| 摘要 |
PURPOSE:To improve steering stability on a rough road, by judging whether a road surface is rough or not by means of a vertical acceleration sensor installed on a car body floor and increasing an amount of rear wheel steering in the same phase when the road is judged to be rough. CONSTITUTION:A control unit 9 comprises a rear wheel steering angle operation unit 91 for operating a target value of rear wheel steering angle from a differential oil pressure signal inputted from an operation amplifying unit 7 and a vehicle speed signal inputted from a vehicle speed sensor 8 and a rough road judging unit 92 for judging whether a road is rough or not from a vertical acceleration signal of a vertical acceleration sensor 16. The vertical acceleration signal is inputted to the rough road judging unit 92 through a high pass filter HPF, and when the road is judged to be rough, a signal is transmitted to the rear wheel steering operation unit 91 so as to change a relation 'differential oil pressure-rear wheel steering angle set characteristics' in the direction to increase a steering amount in the direction of same phase. |
