control torque. Similarly, active pitch control torque can be determined through active and / or passive methods. The active method involves determining the longitudinal acceleration without applied suspension forces based on the desired pitch angle, and then using the determined longitudinal acceleration to plan the active pitch control torque. The passive method applies the active pitch control torque using a feedback iterative approach to bring the current pitch angle closer to the desired pitch angle. A combined active and passive method involves superimposing the active pitch control torques obtained from both methods to obtain a new active pitch control torque.

[0029] Based on the above example, the active roll control torque can be determined using the current roll angle, current lateral acceleration, and desired roll angle in the following manner: Determine the desired lateral acceleration based on the desired roll angle and the passive roll gradient; The feedforward active roll control torque is determined based on the desired lateral acceleration, the current lateral acceleration, the vehicle mass, and the vehicle roll radius. Based on the current roll angle and the desired roll angle, determine the roll angle difference, and based on the roll angle difference and the first proportional-integral-derivative controller, determine the feedback active roll control torque; The sum of the feedforward active roll control torque and the feedback active roll control torque is taken as the active roll control torque.

[0030] Here, the passive roll gradient is the ratio of the uncontrolled roll angle to the corresponding lateral acceleration when no active suspension control is applied. The desired lateral acceleration is the lateral acceleration corresponding to the desired roll angle when no active suspension control is applied. The feedforward active roll control torque is a portion of the active roll control torque obtained through active adjustment. The roll angle difference is the difference between the current roll angle and the desired roll angle. The first proportional-integral-derivative (PID) controller is a PID controller used for feedback adjustment when the roll angle difference is 0. The feedback active roll control torque is a portion of the active roll control torque with hysteresis correction.

[0031] Specifically, the ratio of the desired roll angle to the passive roll gradient is taken as the desired lateral acceleration. Then, the difference between the current lateral acceleration and the desired lateral acceleration is multiplied sequentially by the vehicle mass and the vehicle roll radius to obtain the feedforward active roll control torque. The difference between the current roll angle and the desired roll angle is defined as the roll angle difference. With the roll angle difference set to zero, a feedback active roll control torque is output through a first proportional-integral-derivative controller. The sum of the feedforward active roll control torque and the feedback active roll control torque is taken as the active roll control torque.

[0032] For example, the desired lateral acceleration can be determined using the following formula:

[0033] in, It is the desired lateral acceleration. It is the desired roll angle. It is a passive tilt gradient.

[0034] Based on the above example, the feedforward active roll control torque can be determined using the following formula:

[0035] in, It is the feedforward active roll control torque. It's the car body quality. It is the vehicle's roll radius. It is the current lateral acceleration. It is the desired lateral acceleration.

[0036] Furthermore, the active roll control torque is determined using the following formula:

[0037] in, For feedforward active roll control torque, To provide feedback on the active roll control torque, This is the active roll control torque.

[0038] Based on the above example, the active pitch control torque can be determined according to the current pitch angle and the desired pitch angle in the following way: Determine the desired longitudinal acceleration based on the desired pitch angle and passive pitch gradient; The feedforward active pitch control torque is determined based on the desired longitudinal acceleration, vehicle mass, and vehicle pitch radius. Based on the current pitch angle and the desired pitch angle, determine the pitch angle difference, and based on the pitch angle difference and the second proportional-integral-derivative controller, determine the feedback active pitch control torque; The sum of the feedforward active pitch control torque and the feedback active pitch control torque is taken as the active pitch control torque.

[0039] Here, passive pitch gradient is the ratio of the uncontrolled pitch angle to the corresponding longitudinal acceleration when no active suspension control is applied. Desired longitudinal acceleration is the longitudinal acceleration corresponding to the desired pitch angle when no active suspension control is applied. Feedforward active pitch control torque is a portion of the active pitch control torque obtained through active adjustment. Pitch angle difference is the difference between the current pitch angle and the desired pitch angle. The second proportional-integral-derivative (PID) controller is used for feedback adjustment to ensure the pitch angle difference is zero. Feedback active pitch control torque is a portion of the active pitch control torque used for hysteresis correction.

[0040] Specifically, the ratio of the desired pitch angle to the passive pitch gradient is taken as the desired longitudinal acceleration. Then, the desired longitudinal acceleration is multiplied sequentially by the vehicle mass and the vehicle pitch radius to obtain the feedforward active pitch control torque. The difference between the current pitch angle and the desired pitch angle is defined as the pitch angle difference. With the goal of achieving a pitch angle difference of 0, the second proportional-integral-derivative controller outputs the feedback active pitch control torque. The sum of the feedforward active pitch control torque and the feedback active pitch control torque is taken as the active pitch control torque.

