【作者】 于军；

【导师】 张仲甫；

【作者基本信息】 武汉理工大学 ， 机械制造及其自动化， 2009， 博士

【摘要】 空气悬架系统是目前汽车悬架中最先进的汽车悬架系统之一。它可以减少整车的振动噪声,降低车轮的动载荷,提高乘坐舒适性,保护路面。近年来,在高等级客车,载重货车和高等级轿车上的应用越来越广。但是空气悬架中的主动控制悬架系统的研究目前还在试验阶段,技术不成熟。本文对空气悬架控制器进行了研究。针对空气悬架系统的关键技术:控制器的控制算法,相应执行机构,电控单元(ECU),相关传感器和试验台进行了分析和设计。取得了一些阶段性的成果。在控制算法方面,首次提出综合参考模型自适应法。该算法将控制算法分为两个部分,离线部分和在线部分。离线算法的核心是基于线性二次高斯(Linear Quadratic Gaussian,LQG)算法。在线性系统的基础上,综合舒适性和操纵性要求构造二次型指标,求出最优反馈,构成最优控制系统。在线部分的核心基于李亚普洛夫参考模型自适应算法。参考模型为离线算法得出的最优系统,在不同的工作点,采用不同的参考模型。利用自适应算法的特点,可消除悬架系统时变和线性化的影响。同时,由于自适应算法满足李亚普洛夫稳定要求,可使系统保持稳定。本算法具有算法简单,物理意义明确的优点。在主动空气悬架的执行机构方面,首次提出了可调电磁减振器和不可调液压减振器串联的设计方案。该设计具有电磁控制系统容易调节,响应快速的特点。同时利用液压减振器消耗部分能量,可以减少电磁减振器的体积和制造难度,提高系统的可靠性。利用自主研制的测试系统,完成了电磁减振器的性能参数的测试。对于悬架系统的检测单元,设计了空气悬架加速度传感器驱动电路。根据空气悬架系统对位移传感器的要求,设计了差动变压器式悬架位移传感器,利用自主研制的位移测试系统,测试了位移传感器的参数。在控制器架构方面,首次提出了基于主控制器和执行控制器的分级结构,通过将控制器赋予不同的功能,使悬架的安全性,可靠性得到提高。在控制器研究中,悬架试验台是重要的研究条件。本文对试验台进行了设计。并对悬架试验台中的液压伺服系统进行了优化设计。对电控系统进行了分析和设计。在以上研究的基础上,提出了空气悬架控制的综合控制策略。分析了汽车的不同运行状态,对空气悬架的不同要求。提出了在分级控制器架构中,实现综合控制策略的总体方案。更多还原

【Abstract】 Air suspension system is the most advanced one among the existing vehicle suspension systems. It can reduce noise of whole vehicle caused by vibration, decrease the dynamic load of wheels, improve the ride comfort and protect the road surface. In recent years, it has an extensive application in high-level buses, heavy trucks and limousines. However, the research into active control suspension system of air suspension is still in experimental stage and is technologically immature. This dissertation has made research into air suspension controller and also analysized and designed the control algorithm of controller, relevant actuator, electronic control unit (ECU), related transducer and test platform.The optimal adaptive algorithm has origirally been proposed for the control algorithm. Such an algorithm divided the control algorithm into two parts: offline part and online part. The core of offline algorithm is based on LQG algorithm. On the base of linear system, it has integrated the requirements for comfortability and handling to establish the quadratic performance index, so as to obtain the optimal feedback, and to form the optimal controlling system. While the core of online part is based on Lyapunov Reference Model Adaptive Algorithm. The reference model is the optimal system obtained by the offline algorithm, which can eliminate the impacts of time variation and linearization of suspension system at different work location by using different reference models and utilizing the features of adapive algorithm. Meanwhile, as the adaptive algorithm meets the requirement of Lyapunov stability, it can stablize the system. Such an algorithm is featured by conciceness and clear physical meanings.A design scheme for cascaded connection of adjustable electromagnetic vibration absorber and fixed hydraulic vibration absorber have been brought into the actuator of active air suspension. The design provides easy adjustment and rapid response for electromagnetic control system. Meanwhile, owing to the consideration of structure, the hydraulic vibration absorber can be used to consume partial power, whereby to reduce the volume and difficulty in manufacture of electromagnetic vibration absorber and to improve the reliability of the system. It also tests the performance of electromagnetic vibration absorber by home-made testing system.Drive circuit used for acceleration transducer has been designed for testing unit of suspension system. This dissertation has designed a differential transformer type of displacement transducer and its drive circuit, and enployed displacement testing system to test the performance of the displacement transducer.A hierarchical structure based on main controller and executive controller has firstly been put forwards to the controller frame, improving the suspension systen in safety and reliability by allocating different functions to controllers.The suspension test platform is an important condition in the controller reseach. In this dissertation, a test platform has been designed, and an optimum design has been performed for the hydraulic servo system in the suspension test platform, and the electronic control system has been analysized and designed.Basing on the above-mentioned research, this dissertation has presented the comprehensive strategy for the air suspension control, analysized the different requirements of different movement state of automobiles on air suspentions, and proposed the overall scheme for the realization of comprehensive control strategy in the frame of hierarchical controller.更多还原