Determining required lateral acceleration of vehicle

Abstract

A method for determining a desired lateral acceleration of a vehicle is provided. The method may include determining a first raw lateral acceleration request based at least in part on a steering wheel angle of the vehicle. The method may also include determining a maximum allowable lateral acceleration based at least in part on the tire slip model. The method may also include determining a desired lateral acceleration based at least in part on the first raw lateral acceleration request and the maximum allowable lateral acceleration. The method may also include adjusting operation of the vehicle based at least in part on the desired lateral acceleration.

Description

Technical Field This disclosure relates to systems and methods for determining the desired lateral acceleration of a vehicle. Background Technology To enhance vehicle performance and capabilities, vehicles can be equipped with active downforce systems to provide greater traction under certain conditions. For example, a vehicle may include one or more aerodynamic elements, such as spoilers, fins, wings, diffusers, etc., which can be moved or adjusted using electromechanical, hydraulic, and / or pneumatic actuation systems. The actuation system can precisely control the position and angle of the aerodynamic elements to generate frontal and / or rearward downforce on the vehicle. By generating additional downforce, active downforce systems can increase frontal and / or rearward traction, thereby improving grip on the road surface. Increased traction can enable more aggressive cornering, improved acceleration, and better braking performance. However, current active downforce systems may fail to determine the lateral acceleration required by the occupants. Therefore, current active downforce systems may hinder or prevent the driver from intentionally performing certain vehicle maneuvers. Therefore, while current active downforce systems and methods achieve their intended purpose, a new and improved system and method are needed to determine the required lateral acceleration of a vehicle. Summary of the Invention According to several aspects, a method for determining a desired lateral acceleration of a vehicle is provided. The method may include determining a first initial lateral acceleration request based at least in part on the vehicle's steering wheel angle. The method may also include determining a maximum permissible lateral acceleration based at least in part on a tire slip model. The method may further include determining the desired lateral acceleration based at least in part on the first initial lateral acceleration request and the maximum permissible lateral acceleration. The method may also include adjusting the vehicle's operation based at least in part on the desired lateral acceleration. In another aspect of this disclosure, determining the first initial lateral acceleration request may further include determining the vehicle's steering wheel angle. Determining the first initial lateral acceleration request may further include determining the longitudinal component of the vehicle's velocity. Determining the first initial lateral acceleration request may further include determining the vehicle's wheelbase. Determining the first initial lateral acceleration request may further include determining the first initial lateral acceleration request based at least in part on the steering wheel angle, the longitudinal component of the velocity, and the wheelbase. In another aspect of this disclosure, determining the first initial lateral acceleration request may further include determining the vehicle's understeer coefficient based at least in part on the longitudinal component of the velocity. Determining the first initial lateral acceleration request may also include determining the first initial lateral acceleration request based at least in part on the steering wheel angle, the longitudinal component of the velocity, the wheelbase, and the understeer coefficient. In another aspect of this disclosure, determining the maximum permissible lateral acceleration may further include determining the front and rear downforces of the vehicle. Determining the maximum permissible lateral acceleration may also include determining the maximum permissible lateral force using a tire slip model, at least in part based on the front and rear downforces. Determining the maximum permissible lateral acceleration may also include determining the maximum permissible lateral acceleration based at least in part on the maximum permissible lateral force. In another aspect of this disclosure, determining the front downforce and rear downforce may further include determining baseline front downforce and baseline rear downforce based at least in part on the vehicle's weight. Determining the front downforce and rear downforce may further include determining aerodynamic front downforce and aerodynamic rear downforce provided by the vehicle's active downforce components. Determining the front downforce and rear downforce may further include determining the front downforce based at least in part on baseline front downforce and aerodynamic front downforce. Determining the front downforce and rear downforce may further include determining the rear downforce based at least in part on baseline rear downforce and aerodynamic rear downforce. In another aspect of this disclosure, determining the required lateral acceleration based at least in part on the first original lateral acceleration request and the maximum permissible lateral acceleration may further include determining a second original lateral acceleration request based at least in part on the first original lateral acceleration request and the maximum permissible lateral acceleration. Determining the required lateral acceleration based at least in part on the first original lateral acceleration request and the maximum permissible lateral acceleration may further include determining the required lateral acceleration based at least in part on the second original lateral acceleration request. In another aspect of this disclosure, determining the required lateral acceleration based at least in part on the second original lateral acceleration request may further include determining an occupant effort index based at least in part on one or more occupant inputs. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request may further include determining the required lateral acceleration change state based at least in part on the second original lateral acceleration request and one or more historical second original lateral acceleration requests. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request may further include determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state. In another aspect of this disclosure, determining the occupant effort index may further include determining the rate of change of one or more occupant inputs. The one or more occupant inputs include at least one of accelerator pedal position, brake pedal position, and steering wheel angle. Determining the occupant effort index may also include determining the occupant effort index based at least in part on the rate of change of one or more occupant inputs. A high occupant effort index corresponds to a high rate of change of one or more occupant inputs. In another aspect of this disclosure, determining the desired lateral acceleration change state may further include calculating the difference between the second original lateral acceleration request and a previous second original lateral acceleration request from one or more historical second original lateral acceleration requests. Determining the desired lateral acceleration change state may further include determining the desired lateral acceleration change state as a small increase state in response to determining that the magnitude of the difference is less than a first threshold and the second original lateral acceleration request is greater than the previous second original lateral acceleration request. Determining the desired lateral acceleration change state may further include determining the desired lateral acceleration change state as a large increase state in response to determining that the magnitude of the difference is greater than or equal to the first threshold and the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request. Determining the desired lateral acceleration change state may further include determining the desired lateral acceleration change state as a small decrease state in response to determining that the magnitude of the difference is less than a second threshold and the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request. Determining the desired lateral acceleration change state may further include determining that the desired lateral acceleration change state is a significantly reduced state in response to determining that the magnitude of the difference is greater than or equal to a second threshold and the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request. In another aspect of this disclosure, determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include determining that the required lateral acceleration is equal to the second original lateral acceleration request in response to determining that the required lateral acceleration change state is a small increase. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include determining that the required lateral acceleration is equal to the minimum of the second original lateral acceleration request and the sum of the previous second original lateral acceleration request and a predetermined constant in response to determining that the required lateral acceleration change state is a large increase. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include determining that the required lateral acceleration is equal to the second original lateral acceleration request in response to determining that the required lateral acceleration change state is a small decrease and the vehicle's steering wheel angle is within a predetermined range near zero. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include determining that the required lateral acceleration is equal to the previous second original lateral acceleration request in response to determining that the required lateral acceleration change state is a small decrease and the vehicle's steering wheel angle is outside a predetermined range near zero. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include reducing the required lateral acceleration from the previous second original lateral acceleration request to the second original lateral acceleration request at a limited rate in response to determining that the required lateral acceleration change state is a large decrease. The limited rate is determined at least in part based on the occupant effort index. According to several aspects, a system for determining a desired lateral acceleration of a vehicle is provided. The system may include one or more vehicle sensors. The system may also include one or more aerodynamic actuators. The system may further include a controller in electrical communication with the one or more vehicle sensors and the one or more aerodynamic actuators. The controller is programmed to determine a first initial lateral acceleration request based at least in part on a steering wheel angle of the vehicle determined using the one or more vehicle sensors. The controller is also programmed to determine a maximum permissible lateral acceleration based at least in part on a tire slip model. The controller is further programmed to determine the desired lateral acceleration based at least in part on the first initial lateral acceleration request and the maximum permissible lateral acceleration. The controller is also programmed to adjust the operation of the one or more aerodynamic actuators at least in part based on the desired lateral acceleration. In another aspect of this disclosure, to determine the first initial lateral acceleration request, the controller is also programmed to use one or more vehicle sensors to determine the vehicle's steering wheel angle. To determine the first initial lateral acceleration request, the controller is also programmed to use one or more vehicle sensors to determine the longitudinal component of the vehicle's velocity. To determine the first initial lateral acceleration request, the controller is also programmed to determine the vehicle's wheelbase. To determine the first initial lateral acceleration request, the controller is also programmed to determine the vehicle's understeer coefficient based at least in part on the longitudinal component of the velocity. To determine the first initial lateral acceleration request, the controller is also programmed to determine