| US 7,591,170 B2 | ||
| Rough road detection system | ||
| Jian Lin, Beverly Hills, Mich. (US); Yong Xu, Ann Arbor, Mich. (US); Wenbo Wang, Novi, Mich. (US); and Michael R. Grimes, Saline, Mich. (US) | ||
| Assigned to GM Global Technology Operations, Inc., Detroit, Mich. (US) | ||
| Filed on Jan. 23, 2007, as Appl. No. 11/625,834. | ||
| Prior Publication US 2008/0173081 A1, Jul. 24, 2008 | ||
| Int. Cl. G01M 19/00 (2006.01) | ||
| U.S. Cl. 73—105 [73/114.25] | 24 Claims |
| 1. A rough road detection system, comprising:
an engine speed module that generates an engine speed signal based on a crank signal;
a feature space module that generates a frequency domain signal based on said engine speed signal;
a normalization module that generates a normalized signal based on said frequency domain signal and a normalization value
that varies in accordance with said engine speed signal; and
a rough road module that determines whether a rough road condition exists based on said normalized signal.
|