【作者】 施青平；

【导师】 莫易敏；

【作者基本信息】 武汉理工大学 ， 机械设计及理论， 2010， 博士

【摘要】 随着汽车行业的不断发展,人们对汽车的舒适性、节能性、安全性及环保性有了越来越高的要求,作为提高这些性能的产品——自动离合器得到了快速发展与广泛的应用。自动离合器是在手动变速箱基础上,取消了离合踏板,实现自动离合的汽车动力传递装置。它顺应了功能完善与价格低廉的产品发展趋势,不仅使得驾驶操控更为简单方便、起步换挡加速快以及驾驶舒适；同时具有造价便宜、容易维护、使用经济等优点。本文结合微型汽车的特点,研究自动离合器接合过程及位置跟踪的控制策略,并以N1型微型汽车为实验载体,研究自动离合器系统。本文的主要研究内容及创新点如下：(1)研究离合器动力学及摩擦学性能。在离合器动力学模型研究过程中,针对微型汽车离合器的分离力过大或预紧力不足等问题,分析离合器关键参数对其动力学性能的影响,提出一种基于离合器参数设计方法。针对离合器起步抖动问题,通过实验研究离合器滑摩速度对其摩擦磨损的影响,提出采用自动控制的方式来控制微型汽车起步过程中离合器的接合速度。(2)提出一种基于多模控制方式的离合器接合过程总体控制策略。为了实现离合器“快—慢—快”的接合规律,本文采用“比例—模糊—PID”多模控制方式。在空载滑动阶段采用比例控制满足其快速性,滑摩工作阶段采用模糊控制提高其抗阻尼特性,同步运转阶段采用PID控制以克服模糊控制带来的稳态精度问题。仿真表明,多模控制充分发挥了各种控制方式的优点,较其它任何单一控制有更好的控制效果。(3)研究离合器驱动机构位置跟踪控制系统。好的控制策略能否达到一个良好的运行效果,还有一个关键问题就是执行机构的控制。本文提出了采用模糊自适应PID控制器实现对离合器位置跟踪系统的控制。仿真结果表明,模糊自适应PID能够很好地实现位置跟踪控制,具有良好的动、静态性能,对系统参数的变化表现出了良好的鲁棒性,且提高了系统的快速性。(4)研究离合器自动控制系统的实现。以ATmegal6高性能单片机为核心,针对微型汽车Nl车型设计了自动离合器控制器,设计并实现了各个模块的硬件电路及接口电路及其控制软件。根据微型汽车各电子控制装置的特点,研究了基于K总线的信号获取方法。研究K线通讯协议,开发了应用程序,采用这种简便可靠的新方式实现了将信号采集由复杂的硬件完成简化为直接读取数字信号。(5)对系统进行了台架实验与装车实验。在实验台架上模拟了不同油门开度下及不同的坡度下的起步情况。经试验经台架实验采集数据和曲线拟合,说明车辆起步时不仅能充分体现驾驶员意图,并且起步顺利、平稳,发动机转速波动小。目前样车行驶已装车运行,系统运行良好,车辆舒适性和安全性均达到要求,整个系统取得了较好的成效。更多还原

【Abstract】 With the continuous development of automobile industry, people have more and more requirements of the performances of car including comfort, energy efficiency, safety and environment. ACS (Automatic Cluth System) which meets these high performances is developed rapidly and used widely. Automatic is a kind of power transmission equipment which can clutch automatically based on the clutch manual gearbox and cancells the clutch pedal. It conforms to functional and affordable product development trends.it makes driving more simple and convenient, faster acceleration in start and shifting. Furthermore it is low cost and easy maintenance. Aiming at the characteristics of micro-cars and experimenting based on N1 type of General Motor Corporation, the automatic clutch system is studied and implemented in this paper. Main reseach work and innovation are as follows.(1) Research on dynamics and the tribology performance of clutch. The clutch parameter calibration and design system is studied and completed. A method of using computer-aided design to complete design and simulation of clutch is proposed. Parameters can be judged after adjustment to obtain the most reasonable parameters of the clutch.The adjustmen will not stop until the clutch diaphragm spring and control agencies meet the requirements.Aiming at clutch shakes of starting, the experiment that sliding speed of cluth brings impact to friction and wear is studied. Automatic clutch is brought to control the speed in starting process.(2) The overall control strategy based on multi-mode control mode of clutch binding process is proposed. A multi-mode control way "proportion-fuzzy-PID"is adopted in order to realize the clutch "fast-slow-speed" of the engagement rule in this paper. In no-load sliding stage, proportional control meets its swiftness; in slipping work stage, fuzzy control improves the anti-damping characteristics; and in synchronicity stage, PID control can solve steady precision problem. Simulation shows that the multi-mode control can play its’advantages of each control mode respectively and has a better control effect than any other single control.(3) The speed control problem of executive equipment control system is studied. Good control strategy can achieve good operating results or not, another key issue is control of the implementing agencies. The dual-loop control system is adopted. The traditional PID control algorithm is used to control current and fuzzy-adaptive PID control algorithm is used to control displacement. Simulations and experiments show that it can track position accurately and it has good dynamic and static performance. In addition, it is strong robustness of adapting to changes in system parameters and improves respond speed. The control system of executive equipment can meet the requirements of clutch engagement.(4) The control system of automatic clutch is designed and realized. Aiming at the N1 model of micro car, various modules of the hardware circuit and interface circuit and software are designed and implemented at the core of ATmegal6 microcontroller with high-performance. According to characteristics of electronic control unit of the micro-car, the communication protocols of K line is studied and the application programme is developed.some signals that is adopted by hardware sensors before is now read from ECU by K line communication. it simplifies the system greatly and improves reliability.(5) Bench test and loading test of the system is studied. Startup tests in operating conditions are made. Start conditions with the different degrees of throttle opening and the different slope are simulated by bench test. The collecting data of bench test and fitting curve show that the vehicle can start successfully and smoothy in various conditions.the whole starting process can fully reflect the intention of the driver and the engine speed fluctuation is small. The whole system has been installed in prototype car and operated for Period of time. The system runs well.更多还原