the first initial lateral acceleration request using the following formula, based at least in part on the steering wheel angle, the longitudinal component of the velocity, the wheelbase, and the understeer coefficient: Where A y,req,raw,1 This is the first original lateral acceleration request, δ is the steering wheel angle, and V... x It is the longitudinal component of the velocity, L is the wheelbase, and K is the longitudinal component of the velocity. us It is the understeer coefficient. In another aspect of this disclosure, to determine the maximum permissible lateral acceleration, the controller is also programmed to use one or more vehicle sensors to determine the front and rear downforces of the vehicle. To determine the maximum permissible lateral acceleration, the controller is also programmed to use a tire slip model to determine the maximum permissible lateral force based at least in part on the front and rear downforces. To determine the maximum permissible lateral acceleration, the controller is also programmed to determine the maximum permissible lateral acceleration based at least in part on the maximum permissible lateral force. In another aspect of this disclosure, in order to determine the required lateral acceleration at least in part based on the first original lateral acceleration request and the maximum permissible lateral acceleration, the controller is also programmed to determine a second original lateral acceleration request at least in part based on the first original lateral acceleration request and the maximum permissible lateral acceleration. In order to determine the required lateral acceleration at least in part based on the first original lateral acceleration request and the maximum permissible lateral acceleration, the controller is also programmed to determine an occupant effort index at least in part based on one or more occupant inputs. In order to determine the required lateral acceleration at least in part based on the first original lateral acceleration request and the maximum permissible lateral acceleration, the controller is also programmed to determine the required lateral acceleration change state at least in part based on the second original lateral acceleration request and one or more historical second original lateral acceleration requests. In order to determine the required lateral acceleration at least in part based on the first original lateral acceleration request and the maximum permissible lateral acceleration, the controller is also programmed to determine the required lateral acceleration at least in part based on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state. In another aspect of this disclosure, to determine the occupant effort index, the controller is also programmed to determine the rate of change of one or more occupant inputs. The one or more occupant inputs include at least one of accelerator pedal position, brake pedal position, and steering wheel angle. To determine the occupant effort index, the controller is also programmed to determine the occupant effort index at least in part based on the rate of change of one or more occupant inputs. A high occupant effort index corresponds to a high rate of change of one or more occupant inputs. In another aspect of this disclosure, to determine the desired lateral acceleration change state, the controller is further programmed to calculate the difference between the second original lateral acceleration request and a previous second original lateral acceleration request of one or more historical second original lateral acceleration requests. To determine the desired lateral acceleration change state, the controller is further programmed to determine the desired lateral acceleration change state as a small increase state in response to determining that the magnitude of the difference is less than a first threshold and the second original lateral acceleration request is greater than a previous second original lateral acceleration request. To determine the desired lateral acceleration change state, the controller is further programmed to determine the desired lateral acceleration change state as a large increase state in response to determining that the magnitude of the difference is greater than or equal to the first threshold and the second original lateral acceleration request is greater than a previous second original lateral acceleration request. To determine the desired lateral acceleration change state, the controller is further programmed to determine the desired lateral acceleration change state as a small decrease state in response to determining that the magnitude of the difference is less than a second threshold and the second original lateral acceleration request is less than or equal to a previous second original lateral acceleration request. To determine the desired lateral acceleration change state, the controller is also programmed to determine the desired lateral acceleration change state as a significantly reduced state in response to determining that the magnitude of the difference is greater than or equal to a second threshold and the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request. In another aspect of this disclosure, in order to determine the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state, the controller is further programmed to determine that the required lateral acceleration is equal to the second original lateral acceleration request in response to determining that the required lateral acceleration change state is a small increase. To determine the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state, the controller is further programmed to determine that the required lateral acceleration is equal to the minimum of the second original lateral acceleration request and the sum of the previous second original lateral acceleration request and a predetermined constant in response to determining that the required lateral acceleration change state is a large increase. To determine the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state, the controller is further programmed to determine that the required lateral acceleration is equal to the second original lateral acceleration in response to determining that the required lateral acceleration change state is a small decrease and the vehicle's steering wheel angle is within a predetermined range near zero. To determine the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state, the controller is further programmed to determine that the required lateral acceleration is equal to the previous second original lateral acceleration request in response to determining that the required lateral acceleration change state is a small decrease and the vehicle's steering wheel angle is outside a predetermined range near zero. To determine the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state, the controller is further programmed to reduce the required lateral acceleration from the previous second original lateral acceleration to the second original lateral acceleration request at a defined rate in response to determining that the required lateral acceleration change state is a large decrease. The defined rate is determined at least in part based on the occupant effort index. According to several aspects, a method for determining a desired lateral acceleration of a vehicle is provided. The method may include using one or more vehicle sensors to determine the vehicle's steering wheel angle. The method may further include using one or more vehicle sensors to determine the longitudinal component of the vehicle's velocity. The method may further include determining the vehicle's wheelbase. The method may further include determining the vehicle's understeer coefficient based at least in part on the longitudinal component of the velocity. The method may further include determining a first initial lateral acceleration request using the following formula, based at least in part on the steering wheel angle, the longitudinal component of the velocity, the wheelbase, and the understeer coefficient: Where A y,req,raw,1 This is the first original lateral acceleration request, δ is the steering wheel angle, and V... x It is the longitudinal component of the velocity, L is the wheelbase, and K is the longitudinal component of the velocity. usThis is the understeer coefficient. The method may also include determining the maximum permissible lateral acceleration based at least in part on a tire slip model. The method may also include determining a second original lateral acceleration request based at least in part on a first original lateral acceleration request and the maximum permissible lateral acceleration. The method may also include determining an occupant effort index based at least in part on one or more occupant inputs. The method may also include determining the desired lateral acceleration change state based at least in part on the second original lateral acceleration request and one or more historical second original lateral acceleration requests. The method may also include determining the desired lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the desired lateral acceleration change state. The method may also include adjusting the operation of one or more aerodynamic actuators of the vehicle based at least in part on the desired lateral acceleration. In another aspect of this disclosure, determining the desired lateral acceleration change state may further include calculating the difference between the second original lateral acceleration request and a previous second original lateral acceleration request from one or more historical second original lateral acceleration requests. Determining the desired lateral acceleration change state may further include determining that the desired lateral acceleration change state is a small increase state in response to determining that the magnitude of the difference is less than a first threshold and the second original lateral acceleration request is greater than the previous second original lateral acceleration request. Determining the desired lateral acceleration change state may further include determining that the desired lateral acceleration change state is a large increase state in response to determining that the magnitude of the difference is greater than or equal to the first threshold and the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request. Determining the desired lateral acceleration change state may further include determining that the desired lateral acceleration change state is a small decrease state in response to determining that the magnitude of the difference is less than a second threshold and the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request. Determining the desired lateral acceleration change state may further include determining that the desired lateral acceleration change state is a significantly reduced state in response to determining that the magnitude of the difference is greater than or equal to a second threshold and the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request. In another aspect of this disclosure, determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include determining that the required lateral acceleration is equal to the second original lateral acceleration request in response to determining that the required lateral acceleration change state is a small increase. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include determining that the required lateral acceleration is equal to the minimum of the second original lateral acceleration request and the sum of the previous second original lateral acceleration request and a predetermined constant in response to determining that the required lateral acceleration change state is a large increase. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include determining that the required lateral acceleration is equal to the second original lateral acceleration request in response to determining that the required lateral acceleration change state is a small decrease and the vehicle's steering wheel angle is within a predetermined range near zero. