| 摘要 |
PURPOSE:To ease strong understeer by preventing a rear wheel steering angle from becoming unstable operationally by the fact that an in-phase steering angle is lowered temporarily in the middle of turning back a steering wheel in the case of changing lanes and so on by rapid steering wheel operation, and lowering the rear wheel steering angle temporarily in the middle of turning back the steering wheel in the case of a turning travel and so on by slow steering wheel operation. CONSTITUTION:In a step 21, when a judgment is made such that a rear wheel steering angle is in a steering wheel steering angle area such as changing between the maximum in phase steering angle and the maximum antiphase steering angle, a rear wheel steering angle target value delta10 obtained in a step 25 is not used as it is and a value delta1 obtained after multiplying its value by a first-order lag element of time constant T in a step 26 is used as a rear wheel steering angle deltar in a step 27. Thereby, when steering operation is fast, the first-order lag element becomes and when the steering operation is slow, the first-order lag element becomes ineffective, so that contradictory request characteristics when the steering operation is fast or slow can be reconciled with each other. |
