| 摘要 |
<p>PROBLEM TO BE SOLVED: To impart steering reaction considering the frictional condition between steered wheels and road surface and to insure steering controllability on the road surface with reduced frictional condition of the road surface by setting a controlled variable against a reaction imparting means, based on the frictional condition between the steered wheels and the road surface in addition to the steering condition. SOLUTION: At running a vehicle, the output signals of a steering angle sensor 14, a vehicle speed sensor 41, and the like are read in a control device 30, and at first transmission ratio G is set by using a map based on the steering angleθand the vehicle speed V. Next, (1/G)*θis computed based on the transmission ratio G and the steering angleθto obtain the target stroke position Xt of a rack shaft 23, and the controlled variable Tw for a steering motor 22 is set from it and the actual stroke position Xr. Further the steering angleθand lateral acceleration Gy detected by a lateral acceleration sensor 43 are respectively read in, the value of a coefficient of friction on a road showing the frictional condition between wheels 21 and the road surface is estimated based on these values, and the controlled variable Th for a reaction motor 11 is set by using gain coefficient Kp set based on the coefficient.</p> |