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include determining that the required lateral acceleration is equal to the previous second original lateral acceleration request in response to determining that the required lateral acceleration change state is a small decrease and the vehicle's steering wheel angle is outside a predetermined range near zero. Determining the required lateral acceleration based at least in part on the second original lateral acceleration request, the occupant effort index, and the required lateral acceleration change state may further include reducing the required lateral acceleration from the previous second original lateral acceleration request to the second original lateral acceleration request at a limited rate in response to determining that the required lateral acceleration change state is a large decrease. The limited rate is determined at least in part based on the occupant effort index. Further areas of application will become apparent from the description provided herein. It should be understood that these descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. Figure 1 This is a schematic diagram of a system for determining the desired lateral acceleration of a vehicle according to an exemplary embodiment; Figure 2 This is a flowchart of a method for determining the desired lateral acceleration of a vehicle according to an exemplary embodiment; Figure 3 This is a flowchart of a method for determining the maximum permissible lateral acceleration according to an exemplary embodiment; Figure 4 This is a flowchart of a method for determining a desired lateral acceleration change state according to an exemplary embodiment; and Figure 5 This is a flowchart of a method for determining a desired lateral acceleration according to an exemplary embodiment. Detailed Implementation The following description is merely exemplary in nature and is not intended to limit this disclosure, its application, or its uses. When performing certain driving maneuvers (e.g., drifting or high-speed cornering), vehicle occupants may expect to generate lateral acceleration. To increase occupant comfort and vehicle performance, vehicle operation can be adjusted to help occupants achieve the desired lateral acceleration. Therefore, determining the desired lateral acceleration of a vehicle is advantageous. Consequently, this disclosure provides a new and improved system and method for determining the desired lateral acceleration of a vehicle, taking into account vehicle dynamics and occupant behavior. refer to Figure 1 The diagram illustrates a system for determining the desired lateral acceleration of a vehicle and is generally indicated by reference numeral 10. System 10 is shown together with an exemplary vehicle 12. Although a passenger vehicle is shown, it should be understood that vehicle 12 can be any type of vehicle without departing from the scope of this disclosure. System 10 typically includes a controller 14, one or more vehicle sensors 16, and one or more aerodynamic actuators 18. The controller 14 is used to implement method 100 for determining the desired lateral acceleration of the vehicle, as described below. The controller 14 includes at least one processor 20 and a non-transitory computer-readable storage device or medium 22. The processor 20 may be a custom or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor among a plurality of processors associated with the controller 14, a semiconductor-based microprocessor (in the form of a microchip or chipset), a macroprocessor, a combination thereof, or generally a device for executing instructions. Computer-readable storage device or medium 22 may include volatile and non-volatile storage devices such as read-only memory (ROM), random access memory (RAM), and keep-alive memory (KAM). KAM is a persistent or non-volatile memory that can be used to store various operational variables when the processor 20 is powered off. Computer-readable storage device or medium 22 may be implemented using multiple storage devices, such as programmable read-only memory (PROM), electrical PROM (EPROM), electrically erasable PROM (EEPROM), flash memory, or other electrical, magnetic, optical, or combined storage devices capable of storing data, some of which represents executable instructions used by controller 14 to control various systems of vehicle 12. The controller 14 may also consist of multiple controllers that are electrically communicating with each other. The controller 14 may interconnect with additional systems and / or controllers of the vehicle 12, thereby allowing the controller 14 to access data such as the speed, acceleration, braking and steering wheel angle of the vehicle 12. The controller 14 communicates electrically with one or more vehicle sensors 16 and one or more aerodynamic actuators 18. In one exemplary embodiment, electrical communication is established using, for example, a CAN network, a FLEXRAY network, a local area network (e.g., WiFi, Ethernet, etc.), a Serial Peripheral Interface (SPI) network, etc. It should be understood that various additional wired and wireless technologies and communication protocols used for communicating with the controller 14 are within the scope of this disclosure. It should also be understood that, within the scope of this disclosure, electrical communication also includes the transfer of power and / or energy between electrical devices (e.g., using wired and / or wireless power transmission technologies). One or more vehicle sensors 16 are used to acquire information related to the vehicle 12. In an exemplary embodiment, the one or more vehicle sensors 16 include at least an accelerator pedal position sensor 24a, a brake pedal position sensor 24b, and a steering wheel angle sensor 26. In another exemplary embodiment, one or more vehicle sensors 16 further include sensors for determining performance data regarding the vehicle 12. In a non-limiting example, one or more vehicle sensors 16 further include at least one of the following: a motor speed sensor, a motor torque sensor, an electric drive motor voltage and / or current sensor, a brake position sensor, a coolant temperature sensor, a cooling fan speed sensor, a transmission oil temperature sensor, a front suspension ride height sensor, a rear suspension ride height sensor, a yaw rate sensor, one or more wheel speed sensors, and an inertial measurement unit (IMU). In another exemplary embodiment, the one or more vehicle sensors 16 further include sensors for determining information about the environment inside the vehicle 12. In a non-limiting example, the one or more vehicle sensors 16 may also include at least one of a seat occupancy sensor, a cabin air temperature sensor, a cabin motion detection sensor, a cabin camera, a cabin microphone, etc. In another exemplary embodiment, one or more vehicle sensors 16 may further include sensors for determining information about the environment surrounding the vehicle 12. In a non-limiting example, one or more vehicle sensors 16 may also include at least one of an ambient air temperature sensor, a barometric pressure sensor, a vehicle communication system, a global navigation satellite system (GNSS), and / or a camera and / or video camera, positioned to observe the environment in front of the vehicle 12. In another exemplary embodiment, at least one of the one or more vehicle sensors 16 is a sensing sensor capable of sensing objects in the environment surrounding the vehicle 12 and / or measuring distances. In a non-limiting example, the one or more vehicle sensors 16 include a stereo camera with distance measurement capabilities. In one example, at least one of the one or more vehicle sensors 16 is fixed inside the vehicle 12, for example, fixed in the roof lining of the vehicle 12, having a field of view through the windshield of the vehicle 12. In another example, at least one of the one or more vehicle sensors 16 is fixed outside the vehicle 12, for example, fixed on the roof of the vehicle 12, having a field of view of the environment surrounding the vehicle 12. It should be understood that various additional types of sensing sensors, such as LiDAR sensors, ultrasonic ranging sensors, radar sensors, and / or time-of-flight sensors, are all within the scope of this disclosure. As described above, the one or more vehicle sensors 16 are in electrical communication with the controller 14. An accelerator pedal position sensor 24a is used to measure the position of the accelerator pedal of vehicle 12. In an exemplary embodiment, the accelerator pedal position sensor 24a is an electromechanical sensor that converts the mechanical movement of the accelerator pedal into an electrical signal. In a non-limiting example, the accelerator pedal position sensor 24a includes a potentiometer having at least a first terminal and a second terminal electrically connected to a brush. The brush of the potentiometer is fixed (e.g., via a mechanical linkage, gear set, etc.) to the accelerator pedal. Therefore, the resistance measured between the first terminal (i.e., the brush) and the second terminal is proportional to the position of the accelerator pedal. Thus, by measuring the resistance between the first and second terminals of the potentiometer, the controller 14 determines the position of the accelerator pedal. It should be understood that additional sensors (e.g., rotary encoders, proximity sensors, etc.) used to measure the accelerator pedal position are also within the scope of this disclosure. Brake pedal position sensor 24b is used to measure the position of the brake pedal of vehicle 12. In an exemplary embodiment, brake pedal position sensor 24b is an electromechanical sensor that converts the mechanical movement of the brake pedal into an electrical signal. In a non-limiting example, brake pedal position sensor 24b includes a potentiometer having at least a first terminal and a second terminal electrically connected to brushes. The brushes of the potentiometer are fixed (e.g., via a mechanical linkage, gear set, etc.) to the brake pedal. Therefore, the resistance measured between the first terminal (i.e., the brushes) and the second terminal is proportional to the position of the brake pedal. Thus, by measuring the resistance between the first and second terminals of the potentiometer, controller 14 determines the position of the brake pedal. It should be understood that additional sensors (e.g., rotary encoders, proximity sensors, etc.) used to measure the position of the brake pedal are within the scope of this disclosure. A steering wheel angle sensor 26 is used to measure the position (i.e., angle) of the steering wheel of the vehicle 12. In an exemplary embodiment, the steering wheel angle sensor 26 is an electromechanical sensor that converts the mechanical movement of the steering wheel into an electrical signal. In a non-limiting example, the steering wheel angle sensor 26 includes a potentiometer having at least a first terminal and a second terminal electrically connected to brushes. The brushes of the potentiometer are fixed (e.g., via a mechanical linkage, gear set, etc.) to the steering wheel. Therefore, the resistance measured between the first terminal (i.e., the brushes) and the second terminal is proportional to the position of the steering wheel. Thus, by measuring the resistance between the first and second terminals of the potentiometer, the controller 14 determines the position of the steering wheel and therefore the steering wheel angle. It should be understood that additional sensors (e.g., rotary encoders, proximity sensors, etc.) used to measure the position of the steering wheel are within the scope of this disclosure. One or more aerodynamic actuators 18 are used to adjust drag on the vehicle 12 and / or adjust aerodynamic downforce on the vehicle 12. In an exemplary embodiment, the one or more aerodynamic actuators 18 include a front aerodynamic actuator 18a and a rear aerodynamic actuator 18b. A front aerodynamic actuator 18a is used to regulate front downforce 26a at or near the front axle 28a of the vehicle 12. Within the scope of this disclosure, the term "downforce" refers to a component of force perpendicular to the relative direction of motion of the vehicle 12 (i.e., longitudinally, towards the road surface 36). Within the scope of this disclosure, the term "front downforce" refers to downforce applied at or near the front axle 28a of the vehicle 12. The front aerodynamic actuator 18a includes a first aerodynamic body 30a, a first pivot 32a, and a first actuator motor 34a. The first aerodynamic body 30a is used to regulate drag and / or aerodynamic downforce by disrupting the airflow through the vehicle 12. In an exemplary embodiment, the first aerodynamic body 30a is configured as an airfoil spoiler. In this disclosure, the term "airfoil" is defined as having the shape of an airfoil, i.e., a fin having an airfoil shape defined by a streamlined cross-sectional shape, generating lift for flight or by fluid propulsion. The term "spoiler" refers to an aerodynamic device capable of disrupting the airflow through the vehicle 12 when the vehicle 12 is in motion, thereby adjusting drag and / or regulating aerodynamic downforce on the vehicle 12. The first pivot 32a is used to realize rotational movement between the first aerodynamic body 30a and the vehicle 12. In an exemplary embodiment, the first pivot 32a is a hinge. In a non-limiting example, the hinge includes a pivot pin (not shown) and two hinge plates (not shown) mechanically