| 摘要 |
PURPOSE:To increase the degree of freedom in setting the yaw response in a wide range of turning stage by setting the steering ratio so as to satisfy a prescribed equation, in a four-wheel vehicle in which the steering ratio of a rear wheel to a front wheel is controlled in variable ways according to the lateral accelerating speed. CONSTITUTION:When an electric motor 11 as actuator is driven by a controller 29 on the basis of the detection signals of a front wheel steering angle sensor 24, rear when steering angle sensor 25, car speed sensor 26, lateral accelerating speed sensor 27, and a yaw rate sensor 28, and the steering for the rear wheels 19 and 19 are controlled in correspondence with the steering for front wheel 9 and 9, the steering ratio of the rear wheel 19 for the front wheel 9 is controlled in variable ways according to the lateral accelerating speed, and the steering ratio g(y''0) is set within a range of f1(y''0)-g(y''0)Xf2(y''0)>=0. In this case, f1(y''0)=Cfo/mf, f2(y''0)=Cro/mr, and y''0 is lateral accelerating speed, Cfo, Cro is the equivalent cornering power of the front and rear wheels in the stationary circular turning state, and mf, mr is the equivalent mass on the front and rear axles. In the above-described equation, y'' represents y. |
