【作者】 刘志强；

【导师】 李庆芬；

【作者基本信息】 哈尔滨工程大学 ， 机械设计及理论， 2011， 博士

【摘要】 油气弹簧是一种以惰性气体(一般为氮气)作为弹性介质,以油液作为阻尼介质的气体弹簧。采用油气弹簧作为弹性元件的车辆油气悬挂系统,由于具有良好的非线性刚度和阻尼特性,能够最大限度地满足工程车辆平顺性要求,近年来成为车辆悬挂装置研究的重点内容。本文分析了油气弹簧的工作原理,并对工程中的油气悬挂系统进行了力学建模,建立了油气弹簧系统非线性数学模型,给出了油气弹簧活塞杆输出力具体表达式,对油气弹簧系统活塞杆输出力与活塞位移及速度之间关系进行了数值仿真。依据本文油气弹簧非线性数学模型,研究了油气弹簧系统阻尼特性及刚度特性,并详细研究了各种因素对油气弹簧阻尼特性和刚度特性的影响,给出了油气弹簧系统刚度和阻尼线性化处理公式,为车辆油气悬架系统动力学建模提供了合理的刚度及阻尼参数。本文建立了车辆油气悬挂系统两自由度动力学模型,并通过Simulink仿真模拟了不同等级路面位移激励,对车辆油气悬挂系统在此激励作用下悬架系统响应进行了数值仿真,分析了油气悬架系统的频率特性。针对本文所建立的油气悬架系统动力学模型研究了主动油气悬架系统的PID控制结构,并对主动油气悬架系统及被动油气悬架系统在不同路面激励下悬架加速度、动挠度及负重轮胎载荷进行了数值仿真。本文应用ADAMS动力学仿真软件建立了车辆油气悬架系统的机械模型,同时建立了车辆油气悬架系统ADAMS与MATLAB联合仿真模型,为油气悬架系统的动力学仿真提供了一种新的途经。研究结果表明车辆采用主动油气悬架其车体振动加速度均方根值较被动油气悬架系统减小三分之一,悬架动行程均方根值减小百分之六、车辆动载荷均方根值减小三分之一,这可显著提高车辆乘坐舒适性及车辆行驶平顺性。本文系统建立了油气弹簧及车辆油气悬架系统的动力学模型,推导了油气弹簧及车辆油气悬架系统的动力学方程,该模型及方程可用于解决工程中油气悬架系统的动力学问题,本文的研究方法具有一定的理论意义及工程应用价值,本文的研究结果对于工程中油气弹簧的理论分析及设计具有一定的参考价值。更多还原

【Abstract】 Hydro-pneumatic spring is a kind of gas spring which uses inert gas (usually nitrogen) as spring medium and hydraulic oil as damping medium. Due to the nonlinear stiffness characteristics and nonlinear damping characteristics, vehicle hydro-pneumatic suspension system which takes hydro-pneumatic spring as the elastic element can meet the engineering requirements of vehicle ride comfort to the best. It becomes the focus of vehicle suspension study in recent years.Based on the analysis of hydro-pneumatic spring principles, a nonlinear mathematical model of hydro-pneumatic spring system is established with the system mechanical modeling in engineering. Specific equations of output force of hydro-pneumatic spring piston rod are given. At the same time, the relationship between output force and displacement, velocity of hydro-pneumatic spring system piston arc analyzed and studied by numerical simulation.According to the nonlinear mathematical model, damping and stiffness characteristics of hydro-pneumatic spring system and various factors which impact them are studied. The stiffness and damping linearization formula of vehicle hydro-pneumatic spring is given which provides a reasonable stiffness and damping parameters for system dynamics modeling. Two degrees of freedom dynamic model of vehicle hydro-pneumatic spring system is established. The hydro-pneumatic spring suspension system response is numerically simulated by Simulink software with different level road displacement excitation. The frequency characteristics of the system is also been analyzed.The PID controller structure on the active hydro-pneumatic suspension system is designed on the basis of established hydro-pneumatic spring suspension system dynamic model. The parameters of suspension acceleration, suspension deflections and tire load weight are simulated to both active and passive suspension systems under different road conditions. Eventually, a mechanical model of the system is established by ADAMS dynamic simulation software. The union simulation model of ADAMS and MATLAB of hydro-pneumatic spring suspension system is also been established which provides a new method for dynamic simulation of ydro-pneumatic spring suspension system. The study results show that by using active suspension system, the acceleration RMS value of the vehicle body can be reduced by one-third, the suspension dynamic travel RMS value is reduced six percentage points and the vehicle dynamic load RMS value is reduced one-third which means active suspension system can significantly improve vehicle riding comfort.Hydro-pneumatic spring and vehicle hydro-pneumatic spring suspension system dynamics model are established in this paper. Dynamics equations of hydro-pneumatic spring and vehicle hydro-pneumatic spring suspension system are also been derived. Those models and equations can be used to sovle dynamics questions in engineering of hydro-pneumatic spring suspension system. The research method of this paper has theoretical significance and engineering applications. The results of this study also has reference value in theory analysis and design of hydro-pneumatic spring.更多还原