connected to the pivot pin. The pivot pin allows the hinge plates to rotate relative to each other, and the hinge plates are attached to corresponding components (i.e., one attached to the vehicle 12 and one attached to the first aerodynamic body 30a) to facilitate their rotational movement. It should be understood that the first pivot 32a may include any mechanical structure or linkage that allows rotational or pivotal movement, including any combination of, for example, hinges, bearings, pivot pins, ball joints, rotary joints, bushings, universal joints, U-pins, trunnions, etc. The first actuator motor 34a is used to actuate (i.e., move) the first aerodynamic body 30a to adjust drag and / or aerodynamic downforce. In one exemplary embodiment, the first actuator motor 34a is a motor (e.g., a DC brushed motor, a DC brushless motor, an AC motor, a linear actuator, etc.) connected to the first aerodynamic body 30a via a first pivot 32a. In another exemplary embodiment, the first actuator motor 34a includes a pneumatic or hydraulic actuator. It should be understood that any actuator operable to actuate (i.e. move) the first aerodynamic body 30a is within the scope of this disclosure. Furthermore, any mechanical construction for connecting the first actuator motor 34a to the first aerodynamic body 30a, including, for example, chains, belts, pulleys, gears, linkages, etc., is within the scope of this disclosure. In a non-limiting example, the first actuator motor 34a includes a relative or absolute positioning device, such as a rotary encoder, such that the controller 14 can determine the position of the first actuator motor 34a, and thus the position of the first aerodynamic body 30a. The first actuator motor 34a is in electrical communication with and can be controlled by the controller 14, as will be discussed in more detail below. The rear aerodynamic actuator 18b is used to regulate the rear downforce 26b at or near the rear axle 28b of the vehicle 12. Within the scope of this disclosure, the term "rear downforce" refers to the downforce applied at or near the rear axle 28b of the vehicle 12. The rear aerodynamic actuator 18b includes a second aerodynamic body 30b, a second pivot 32b, and a second actuator motor 34b. The second aerodynamic body 30b is used to regulate drag and / or aerodynamic downforce by disrupting the airflow through the vehicle 12. In an exemplary embodiment, the second aerodynamic body 30b is configured as an airfoil spoiler. The second pivot 32b is used to realize rotational movement between the second aerodynamic body 30b and the vehicle 12. In an exemplary embodiment, the second pivot 32b is a hinge. In a non-limiting example, the hinge includes a pivot pin (not shown) and two hinge plates (not shown) mechanically connected to the pivot pin. The pivot pin allows the hinge plates to rotate relative to each other, and the hinge plates are attached to corresponding components (i.e., one attached to the vehicle 12 and one attached to the second aerodynamic body 30b) to facilitate their rotational movement. It should be understood that the second pivot 32b may include any mechanical structure or linkage that allows rotational or pivotal movement, including any combination of, for example, hinges, bearings, pivot pins, ball joints, rotary joints, bushings, universal joints, U-pins, trunnions, etc. The second actuator motor 34b is used to actuate (i.e., move) the second aerodynamic body 30b to adjust drag and / or aerodynamic downforce. In one exemplary embodiment, the second actuator motor 34b is a motor (e.g., a DC brushed motor, a DC brushless motor, an AC motor, a linear actuator, etc.) connected to the second aerodynamic body 30b via a second pivot 32b. In another exemplary embodiment, the second actuator motor 34b includes a pneumatic or hydraulic actuator. It should be understood that any actuator operable to actuate (i.e., move) the second aerodynamic body 30b is within the scope of this disclosure. Furthermore, any mechanical construction for connecting the second actuator motor 34b to the second aerodynamic body 30b, including, for example, chains, belts, pulleys, gears, linkages, etc., is within the scope of this disclosure. In a non-limiting example, the second actuator motor 34b includes a relative or absolute positioning device, such as a rotary encoder, such that the controller 14 can determine the position of the second actuator motor 34b and thus the position of the second aerodynamic body 30b. The second actuator motor 34b is in electrical communication with and can be controlled by the controller 14, as will be discussed in more detail below. In one exemplary embodiment, the front aerodynamic actuator 18a is positioned closer to the front axle 28a than the rear axle 28b, such that the front aerodynamic actuator 18a effectively regulates the front downforce 26a. In a non-limiting example, the front aerodynamic actuator 18a is mounted near and / or above the trunk, hood, front bumper, etc. of the vehicle 12. The rear aerodynamic actuator 18b is positioned closer to the rear axle 28b than the front axle 28a, such that the rear aerodynamic actuator 18b effectively regulates the rear downforce 26b. In a non-limiting example, the rear aerodynamic actuator 18b is mounted near and / or above the trunk, rear spoiler, rear bumper, etc. of the vehicle 12. refer to Figure 2A flowchart of a method 100 for determining a desired lateral acceleration of a vehicle is provided. Method 100 begins at block 102 and proceeds to block 104. At block 104, controller 14 uses one or more vehicle sensors 16 to perform multiple measurements. In an exemplary embodiment, controller 14 uses a steering wheel angle sensor 26 to determine the steering wheel angle of the vehicle. Controller 14 also uses one or more vehicle sensors 16 (e.g., motor speed sensors, wheel speed sensors, etc.) to determine the speed of vehicle 12 and the longitudinal component of the speed of vehicle 12. Within the scope of this disclosure, the term "longitudinal" refers to a direction parallel to the direction of travel of vehicle 12. The term "lateral" refers to a direction perpendicular to the direction of travel of vehicle 12. Controller 14 also uses accelerator pedal position sensor 24a, brake pedal position sensor 24b, and steering wheel angle sensor 26 to measure one or more occupant inputs. Within the scope of this disclosure, occupant inputs are control commands provided to vehicle 12 by an occupant of vehicle 12 (e.g., a driver). In a non-limiting example, one or more occupant inputs include at least one of the following: accelerator pedal position, brake pedal position, and steering wheel angle. It should be understood that, without departing from the scope of this disclosure, controller 14 may use any of one or more vehicle sensors 16 to measure and / or determine various additional quantities or values. It should also be understood that controller 14 may store one or more previous measurements from one or more vehicle sensors 16 in medium 22 of controller 14 for later retrieval, thereby allowing historical and trend analysis of the measurements. Following block 104, method 100 proceeds to blocks 106 and 108. At block 106, controller 14 determines a first raw lateral acceleration request. Within the scope of this disclosure, the first raw lateral acceleration request is an occupant request for vehicle 12, a desired or anticipated lateral acceleration of vehicle 12, as determined prior to any post-processing based on vehicle dynamics and occupant control inputs. In an exemplary embodiment, the first raw lateral acceleration request is based at least in part on the steering wheel angle, the longitudinal component of the vehicle 12's velocity, and the wheelbase L of vehicle 12. Figure 1 (As shown) and the understeer coefficient of vehicle 12 are used to determine the longitudinal components of the steering wheel angle and speed of vehicle 12. As discussed in reference box 104 above, one or more vehicle sensors 16 are used to determine the longitudinal components of the steering wheel angle and speed of vehicle 12. In one exemplary embodiment, the wheelbase L is retrieved from the medium 22 of the controller 14. Within the scope of this disclosure, the understeer coefficient is a vehicle dynamics parameter used to characterize the stability and dynamic handling behavior of a vehicle, particularly relating to steering and the tendency of the vehicle to oversteer or understeer. In one exemplary embodiment, the understeer coefficient is related to the suspension system geometry of the vehicle 12, the weight distribution of the vehicle 12, the powertrain design of the vehicle 12, the longitudinal speed of the vehicle 12, etc. In a non-limiting example, a lookup table (LUT) is used to determine the understeer coefficient, which maps the longitudinal component of the vehicle 12's speed to the understeer coefficient. The LUT has a key column (i.e., a key column for the longitudinal component of the vehicle 12's speed) and a value column (i.e., a value column for the understeer coefficient). In an exemplary embodiment, the LUT includes multiple rows, each of which maps a unique longitudinal component of the vehicle 12's speed in the key column to a value in the value column (i.e., the understeer coefficient). The LUT is stored in medium 22 of controller 14. In one exemplary embodiment, the multiple rows of the LUT are predetermined. In another exemplary embodiment, the multiple rows of the LUT can be modified by an occupant using, for example, a human-machine interface device. In yet another exemplary embodiment, the multiple rows of the LUT can be updated over the air (OTA) using a vehicle communication system. It should be understood that any method (e.g., programming data structures, logical equations, mathematical functions, etc.) that maps multiple keys (i.e., the longitudinal component of the speed of vehicle 12) to multiple values ​​(i.e., the understeer coefficient) is within the scope of this disclosure. It should also be understood that the LUT can be a multidimensional LUT having multiple key columns related to the suspension system geometry or operation of vehicle 12, the weight distribution of vehicle 12, the powertrain design or operation of vehicle 12, etc. In one exemplary embodiment, the controller 14 uses a formula to determine the first initial lateral acceleration request: Where A y,req,raw,1 This is the first original lateral acceleration request, δ is the steering wheel angle, and V... x It is the longitudinal component of the velocity, L is the wheelbase, and K is the longitudinal component of the velocity. us This is the understeering coefficient. After box 106, method 100 proceeds to box 110, which will be discussed in more detail below. At block 108, controller 14 determines the maximum permissible lateral acceleration. Within the scope of this disclosure, the maximum permissible lateral acceleration is the maximum lateral acceleration achievable by the vehicle, which is limited by, for example, tire traction. The determination of the maximum permissible lateral acceleration will be discussed in more detail below. Following block 108, method 100 proceeds to block 110. At block 110, controller 14 determines a second raw lateral acceleration request. Within the scope of this disclosure, the second raw lateral acceleration request is the lateral acceleration of vehicle 12 requested, required, or desired by the occupants of vehicle 12, determined based on vehicle dynamics and occupant control inputs and based on the maximum permissible lateral acceleration determined at block 108. In an exemplary embodiment, to determine the second raw lateral acceleration request, controller 14 compares the first raw lateral acceleration request determined at block 106 with the maximum permissible lateral acceleration determined at block 108. The second raw lateral acceleration request is determined to be the minimum of the first raw lateral acceleration request and the maximum permissible lateral acceleration. Furthermore, controller 14 stores the second raw lateral acceleration request in medium 22 of controller 14 for later retrieval and analysis. Previously determined second raw lateral acceleration requests stored in medium 22 of controller 14 are referred to as one or more historical second raw lateral acceleration requests. Following block 110, method 100 proceeds to blocks 112 and 114. At block 112, controller 14 determines an occupant effort index. Within the scope of this disclosure, the occupant effort index quantifies the amount of effort an occupant exerts while controlling vehicle 12. In other words, the occupant effort index quantifies the level of activity an occupant displays in driving vehicle 12. In one exemplary embodiment, the occupant effort index is determined at least in part based on