Determining a desired lateral acceleration for a vehicle

A system for determining a desired lateral acceleration for a vehicle, the system comprising:

• one or more vehicle sensors;
• one or more aerodynamic actuators;
• and
• a controller in electrical communication with the one or more vehicle sensors and the one or more aerodynamic actuators, wherein the controller is programmed to:
• determine a first raw lateral acceleration request based at least in part on a steering wheel angle of the vehicle determined using the one or more vehicle sensors;
• determine a maximum allowed lateral acceleration based at least in part on a tire slip model;
• determine the desired lateral acceleration based at least in part on the first raw lateral acceleration request and the maximum allowed lateral acceleration;
• and
• adjust an operation of the one or more aerodynamic actuators based at least in part on the desired lateral acceleration.

A method for determining a desired lateral acceleration for a vehicle, the method comprising:

• determining a steering wheel angle of the vehicle using one or more vehicle sensors;
• determining a longitudinal component of a velocity of the vehicle using the one or more vehicle sensors;
• determining a wheelbase of the vehicle;
• determining an understeer coefficient of the vehicle based at least in part on the longitudinal component of the velocity;
• determining a first raw 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 using a formula:
• A
• y
• ,
• req
• ,
• raw
• ,
• 1
• =
• δ
• ⁢
• V
• x
• 2
• L
• +
• K
• us
• ⁢
• V
• x
• 2
• wherein Ay,req,raw,1 is the first raw lateral acceleration request, & is the steering wheel angle, Vx is the longitudinal component of the velocity, L is the wheelbase, and Kus is the understeer coefficient;
• determining a maximum allowed lateral acceleration based at least in part on a tire slip model;
• determining a second raw lateral acceleration request based at least in part on the first raw lateral acceleration request and the maximum allowed lateral acceleration;
• determining an occupant effort index based at least in part on one or more occupant 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;
• determining the desired lateral acceleration based at least in part on the second raw lateral acceleration request, the occupant effort index, and the desired lateral acceleration change state;
• and
• adjusting an operation of one or more aerodynamic actuators of the vehicle based at least in part on the desired lateral acceleration.