Method and system for determining desired tire grip in active downforce control

Abstract

The present disclosure relates to a method for downforce control. The method includes: receiving sensor data from a sensor; determining a first demanded normal force at a first axle of the vehicle and a second demanded normal force at a second axle of the vehicle using the sensor data by employing feed-forward control; determining a first demand normal force adjustment amount at a first axle of the vehicle and a second demand normal force adjustment amount at a second axle of the vehicle using the sensor data by employing feedback control; fusing a first demand normal force at a first axle of the vehicle with the first demand normal force adjustment amount to determine a first adjustment normal force demand at the first axle; and fusing the second demand normal force with the second demand normal force adjustment amount to determine a second adjustment normal force demand at the second axle.

Description

Technical Field

[0001] The present disclosure relates to methods and systems for determining desired tire grip in active downforce control of a vehicle. Background Art

[0002] This introduction generally introduces the background of the invention. The presently mentioned work of the inventors (i.e., the work described in this introduction) and aspects of this specification that did not otherwise qualify as prior art at the time of filing are not to be explicitly or implicitly identified as prior art against the present invention.

[0003] Downforce refers to the vertical load created by the aerodynamic parts of a vehicle during motion. Some vehicles include actuators to control downforce. Summary of the invention

[0004] The present disclosure describes a method for determining required tire grip in active downforce control of a vehicle. The method also includes: receiving sensor data from a plurality of sensors of a vehicle, wherein the vehicle includes a vehicle body, a first axle coupled to the vehicle body, a second axle coupled to the vehicle body, a first aerodynamic actuator coupled to the vehicle body, and a second aerodynamic actuator coupled to the vehicle body, wherein the first aerodynamic actuator includes a first aerodynamic body that can move relative to the vehicle body, and the second aerodynamic actuator includes a second aerodynamic body that can move relative to the vehicle body. The method also includes: determining a first required normal force at a first axle of the vehicle and a second required normal force at a second axle of the vehicle by using a tire friction circle and the sensor data by using feedforward control. The method also includes: determining a first required normal force adjustment at a first axle of the vehicle and a second required normal force adjustment at a second axle of the vehicle by using the sensor data by using feedback control. The method also includes: fusing the first required normal force at the first axle of the vehicle with the first required normal force adjustment to determine a first adjusted normal force requirement at the first axle. The method also includes: fusing the second required normal force with the second required normal force adjustment to determine a second adjusted normal force requirement at the second axle. The method also includes: determining a first position of the first aerodynamic body relative to the vehicle body and a second position of the second aerodynamic body relative to the vehicle body based on the first adjusted normal force requirement and the second adjusted normal force requirement, respectively. The method also includes: commanding the first aerodynamic actuator to move the first aerodynamic body to the first position relative to the vehicle body. The method also includes: commanding the second aerodynamic actuator to move the second aerodynamic body to the second position relative to the vehicle body. The method described in this paragraph improves vehicle technology by determining the amount of additional tire grip that the first aerodynamic actuator and the second aerodynamic actuator need to achieve in order to keep the vehicle stable in certain driving scenarios. This will be important information shared between vertical and planar motion control.

[0005] Implementations may include one or more of the following features. The method may include commanding a second aerodynamic actuator to move a second aerodynamic body to a second position relative to the vehicle body. The method may include determining a first tire load-carrying capacity normal force adjustment at a first axle and a second tire load-carrying capacity normal force adjustment at a second axle. The method may include determining a first tire load-carrying capacity normal force adjustment at a first axle and a second tire load-carrying capacity normal force adjustment at a second axle. The method may include determining a first understeer angle-based normal force adjustment at the first axle and a second understeer angle-based normal force adjustment at the second axle. The method may include determining a first understeer angle-based normal force adjustment at the first axle and a second understeer angle-based normal force adjustment at the second axle. The method may include determining a first wheel stability-based normal force adjustment at the first axle and a second wheel stability-based normal force adjustment at the second axle. The method may include determining a first wheel stability-based normal force adjustment at the first axle and a second wheel stability-based normal force adjustment at the second axle. The method may include determining a first body stability-based normal force adjustment at a first axle and a second body stability-based normal force adjustment at a second axle. The method may include determining a first body stability-based normal force adjustment at a first axle and a second body stability-based normal force adjustment at a second axle. The method may include fusing a first tire load capacity normal force adjustment, a first understeer angle-based normal force adjustment, a first wheel stability-based normal force adjustment, and a first body stability-based normal force adjustment to determine a first required normal force adjustment. The method may include fusing a second tire load capacity normal force adjustment, a second understeer angle-based normal force adjustment, a second wheel stability-based normal force adjustment, and a second body stability-based normal force adjustment to determine a second required normal force adjustment. The method may include fusing a first required normal force at a first axle of the vehicle with the first required normal force adjustment, and fusing the second required normal force with the second required normal force adjustment using a neural network or fuzzy logic.