one or more occupant inputs. As described above, one or more occupant inputs are control commands provided by the occupant to vehicle 12. In a non-limiting example, a high occupant effort index means that the occupant is highly engaged in controlling vehicle 12, such as through high-amplitude and / or high-frequency manipulation of vehicle controls (e.g., steering wheel, accelerator pedal, brake pedal, etc.). In one exemplary embodiment, to determine the occupant effort index, controller 14 determines the rate of change of one or more occupant inputs measured at frame 106 within a predetermined time window (e.g., the first thirty seconds). In a non-limiting example, controller 14 analyzes saved historical measurements from accelerator pedal position sensor 24a to determine the rate of change of accelerator pedal position within the predetermined time window. In another non-limiting example, controller 14 analyzes saved historical measurements from brake pedal position sensor 24b to determine the rate of change of brake pedal position within the predetermined time window. In yet another non-limiting example, controller 14 analyzes saved historical measurements from steering wheel angle sensor 26 to determine the rate of change of steering wheel angle within the predetermined time window. The controller 14 then determines the occupant effort index based on the rate of change of one or more occupant inputs. In a non-limiting example, the occupant effort index is positively correlated with the rate of change of one or more occupant inputs, such that a high occupant effort index corresponds to a high rate of change of one or more occupant inputs. It should be understood that any method of mapping the rate of change of one or more occupant inputs to the occupant effort index (e.g., programming data structures, logical equations, mathematical functions, lookup tables, etc.) is within the scope of this disclosure. In another exemplary embodiment, to determine the occupant effort index, controller 14 determines the maximum magnitude of one or more occupant inputs measured at frame 106 within a predetermined time window (e.g., the first thirty seconds). In a non-limiting example, controller 14 analyzes saved historical measurements from accelerator pedal position sensor 24a to determine the maximum magnitude of the accelerator pedal position within the predetermined time window. In another non-limiting example, controller 14 analyzes saved historical measurements from brake pedal position sensor 24b to determine the maximum magnitude of the brake pedal position within the predetermined time window. In another non-limiting example, controller 14 analyzes saved historical measurements from steering wheel angle sensor 26 to determine the maximum magnitude of the steering wheel angle within the predetermined time window. The controller 14 then determines the occupant effort index based on the maximum amplitude of one or more occupant inputs. In a non-limiting example, the occupant effort index is positively correlated with the maximum amplitude of one or more occupant inputs, such that a high occupant effort index corresponds to a high maximum amplitude of one or more occupant inputs. It should be understood that any method of mapping the maximum amplitude of one or more occupant inputs to the occupant effort index (e.g., programming data structures, logical equations, mathematical functions, lookup tables, etc.) is within the scope of this disclosure. Following box 112, method 100 proceeds to box 116, as will be discussed in more detail below. At block 114, controller 14 determines the desired lateral acceleration change state. Within the scope of this disclosure, the desired lateral acceleration change state characterizes the change of the second original lateral acceleration request compared to one or more historical second original lateral acceleration requests stored in medium 22 of controller 14. In an exemplary embodiment, the desired lateral acceleration change state includes one of the following: a small increase state, a large increase state, a small decrease state, and a large decrease state. The determination of the desired lateral acceleration change state will be discussed in more detail below. Following block 114, method 100 proceeds to block 116. At block 116, controller 14 determines the desired lateral acceleration. Within the scope of this disclosure, the desired lateral acceleration is the lateral acceleration of vehicle 12 requested, required, or desired by the occupants of vehicle 12, determined based on vehicle dynamics and occupant control inputs after post-processing of the maximum permissible lateral acceleration determined at block 108, the occupant effort index determined at block 112, and the desired lateral acceleration change state determined at block 114. The desired lateral acceleration is suitable for controlling or regulating the operation of vehicle 12, as will be discussed in more detail below. The determination of the desired lateral acceleration will be discussed in more detail below. After block 116, method 100 proceeds to block 118. At block 118, controller 14 adjusts the operation of one or more aerodynamic actuators 18 based at least in part on the desired lateral acceleration determined at block 116. In an exemplary embodiment, controller 14 adjusts one or both of the front aerodynamic actuator 18a and the rear aerodynamic actuator 18b to change one or both of the front downforce 26a and the rear downforce 26b to allow and / or assist vehicle 12 in achieving the desired lateral acceleration determined at block 116. In a non-limiting example, when vehicle 12 passes through a corner or turns, the occupants may wish to perform a drift maneuver involving oversteer and loss of traction and lateral acceleration. Therefore, using method 100 as described above, controller 14 identifies the occupant's desired lateral acceleration when attempting to initiate a drift maneuver. In a non-limiting example, a rapid change in steering wheel angle and accelerator pedal position by an occupant with a high occupant effort index identified at block 112 could indicate drift maneuver initiation. Then, at block 118, controller 14 adjusts one or both of the front aerodynamic actuator 18a and the rear aerodynamic actuator 18b to change one or both of the front downforce 26a and the rear downforce 26b to allow and / or assist vehicle 12 in achieving the desired lateral acceleration to perform a drift maneuver (e.g., by increasing front downforce 26a relative to rear downforce 26b to facilitate oversteer). In another non-limiting example, an occupant may wish to perform high-speed cornering maneuvers involving instantaneous lateral acceleration while maintaining traction as the vehicle 12 passes through a corner or turns. Therefore, using method 100 as described above, controller 14 identifies the occupant's desired lateral acceleration when the occupant initiates high-speed cornering maneuvers. In a non-limiting example, corresponding to the low occupant effort index identified at block 112, slow and smooth changes in the occupant's steering wheel angle and accelerator pedal position can indicate the initiation of high-speed cornering maneuvers. Then, at block 118, controller 14 adjusts one or both of the front aerodynamic actuator 18a and the rear aerodynamic actuator 18b to change one or both of the front downforce 26a and the rear downforce 26b to allow and / or assist the vehicle 12 in achieving the desired lateral acceleration to perform high-speed cornering maneuvers (e.g., making the front downforce 26a equal to approximately 40 percent of the total downforce and the rear downforce 26b equal to approximately 60 percent of the total downforce to improve cornering stability). It should be understood that the aforementioned scenarios are merely exemplary in nature, and system 10 and method 100 can be used to control various additional aspects of the operation of vehicle 12 based on the desired lateral acceleration determined at block 116, including, for example, suspension ride height, suspension stiffness, steering sensitivity, brake pedal sensitivity, accelerator pedal sensitivity, traction control and / or stability control system, anti-lock braking system, etc. Following block 118, method 100 proceeds to a standby state at block 120. In one exemplary embodiment, controller 14 repeatedly exits standby state 120 and restarts method 100 at block 102. In a non-limiting example, controller 14 exits standby state 120 and restarts method 100 on a timer, for example, every three hundred milliseconds. refer to Figure 3A flowchart of an exemplary embodiment 108a of block 108 (i.e., a method for determining the maximum permissible lateral acceleration) is shown. Exemplary embodiment 108a of block 108 begins at blocks 302 and 304. At block 302, controller 14 determines the baseline front downforce applied to the front axle 28a of vehicle 12. Within the scope of this disclosure, the baseline front downforce is the downforce applied to the front axle 28a by the weight of vehicle 12 and typical aerodynamic effects, regardless of the effects of one or more aerodynamic actuators 18. In one exemplary embodiment, the baseline front downforce is predetermined based on the known total weight of vehicle 12, the known weight distribution of vehicle 12, and known typical aerodynamic effects determined from a vehicle speed-based lookup table and retrieved from the cross-section 22 of controller 14. In another exemplary embodiment, controller 14 uses one or more vehicle sensors 16 (e.g., front suspension ride height sensors) to measure the baseline front downforce of vehicle 12. Following block 302, exemplary embodiment 108a of block 108 proceeds to block 306. At block 306, controller 14 determines the aerodynamic downforce provided by front aerodynamic actuator 18a. In an exemplary embodiment, the aerodynamic downforce provided by front aerodynamic actuator 18a is determined using a multidimensional lookup table (LUT) that maps the speed of vehicle 12 and the position of first actuator motor 34a (and therefore the position of first power body 30a) to the aerodynamic downforce provided by front aerodynamic actuator 18a. The LUT has two key columns (i.e., one for the speed of vehicle 12 and one for the position of first actuator motor 34a) and one value column (i.e., one for the aerodynamic downforce provided by front aerodynamic actuator 18a). In one exemplary embodiment, the LUT comprises multiple rows, each row mapping a unique combination of the speed of the vehicle 12 and the position of the first actuator motor 34a in two key columns to a value in a value column (i.e., the aerodynamic downforce provided by the front aerodynamic actuator 18a). The LUT is stored in medium 22 of the controller 14. In one exemplary embodiment, the multiple rows of the LUT are predetermined. In another exemplary embodiment, the multiple rows of the LUT can be modified by an occupant using, for example, a human-machine interface device. In yet another exemplary embodiment, the multiple rows of the LUT can be updated over the air (OTA) using a vehicle communication system. It should be understood that any method (e.g., programming data structures, logical equations, mathematical functions, etc.) mapping multiple keys (i.e., the speed of the vehicle 12 and the position of the first actuator motor 34a) to multiple values ​​(i.e., the aerodynamic downforce provided by the front aerodynamic actuator 18a) is within the scope of this disclosure. Following block 306, exemplary embodiment 108a of block 108 proceeds to block 308. At block 308, controller 14 determines front downforce 26a based at least in part on the baseline front downforce determined at block 302 and the aerodynamic front downforce determined at block 306. In an exemplary embodiment, front downforce 26a is determined as the sum of the baseline front downforce determined at block 302 and the aerodynamic front downforce determined at block 306. Following block 308, exemplary embodiment 108a of block 108 proceeds to block 310, as will be discussed in more detail below. At block 304, controller 14 determines the baseline rear downforce applied to the rear axle 28b of vehicle 12. Within the scope of this disclosure, the baseline rear downforce is the downforce applied to the rear axle 28b by the weight of vehicle 12 and typical aerodynamic effects, regardless of the effects of one or more aerodynamic actuators 18. In one exemplary embodiment, the baseline rear downforce is predetermined based on the known total weight of vehicle 12, the known weight distribution of vehicle 12, and known typical aerodynamic effects determined from a vehicle speed-based lookup table and retrieved from medium 22 of controller 14. In another exemplary embodiment, controller 14 uses one or more vehicle