燃料电池轿车动力总成悬置系统的优化设计

以某燃料电池车为研究对象,建立了电机动力总成悬置系统的动力学模型,通过分析动力总成悬置系统的耦合特性和加速工况时的瞬态振动,指出了原始设计不合理的地方.在此基础上,以悬置位置与悬置刚度为设计变量,以加速工况悬置处的瞬态动反力为目标函数.运用遗传算法对动力总成悬置系统进行了优化设计,从而有效地改善了动力总成悬置系统的隔振性能.     

燃料电池轿车驱动电机悬置的优化设计

通过试验对驱动电机单元进行了振动特性分析,评价了电机3个悬置的隔振性能;并在机械系统动力学分析软件(ADAMS)中建立驱动电机与副车架耦合动力学模型,分别计算了刚性副车架和柔性副车架悬置系统的模态,对比分析得出副车架柔性化后降低了悬置系统的模态频率.以电机振动的主要激励频率为输入,以传递到车身力最小为目标函数,对悬置的刚度阻尼参数进行了优化分析,优化后的悬置的隔振性能得到了改善,达到隔振的目的.     

汽车动力传动系统悬置的设计

随着人们对车辆舒适性要求的不断提高,开展动力传动系统的悬置设计有着重要的现实意义.建立汽车通用四点式悬置系统的数学模型,并确定悬置系统的惯性矩阵、刚度矩阵和阻尼矩阵,并为悬置系统的优化设计提供了模型基础.     

基于灵敏度分析的发动机悬置系统稳健优化设计

本文基于灵敏度分析的发动机悬置系统稳健优化设计为研究课题,以发动机悬置系统能量解耦作为本研究的参照目标,以悬置刚度参数为设计变量,考虑各种因素对悬置刚度参数灵敏度的影响,建立了多目标优化数学模型。采用遗传优化算法对发动机悬置系统刚度参数进行了稳健优化设计,并用蒙特卡罗方法进行了分析。研究结果表明,本次研究所采用的方法和建立的模型能够有效的降低发动机悬置系统能量解耦度对悬置刚度参数的灵敏度,有效的优化设计了发动机悬置系统,提高了实用性。     

某机床伺服电机悬置刚度区间型稳健优化方法研究

安装误差、测量误差及老化等原因导致悬置刚度在其设计值附近产生波动,使得悬置系统的频率和解耦率与其设计值之间也存在一定程度偏差。文中采用区间数表征悬置刚度、悬置系统的频率及解耦率的不确定性。为提高悬置系统解耦率及频率配置的稳健性,提出区间型稳健优化模型对悬置刚度进行稳健优化设计。对某机床伺服电机悬置系统的稳健优化结果表明,稳健优化方法可以较大幅度提高悬置系统在垂直和绕电机轴方向频率配置的稳健性。对优化结果进行了水平分析,验证了稳健优化方法的有效性。     

基于应变能分析的后副车架电机前悬置安装点动刚度优化设计

NVH是整车性能的重要衡量指标之一,电动汽车电驱动后独立悬架中,电驱动动力总成一般通过3个或4个悬置安装在后副车架上,而后副车架电机悬置安装点动刚度对动力总成隔振与噪音有很大的影响。为了保证整车的NVH性能,需要对后副车架的电机悬置安装点进行必要的动刚度分析与优化。现通过CAE分析得出其前悬置安装点在高低频段X、Z向动刚度较低,需要进行优化。通过约束模态与动刚度联合分析识别出动刚度低谷所在频率值,然后针对这几个频率值进行动刚度应变能分析,通过应变能的分布对后副车架结构进行优化设计,做到有针对性加强,从而提高电机前悬置安装点X、Z向动刚度,使得X向动刚度与Z向动刚度均达到了15000 N/mm的目标值。整个优化设计完成后后副车架的总质量没有增加,在充分提升动刚度的同时做到轻量化,同时该分析优化方法对其他电动车副车架悬置点动刚度优化提供了借鉴方法。     

空气弹簧液压悬置动特性及隔振特性研究

研究了具有可变刚度阻尼的发动机空气弹簧液压悬置的动特性和隔振特性。针对影响发动机空气弹簧液压悬置动特性的关键参数上液室等效体积刚度,采用理论和试验方法研究了上液室等效体积刚度的等效值,基于该等效值建立了空气弹簧液压悬置的理论模型,对空气腔开闭两种工况进行了空气弹簧液压悬置动特性的仿真和试验研究。搭建了发动机空气弹簧液压悬置系统试验台架,研究了台架各种激励频率下的空气弹簧液压悬置的隔振特性。结果表明:本研究采用的上液室等效体积刚度进行空气弹簧进行建模是正确、可行的,提高了空气弹簧建模效率和准确性;空气弹簧液压悬置在空气腔开启和关闭两种状态下,峰值动刚度增大幅值达78.5%,峰值阻尼角增大幅值达250%。台架试验表明:当台架激励频率小于25Hz时,悬置采用大刚度大阻尼;当台架激励频率大于等于25 Hz时,悬置采用小刚度小阻尼;悬置隔振率提升明显,不同频率下提升幅值达10%～67%。     

