汽车检测与维修论文 浅谈四轮转1.docxVIP

X应用职业技术学院毕业设计（论文） PAGE X应用职业技术学院 毕 业 论 文 题 目 浅谈四轮转向系统结构原理 学生姓名 系部名称 汽车工程系 专业班级 汽修三班 指导教师 教研室 汽车工程教研室 起止时间 年 月 教 务 处 制 PAGE I 摘 要 四轮转向(4WS,4 Wheel Steering)除了传统的以前轮为转向轮，后两轮也是转向轮，即四轮转向。在20世纪80年代中期开始发展，其主要目的是提高汽车在高速行驶或在侧向风力作用时的操作稳定性，改善在低速下的操纵轻便性，以及减小在停车场时的转弯半径。四轮转向主要有两种方式：当后轮转向与前轮转向方向相同时称为同向位转向；当后轮转向与前轮转向方向相反时称为逆向位转向。 将横摆力矩控制(DYC)与四轮转向(4WS)系统相结合，建立侧偏角和横摆角速度具有最佳输出响应的车辆理想模型。采用前馈和反馈控制相结合跟踪理想模型的控制策略，设计出最优控制器，并分别在低速和高速下进行仿真分析。结果表明：四轮转向模型与横摆力矩控制相结合，采用跟踪理想模型的控制策略能够有效地同时控制汽车转向侧偏角和横摆角速度，得到较好的瞬态及稳态响应，有效地减轻驾驶员操纵负担，提高了车辆操纵稳定性。尤其在高速行驶时，仍能获得较好的输出响应，利于提高行车安全性。 关键词:四轮转向；组成；构造；原理；优缺点；安全 X应用职业技术学院毕业设计（论文） PAGE III Abstract Four-wheel steering (4WS, 4 Wheel Steering) before addition to the traditional round of the steering wheel, steering wheel after two rounds is that the four-wheel steering. In the 20th century began to develop the mid-80s, its main purpose is to improve the car at high speeds or when the lateral wind loads, operational stability, improve the manipulation of light at low speed, as well as reduce the turning radius in the parking lot. Four-wheel steering mainly in two ways: when the rear wheel steering and front wheel steering in the same direction as the same shift to the position; when the rear wheel steering and front wheel steering in the opposite direction is called reverse position when turning. The yaw moment control (DYC) and four-wheel steering (4WS) system combined with the establishment slip angle and yaw rate vehicle response with the best output of the ideal model. Feedforward and feedback control by the combination of the ideal model tracking control strategy, design the optimal controller, respectively, under the low and high speed simulation. The results showed that: four-wheel steering and yaw moment control model combined with the ideal model tracking control strategy can effectively control both steering slip angle and yaw rate, get a better transient and steady-state response, effectively reduce the burden on the driver control to improv