sensors 16 (e.g., rear suspension ride height sensors) to measure the baseline rear downforce of vehicle 12. Following block 304, exemplary embodiment 108a of block 108 proceeds to block 312. At block 312, controller 14 determines the aerodynamic downforce provided by rear aerodynamic actuator 18b. In an exemplary embodiment, the aerodynamic downforce provided by rear aerodynamic actuator 18b is determined using a multidimensional lookup table (LUT) that maps the speed of vehicle 12 and the position of second actuator motor 34b (and therefore the position of second aerodynamic body 30b) to the aerodynamic downforce provided by rear aerodynamic actuator 18b. The LUT has two key columns (i.e., one for the speed of vehicle 12 and one for the position of second actuator motor 34b) and one value column (i.e., one for the aerodynamic downforce provided by rear aerodynamic actuator 18b). In one exemplary embodiment, the LUT comprises multiple rows, each row mapping a unique combination of the speed of the vehicle 12 and the position of the second actuator motor 34b in the two key columns to a value in the value column (i.e., the aerodynamic downforce provided by the rear aerodynamic actuator 18b). The LUT is stored in medium 22 of the controller 14. In one exemplary embodiment, the multiple rows of the LUT are predetermined. In another exemplary embodiment, the multiple rows of the LUT can be modified by an occupant using, for example, a human-machine interface device. In yet another exemplary embodiment, the multiple rows of the LUT can be updated over the air (OTA) using a vehicle communication system. It should be understood that any method (e.g., programming data structures, logical equations, mathematical functions, etc.) that maps multiple keys (i.e., the speed of the vehicle 12 and the position of the second actuator motor 34b) to multiple values ​​(i.e., the aerodynamic downforce provided by the rear aerodynamic actuator 18b) is within the scope of this disclosure. Following block 312, exemplary embodiment 108a of block 108 proceeds to block 314. At block 314, controller 14 determines rear downforce 26b based at least in part on the baseline rear downforce determined at block 304 and the aerodynamic rear downforce determined at block 312. In an exemplary embodiment, rear downforce 26b is determined as the sum of the baseline rear downforce determined at block 304 and the aerodynamic rear downforce determined at block 312. Following block 314, exemplary embodiment 108a of block 108 proceeds to block 310, as will be discussed in more detail below. At block 310, controller 14 determines the maximum permissible lateral acceleration based at least in part on the front downforce 26a determined at block 308 and the rear downforce 26b determined at block 314. As described above, the maximum permissible lateral acceleration is the maximum lateral acceleration achievable by the vehicle, limited, for example, by tire traction. In an exemplary embodiment, controller 14 first determines the maximum permissible lateral force. Within the scope of this disclosure, the maximum permissible lateral force is the maximum lateral force that the tires of vehicle 12 can withstand without losing traction. In a non-limiting example, to determine the maximum permissible lateral force, controller 14 uses a tire slip model. Within the scope of this disclosure, a tire slip model is a mathematical representation capturing the complex interaction between the tires of vehicle 12 and road surface 36. The tire slip model is used to predict tire behavior under various driving conditions, with particular attention to the relationship between the forces applied to the tires and the resulting slip. Slip is the relative motion between the tire and road surface 36. The tire slip model considers factors such as the tire's rubber composition, tread pattern, inflation pressure, characteristics of road surface 36 (including its texture and coefficient of friction), the front downforce 26a determined at box 308 (which relates to the normal force on the front tires of vehicle 12), and the rear downforce 26b determined at box 314 (which relates to the normal force on the rear tires of vehicle 12). At the heart of the tire slip model is the concept of a slip angle, which is the angle between the direction the tire is pointing (related to the steering wheel angle) and the actual direction of travel of the tire contact patch on road surface 36. To determine the maximum permissible lateral force, the tire slip model employs a function relating the slip angle, the front downforce 26a determined at box 308, and the rear downforce 26b determined at box 314, to the lateral force generated by the tire. As the slip angle increases, the lateral force, based on the normal force (i.e., downforce) applied to the tire, also increases to a certain point. This point represents the peak value of the tire's grip; beyond this peak, any further increase in the slip angle results in a decrease in lateral force, indicating that the tire has reached its grip limit and begins to slip. By analyzing this relationship, the model can predict the maximum permissible lateral force the tire can withstand before slippage occurs, based on the front downforce 26a determined at box 308 and the rear downforce 26b determined at box 314. It should be understood that the foregoing description of the tire slip model is merely exemplary in nature, and various additional mathematical, physical-based and / or computer-based models can be used to determine the maximum permissible lateral force based on the downforce 26a determined at box 308 and the rear downforce 26b determined at box 314. After determining the maximum permissible lateral force, controller 14 then determines the maximum permissible lateral acceleration based at least in part on the maximum permissible lateral force. In an exemplary embodiment, the maximum permissible lateral acceleration is determined based at least in part on the maximum permissible lateral force using Newtonian mechanics (e.g., Newton's second law of motion). Following block 310, exemplary embodiment 108a of block 108 ends, and method 100 continues as described above. refer to Figure 4The diagram illustrates a flowchart of an exemplary embodiment 114a of block 114 (i.e., a method for determining a desired lateral acceleration change state). Exemplary embodiment 114a of block 114 begins at block 402. At block 402, controller 14 calculates the difference between a second original lateral acceleration request determined at block 110 and a previous second original lateral acceleration request from one or more historical second original lateral acceleration requests. Within the scope of this disclosure, the previous second original lateral acceleration request is the most recently determined second original lateral acceleration request from one or more historical second original lateral acceleration requests (e.g., determined during a previous execution of method 100). Following block 402, exemplary embodiment 114a of block 114 proceeds to block 404. At block 404, controller 14 determines whether the second initial lateral acceleration request determined at block 110 is greater than or less than the previous second initial lateral acceleration request. If the second initial lateral acceleration request determined at block 110 is less than or equal to the previous second initial lateral acceleration request, then exemplary embodiment 114a of block 114 proceeds to block 406, as will be discussed in more detail below. If the second initial lateral acceleration request determined at block 110 is greater than the previous second initial lateral acceleration request, then exemplary embodiment 114a of block 114 proceeds to block 408. At block 408, controller 14 compares the magnitude of the difference calculated at block 402 with a first threshold. If the magnitude of the difference calculated at block 402 is less than the first threshold, then exemplary embodiment 114a of block 114 proceeds to block 410, as will be discussed in more detail below. If the magnitude of the difference calculated at block 402 is greater than or equal to the first threshold, then exemplary embodiment 114a of block 114 proceeds to block 412. At block 412, in response to determining that the magnitude of the difference calculated at block 402 is greater than or equal to a first threshold and that the second original lateral acceleration request is greater than the previous second original lateral acceleration request, the desired lateral acceleration change state is determined to be a significantly increased state. After block 412, exemplary embodiment 114a of block 114 ends, and method 100 continues as described above. At block 410, in response to determining that the magnitude of the difference calculated at block 402 is less than a first threshold and that the second original lateral acceleration request is greater than the previous second original lateral acceleration request, the desired lateral acceleration change state is determined to be a small-amplitude increase state. After block 410, exemplary embodiment 114a of block 114 ends, and method 100 continues as described above. At block 406, controller 14 compares the magnitude of the difference calculated at block 402 with a second threshold. If the magnitude of the difference calculated at block 402 is less than the second threshold, exemplary embodiment 114a of block 114 proceeds to block 414, as will be discussed in more detail below. If the magnitude of the difference calculated at block 402 is greater than or equal to the second threshold, exemplary embodiment 114a of block 114 proceeds to block 416. At block 416, in response to determining that the magnitude of the difference calculated at block 402 is greater than or equal to a second threshold and the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request, the desired lateral acceleration change state is determined to be a significantly reduced state. After block 416, exemplary embodiment 114a of block 114 ends, and method 100 continues as described above. At block 414, in response to determining that the magnitude of the difference calculated at block 402 is less than a second threshold and that the second original lateral acceleration request is less than or equal to the previous second original lateral acceleration request, the desired lateral acceleration change state is determined to be a small-amplitude decrease state. After block 414, exemplary embodiment 114a of block 114 ends, and method 100 continues as described above. refer to Figure 5 The diagram illustrates a flowchart of an exemplary embodiment 116a of block 116 (i.e., a method for determining a desired lateral acceleration). Exemplary embodiment 116a of block 116 begins at block 502. At block 502, if the desired lateral acceleration change state determined at block 114 is not a small increase, then exemplary embodiment 116a of block 116 proceeds to block 504, as will be discussed in more detail below. If the desired lateral acceleration change state determined at block 114 is a small increase, then exemplary embodiment 116a of block 116 proceeds to block 506. At block 506, in response to determining that the desired lateral acceleration change state is a small increase state, the desired lateral acceleration is determined to be equal to the second original lateral acceleration request determined at block 110. After block 506, exemplary embodiment 116a of block 116 ends, and method 100 continues as described above. At block 504, if the desired lateral acceleration change state determined at block 114 is not a significantly increased state, then exemplary embodiment 116a of block 116 proceeds to block 508, as will be discussed in more detail below. If the desired lateral acceleration change state determined at block 114 is a significantly increased state, then exemplary embodiment 116a of block 116 proceeds to block 510. At box 510, in response to determining that the desired lateral acceleration change state is a significantly increased state, the desired lateral acceleration is determined to be the minimum of the sum of the second initial lateral acceleration request determined at box 110, the previous second initial lateral acceleration request, and a predetermined constant. In a non-limiting example, the desired lateral acceleration is determined by the following formula: A y,desired =min(A y,req,raw,2 A y,req,raw,2,prev +C) (2) Where A y,desired It is the required lateral acceleration, A y,req,raw,2 The second original lateral acceleration request is determined at box 110, A y,req,raw,2,prev This is the previous second original lateral acceleration request, and C is a predetermined constant. After block 510, exemplary embodiment 116a of block 116 ends, and method 100 continues as described above.

