Patent ID: 7325446
Filing Date: 2008-02-05
Classification: G01M

Abstract:
1. A rough road detection system for an engine having a crankshaft, comprising: a control module that receives a crankshaft speed signal, that determines a crankshaft rotation time based on said crankshaft speed signal, that determines a crankshaft acceleration and a crankshaft jerk based on said crankshaft rotation time, that detects a crankshaft disturbance based on said crankshaft acceleration and said crankshaft jerk, and that counts a number of crankshaft disturbances; and a comparison module that communicates with said control module, that determines a dispersion value and an asymmetry value based on said crankshaft disturbances, and that determines whether rough road conditions exist based on first and second comparisons, wherein said first comparison is between said dispersion value and a first predetermined threshold value, and wherein said second comparison is between said asymmetry value and a second predetermined threshold value.