【作者】 姚嘉凌；

【导师】 郑加强； 蔡伟义； 闵永军；

【作者基本信息】 南京林业大学 ， 机械设计及理论， 2009， 博士

【摘要】 磁流变半主动悬架系统的两个关键技术目前仍不成熟。磁流变减振器现有的数学模型普遍存在某些缺陷:要么简单但不精确,不能反映其滞回特性;要么精确但太复杂,不便于实施控制。控制策略也存在类似的问题,简单的控制策略效果差强人意,而复杂的控制策略则偏向复杂的控制理论,与实际工况差异很大,且多以仿真结束,没有试验验证。本文以“精确而简单”为目标,对磁流变半主动悬架系统进行研究,主要研究工作和结论如下:(1)对磁流变减振器进行了特性试验,提出了磁流变减振器复合多项式模型。此模型能准确地反映控制电流的饱和特性,且在模型中引入频率和振幅因素。通过数值仿真与试验数据对比,证明其比一般多项式模型更能准确地反映实际工程应用情况。(2)研制了1/4模拟悬架机械装置,并基于虚拟仪器系统建立了通用的磁流变半主动悬架实时测控试验平台,为控制器的快速原型开发奠定了基础。(3)设计了一个新颖的半主动悬架模型参考滑模控制器。此控制器易于实现,不需要测量路面输入信号和减振器的阻尼力。其采用一个改进的理想天棚控制系统作为参考模型,使实际被控半主动悬架系统和参考模型问的误差动力学系统产生滑动模态,仿真计算和控制器快速原型试验证实了其比被动悬架、实际天棚控制及模糊控制具有更好的综合性能,可用于实车控制器的开发。更多还原

【Abstract】 The two key technologies of magnetorheological (MR) semi-active suspension system are still immature. The present mathematic models of MR dampers have common limitation that either it is simple but imprecise, and can’t reflect hysteretic characteristic of dampers, or it is accurate but too complex to conduct control conveniently. Meanwhile, there are the same problems for control strategy. Effect of a strategy won’t be good enough if it is simple, while a complex control scheme usually utilizes complex automatic control theory and is large difference from the real conditions, and can only be verified by simulating but can’t be by experiment. Therefore, taking accurate and simple as a goal, the MR semi-active suspension system has been researched. The main contributions and innovation conclusions of the dissertation include the followings:(1) A composite polynomial model of MR dampers has been proposed after damping characteristic experiments have been conducted on a MR damper. The affections of amplitude and frequency are considered in this model which can accurately reflect current saturation behavior. Comparing numerical simulation with experiment data, it is verified that this model can more accurately reflect the real engineering conditions compared with the common polynomial model.(2) A quarter-car suspension mechanical test rig has been set up, and based on virtual instrument system, the real time control experiment platform of MR suspension system in universal use has been set up, and it lays foundation on developing rapid control prototyping.(3) A new model reference sliding mode controller for semi-active suspension system has been presented. The proposed controller is easy to be carried out and eliminates the necessity of road signal as well as measuring damping force. The controller uses an approximate ideal skyhook system as a reference model, and generates an asymptotically stable sliding mode in the error dynamics between the plant and the reference mode states. A simulation study and the rapid control prototyping experiments have been performed, and results show that compared to passive suspension, practical control and fuzzy logical control, the proposed controller shows better integrated performance, and should be directly transferable to commercial semi-active vehicle suspension implementations.更多还原