[0001] At block 508, if the desired lateral acceleration change state determined at block 114 is not a small decrease state, then exemplary embodiment 116a of block 116 proceeds to block 512, as will be discussed in more detail below. If the desired lateral acceleration change state determined at block 114 is a small decrease state, then exemplary embodiment 116a of block 116 proceeds to block 514. In block 514, controller 14 compares the steering wheel angle to a predetermined range near zero. In a non-limiting example, the predetermined range near zero includes plus or minus ten degrees relative to zero, where zero represents straight-line driving. If the steering wheel angle is within the predetermined range near zero, exemplary embodiment 116a of block 116 proceeds to block 516, as will be discussed in more detail below. If the steering wheel angle is outside the predetermined range near zero, exemplary embodiment 116a of block 116 proceeds to block 518. At block 518, in response to determining that the desired lateral acceleration change state is a small decrease and that the steering wheel angle of vehicle 12 is outside a predetermined range near zero, the desired lateral acceleration is determined to be equal to the previous second original lateral acceleration request. After block 518, exemplary embodiment 116a of block 116 ends, and method 100 continues as described above. At block 516, in response to determining that the desired lateral acceleration change state is a small decrease and that the steering wheel angle of vehicle 12 is within a predetermined range near zero, the desired lateral acceleration is determined to be equal to the second original lateral acceleration request. After block 516, exemplary embodiment 116a of block 116 ends, and method 100 continues as described above. In block 512, in response to determining that the desired lateral acceleration change state is a significantly reduced state, the desired lateral acceleration is reduced at a defined rate from the previous second initial lateral acceleration request to the second initial lateral acceleration request determined at block 110. In one exemplary embodiment, the defined rate is determined at least in part based on the occupant effort index. In one non-limiting example, the defined rate is positively correlated with the occupant effort index. In another non-limiting example, the defined rate is negatively correlated with the occupant effort index. In another exemplary embodiment, the limited rate is also determined at least in part based on the steering wheel angle. In one non-limiting example, the limited rate is positively correlated with the magnitude of the difference between the steering wheel angle and zero. In another non-limiting example, the limited rate is negatively correlated with the magnitude of the difference between the steering wheel angle and zero. It should be understood that any method for determining the limited rate based at least in part on the occupant effort index and / or steering wheel angle is within the scope of this disclosure. In one exemplary embodiment, the required lateral acceleration is gradually reduced from the previous second initial lateral acceleration request at a defined rate over a defined time period until the required lateral acceleration equals the second initial lateral acceleration request determined at block 110. After block 512, exemplary embodiment 116a of block 116 ends, and method 100 continues as described above. The system 10 and method 100 of this disclosure offer several advantages. By determining the first raw lateral acceleration request according to Equation 1 as described above, an understeer coefficient is used to account for the understeer characteristics of the vehicle 12. Furthermore, using method 100, a tire slip model is used to determine the maximum permissible lateral acceleration, while taking into account the effects of active downforce provided by one or more aerodynamic actuators 18. Additionally, a second raw lateral acceleration request is post-processed based on occupant behavior using an occupant effort index. The descriptions in this disclosure are merely exemplary in nature, and changes that do not depart from the spirit and scope of this disclosure are intended to fall within its scope. Such changes should not be considered as departing from the spirit and scope of this disclosure.