[0006] The present application also describes a tangible, non-transitory machine-readable medium containing machine-readable instructions. When the machine-readable instructions are executed by a processor, the processor is caused to perform the above method.

[0007] The present disclosure also describes a vehicle. The vehicle includes a vehicle body, a first axle coupled to the vehicle body, a second axle coupled to the vehicle body, a plurality of sensors disposed in the vehicle body, and a vehicle controller disposed in the vehicle body. The vehicle controller communicates with the sensors. The vehicle controller is programmed to perform the above method.

[0008] Other applicable fields of the present disclosure will become apparent from the detailed description provided below.It should be understood that the detailed description and specific examples are only for illustrative purposes and are not intended to limit the scope of the present invention.

[0009] The above features, advantages and other features and advantages of the systems and methods of the present disclosure are apparent from the detailed description (including the claims) and exemplary embodiments taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be more fully understood based on this detailed description and the accompanying drawings, in which:

[0011] Figure 1 is a side view of a vehicle including a system for data driven downforce control; and

[0012] Figure 2 is a flow chart of a method for data driven downforce control. DETAILED DESCRIPTION

[0013] Several examples of the present disclosure illustrated in the accompanying drawings will now be discussed in detail. The same or similar reference numerals are used throughout the drawings and description to represent the same or similar parts or steps.

[0014] See also Figure 1 , the vehicle 10 includes (or communicates with) a system 11 for data-driven downforce control. Although the system 11 is shown inside the vehicle 10, it is contemplated that the system 11 may be located outside the vehicle 10. As a non-limiting example, the system 11 may communicate wirelessly with the vehicle 10. Although the vehicle 10 is shown as a two-door sedan, it is contemplated that the vehicle 10 may be another type of vehicle (such as a pickup truck, a sedan, a sport utility vehicle (SUV), a recreational vehicle (RV), etc.). The system 11 determines the amount of additional tire grip that the first aerodynamic actuator 41 and the second aerodynamic actuator 42 need to achieve in certain driving scenarios in order to keep the vehicle 10 stable. This will be important information shared between vertical and planar motion control. Different stability criteria, including axle, wheel, and body stability, are integrated together to calculate the amount of additional grip required at each of the first axle 14 and the second axle 16 of the vehicle 10.

[0015] The system 11 is used for active downforce and includes a feedforward portion for fast response and a feedback portion for robustness and disturbance rejection for uncertainty. Specifically, the system 11 calculates the correct required normal force at the first axle 14 and the second axle 16 to keep the vehicle 10 stable with minimal drag. The feedback portion of the system 11 is only responsible for the adjustment of the feedforward portion. The system 11 also includes a sub-control module that uses tire friction ellipse margin, axle stability, body stability, and wheel stability to independently calculate the correct adjustment required for the required normal force based on the feedforward control. The final adjustment for the required normal force is then determined in the fusion logic, which can be adjusted based on several factors. The fusion of all sub-control algorithms can be customized based on the vehicle platform and application. In summary, physics-based open-loop algorithms and closed-loop algorithms (e.g., feedback control) are integrated and fused together to better estimate the amount of additional tire grip required at the first axle 14 and the second axle 16 of the vehicle 10.