[0041] For example, the desired longitudinal acceleration can be determined using the following formula:

[0042] in, It is the expected longitudinal acceleration. It is the expected pitch angle. It is a passive pitch gradient.

[0043] Based on the above example, the feedforward active pitch control torque can be determined using the following formula:

[0044] in, It is the feedforward active pitch control torque. It's the car body quality. It is the vehicle's pitch radius. It is the desired longitudinal acceleration.

[0045] Furthermore, the active pitch control torque is determined using the following formula:

[0046] in, For feedforward active pitch control torque, To provide feedback on the active pitch control torque, This is for active pitch control torque.

[0047] S130. Based on the active roll control torque, active pitch control torque, and preset cost function, the control active force corresponding to each suspension is obtained.

[0048] The preset cost function is a function constructed with the goal of minimizing the cost, based on the first relationship between the active roll control torque and the corresponding active control force of each suspension, and the second relationship between the active pitch control torque and the corresponding active control force of each suspension. The active control force is the control force for each suspension determined by combining the active roll control torque and the active pitch control torque.

[0049] Specifically, by substituting the active roll control torque and the active pitch control torque into the preset cost function and solving the preset cost function, the control active force corresponding to each suspension can be obtained.

[0050] It should be noted that the preset cost function can be solved in any way, and there are no specific restrictions on the specific solution method.

[0051] For example, the first relationship between the active roll control torque and the corresponding active control force of each suspension is:

[0052] The second relationship between the active pitch control torque and the corresponding active control force of each suspension is:

[0053] The preset cost function is:

[0054] in, For active roll control torque, For active pitch control torque, This is the distance from the vehicle's center of gravity to the left wheel. This is the distance from the vehicle's center of gravity to the right wheel. This is the distance from the vehicle's center of gravity to the front axle. This is the distance from the vehicle's center of gravity to the rear axle. It is the control force corresponding to the left front suspension. It is the control force corresponding to the right front suspension. It is the control force corresponding to the left rear suspension. It is the control force corresponding to the right rear suspension. f (·) represents the preset cost function.

[0055] The suspension active force control method under steering conditions provided in this application embodiment determines the desired roll angle based on the current lateral acceleration and roll angle planning scheme, and determines the desired pitch angle based on the desired roll angle, steering direction, and pitch angle planning scheme. This helps to suppress the roll angle under steering conditions and provides a certain pitch angle to reduce the front of the vehicle and provide better visibility. Furthermore, it determines the active roll control torque based on the current roll angle, current lateral acceleration, and desired roll angle, and determines the active pitch control torque based on the current pitch angle and desired pitch angle. Based on the active roll control torque, active pitch control torque, and a preset cost function, the corresponding control active force for each suspension is obtained. This achieves active planning and control of the vehicle's attitude under steering conditions, improving driving safety.

[0056] Figure 2 This is a flowchart of another suspension active force control method under steering conditions provided in this application embodiment. Based on the above embodiments, the process of determining the desired roll angle and desired pitch angle, as well as the process of solving the corresponding control active force for each suspension, are illustrated by example. See [link to documentation]. Figure 2 The specific methods for controlling the active force of the suspension under this steering condition include: S210. In response to the current lateral acceleration being less than the lateral acceleration threshold, the desired roll angle is determined to be 0. In response to the current lateral acceleration being greater than or equal to the lateral acceleration threshold, the desired roll angle corresponding to the current lateral acceleration is determined based on the current lateral acceleration, the lateral acceleration threshold, and the control roll gradient.

[0057] The passive roll gradient is the ratio of the uncontrolled roll angle to the lateral acceleration threshold corresponding to the lateral acceleration threshold. The controlled roll gradient is the ratio of the desired roll angle to the lateral acceleration after control is applied to the suspension. The controlled roll gradient is less than the passive roll gradient. The lateral acceleration threshold is used to distinguish the lateral acceleration in the two stages of the roll angle planning scheme.

[0058] Specifically, if the current lateral acceleration is less than the lateral acceleration threshold, it is determined that the lateral acceleration is small, and the desired roll angle is directly set to 0. If the current lateral acceleration is greater than or equal to the lateral acceleration threshold, it means that the desired roll angle cannot be directly set to 0 at this time, and roll angle can only be planned and suppressed. Therefore, it can be determined that the desired roll angle corresponding to the lateral acceleration threshold is still 0. Combined with controlling the roll gradient, the linear function relationship between the desired roll angle and the lateral acceleration at this stage can be determined. Substituting the current lateral acceleration into this linear function relationship, the desired roll angle corresponding to the current lateral acceleration is obtained.