Claims

1. A method for determining a desired lateral acceleration of a vehicle, the method comprising: determining a first raw lateral acceleration request based at least in part on a steering wheel angle of the vehicle; determining a maximum allowable lateral acceleration based at least in part on a tire slip model; determining the desired lateral acceleration based at least in part on the first raw lateral acceleration request and the maximum allowable lateral acceleration; and adjusting operation of the vehicle based at least in part on the desired lateral acceleration. Determining the first raw lateral acceleration request further comprises:

2. The method of claim 1, wherein, determining the steering wheel angle of the vehicle; determining a longitudinal component of a speed of the vehicle; determining a wheelbase of the vehicle; and determining the first raw lateral acceleration request based at least in part on the steering wheel angle, the longitudinal component of the speed, and the wheelbase. Determining the first raw lateral acceleration request further comprises:

3. The method of claim 2, wherein, determining an understeer coefficient of the vehicle based at least in part on the longitudinal component of the speed; and determining the first raw lateral acceleration request based at least in part on the steering wheel angle, the longitudinal component of the speed, the wheelbase, and the understeer coefficient. Determining the maximum allowable lateral acceleration further comprises:

4. The method of claim 1, wherein, determining a front downforce and a rear downforce of the vehicle; determining a maximum allowable lateral force using the tire slip model based at least in part on the front downforce and the rear downforce; and determining the maximum allowable lateral acceleration based at least in part on the maximum allowable lateral force. Determining the front downforce and the rear downforce further comprises:

5. The method of claim 4, wherein, determining a baseline front downforce and a baseline rear downforce based at least in part on a weight of the vehicle; determining an aerodynamic front downforce and an aerodynamic rear downforce provided by an active downforce component of the vehicle; and determining the front downforce based at least in part on the baseline front downforce and the aerodynamic front downforce; and determining the rear downforce based at least in part on the baseline rear downforce and the aerodynamic rear downforce. Determining the desired lateral acceleration based at least in part on the first raw lateral acceleration request and the maximum allowable lateral acceleration further comprises:

6. The method of claim 1, wherein, determining a second raw lateral acceleration request based at least in part on the first raw lateral acceleration request and the maximum allowable lateral acceleration; and determining the desired lateral acceleration based at least in part on the second raw lateral acceleration request. Determining the desired lateral acceleration based at least in part on the second raw lateral acceleration request further comprises:

7. The method of claim 6, wherein, determining a passenger effort index based at least in part on one or more passenger inputs; determining a desired lateral acceleration change state based at least in part on the second raw lateral acceleration request and one or more historical second raw lateral acceleration requests; and determining the desired lateral acceleration based at least in part on the second raw lateral acceleration request, the passenger effort index, and the desired lateral acceleration change state. Determining the passenger effort index further comprises:

8. The method of claim 7, wherein, ​ determining a rate of change of the one or more occupant inputs, wherein the one or more occupant inputs include at least one of an accelerator pedal position, a brake pedal position, and a steering wheel angle; determining the occupant effort index based at least in part on the rate of change of the one or more occupant inputs, wherein a high occupant effort index corresponds to a high rate of change of the one or more occupant inputs.

9. The method of claim 7, wherein, determining the required lateral acceleration change state further includes: calculating a difference between the second raw lateral acceleration request and a previous second raw lateral acceleration request of one or more historical second raw lateral acceleration requests; determining the required lateral acceleration change state is a small magnitude increase state in response to determining that a magnitude of the difference is less than a first threshold and the second raw lateral acceleration request is greater than the previous second raw lateral acceleration request; determining the required lateral acceleration change state is a large magnitude increase state in response to determining that the magnitude of the difference is greater than or equal to the first threshold and the second raw lateral acceleration request is greater than the previous second raw lateral acceleration request; determining the required lateral acceleration change state is a small magnitude decrease state in response to determining that the magnitude of the difference is less than a second threshold and the second raw lateral acceleration request is less than or equal to the previous second raw lateral acceleration request; and determining the required lateral acceleration change state is a large magnitude decrease state in response to determining that the magnitude of the difference is greater than or equal to the second threshold and the second raw lateral acceleration request is less than or equal to the previous second raw lateral acceleration request.

10. The method of claim 9, wherein, determining the required lateral acceleration based at least in part on the second raw lateral acceleration request, the occupant effort index, and the required lateral acceleration change state further includes: determining the required lateral acceleration is equal to the second raw lateral acceleration request in response to determining that the required lateral acceleration change state is the small magnitude increase state; determining the required lateral acceleration is equal to a minimum of a sum of the second raw lateral acceleration request and a predetermined constant in response to determining that the required lateral acceleration change state is the large magnitude increase state; determining the required lateral acceleration is equal to the second raw lateral acceleration request in response to determining that the required lateral acceleration change state is the small magnitude decrease state and the steering wheel angle of the vehicle is within a predetermined range around zero; determining the required lateral acceleration is equal to the previous second raw lateral acceleration request in response to determining that the required lateral acceleration change state is the small magnitude decrease state and the steering wheel angle of the vehicle is outside the predetermined range around zero; and determining the required lateral acceleration is decreased from the previous second raw lateral acceleration request to the second raw lateral acceleration request at a defined rate in response to determining that the required lateral acceleration change state is the large magnitude decrease state, wherein the defined rate is determined at least in part dependent on the occupant effort index.

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