无级变速器(简称CVT)结构简单，可以实现速比在一定范围内的连续变化，使发动机始终保持在最佳区域内工作，有效提高了整车的经济性、动力性以及平顺性。针对CVT速比控制系统非线性、时滞等问题，本文将智能控制理论遗传算法引入CVT速比控制系统进行研究，以寻求更佳的控制效果。主要工作内容如下： 分析摆销链式CVT的结构和工作原理，确定汽车工作过程中各参数之间的动态关系；分析CVT速比变化规律，对汽车起步工况、加速工况和减速工况的速比控制策略进行详细分析与制定；利用Matlab对发动机试验数据进行拟合处理，得到发动机输出转矩模型和燃油消耗率模型，并进一步处理得到了基于发动机转速调节特性的最佳经济性和动力性曲线；对CVT无级变速传动系统进行分析，并对其液压系统进行适当简化，建立传动系统数学模型和仿真模型，主要包括发动机仿真子模型、目标速比子模型和速比模糊控制器仿真子模型；在Simulink/Cruise联合仿真平台上对速比模糊控制器进行验证；对比传统的速比控制方法，使用遗传算法对模糊控制器参数进行优化，并在汽车常用工况下进行仿真验证。 本文对摆销链式CVT速比控制策略的研究与分析，为后期控制策略开发提供了理论基础，对国产汽车无级变速领域的创新发展具有一定的理论指导意义。

Continuously Variable Transmission (CVT) is simple in structure and can realize continuous change of speed ratio within a certain range. so that the engine always keeps working in the optimum area, and improves the economy, power and smoothness of the whole vehicle effectively. Aiming at nonlinear and time delay problems of CVT speed ratio control system, Intelligent control can solve the control problems of complex systems which are difficult to be solved by traditional methods. In this paper, genetic algorithm is introduced into the control system of CVT to explore better control effect. The main work contents are as follows: Then the structure and working principle of rocker-pin jointed CVT were analyzed, the dynamic relationship between the parameters was determine in the process of automobile operation. The change rule of CVT speed ratio is analyzed, and control strategy of CVT speed ratio in three common working conditions was determined. Secondly, the engine test data were analyzed and processed in Matlab to obtain the engine's output torque model and fuel consumption rate model, then further processing to obtain the engine's optimal economic and power performance curve. Then CVT drive system was analyzed with its hydraulic system is simplified appropriately, the mathematical model of drive system and simulation model were established, It mainly includes engine simulation sub-model, target speed ratio sub-model and speed ratio fuzzy controller simulation sub-model. Then the controller was verified on the co-simulation platform of Simulink and Cruise. Compared with the traditional speed ratio control method, genetic algorithm was used to optimize the parameters of the fuzzy controller, and the simulation was carried out under the common working conditions. The research and analysis of the CVT speed ratio control strategy in this paper provide a theoretical basis for the later development of theoretical guiding significance for the innovation and development in the field of CVT in domestic automobiles.the control strategy, and there was a certain