[0016] In addition, the vehicle 10 includes a vehicle controller 34 and one or more sensors 40 in communication with the vehicle controller 34. The sensor 40 collects information and generates sensor data indicating the collected information. As non-limiting examples, the sensor 40 may include a global navigation satellite system (GNSS) transceiver or receiver, a yaw rate sensor, a chassis height sensor, a speed sensor, a lidar, a radar, an ultrasonic sensor, and a camera, etc. The GNSS transceiver or receiver is configured to detect the position of the vehicle 10 on the earth. The speed sensor is configured to detect the speed of the vehicle 10. The yaw rate sensor is configured to determine the heading of the vehicle 10. The camera may have a large enough field of view to capture images of the front, rear, and sides of the vehicle 10. The chassis height sensor is configured to measure the chassis height of the vehicle 10. The ultrasonic sensor can detect static and / or dynamic objects.

[0017] The vehicle controller 34 is programmed to receive sensor data from the sensors 40 and includes at least one processor 44 and a non-transitory computer-readable storage device or medium 46. The processor 44 may be a custom processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor of several processors associated with the vehicle controller 34, a semiconductor-based microprocessor (in the form of a microchip or chipset), a macroprocessor, or a combination thereof, or generally a device for executing instructions.

[0018] The instructions may include one or more separate programs, each of which includes a series of ordered executable instructions for implementing logical functions. When the instructions are executed by the processor 44, the processor 44 receives and processes the signal from the camera, executes the logic, calculation, method and / or algorithm for automatically controlling the components of the vehicle 10, and generates a control signal to the actuator (e.g., the first aerodynamic actuator and / or the second aerodynamic actuator 42) to automatically control the components of the vehicle 10 based on the logic, calculation, method and / or algorithm. Although Figure 1 Although a single vehicle controller 34 is shown in the figure, the system 11 may include multiple controllers 34 that communicate via a suitable communication medium or combination of communication media and cooperate to process sensor signals, execute logic, calculations, methods and / or algorithms, and generate control signals to automatically control the features of the system 11. In various embodiments, one or more instructions of the vehicle controller 34 are included in the system 11. The non-transitory computer-readable storage device or medium 46 contains machine-readable instructions (e.g., such as Figure 2 ), when these machine-readable instructions are executed by one or more processors, the processor 44 executes the method 100 ( Figure 2 ).

[0019] The vehicle 10 includes a body 12, a first or rear axle 14, and a second or front axle 16. The first axle 14 and the second axle 16 are coupled to the body 12. In addition, each of the first axle 14 and the second axle 16 is configured to rotate relative to the body 12. The vehicle 10 further includes one or more first or rear tires 18 coupled to the first axle 14 and one or more second or front tires 20 coupled to the second axle 16.

[0020] The vehicle 10 includes a first or rear aerodynamic actuator 41 and a second or front aerodynamic actuator 42, each of which communicates with the vehicle controller 34. The first aerodynamic actuator 41 includes a first aerodynamic body 48, and the second aerodynamic actuator 42 includes a second aerodynamic body 50. Each of the first aerodynamic body 48 and the second aerodynamic body 50 can be configured as a wing-shaped spoiler. In the present disclosure, the term "wing-shaped" is defined as having the shape of a wing (i.e., a wing having an airfoil shape defined by a streamlined cross-sectional shape that generates lift for flight or propulsion through a fluid). The term "spoiler" refers to an aerodynamic device that is capable of disrupting the movement of air passing through the vehicle 10 when the vehicle 10 is moving, thereby reducing drag and / or causing aerodynamic downforce on the vehicle 10. The term "downforce" refers to a force component perpendicular to the relative direction of motion of the vehicle 10 (i.e., longitudinally toward the road surface 13). For example, a spoiler can diffuse air by increasing the amount of turbulence flowing through it. The first aerodynamic actuator 41 is closer to the first axle 14 than the second axle 16 to control rear downforce 43 at or near the first axle 14. The second aerodynamic actuator 42 is closer to the second axle 16 than the first axle 14 to control front downforce 45 at or near the second axle 16. The rear downforce 43 and the front downforce 45 may be determined using sensor data from a sensor 40 (e.g., a ride height sensor).

