US 12,472,956 B2
Method and system for determining the desired tire grip in active downforce control
Mohammad Pournazeri, Etobicoke (CA); Reza Hajiloo, Richmond Hill (CA); Naser Mehrabi, Richmond Hill (CA); Ehsan Asadi, Markham (CA); Seyedalireza Kasaiezadeh Mahabadi, Novi, MI (US); and Gianmarc Coppola, Richmond Hill (CA)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM Global Technology Operations LLC, Detroit, MI (US)
Filed on Jul. 11, 2023, as Appl. No. 18/350,508.
Prior Publication US 2025/0018956 A1, Jan. 16, 2025
Int. Cl. B60W 40/13 (2012.01); B62D 37/02 (2006.01); G06N 3/04 (2023.01)
CPC B60W 40/13 (2013.01) [B62D 37/02 (2013.01); G06N 3/04 (2013.01); B60W 2530/20 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for downforce control, comprising:
receiving sensor data from a plurality of sensors of a vehicle, wherein the vehicle includes a vehicle body, a first axle coupled to the vehicle body, a second axle coupled to the vehicle body, a first aerodynamic actuator coupled to the vehicle body, and a second aerodynamic actuator coupled to the vehicle body, the first aerodynamic actuator includes a first aerodynamic body movable relative to the vehicle body, the second aerodynamic actuator includes a second aerodynamic body movable relative to the vehicle body;
using a feedforward control to determine a first requested normal force at the first axle of the vehicle and a second requested normal force at the second axle of the vehicle using the sensor data, wherein the feedforward control is physics-based and calculates a required front force and a required lateral force to achieve a desired lateral acceleration based on a steering input and a vehicle velocity from the sensor data;
using a feedback control to determine a first requested normal force adjustment at the first axle of the vehicle and a second requested normal force adjustment at the second axle of the vehicle using the sensor data, wherein the feedback control includes sub-control modules that independently calculate adjustments using tire-friction ellipse margin, axle stability, body stability, and wheel stability;
fusing the first requested normal force at the first axle of the vehicle from the feedforward control with the first requested normal force adjustment from the feedback control to determine a first-adjusted normal force request at the first axle by adding the first requested normal force adjustment to the first requested normal force to determine a first-adjusted normal force request at the first axle;
fusing the second requested normal force from the feedforward control with the second requested normal force adjustment from the feedback control to determine a second-adjusted normal force request at the second axle by adding the second requested normal force adjustment to the second requested normal force to determine a second-adjusted normal force request at the second axle;
determining a first position of the first aerodynamic body relative to the vehicle body and a second position of the second aerodynamic body relative to the vehicle body based on the first-adjusted normal force request and the second-adjusted normal force request, respectively;
commanding the first aerodynamic actuator to move the first aerodynamic body to the first position relative to the vehicle body; and
commanding the second aerodynamic actuator to move the second aerodynamic body to the second position relative to the vehicle body.