| 摘要 |
PROBLEM TO BE SOLVED: To provide a road surface friction coefficient estimation device capable of ensuring the high road surface friction coefficient estimation accuracy irrespective of the phase difference between the vehicle body acceleration and the slip ratio. SOLUTION: The road surface friction coefficient estimation device 2 comprises a wheel speed operation unit 201 to detect the speeds Vd, Vf of a driving wheel and a driven wheel, a band pass filter 203 to calculate the acceleration Af, a slip ratio operation unit 202 to calculate the slip ratio S, a regression coefficient correlation coefficient operation unit 208 to operate regression coefficients K<SB>1</SB>, K<SB>2</SB>which are the inclination of the regression line to approximate the relationship between the acceleration Af and the slip ratio S by a linear expression, and to calculate the road surface friction coefficientμfrom the regression coefficients K<SB>1</SB>, K<SB>2</SB>, and further comprises a phase compensator 206 to change the phase of the slip ratio S, a phase difference detection means to detect the phase difference between the acceleration Af and the slip ratio S, and a phase compensation characteristic correction unit 207 to change the filter parameter of the phase compensator 206 so that the phase difference becomes zero. COPYRIGHT: (C)2006,JPO&NCIPI
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