无级变速器金属带的滑移率评估方法

Evaluation of metal belt CVT′s slip ratio

为了在无级变速器的夹紧力控制过程中实现优化控制,检测了金属带的滑移率,采用皮尔逊相关系数对滑移率进行估算,理论分析了将相关系数用于滑移率计算的可行性,试验研究了滑移率与相关系数的关系以及速比变化率、样本数等因素对相关系数的影响.试验结果表明:相关系数能够有效地对滑移率进行评估.将该滑移率评估方法在无级变速器夹紧力的防滑控制中进行应用,并在转鼓试验台上进行实车试验.结果表明,利用滑移率进行夹紧力控制的整车与传统控制方式的整车相比,在燃油经济性上有了大幅度的提高.

In order to achieve optimal control,Pearson correlation coefficient was used to evaluate the slip ratio of the metal belt during the process of clamp force control used on CVT.The feasibility of evaluating the slip ratio by taking the coefficient into calculation was theoretically studied.Experiments were run to analyze the relationship between the slip ratio and the correlation coefficient,and how the change of speed ratio and sample number could affect the coefficient.The results indicate that the correlation coefficient can be used to evaluate the slip ratio effectively.This method of evaluating the slip rate was introduced in the clamp force control used on CVT and tested on rotary drum test bench.Comparing with common control strategy,the economic performance of vehicle increases greatly in ground tests through the clamp force control using slip rate evaluation.