【作者】 胡朝峰；

【导师】 过学迅；

【作者基本信息】 武汉理工大学 ， 车辆工程， 2006， 硕士

【摘要】 变速器作为车辆传动系统的重要组成部分,其技术的发展,是衡量车辆技术水平的一项重要指标。金属带式无级变速器能充分利用发动机的功率场,连续的改变传动速比,是理想的变速器。金属带式无级变速器以其结构简单紧凑、操纵方便、性能优良等优点而倍受青睐,世界上许多汽车厂商都在致力于其研制和开发。电—液控制系统是金属带式无级变速器的核心部分。本文以Honda轿车无级变速器为参考对象,对其电—液控制系统进行了开发。 论文简要介绍了无级变速器技术的发展过程、研究现状和发展趋势,分析了金属带式无级变速器传动技术的特点和研究的关键技术。由于金属带的特殊结构,要实现速比和夹紧力的精确控制是十分复杂的,通过对金属带式无级变速器的变速机理进行分析,确定了稳态下无级变速器带轮夹紧力、速比和控制目标的关系。借以电—液控制方案的优势,本研究采用双压力回路电—液控制系统。分别建立了速比控制阀和夹紧力控制阀的数学模型,对它们的特性进行了分析,应用脉宽调制技术对无级变速器控制阀进行控制。由于金属带式无级变速器特殊的传动机理,使得夹紧力和速比的控制相互影响,普通的控制方法不能得到令人满意的控制效果,而所设计的智能九点控制能有效的解决这一问题,且控制精度高。借助九点控制策略,分别设计出速比控制器和央紧力控制器。仿真实验结果表明,所设计九点控制器能够满足实际需要。 在所设计的无级变速器实时控制虚拟实验平台基础上,提出了无级变速器实时控制虚拟实验平台的解决方案,借助设计的dSPACE外围电路进行无级变速器控制系统的开发。通过MATLAB RTW实时仿真工具箱和dSPACE实时系统,产生无级变速器控制阀所需的脉宽调制信号,对无级变速器进行实时仿真控制,实验过程和控制结果表明,所设计的控制器能够满足无级变速器的控制要求,基本上反映了金属带式无级变速器电—液控制系统的主要特征,为进一步研究和改进打下了基础。更多还原

【Abstract】 Transmission is regarded as one of the important parts of the automobile transmission system, the development of its science and technology is an evidence of automobile’s technology. The metal belt continuously variable transmission (CVT) can use the engine power completely, and change the transmission ratio continuously, so it’s an ideal transmission. The metal belt CVT is favored because of the simplicity and compaction of its structure and the convenience of its operated stability and its super performance. Now many automobile factories are decided to research and exploit for it. The electro-hydraulic control system is the key part of the metal belt CVT. The thesis is studied toward the electro-hydraulic control system of the metal belt CVT for Honda car.The development process, the status research and the direction process of CVT are introduced in this paper. The characteristics and the key technology of metal belt CVT are analyzed. Due to the special structure of metal belt, it is much complicated to realize clamping force and ratio control. On the basis of stable force balance, the relationship between clamping force, speed ratio and controlling aim is established, which is based on the working principle of CVT. The electro-hydraulic control system applied in this paper is a double circuit system. The mathematical models of clamp and ratio control valves are established, and the characteristics of valves are analyzed. The applying of the pulse width modulation (PWM) is introduced to control CVT. Due to the special delivery of metal belt CVT the ordinary control methods are not satisfied. The nine point control can solve the problem with great efficiency, and its effect is perfect. The clamp and ratio controllers are designed respectively based on the exploitation of nine point control method. The results of simulation show that the nine point controller can be used in the practical system.The virtual experimental platform real-time control of vehicle CVT is designed, and its resolve project is put forward. The control system of CVT is exploited based on the design periphery circuit of dSPACE. Through MATLAB toolbox of RTW and the real-time simulation system dSPACE, the PWM signals have been achieved andthe real-time simulation of CVT has been made. The process of experiment and the results of control show that the developed electro-hydraulic control system can meet the demand of CVT control, and the system is applicable in practical system. The main characteristics of the electro-hydraulic control system are reflected basically, which is the foundation of further research.更多还原