US 11,787,414 B2
GPS enhanced friction estimation
Nikolai K. Moshchuk, Grosse Pointe Farms, MI (US); David Perez-Chaparro, Ferndale, MI (US); Kausalya Singuru, Troy, MI (US); Hualin Tan, Novi, MI (US); Jin-Jae Chen, Canton, MI (US); and Ping Mi, Novi, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM Global Technology Operations LLC, Detroit, MI (US)
Filed on Jul. 23, 2021, as Appl. No. 17/383,987.
Prior Publication US 2023/0042818 A1, Feb. 9, 2023
Int. Cl. B60W 40/068 (2012.01); B60W 60/00 (2020.01); B60W 30/02 (2012.01)
CPC B60W 40/068 (2013.01) [B60W 60/001 (2020.02); B60W 30/02 (2013.01); B60W 2520/14 (2013.01); B60W 2520/20 (2013.01); B60W 2530/20 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of controlling a vehicle, comprising:
obtaining a measured yaw rate, a measured time derivative of the yaw rate, and a slip angle of the vehicle based on dynamics of the vehicle;
obtaining a model-based yaw rate and a model-based time derivative of the yaw rate for the vehicle using a tire model;
determining a metric based on a difference between the measured yaw rate and the model-based yaw rate and a difference between the measured time derivative of the yaw rate and the model-based time derivative of the yaw rate;
determine a low friction condition when the metric is greater than a threshold value and an absolute value of the slip angle is greater than one; and
controlling the vehicle based on the low friction condition.