燃料电池轿车动力总成分段线性的悬置系统非线性振动特性

针对燃料电池轿车电动动力非线性总成悬置系统及其振动特性,建立一种基于平均法的动力总成悬置系统非线性振动分析方法。建立2自由度分段非线性动力学模型,基于平均法推导得到系统的幅频特性函数,通过仿真计算讨论悬置系统共振特性的非线性特征,同时分析动力总成质量、悬置非线性弹簧刚度特性、阻尼系数以及激振幅值对幅频特性的影响。分析结果表明,平均法可以用于非线性动力总成悬置系统的振动分析,悬置系统参数与激励幅值对于系统特性的灵敏度分析结果可以应用于悬置系统的匹配设计。     

发动机动力总成悬置系统模态分析与优化

悬置系统设计的核心是合理设计悬置元件的位置、角度和刚度,以提高悬置系统各向谐振模态解耦度,并使各向自振频率分别避开发动机怠速频率、车架、车身各向自振频率等,从而提高悬置系统的隔振效果。在悬置系统模态分析的基础上,建立了以提高悬置系统解耦度和各向谐振频率尽可能接近期望值为目标的悬置系统自动优化设计数学模型,并以某发动机动力总成悬置系统为应用案例,对其悬置元件的位置、角度和刚度进行自动优化设计计算,获得了预期的优化效果。     

某电动客车动力总成悬置系统优化

对先对某电动客车电机悬置系统的振动传递率进行了测量,在某些工况下,传递率超过了10%,对电机悬置系统进行固有特性分析和优化是很必要的。对电机悬置系统进行固有特性分析后,采用多岛遗传算法,通过改变悬置的位置和刚度对电机悬置系统的能量解耦率进行了优化。原悬置系统只有RX、RZ方向上的能量解耦率在90%以上,X、Y、Z三个方向仅在50%左右,优化后,悬置系统在固有频率的分布上满足要求,各个方向的能量解耦率均在90%以上,提高了悬置系统的隔振性能。     

基于垂向性能研究的新型悬架参数设计

设计了一种用于四轮独立转向独立驱动电动轿车的独立悬架,该悬架采用双横臂、螺旋弹簧结构,悬架连接带轮毂电机的大质量电动车轮。对悬架系统进行简化,建立了悬架二自由度振动模型,采用均方根值分析方法,计算出振动系统的频率响应函数及振动响应的均方根值(包括车身加速度均方根值、车轮相对动载荷均方根值及悬架动挠度均方根值),基于悬架参数对电动车辆垂向性能的研究,提出了新型悬架弹簧刚度和减振器阻尼系数的设计方法,结合仿真及实验验证了设计方法的合理性。     

轮毂电机独立驱动电动汽车动力减振机构设计与研究

采用轮毂电机多轮驱动是电动汽车发展的新方向。它不仅具有简化传动系统结构、减轻整车质量和降低地板高度的优点,而且便于提高传动效率,实现复杂的底盘控制。然而,轮毂电机的引入增加了非簧载质量,不利于电动汽车的行驶平顺性。为此,本文在分析传统集中电机驱动布置与轮毂电机独立驱动布置两类电动汽车系统垂向振动的基础上,提出新型的轮毂电机布置形式与相应的动力减振机构,并以非簧载质量的垂向振动量最小为目标函数,以动力减振机构的弹簧刚度和阻尼参数为设计变量,进行了优化设计,减小了电动汽车行驶过程中的垂向振动,提高了汽车行驶平顺性。此方法可为轮毂电机的设计及布置型式提供借鉴。     

Optimization Design and Performance Analysis of Vehicle Powertrain Mounting System

The design strategies for powertrain mounting systems play an important role in the reduction of vehicular vibration and noise. As stiffness and damping elements connecting the transmission system and vehicle body, the rubber mount exhibits better vibration isolation performance than the rigid connection. This paper presents a complete design process of the mounting system, including the vibration decoupling, vibration simulation analysis, topology optimization, and experimental verification. Based on the 6?degrees?of?freedom vibration coupling model of the powertrain mounting system, an optimization algorithm is used to extract the best design parameters of each mount, thus rendering the mounting system fully decoupled and the natural frequency well configured, and the optimal parameters are used to design the mounting system. Subsequently, vibration simulation analysis is applied to the mounting system, considering both transmission and road excitations. According to the results of finite element analysis, the topological structure of the metal frame of the front mount is optimized to improve the strength and dynamic characteristics of the mounting system. Finally, the vibration bench test is used to verify the availability of the optimization design with the analysis of acceleration response and vibration transmissibility of the mounting system. The results show that the vibration isolation performance of the mounting system can be improved effectively using the vibration optimal decoupling method, and the structural modification of the metal frame can well promote the dynamic characteristics of the mounting system.     

