Patent ID: 6618651
Filing Date: 2003-09-09
Classification: B60T,B60W

Abstract:
A method for estimating longitudinal and lateral velocities in a motor vehicle comprising the steps of:sensing lateral acceleration, Ax, on the motor vehicle; sensing longitudinal acceleration Ay, on the motor vehicle; sensing yaw rate, &PSgr;, on the motor vehicle; determining time-varying gains, L1 and L2, according to the sensed yaw rate and the following formulas; L1=â€ƒ&it;2&it;Î»&it;â€ƒL2=â€ƒ&it;Î»2Î¨L-Î¨,Î¨L={Î¨,for&it;â€ƒ&it;&LeftBracketingBar;Î¨&RightBracketingBar;&GreaterEqual;Î¨0Î¨0&it;sign&af;(Î¨)for&it;â€ƒ&it;&LeftBracketingBar;Î¨&RightBracketingBar;<Î¨02&it;â€ƒ&it;and&it;â€ƒ&it;3â€ƒwhere &lgr; is a positive constant, &PSgr;o is a positive constant, and â€œsignâ€  represents the sign of the way rate; determining estimates of the lateral velocity, Vâ€²x and the longitudinal velocity Vâ€²y, in accordance with the following equation; [&dd;V^x&dd;t&dd;V^y&dd;t]=[0Î¨-Î¨0]&af;[V^xV^y]+[L1L2]&it;(Ym-[10]&af;[V^xV^y])+[1001]&af;[AxAy]1â€ƒwhere Ym is a signal representing a measurement of the longitudinal wheel velocity.