【作者】 吴婷；

【导师】 李刚炎； 胡少良；

【作者基本信息】 武汉理工大学 ， 机械工程， 2014， 硕士

【摘要】 机械式变比转向器是指通过采用变速比齿轮传动实现车辆转向过程中传动比变化的新型转向装置，可兼顾转向省力和转向灵敏的要求，在一定程度上改善转向轻便性与灵敏性之间的矛盾，且不改变原有转向器的空间结构和控制要求。变比曲线是机械式变比转向器设计的依据，涉及转向性能与整车性能的匹配问题，因此研究其设计分析方法具有重要的理论意义和工程应用价值。论文以汽车动力学理论为基础，结合整车参数，采用理论研究与仿真分析相结合的方法，提出一种机械式变比转向器变比曲线的数字设计方法，并建立变比曲线数字模型；利用汽车动力学仿真软件CarSim进行了仿真验证。本文的主要研究工作包括：（1）研究机械式变比转向器变比曲线与转向性能的关系以及转向性能对汽车操纵稳定性的影响，通过分析国内外现有汽车操纵稳定性评价的基本内容、试验方法，确定与转向性能相关的转向性能评价指标，即“转向灵敏度”和“转向力”，同时确定相应的评价试验项目；根据行业标准，确定选择试验的评价指标和评价方法；（2）研究主动转向系统、线控转向系统的建模思路，从整车动力学模型、转向系统模型和轮胎模型等出发，通过理论分析与试验建立汽车转向动力学模型、汽车转向系统模型；（3）分析汽车的稳态响应特性，研究横摆角速度增益和质心侧向加速度增益对理想传动比的影响，依据理论曲线对应的车型参数，结合上述转向系统模型，在MATLAB中仿真出理想传动比曲线，并推导相应的理想传动比数学模型；（4）为了验证机械式变比转向器变比曲线数字设计模型的正确性和可行性，在车辆动力学仿真软件CarSim中调用理想传动比数学模型，对其进行转向性能评价试验项目的工况模拟，通过非线性曲线模型和线性曲线模型的对比仿真验证了模型的正确性和有效性。论文提出的机械式变比转向器变比曲线的设计流程对机械式变比转向器产品的设计具有理论意义和工程应用价值。更多还原

【Abstract】 As one of the important parts of automobile steering system, steering geardetermines the overall vehicle handling performance. The variable ratio steeringsystem can meet the requirements of both steering portability and sensitiveness.Therefore, the study of the design for variable ratio curve of steering system hasimportant practical significances.This paper takes the new product development project as a support. Based on thevehicle dynamics theory, combining with the vehicle parameters, a digital designmethod for the variable ratio curve of steering system is put forward by adopting thecombination of theoretical research and experimental methods. And the variable ratiocurve model is verified in the software CarSim. The paper’s main researches includethe following:Through the research of test and objective and subjective evaluation methods ofvehicle handling stability, the evaluation contents for steering performance are created,then a quantitative evaluation system is established.According to the study of active steering system and wire control steering system,the vehicle steering dynamics model and vehicle steering system model are developedthrough steering system model and the tire model.On the basis of the study of the vehicle steady-state response characteristic, theinfluence of yaw angular velocity and lateral acceleration to the on ideal transmissionratio is analyzed. Combining with steering system model, the formulation of the curvemodel is calculated and simulated in Simulink.Finally, the calculated model is verified in the software CarSim with theenvironment of testing. And the result is satisfied.This research shows the general process of design for variable ratio curve ofsteering system. Methods of the paper have theoretical significance and engineeringvalue for the other similar product.更多还原