[0059] For example, when a vehicle is cornering, the body experiences significant lateral acceleration and roll angle. There is a linear relationship between lateral acceleration and roll angle, and the slope of the curve between them is the passive roll gradient. When the active suspension is not engaged, the passive roll gradient is relatively large. The passive roll gradient without active suspension engagement is shown below. Plan the desired roll angle. Figure 3 This is a schematic diagram illustrating the relationship between uncontrolled roll angle and lateral acceleration, as well as the functional relationship in the roll angle planning scheme, provided in the embodiments of this application. For example... Figure 3 As shown, the roll angle planning scheme is divided into two stages: Stage ①: When lateral acceleration Less than the set lateral acceleration threshold At this stage, the lateral acceleration of the vehicle body is relatively small, and the planned desired roll angle is... .

[0060] Phase 2: When lateral acceleration Greater than or equal to the set lateral acceleration threshold At this time, the planned control roll gradient Less than the passive roll gradient ,Right now Therefore, based on the current lateral acceleration The desired roll angle can be obtained from the current lateral acceleration. .

[0061] S220. In response to a left turn, the pitch angle to be limited is determined based on the first slope and the desired roll angle under the left turn condition; in response to a right turn, the pitch angle to be limited is determined based on the second slope and the desired roll angle under the right turn condition.

[0062] The first slope is the slope of the curve between the preset desired pitch angle and the preset desired roll angle under left-turn conditions. The second slope is the slope of the curve between the preset desired pitch angle and the preset desired roll angle under right-left-turn conditions. The pitch angle to be limited is the product of the first slope or the second slope and the desired roll angle.

[0063] Specifically, if the steering direction is left turn, the product of the first slope under the left turn condition and the desired roll angle is used as the pitch angle to be limited. If the steering direction is right turn, the product of the second slope under the right turn condition and the desired roll angle is used as the pitch angle to be limited.

[0064] S230. Determine the desired pitch angle based on the preset maximum pitch angle and the pitch angle to be limited.

[0065] Among them, the preset maximum pitch angle is the maximum planned pitch angle after the suspension is actively controlled.

[0066] Specifically, if the pitch angle to be limited is less than or equal to the preset maximum pitch angle, then the pitch angle to be limited is determined as the desired pitch angle. If the pitch angle to be limited is greater than the preset maximum pitch angle, then the preset maximum pitch angle is determined as the desired pitch angle.

[0067] For example, when a vehicle is turning, it is desirable for the front of the vehicle to have a certain degree of downward tilt, i.e., the vehicle body maintains a certain pitch angle, to ensure a wider field of vision for the driver. The desired pitch angle can be planned based on the desired roll angle planned for turning. Figure 4 This is a schematic diagram of the functional relationship in the pitch angle planning scheme provided in this application embodiment. Vehicle nodding is defined as positive and tilting up as negative; left tilting is positive and right tilting is negative. To ensure the vehicle's front end remains depressed during turns, providing the driver with better visibility, the planned desired pitch angle is always positive, regardless of whether the vehicle is turning right or left. The planned desired pitch angle in the pitch angle planning scheme is shown in the following formula:

[0068]

[0069] in, For the desired pitch angle, To limit the pitch angle, For the desired roll angle, This is the first slope between the desired pitch angle and the desired roll angle under left-turn conditions. This is the second slope between the desired pitch angle and the desired roll angle under right turn conditions. This is the preset maximum pitch angle.

[0070] S240. Determine the active roll control torque based on the current roll angle, current lateral acceleration, and desired roll angle, and determine the active pitch control torque based on the current pitch angle and desired pitch angle.

[0071] S250. Substitute the active roll control torque and the active pitch control torque into the preset cost function, and calculate the partial derivative of the active force corresponding to each suspension to obtain the partial derivative of the active force corresponding to each suspension.

[0072] Among them, the active force partial derivative is the partial derivative of the control active force corresponding to each suspension in the preset cost function.

[0073] S260. With the goal of minimizing the partial derivative of the active force corresponding to each suspension, perform a search iteration in the negative gradient direction to obtain the control active force corresponding to each suspension.

[0074] For example, the preset cost function is:

[0075] in, For active roll control torque, For active pitch control torque, This is the distance from the vehicle's center of gravity to the left wheel. This is the distance from the vehicle's center of gravity to the right wheel. This is the distance from the vehicle's center of gravity to the front axle. This is the distance from the vehicle's center of gravity to the rear axle. It is the control force corresponding to the left front suspension. It is the control force corresponding to the right front suspension. It is the control force corresponding to the left rear suspension. It is the control force corresponding to the right rear suspension. f (·) represents the preset cost function.