[0021] The first aerodynamic actuator 41 includes a bracket 52 that is directly coupled to the vehicle body 12 and one or more first pivots 54 (e.g., pivot pins, pivot mechanisms, etc.) that pivotally couple the first aerodynamic body 48 to the vehicle body 12. Thus, the first aerodynamic body 48 is movable (e.g., pivotable) relative to the vehicle body 12. The first aerodynamic actuator 41 includes a first motor 56 (or another suitable machine) that communicates with the vehicle controller 34 and is coupled to the first aerodynamic body 48 via the first pivot 54. Thus, the vehicle controller 34 is programmed to actuate the first motor 56 to move the first aerodynamic body 48 relative to the vehicle body 12.

[0022] The second aerodynamic actuator 42 is coupled to the vehicle body 12 and includes one or more second pivots 58 (e.g., pivot pins, pivot mechanisms, etc.) that pivotally couple the second aerodynamic body 50 to the vehicle body 12. Thus, the second aerodynamic body 50 is movable (e.g., pivotable) relative to the vehicle body 12. The second aerodynamic actuator 42 includes a second motor 60 (or another suitable machine) that is in communication with the vehicle controller 34 and coupled to the second aerodynamic body 50 via the second pivot 58. Thus, the vehicle controller 34 is programmed to actuate the second motor 60 to move the second aerodynamic body 50 relative to the vehicle body 12.

[0023] The vehicle 10 includes a user interface 23 that communicates with a vehicle controller 34. The user interface 23 can be, for example, a touch screen in a dashboard, and can include, but is not limited to, an alarm (such as one or more speakers that provide audible sounds, tactile feedback in a vehicle seat or other object, one or more displays, one or more microphones, one or more lights, and / or other devices suitable for providing notifications). The user interface 23 is in electronic communication with the vehicle controller 34 and is configured to receive input from a hearing-impaired vehicle occupant 25 (e.g., a vehicle user or a vehicle passenger). For example, the user interface 23 can include a touch screen and / or buttons configured to receive input from a vehicle occupant. Thus, the vehicle controller 34 is configured to receive input from a vehicle occupant via the user interface 23 and provide output (e.g., auditory, tactile, and / or visual notifications) to the vehicle occupant.

[0024] Figure 2 is a flow chart of a method 100 for downforce control. The method 100 may be executed by the vehicle controller 34 and employs a physics-based open loop that employs drive inputs, vehicle measured and estimated signals (e.g., sensor data), and axle, wheel, and body stability checks to calculate normal force requirements at the first axle 14 and the second axle 16. Because control is based on vehicle physics correlations rather than calibration tables, high control performance is achieved without extensive calibration. If any changes are made to the vehicle 10, minimal recalibration is required. Only parameters associated with the change require recalibration. The method 100 calculates the required normal force at each of the first axle 14 and the second axle 16 of the vehicle 10. Therefore, the method 100 does not require accurate downforce estimation because the normal force estimation can be used as a backup.

[0025] The method 100 begins at step 102. In step 102, the vehicle controller 34 receives inputs (such as sensor data from the sensors 40, driver inputs, stability triggers, and vehicle feedback). As non-limiting examples, the vehicle controller 34 may receive vehicle longitudinal acceleration, vehicle lateral acceleration, vehicle longitudinal speed, chassis height data, front wheel angles, brake pedal pressure or position, throttle position, estimated friction coefficient between the road surface 13 and at least one of the first tire 18 or the second tire 20, steering wheel angle, normal force, downforce, tire trail, understeer angle, slip slope, and wheel ground speed. After the vehicle controller 34 receives the inputs, the method 100 proceeds to step 104.

[0026] In step 104, the vehicle controller 34 determines a first required normal force at the first axle 14 of the vehicle 10 and a second required normal force at the second axle 16 of the vehicle 10 by using a physics-based model (e.g., a half-car model) and the above-mentioned inputs (e.g., sensor data from the sensor 40) by employing feed-forward control. The feed-forward control is based on the idea of ​​calculating the required forward force and lateral force to achieve the required lateral acceleration based on the steering input and the vehicle speed while ensuring that the first axle 14 and the second axle 16 are saturated simultaneously in the extreme maneuvering driving scenario. The physics-based model (e.g., a half-car model) can determine the first required normal force at the first axle 14 of the vehicle 10 and the second required normal force at the second axle 16 of the vehicle 10 using the steering wheel angle, the throttle position, the brake pedal pressure or position, and the longitudinal force at each of the first axle 14 and the second axle 16. As a non-limiting example, feedforward control is described in US Pat. No. 10,065,688 filed on Jul. 18, 2016 by Heil et al., the entire contents of which are incorporated herein by reference. Next, the method 100 proceeds to step 106 .

