US 12,403,905 B1
System and method for downhill headway control for cruise control
Kevin A. O'Dea, Ann Arbor, MI (US); and Chase Goodin, Howell, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM Global Technology Operations LLC, Detroit, MI (US)
Filed on Mar. 4, 2024, as Appl. No. 18/594,356.
Int. Cl. B60W 30/16 (2020.01); B60W 10/18 (2012.01); B60W 50/00 (2006.01)
CPC B60W 30/16 (2013.01) [B60W 10/18 (2013.01); B60W 50/00 (2013.01); B60W 2050/0083 (2013.01); B60W 2300/14 (2013.01); B60W 2520/403 (2013.01); B60W 2552/15 (2020.02); B60W 2554/802 (2020.02)] 20 Claims
OG exemplary drawing
 
1. A cruise control method, comprising:
determining that a host vehicle is traveling downhill;
determining an axle torque command to maintain a predetermined headway distance from the host vehicle to a lead vehicle while the host vehicle is traveling downhill along a roadway, wherein the lead vehicle is immediately in front of the host vehicle, the axle torque command is a function of a road grade of the roadway, the roadway has a road surface, and the road grade is an angle from the road surface to a virtual horizontal line;
determining that a brake of the host vehicle is actuated to provide the axle torque command previously determined;
comparing the axle torque command with a brake exit threshold to determine whether the axle torque command is greater than the brake exit threshold;
in response to determining that the axle torque command is greater than the brake exit threshold, comparing a current headway distance between the host vehicle and the lead vehicle with a headway exit threshold to determine whether the current headway distance between the host vehicle and the lead vehicle is greater than the headway exit threshold; and
in response to determining that the predetermined headway distance between the host vehicle and the lead vehicle is greater than the headway exit threshold, commanding the brake of the host vehicle to disengage to terminate braking.