[0076] According to the preset cost function To each By taking the partial derivatives, we can obtain the partial derivatives of the active forces corresponding to each suspension:

[0077] The search iterative algorithm is based on the negative gradient direction. The control force corresponding to each suspension advances a preset step size in the negative gradient direction each time. :

[0078] The control forces corresponding to each suspension before the current iteration number advances in the negative gradient direction are preset with a step size. The control forces for each suspension are preset after advancing a step size in the negative gradient direction for the current iteration. In the next iteration, the control forces are updated. for .until , , When the gradient reaches its minimum, the iterative search is considered complete. The optimal solution is determined to satisfy both the roll active control torque and the pitch active control torque, thus obtaining the corresponding active control force for each suspension.

[0079] The suspension active force control method under steering conditions provided in this application embodiment, in response to the current lateral acceleration being less than the lateral acceleration threshold, determines the desired roll angle as 0; in response to the current lateral acceleration being greater than or equal to the lateral acceleration threshold, determines the desired roll angle corresponding to the current lateral acceleration based on the current lateral acceleration, the lateral acceleration threshold, and the control roll gradient, so as to reasonably limit the magnitude of the roll angle; in response to the steering direction being left turn, determines the pitch angle to be limited based on the first slope under left turn conditions and the desired roll angle; in response to the steering direction being right turn, determines the pitch angle to be limited based on the second slope under right turn conditions and the desired roll angle, and determines the pitch angle to be limited based on the preset maximum pitch angle and the desired roll angle. The desired pitch angle is determined to plan for a certain pitch angle to lower the vehicle's front end and provide better visibility. Then, the active roll control torque and active pitch control torque are substituted into a preset cost function, and the partial derivatives of the control forces corresponding to each suspension are calculated. The minimum value of the partial derivatives of the control forces corresponding to each suspension is used as the objective, and the search iterative process is performed in the negative gradient direction to obtain the control forces corresponding to each suspension. This allows for a fast and accurate solution to the control forces corresponding to each suspension, enabling reasonable and accurate planning of the vehicle's roll and pitch angles under steering conditions. This improves the solution speed for the active control forces corresponding to each suspension, thereby enhancing driving safety.

[0080] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. For example... Figure 5 As shown, the electronic device 500 includes one or more processors 501 and memory 502.

[0081] The processor 501 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 500 to perform desired functions.

[0082] The memory 502 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 501 may execute the program instructions to implement the suspension active force control method under steering conditions described above in any embodiment of this application, and / or other desired functions. Various contents such as initial extrinsic parameters and thresholds may also be stored in the computer-readable storage medium.

[0083] In one example, the electronic device 500 may further include an input device 503 and an output device 504, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown). The input device 503 may include, for example, a keyboard, a mouse, etc. The output device 504 may output various information to the outside, including warning messages, braking force, etc. The output device 504 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0084] Of course, for the sake of simplicity, Figure 5 Only some of the components of the electronic device 500 relevant to this application are shown in this illustration; components such as buses, input / output interfaces, etc., are omitted. In addition, the electronic device 500 may include any other suitable components depending on the specific application.

[0085] In addition to the methods and devices described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps of the suspension active force control method under steering conditions provided in any embodiment of this application.

[0086] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0087] Furthermore, embodiments of this application may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the suspension active force control method under steering conditions provided in any embodiment of this application.

[0088] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0089] It should be noted that the terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. As shown in the specification and claims of this application, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0090] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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 between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0091] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A method for controlling the active force of a suspension under steering conditions, characterized in that, include: Based on the current lateral acceleration and roll angle planning scheme, determine the desired roll angle, and based on the desired roll angle, steering direction, and pitch angle planning scheme, determine the desired pitch angle. The active roll control torque is determined based on the current roll angle, the current lateral acceleration, and the desired roll angle; and the active pitch control torque is determined based on the current pitch angle and the desired pitch angle. Based on the active roll control torque, the active pitch control torque, and the preset cost function, the control active force corresponding to each suspension is obtained; The preset cost function is a function with the objective of minimizing the value, constructed based on the first relationship between the active roll control torque and the control active force corresponding to each suspension, and the second relationship between the active pitch control torque and the control active force corresponding to each suspension.