[0027] In step 106, the vehicle controller 34 uses sensor data to determine a first required normal force adjustment at the first axle 14 of the vehicle 10 and a second required normal force adjustment at the second axle 16 of the vehicle 10 by using feedback control. Specifically, the vehicle controller 34 includes a sub-control module that uses tire friction ellipse margin, axle stability, body stability, and wheel stability to independently calculate the correct adjustment required for the normal force required for feedforward control. With respect to the tire friction ellipse margin, the load-bearing capacity of the first axle 14 and the second axle 16 is monitored by positioning the longitudinal force component, the lateral force component, and the vertical force component on the tire friction ellipse. U.S. Patent Publication No. US202 / 20161874 filed by Nahidi et al. on November 24, 2020 describes downforce control using a tire friction ellipse, the entire contents of which are incorporated herein by reference. A first tire load-bearing capacity normal force adjustment at the first axle 14 and a second tire load-bearing capacity normal force adjustment at the second axle 16 are calculated to keep a safety margin away from the tire friction ellipse. Due to the uncertainty of the estimated friction coefficient between the road surface 13 and the first tire 18 and the estimated friction coefficient between the road surface 13 and the second tire 20, the tire trail and slip slope stability signals are used to adjust the front and rear friction coefficients used in the tire friction ellipses. As a non-limiting example, the following equations may be used to determine a first tire load capacity normal force adjustment at the first axle 14 and a second tire load capacity normal force adjustment at the second axle 16:

[0028] Equation 1

[0029]

[0030] in:

[0031] ΔF z,req is a first tire load capacity normal force adjustment at the first axle 14 or a second tire load capacity normal force adjustment at the second axle 16;

[0032] F z is an estimate of the vertical force component at the first axle 14 or the second axle 16 when the vehicle 10 is moving;

[0033] F x is an estimate of the longitudinal force component at the first axle 14 or the second axle 16 when the vehicle 10 is moving;

[0034] F y is an estimate of the lateral force component at the first axle 14 or the second axle 16 when the vehicle 10 is moving;

[0035] margin% is the stability margin based on the tire friction ellipse;

[0036] n is the number of axles in vehicle 10; and

[0037] μ is an estimated coefficient of friction between the road surface 13 and at least one of the first tire 18 or the second tire 20 .

[0038] As described above, the tire trail and slip slope stability signals are used to adjust the front and rear friction coefficients used in the tire friction ellipse. For example, if the tire trail is saturated and the friction ellipse is not saturated, the front friction coefficient may be reduced. If the tire trail is not saturated and the friction ellipse is saturated, the front friction coefficient may be reduced. For example, if the slip slope is saturated and the friction ellipse is not saturated, the rear friction coefficient may be reduced. If the slip slope is not saturated and the friction ellipse is saturated, the rear friction coefficient may be reduced. In other cases, neither the front friction coefficient nor the rear friction coefficient is adjusted.

[0039] Step 106 also requires determining a first understeer angle-based normal force adjustment at the first axle 14 and a second understeer angle-based normal force adjustment at the second axle 16 using the understeer angle, the position of the first aerodynamic body 48 movable relative to the vehicle body 12, and the position of the second aerodynamic body 50 movable relative to the vehicle body 12. The understeer angle is used to adjust the required additional tire grip in severe understeer and oversteer conditions. In a relatively severe understeer condition, if the second aerodynamic actuator 42 is not fully deployed, the first understeer angle-based normal force adjustment at the first axle 14 is increased, and if the second aerodynamic actuator 42 is fully deployed, the first understeer angle-based normal force adjustment at the first axle 14 is decreased. In a relatively severe oversteer condition, if the first aerodynamic actuator 41 is not fully deployed, the second understeer angle-based normal force adjustment at the second axle 16 is increased, and if the first aerodynamic actuator 41 is fully deployed, the second understeer angle-based normal force adjustment at the second axle 16 is decreased.

