Patent ID: 6701276
Filing Date: 2004-03-02
Classification: B60R

Abstract:
A method for generating an activating algorithm for processing a sensor signal of an angular rate sensor provided within a safety system of a motor vehicle, by means of which an activation decision for activating at least one safety device of said safety system is made in response to said sensor signal, wherein said sensor signal represents a measure of a rotational velocity (&ohgr;) of a rolling motion occurring when a rollover is imminent, said method comprising the following steps:a) generating a theoretical characteristic rollover curve satisfying: &agr;th(&ohgr;)=âˆ’(&agr;tip/&ohgr;lim)&ohgr;+&agr;tip,&ohgr;&gE;0â€ƒâ€ƒEquation (1) where &ohgr; corresponds to the initial rotational velocity of a rolling motion of said motor vehicle, and &agr;th(&ohgr;) represents an inclination angle of said motor vehicle, wherein the constants &agr;tip and &ohgr;lim are determined based on said motor vehicle, said constants defining a static motor vehicle tip angle limit whichâ€”if exceededâ€”causes the motor vehicle to tip over, said constants further defining a rotational velocity range within which a vehicle rollover will occur in response to &ohgr;&gE;&ohgr;lim, and wherein a rollover risk range Bth is represented by (&ohgr;,&agr;) value pairs, thus |&agr;|&gE;&agr;th(|&ohgr;|) wherein &agr; and &ohgr; are real values, wherein a positive activation decision for activating said at least one safety device is expected, andb) generating an activation algorithm by approximating said theoretical characteristic rollover curve of Equation (1) in the first quadrant with at least first and second low pass filter functions (Y1,n, n=1,2, . . . ; Y2,n, n=1,2, . . . ) to produce at least one approximated rollover curve (1â€²), wherein each low pass filter function has at least one respective activation threshold (S1, S2), wherein cutoff frequencies (fg1, fg2) of said at least first and second low pass filter functions (Y1,n, n=1,2, . . . ; Y2,n, n=1,2, . . . ) and said activation thresholds (S1, S2) are so determined that for a range BF1 of (|&ohgr;|, Y1,n,(&ohgr;)) value pairs and for a range BF2 of (|&ohgr;|, Y2,n,(&ohgr;)) value pairs |Y1,n(&ohgr;)>S1, and |Y2,n(&ohgr;)|>S2 is satisfied wherein Y1,n(&ohgr;) and Y2,n(&ohgr;) are real values, and BF1âŠ‚Bth and BF2âŠ‚Bth appliesâ€ƒâ€ƒEquation (2).