高速转弯时CVT速比快速变化对车辆动力学的影响

The Effect of CVT Speed Ratio's Rapid Variation on Vehicle Dynamics at High Speed Turning

CVT(金属带式无级变速器)速比的快速变化会导致车辆纵向加速度的变化,进而影响车辆的运动速度。利用这个特性,当车辆高速转弯时,可以通过快速变化CVT速比影响车辆动力学特性。建立了多自由度整车和CVT传动系统耦合模型,研究了3种不同CVT速比变化对车辆高速转弯时纵向和侧向力的影响。模型仿真结果表明:车辆过弯时采用快速增加速比然后快速减小速比的控制方式,在减小进弯道速度的同时,可以获得更大的侧向加速度和更小的转弯半径,并对操稳性影响不大。该研究结果可用于研究开发车辆转弯时的CVT速比控制策略。

The rapid shifting of the CVT’s speed ratio will lead to the change of the vehicle’s longitudinal acceleration and then influence its movement.In order to study influence of the speed ratio on the cornering vehicle,a model was established which was coupled with a multi DOF vehicle model and a CVT transmission model.And the performance of longitudinal and lateral movement due to the speed ratio’s change was studied as the vehicle is cornering in high speed.The results show that when the vehicle was cornering,rapidly increasing the speed ratio and then rapidly reducing the speed ratio can achieve greater lateral acceleration and a smaller turning radius while reducing the speed of the entering curve,with little impact on the stability.The research results can be used to improve the CVT speed ratio control strategy of vehicle turning.