[0040] Step 106 also requires determining a first wheel stability-based normal force adjustment at the first axle 14 and a second wheel stability-based normal force adjustment at the second axle 16. Because the front wheels do not experience acceleration torque, the difference between the rear wheel ground speed and the front wheel ground speed can be used as an indicator of the rear wheel stability state. To do this, the difference between the average rear wheel ground speed and the average front wheel ground speed is multiplied by the calibrated average front wheel ground speed. Then, if the result of this calculation is greater than a threshold, the result is considered to be a wheel slip indicator. The wheel slip indicator is used to calculate the first wheel stability-based normal force adjustment at the first axle 14 and the second wheel stability-based normal force adjustment at the second axle 16.

[0041] Step 106 also requires determining a first body stability based normal force adjustment at the first axle 14 and a second body stability based normal force adjustment at the second axle 16. The sideslip-yaw rate phase plane is monitored to detect early signs of body instability. When the early sign flag is raised, the change in lateral acceleration is monitored. If the lateral acceleration difference monitored at a predetermined time is greater than a predetermined threshold, then body stability control is enabled. After step 106, the method 100 continues to step 108.

[0042] In step 108, the vehicle controller 34 fuses the first tire load-bearing capacity normal force adjustment, the first understeer angle-based normal force adjustment, the first wheel stability-based normal force adjustment, and the first body stability-based normal force adjustment to determine a first required normal force adjustment to determine the first required normal force adjustment at the first axle 14 of the vehicle 10. In addition, the vehicle controller 34 fuses the second tire load-bearing capacity normal force adjustment, the second understeer angle-based normal force adjustment, the second wheel stability-based normal force adjustment, and the second body stability-based normal force adjustment to determine the second required normal force adjustment at the second axle 16 of the vehicle 10. For the fusion, the vehicle controller 34 may select the largest adjustment among the first tire load-bearing capacity normal force adjustment, the first understeer angle-based normal force adjustment, the first wheel stability-based normal force adjustment, and the first body stability-based normal force adjustment to determine the first required normal force adjustment at the first axle 14 of the vehicle 10. Similarly, for fusion, the vehicle controller 34 may select the maximum adjustment amount among the second tire load capacity normal force adjustment amount, the second understeer angle-based normal force adjustment amount, the second wheel stability-based normal force adjustment amount, and the second vehicle body stability-based normal force adjustment amount to determine the second required normal force adjustment amount at the second axle 16 of the vehicle 10. Then, the vehicle controller 34 fuses the first required normal force (determined by feedforward control) at the first axle 14 of the vehicle 10 with the first required normal force adjustment amount, for example, by adding the first required normal force adjustment amount to the first required normal force, thereby determining the first adjusted normal force requirement at the first axle 14. In addition, the vehicle controller 34 fuses the second required normal force (determined by feedforward control) at the second axle 16 with the second required normal force adjustment amount, for example, by adding the second required normal force adjustment amount to the second required normal force, thereby determining the second adjusted normal force requirement at the second axle 16. Next, each of the adjusted normal force demand and the second adjusted normal force demand is filtered using the maximum normal force and the minimum normal force. Therefore, during the fusion process, all normal force demand adjustments from the feedback control are combined with the normal force demand from the feedforward control. Alternatively, instead of using the maximum adjustment among the adjustments determined by the feedback control, the vehicle controller 34 may use a weighted average method with a more advanced weight scheduling algorithm to fuse the first demand normal force adjustment and the first demand normal force adjustment. A neural network or fuzzy logic may be used to perform any of the fusion operations described herein. For example, fuzzy logic or a neural network may be used to fuse the first demand normal force at the first axle of the vehicle with the first demand normal force adjustment, and to fuse the second demand normal force with the second demand normal force adjustment. Then, the method 100 proceeds to step 110.

[0043] In step 110, the vehicle controller 34 determines the position of the first aerodynamic body 48 relative to the vehicle body 12 (i.e., the first position) based on the first adjusted normal force demand and determines the position of the second aerodynamic body 50 relative to the vehicle body 12 (i.e., the second position) based on the second adjusted normal force demand. In addition, the vehicle controller 34 commands the first aerodynamic actuator 41 to move the first aerodynamic body 41 to the first position relative to the vehicle body 12, and commands the second aerodynamic actuator 42 to move the second aerodynamic body 50 to the second position relative to the vehicle body 12.

