【作者】 李东；

【导师】 宗长富；

【作者基本信息】 吉林大学 ， 车辆工程， 2011， 硕士

【摘要】 线控转向系统是一种全新的电控转向系统,代表了汽车转向系统未来的发展趋势,因其摆脱了传统机械式连接结构的束缚,驾驶员的力传递特性和角传递特性可以自由设计,因此在改善汽车的操纵稳定性和行驶安全性方面具有更大的优势。路感模拟技术作为线控转向系统的关键开发技术,一方面不仅是驾驶员操纵方向盘获得路面状况和汽车行驶状态的重要信息来源,另一方面也是线控转向系统未来能否尽快应用到汽车上必须解决的重要问题之一,目前国内外各大科研高校、汽车企业都对其进行了专门研究,成为了未来汽车转向系统研究开发的焦点。本文重点围绕汽车线控转向系统的路感模拟控制进行了研究分析和仿真验证。论文第一章讨论了课题的研究意义和目的,对路感的定义及其影响因素等进行了介绍,并针对国内外目前的研究状况作了分析比较。第二章在基于veDYNA车辆动力学分析软件和MatLab的基础上建立了线控转向系统模型,对方向盘、电机、齿轮齿条以及转向车轮进行了动力学分析建模,最终构建出SBW仿真系统。第三章针对SBW的路感模拟控制提出了基于直接测量转向电机电流和车速、方向盘转角的综合路感控制,分别对主控制、辅助控制、阻尼控制和限位控制进行了算法设计。第四章针对本文提出的路感控制进行了仿真结果的验证,对不同的路感控制方案、自由设计路感和不同操纵状态下的路感特性进行了仿真分析,最后选取了中心区转向和双纽线两种典型工况对SBW路感中的路感清晰和转向轻便性进行了仿真结果的评价,进一步验证路感的合理性。第五章对全文进行了总结和展望。更多还原

【Abstract】 As the development of vehicle electronic technology and control theory, more and more chassis integrated control technology are applied to vehicles. Therefore, steer-by-wire system is used to vehicles as a novel electronic system, its large distinct comparing to traditional steering is the cancel between steering wheel and front wheels instead of wire, so we can improve vehicle maneuverability stability、active safety and driver’s comfort by road feeling control and active control.This paper are aimed to study one key technology of steer-by-wire system-road feeling technology and combine with the project named "Research on Key Technology for Vehicle Steering-By-Wire system" and "Research on one Steering-By-Wire system". In this paper, we have a careful study and simulation test on road feeling control strategy for providing driver’s comfortable and realistic road feeling. The main research work is summarized as follows:1) Establish a complete simulation system of SBWBased on veDYNA vehicle dynamic software and MatLab simulation software, we establish a complete model of steer-by-wire (consist of steering wheel, motor, rack and pinion, front wheel, etc) and finish the structure of steer-by-wire.The model is applicable to a variety of working conditions and is also used to test various algorithms. In this paper, we will use this model to simulate road feeling algorithms.2) Research on a direct measured current based method and velocity steering angle for road feeling control strategyBefore the study of road feeling control strategy, we firstly have a control of the actuator’s torque which is the basis of realizing road feeling and the actuator must be have a slowly torque and good position tracking in order to transport a suitable current.For the master control of direct measured current based method, we can obtain road information (include aligning moment and property of tyre) indirectly from the actuator’s torque produced by the actuator when it actuates steering task and provide driver’s feeling information.Assistance control is aimed to the realistic road feeling property of steer-by-wire and is advanced based on master control. It can decrease the road feeling’s torque between large angle, prevent heavy steering and improve steering system’s road feeling.By the introduction of damping control for steer-by-wire, a driver can keep his line tracking when he is driving in dead area, thereby, it not only provide a driver’s certain road feeling, but also prevent the oscillation of steering wheel and improve the road feeling in central area.In order to make a driver have the same road feeling as is the traditional steering in the limit of HW angle, we introduce the lock-to-lock control, which is simulated by increasing the torque in the limit of HW angle. For this, a driver can quickly suit to his driving habit when he drive the steer-by-wire vehicle.Moreover, we have a control on the target current of road feeling motor in order to make the motor transport suitable torque to driver, so we use PID algorithm after the dissertation between target current and real current for transporting voltage to make the motor produce suitable torque.3) Simulation test on the road feeling control strategyIn this paper, we choose some representative simulation test and working conditions to prove the road feeling control strategy. Firstly, we have a simulation comparison between different road feeling control to prove the rationality of various control strategy; Based on the free design of road feeling, we have some different result to meet various driver; Considering different maneuver conditions have its road feeling, so we have some simulation comparison between various velocity and frequency of HW. Finally, we choose "on-center steering" and "∞" test to test the design target of road feeling, from the result, we conclude the control strategy proposed above can make driver have a light steering in low speed and clear road feeling in high speed and then the algorithm is right, it also lay the theory foundation for the development of control unit in future real vehicle.更多还原