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Vehicle speed estimation for antilock braking using a chassis accelerometer

  • US 5,579,230 A
  • Filed: 06/10/1991
  • Issued: 11/26/1996
  • Est. Priority Date: 06/10/1991
  • Status: Expired due to Fees
First Claim
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1. In a vehicle having wheels with wheel speed sensors providing a measure of wheel speed, wheel brakes for braking said wheels, a brake application sensor providing an indication of operation of said wheel brakes for braking said vehicle, and a chassis accelerometer providing a measure of vehicle acceleration that is offset from actual vehicle acceleration due to vehicle inclination, a method of estimating vehicle speed during operation of said brakes for braking said vehicle, the method comprising the steps of:

  • prior to said brake application sensor providing said indication of operation of said wheel brakes, (A) determining actual vehicle speed as represented by said measure of wheel speed provided by said wheel speed sensors, (B) determining actual vehicle acceleration from said determined actual vehicle speed, and (C) determining a difference between said determined actual vehicle acceleration and said measure of vehicle acceleration provided by said chassis accelerometer, said difference comprising an accelerometer bias, andwhile said brake application sensor provides said indication of operation of said wheel brakes, (A) subtracting said accelerometer bias from said measure of vehicle acceleration provided by said chassis accelerometer to obtain a corrected measured vehicle acceleration and (B) estimating vehicle speed by integrating said corrected measured vehicle acceleration from an initial vehicle speed value equal to a last determined actual vehicle speed prior to said indication of operation of said wheel brakes.

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