[0044] Although exemplary embodiments are described above, this does not mean that these embodiments describe all possible forms included in the claims. The words used in this specification are descriptive words, not restrictive words, and it should be understood that various changes can be made without departing from the spirit and scope of the present disclosure. As mentioned above, the features of various embodiments can be combined to form other embodiments of the system and method of the present disclosure that are not explicitly described or shown. Although various embodiments may have been described as providing advantages or being superior to other embodiments or prior art implementations in terms of one or more required characteristics, it should be recognized by those of ordinary skill in the art that one or more features or characteristics can be compromised to achieve the desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, applicability, weight, manufacturability, ease of assembly, etc. Therefore, embodiments described as being less ideal than other embodiments or prior art implementations in terms of one or more characteristics are not outside the scope of the present disclosure and may be ideal for specific applications.

[0045] The drawings are in simplified form and are not to exact scale. Directional terms such as top, bottom, left, right, upward, directly above, above, below, directly below, rear side, and front side may be used in the drawings for convenience and clarity only. These terms and similar directional terms shall not be construed to limit the scope of the present disclosure in any way.

[0046] Embodiments of the present disclosure are described herein. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or reduced to show the details of a particular component. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but should only be interpreted as a representative basis for teaching those skilled in the art to apply the systems and methods of the present disclosure in different ways. As will be understood by those of ordinary skill in the art, the various features shown and described in conjunction with any of the figures may be combined with the features shown in one or more other figures to produce embodiments that are not explicitly shown or described. The combination of features shown provides representative embodiments for typical applications. However, for specific applications or implementations, various combinations and modifications of features consistent with the teachings of the present disclosure may be required.

[0047] Embodiments of the present disclosure may be described herein in terms of functional and / or logical block components and various processing steps. It should be understood that these block components may be implemented by several hardware, software and / or firmware components configured to perform specified functions. For example, embodiments of the present disclosure may employ various integrated circuit components, such as storage elements, digital signal processing elements, logic elements, or lookup tables, etc., which may perform various functions under the control of one or more microprocessors or other control devices. In addition, it will be appreciated by those skilled in the art that embodiments of the present disclosure may be practiced in conjunction with several systems, and the systems described herein are merely exemplary embodiments of the present disclosure.

[0048] For the sake of brevity, the present invention may not describe in detail technologies related to signal processing, data fusion, signaling, control and other functional aspects of the system (and the various operating components of the system). In addition, the lines shown in the various figures included herein are intended to represent exemplary functional relationships and / or physical couplings between various elements. It should be noted that there may be alternative or additional functional relationships or physical connections in an embodiment of the present disclosure.

[0049] This description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, as other modifications will become apparent after studying the drawings, this specification and the appended claims.

Claims

1. A method for downforce control, comprising: receiving sensor data from a plurality of sensors of a vehicle, wherein the vehicle includes a vehicle body, a first axle coupled to the vehicle body, a second axle coupled to the vehicle body, a first aerodynamic actuator coupled to the vehicle body, and a second aerodynamic actuator coupled to the vehicle body, the first aerodynamic actuator including a first aerodynamic body movable relative to the vehicle body, the second aerodynamic actuator including a second aerodynamic body movable relative to the vehicle body; utilizing the sensor data to determine a first desired normal force at a first axle of the vehicle and a second desired normal force at a second axle of the vehicle by employing feed-forward control; utilizing the sensor data to determine a first desired normal force adjustment at a first axle of the vehicle and a second desired normal force adjustment at a second axle of the vehicle by employing feedback control; fusing a first required normal force at a first axle of the vehicle with the first required normal force adjustment to determine a first adjusted normal force requirement at the first axle; fusing the second required normal force with the second required normal force adjustment amount to determine a second adjusted normal force requirement at the second axle; determining a first position of the first aerodynamic body relative to the vehicle body and a second position of the second aerodynamic body relative to the vehicle body based on the first adjusted normal force demand and the second adjusted normal force demand, respectively; commanding the first aerodynamic actuator to move the first aerodynamic body to a first position relative to the vehicle body; and The second aerodynamic actuator is commanded to move the second aerodynamic body to a second position relative to the vehicle body.

