Patent ID: 7400993
Filing Date: 2008-07-15
Classification: G01P

Abstract:
1. A method for calculating rotation-dependent parameters in a system that senses multiple teeth during a single shaft rotation of a toothed speed wheel, the method comprising: sensing passing edges of multiple gear teeth on the toothed speed wheel; generating a signal pulse at one of rising and falling edges of the gear teeth; measuring time between the generated signal pulses; calculating a tooth correction for the span between at least one of rising and falling edges of successive gear teeth according to: and applying the tooth correction to the rotation-dependent parameter calculation according to: where TICS represents circular buffer elements storing counter values associated with pulses, N represents the number of teeth on the speed wheel, t n represents a pointer to the latest TIC entry in a circular buffer, t n−1 is the pointer one entry back from t n , t n−k is the pointer k entries back from t n , [ti] represents t n , Modulus N, and tooth correction [ti] represents the tooth correction associated with an individual span.