Decoupling analysis for a powertrain mounting system with a combination of hydraulic mounts

The existing torque roll axis(TRA) decoupling theories for a powertrain mounting system assume that the stiffness and viscous damping properties are constant. However, real-life mounts exhibit considerable spectrally varying stiffness and damping characteristics, and the influence of the spectrally-varying properties of the hydraulic mounts on the powertrain system cannot be ignored. To overcome the deficiency, an analytical quasi-linear model of the hydraulic mount and the coupled properties of the powertrain and hydraulic mounts system are formulated. The influence of the hydraulic mounts on the TRA decoupling of a powertrain system is analytically examined in terms of eigensolutions, frequency, and impulse responses, and then a new analytical axiom is proposed based on the TRA decoupling indices. With the experimental setup of a fixed decoupler hydraulic mount in the context of non-resonant dynamic stiffness testing procedure, the quasi-linear model of the hydraulic mount is verified by comparing the predictions with the measurement. And the quasi-linear formulation of the coupled system is also verified by comparing the frequency responses with the numerical results obtained by the direct inversion method. Finally, the mounting system with a combination of hydraulic mounts is redesigned in terms of the stiffness, damping and mount locations by satisfying the new axiom. The frequency and time domain results of the redesigned system demonstrate that the torque roll axis of the redesigned powertrain mounting system is indeed decoupled in the presence of hydraulic mounts (given oscillating torque or impulsive torque excitation). The proposed research provides an important basis and method for the research on a powertrain system with spectrally-varying mount properties, especially for the TRA decoupling.     

Vibration and noise control of structural systems using squeeze mode ER mounts

This paper presents vibration and noise control of flexible structures using squeeze mode electro-rheological mounts. After verifying that the damping force of the ER mount can be controlled by the intensity of the electric fild, two different types of ER squeeze mounts have been devised. Firstly, a small size ER mount to support 3 kg is manufactured and applied to the frame structure to control the vibration. An optimal controller which consists of the velocity and the transmitted force feedback signals is designed and implemented to attenuate both the vibration and the transmitted forces. Secondly, a large size of ER mount to support 200 kg is devised and applied to the shell structure to reduce the radiated noise. Dynamic modeling and controller design are undertaken in order to evaluate noise control performance as well as isolation performance of the transmitted force. The radiated noise from the cylindrical shell is calculated by SYSNOISE using forces which are transmitted to the cylindrical shell through two-stage mounting system.     

VARIABLE INERTIAL DAMPER AND ITS APPLICATION IN ZERO-DRIVE GEAR HOBBING MACHINE

A variable inertial damper, whose viscous damping coefficient can be adjusted by changing the gap between inertia wheel and motor spindle, is designed in servomechanism of zero-drive hobbing machine and is directly attached on the motor spindle. The mathematical model of servo system with inertial damper is built. By using theoretical analysis and system simulation, it is demonstrated that the variable inertial damper with optimal damping coefficient and moment of inertia should lead to no resonance point in wider frequency range of exciting force. Therefore, its application in zero-drive hobbing machine makes this system not only achieve higher system stiffness to overcome load torque fluctuation, but also gain better stability.     

转子-机匣系统碰摩的灵敏度研究

针对仅考虑质量偏心的Jeffcott转子碰摩的动力学方程，进行了转子-机理系统碰摩的灵敏度研究，分析了转轴刚度和阻尼、定子刚度和阻尼、偏心距和定子径向刚度对灵敏度的影响，并给出了数值分析解；讨论了参数的变化对碰摩的产生和影响，避免了设计旋转机械的盲目性。     

基于ANSYS的动力总成悬置系统的尺寸优化设计

利用A N SY S软件对某载货汽车动力总成悬置系统的结构进行了尺寸优化设计。通过建立优化数学模型,选择算法参数,得到了满足三向刚度要求的橡胶悬置的几何参数。     

电流变流体机械特性振动响应的研究

电流变流体是一种新型的智能材料,在工程中有广泛的应用前景。本文利用自行设计的测试装置通过对测杆振幅、共振频率等参数的测定,研究电场作用下电流变流体刚度及阻尼变化。根据实验研究提出变参数的粘弹阻尼力学模型,描述电流变流体在电场作用下附加阻尼和附加刚度。