2. The method according to claim 1, characterized in that, The step of determining the desired roll angle based on the current lateral acceleration and roll angle planning scheme includes: In response to the current lateral acceleration being less than the lateral acceleration threshold, the desired roll angle is determined to be 0; In response to the current lateral acceleration being greater than or equal to the lateral acceleration threshold, the desired roll angle corresponding to the current lateral acceleration is determined based on the current lateral acceleration, the lateral acceleration threshold, and the control roll gradient. Wherein, the controlled roll gradient is less than the passive roll gradient, and the passive roll gradient is the ratio of the uncontrolled roll angle corresponding to the lateral acceleration threshold to the lateral acceleration threshold.

3. The method according to claim 1, characterized in that, The step of determining the desired pitch angle based on the desired roll angle, steering direction, and pitch angle planning scheme includes: In response to the steering direction being a left turn, the pitch angle to be limited is determined based on the first slope under the left turn condition and the desired roll angle; In response to the steering direction being a right turn, the pitch angle to be limited is determined based on the second slope under the right turn condition and the desired roll angle; The desired pitch angle is determined based on the preset maximum pitch angle and the pitch angle to be limited.

4. The method according to claim 1, characterized in that, The step of determining the active roll control torque based on the current roll angle, the current lateral acceleration, and the desired roll angle includes: The desired lateral acceleration is determined based on the desired roll angle and the passive roll gradient. The feedforward active roll control torque is determined based on the desired lateral acceleration, the current lateral acceleration, the vehicle mass, and the vehicle roll radius. Based on the current roll angle and the desired roll angle, determine the roll angle difference, and based on the roll angle difference and the first proportional-integral-derivative controller, determine the feedback active roll control torque; The sum of the feedforward active roll control torque and the feedback active roll control torque is taken as the active roll control torque; The passive roll gradient is the ratio of the uncontrolled roll angle to the corresponding lateral acceleration when no active suspension control is applied.

5. The method according to claim 4, characterized in that, The step of determining the feedforward active roll control torque based on the desired lateral acceleration, the current lateral acceleration, the vehicle mass, and the vehicle roll radius includes: The feedforward active roll control torque is determined using the following formula: in, It is the feedforward active roll control torque. It's the car body quality. It is the vehicle's roll radius. It is the current lateral acceleration. It is the desired lateral acceleration.

6. The method according to claim 1, characterized in that, The step of determining the active pitch control torque based on the current pitch angle and the desired pitch angle includes: The desired longitudinal acceleration is determined based on the desired pitch angle and the passive pitch gradient. The feedforward active pitch control torque is determined based on the desired longitudinal acceleration, vehicle mass, and vehicle pitch radius. Based on the current pitch angle and the desired pitch angle, determine the pitch angle difference, and based on the pitch angle difference and the second proportional-integral-derivative controller, determine the feedback active pitch control torque; The sum of the feedforward active pitch control torque and the feedback active pitch control torque is taken as the active pitch control torque; The passive pitch gradient is the ratio of the uncontrolled pitch angle to the corresponding longitudinal acceleration when no active suspension control is applied.

7. The method according to claim 1, characterized in that, The first relationship between the active roll control torque and the corresponding active control force of each suspension is: The second relationship between the active pitch control torque and the corresponding active control force of each suspension is: The preset cost function is: in, For active roll control torque, For active pitch control torque, This is the distance from the vehicle's center of gravity to the left wheel. The distance from the vehicle's center of gravity to the right wheel. The distance from the vehicle's center of gravity to the front axle. The distance from the vehicle's center of gravity to the rear axle. It is the control force corresponding to the left front suspension. It is the control force corresponding to the right front suspension. It is the control force corresponding to the left rear suspension. It is the control force corresponding to the right rear suspension. f (·) represents the preset cost function.

8. The method according to claim 1, characterized in that, The step of calculating the control forces corresponding to each suspension based on the active roll control torque, the active pitch control torque, and a preset cost function includes: Substitute the active roll control torque and the active pitch control torque into the preset cost function, and calculate the partial derivatives of the active control forces corresponding to each suspension to obtain the partial derivatives of the active forces corresponding to each suspension. With the goal of minimizing the partial derivative of the active force corresponding to each suspension, the search iteratively proceeds in the negative gradient direction to obtain the control active force corresponding to each suspension.

9. An electronic device, characterized in that, The electronic device includes: Processor and memory; The processor executes the steps of the suspension active force control method under steering conditions as described in any one of claims 1 to 8 by calling the program or instructions stored in the memory.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program or instructions that cause a computer to perform the steps of the suspension active force control method under steering conditions as described in any one of claims 1 to 8.

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