无级变速器(CVT)的速比控制是使动力系统达到最佳燃油利用率的关键． 针对传 统比例 －积分 －微分(PID)速比控制的响应较慢、难以实现实时精确控制的问题，本研究提 出了基于马尔科夫模型动力需求预测的 CVT 目标速比决策方法，采用聚类分析的 K-means 算法求解转矩需求值不同区间的边界值，对动力需求的马尔可夫模型进行状态空间划分，统 计 NEDC 循环工况得到的需求转矩规律;提出预控加积分分离 PID 的速比控制方法，引入微分 先行，并加入速比预控系统来决策目标速比变化率，可以实现速比的快速跟随，同时减弱速比 超调现象;提出主、从动轮压力控制策略，采用带有 Smith 修正的 PID 控制器，可防止系统超调， 弥补液压系统的缺陷． 台架试验表明，该方法可以抑制速比控制超调现象，提高速比控制精度．

The speed ratio control of CVT is the key technology to optimal fuel efficiency of the power system． Ai- ming at the problem of slow response and difficulty of real-time precise control for traditional PID ratio control， CVT target speed ratio decision method based on Markov model for predicting power demand was proposed． K- means algorithm of cluster analysis was used to solve the problem． The boundary value of the different moments of the moment demand value was used to divide the state space of the dynamic demand Markov model，and the de- mand torque law obtained by the NEDC cycle condition was calculated． The speed ratio control method of the pre- control plus integral separation PID was proposed． Introducing the differential first and adding the speed ratio pre- control system to determine the target speed ratio change rate can achieve fast follow-up of the speed ratio，and at the same time weaken the speed ratio overshoot phenomenon． The main and driven wheel pressure control strategy was proposed，and the PID controller with Smith correction was adopted． This method can prevent the system from overshooting and make up for the defects of the hydraulic system． The bench test shows that this method can sup- press the overshoot phenomenon in speed ratio control and improve the speed ratio control accuracy．