| 摘要 |
PROBLEM TO BE SOLVED: To shortly and precisely converge estimates of a neutral angleθ<SB>c</SB>, and quantitatively evaluate the reliability (precision) of the obtained estimates. SOLUTION: In Step 360, according to an equation: y=(V-V<SB>0</SB>)×(T<SB>0</SB>-|T|)×(ω<SB>0</SB>-|ω|)×(dT<SB>0</SB>-|dT|), a value of a forgetting factorλ(=1-Gy) is obtained (sample reliability computing means). Such dynamic optimization of the forgetting factorλcan decide the forgetting factorλat an optimal value depending on the reliability y of sampling valuesθ<SB>a</SB>as a neutral angleθ<SB>c</SB>. Reliability X of the neutral angleθ<SB>c</SB>is defined by a differential equation: dX=G2×(ΔΘ-|θ<SB>a</SB>-θ<SB>c</SB>|)×y.ΔΘcan be a constant indicative of an angle, for example, about 10°. Such computation of the reliability X is executed at the timing of Step 680 (neutral angle reliability computing means). The introduction of the index X can facilitate optimization of steering wheel returning torque T<SB>r</SB>. COPYRIGHT: (C)2003,JPO |