2. The method according to claim 1, wherein: By adopting the feedback control, the sensor data is used to determine a first required normal force adjustment at a first axle of the vehicle and a second required normal force adjustment at a second axle of the vehicle, including: determining a first tire load-bearing capacity normal force adjustment at the first axle and a second tire load-bearing capacity normal force adjustment at the second axle.

3. The method according to claim 2, wherein: By adopting the feedback control, the sensor data is used to determine a first required normal force adjustment at a first axle of the vehicle and a second required normal force adjustment at a second axle of the vehicle, including: determining a first normal force adjustment based on an understeer angle at the first axle and a second normal force adjustment based on an understeer angle at the second axle.

4. The method according to claim 3, wherein: By adopting the feedback control, the sensor data is used to determine a first required normal force adjustment at a first axle of the vehicle and a second required normal force adjustment at a second axle of the vehicle, including: determining a first normal force adjustment based on wheel stability at the first axle and a second normal force adjustment based on wheel stability at the second axle.

5. The method according to claim 4, wherein: By adopting the feedback control, the sensor data is used to determine a first required normal force adjustment at a first axle of the vehicle and a second required normal force adjustment at a second axle of the vehicle, including: determining a first normal force adjustment based on vehicle body stability at the first axle and a second normal force adjustment based on vehicle body stability at the second axle.

6. The method according to claim 5, further comprising: The first required normal force adjustment amount is determined by fusing the first tire load-bearing capacity normal force adjustment amount, the first understeer angle-based normal force adjustment amount, the first wheel stability-based normal force adjustment amount, and the first vehicle body stability-based normal force adjustment amount; as well as The second tire load-bearing capacity normal force adjustment, the second understeer angle-based normal force adjustment, the second wheel stability-based normal force adjustment and the second vehicle body stability-based normal force adjustment are integrated to determine the second required normal force adjustment.

7. The method according to claim 6, further comprising: A neural network is used to fuse the first required normal force at the first axle of the vehicle with the first required normal force adjustment, and to fuse the second required normal force with the second required normal force adjustment.

8. A tangible, non-transitory machine-readable medium comprising machine-readable instructions that, when executed by a processor, cause the processor to: receiving sensor data from a plurality of sensors of the vehicle, wherein: The vehicle includes a vehicle body, a first axle coupled to the vehicle body, a second axle coupled to the vehicle body, a first aerodynamic actuator coupled to the vehicle body, and a second aerodynamic actuator coupled to the vehicle body, the first aerodynamic actuator including a first aerodynamic body movable relative to the vehicle body, the second aerodynamic actuator including a second aerodynamic body movable relative to the vehicle body; utilizing the sensor data to determine a first desired normal force at a first axle of the vehicle and a second desired normal force at a second axle of the vehicle by employing feed-forward control; utilizing the sensor data to determine a first desired normal force adjustment at a first axle of the vehicle and a second desired normal force adjustment at a second axle of the vehicle by employing feedback control; fusing a first required normal force at a first axle of the vehicle with the first required normal force adjustment to determine a first adjusted normal force requirement at the first axle; fusing the second required normal force with the second required normal force adjustment amount to determine a second adjusted normal force requirement at the second axle; determining a first position of the first aerodynamic body relative to the vehicle body and a second position of the second aerodynamic body relative to the vehicle body based on the first adjusted normal force demand and the second adjusted normal force demand, respectively; commanding the first aerodynamic actuator to move the first aerodynamic body to a first position relative to the vehicle body; and The second aerodynamic actuator is commanded to move the second aerodynamic body to a second position relative to the vehicle body.

9. The tangible, non-transitory machine-readable medium of claim 8, wherein: The tangible, non-transitory machine-readable medium further includes machine-readable instructions that, when executed by the processor, cause the processor to: A first tire load capacity normal force adjustment at the first axle and a second tire load capacity normal force adjustment at the second axle are determined.

10. The tangible, non-transitory machine-readable medium of claim 9, wherein: The tangible, non-transitory machine-readable medium further includes machine-readable instructions that, when executed by the processor, cause the processor to: A first understeer angle based normal force adjustment at the first axle and a second understeer angle based normal force adjustment at the second axle are determined.

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