Dynamic Parameter Estimation of a MacPherson Strut Suspension

The dynamic parameters of a MacPherson strut suspension were estimated from the kinematic responses and measured external forces on the system. First, Lagrange equation was used to develop the equations of motion of the system, and then equations of motion were written as linear with respect to the dynamic parameters being estimated. The generalized coordinate partitioning technique was applied to create a reduced set of equations of motion of the constrained dynamic system. In this method only the measurements of positions and kinematic responses of the independent coordinates, and the external forces applied on the system are required as inputs. The rank deficient linear system was solved by QR decomposition. Good correlation was obtained between the actual parameters and the estimated parameters, by comparison between the simulated system response from the actual parameters and from the estimated parameters.     

Dynamic Parameter Estimation of a MacPherson Strut Suspension

SUMMARY

The dynamic parameters of a MacPherson strut suspension were estimated from the kinematic responses and measured external forces on the system. First, Lagrange equation was used to develop the equations of motion of the system, and then equations of motion were written as linear with respect to the dynamic parameters being estimated. The generalized coordinate partitioning technique was applied to create a reduced set of equations of motion of the constrained dynamic system. In this method only the measurements of positions and kinematic responses of the independent coordinates, and the external forces applied on the system are required as inputs. The rank deficient linear system was solved by QR decomposition. Good correlation was obtained between the actual parameters and the estimated parameters, by comparison between the simulated system response from the actual parameters and from the estimated parameters.     

Simulation of Dynamical Behaviour of a Front Wheel Suspension

Abstract

A MacPherson front wheel suspension and its components are modelled with the finite element method. Nonlinearities due to both the geometry and the characteristics of the components (springs, dampers and bushings) are considered. The force due to a given compression/elongation of the spring strut is calculated and compared with experimental results. Kinematical results, change in track width and camber angle, are also shown and compared with experimental results. Good agreement between numerical and experimental results is obtained.     

Simulation of Dynamical Behaviour of a Front Wheel Suspension

A MacPherson front wheel suspension and its components are modelled with the finite element method. Nonlinearities due to both the geometry and the characteristics of the components (springs, dampers and bushings) are considered. The force due to a given compression/elongation of the spring strut is calculated and compared with experimental results. Kinematical results, change in track width and camber angle, are also shown and compared with experimental results. Good agreement between numerical and experimental results is obtained.     

Sequential Approximate Optimization of MacPherson Strut Suspension for Minimizing Side Load by Using Progressive Meta-Model Method

In a MacPherson strut suspension, the side load is inevitably generated and it causes friction at the damper reducing riding comfort. In this paper, to solve this problem, progressive meta-model based sequential approximate optimization (SAO) is performed to minimize the side load. To calculate the side load, a wheel travel analysis is performed by using flexible multi-body dynamics (FMBD) model of suspension, which can consider both finite element method (FEM) and multi-body dynamics (MBD). In the optimal design process, meta-model is generated by using extracted sampling points and radial basis function (RBF) method. As a result of optimal design, spring setting positions that minimize the side load are obtained and by using optimal spring setting positions, the suspension FMBD model was constructed.     

Base Dynamic Parameter Estimation of a MacPherson Suspension Mechanism

Summary A MacPherson suspension mechanism is modeled as a two degrees of freedom spatial mechanism. Its dynamic response under two excitement forces is simulated with the motion equations in Euler Parameters with the off-the-center-of-mass body-fixed coordinates derived in this paper. Simulation results are sampled and input into a numerical estimation routine based on singular value decomposition (SVD). Accurate numerical estimation results are achieved. A set of base dynamic parameters in symbolic expressions is also derived from the numerical results utilizing the concepts of mass transfer and moments of inertia transfer. This makes it possible to apply the estimation results to any MacPherson suspension mechanism with the same joint configuration. The potential applications of the symbolic base dynamic parameters in suspension design are also considered.     

Base Dynamic Parameter Estimation of a MacPherson Suspension Mechanism

Summary A MacPherson suspension mechanism is modeled as a two degrees of freedom spatial mechanism. Its dynamic response under two excitement forces is simulated with the motion equations in Euler Parameters with the off-the-center-of-mass body-fixed coordinates derived in this paper. Simulation results are sampled and input into a numerical estimation routine based on singular value decomposition (SVD). Accurate numerical estimation results are achieved. A set of base dynamic parameters in symbolic expressions is also derived from the numerical results utilizing the concepts of mass transfer and moments of inertia transfer. This makes it possible to apply the estimation results to any MacPherson suspension mechanism with the same joint configuration. The potential applications of the symbolic base dynamic parameters in suspension design are also considered.     

麦弗逊式悬架车轮外倾角偏差的分析

为保证车轮外倾角在制造和装配过程中的设计误差满足设计公差要求,文章基于空间几何方法简化的外倾角计算公式,以国内某车型为基础,从零件设计尺寸公差和总装装配过程出发,对麦弗逊式悬架形式的汽车制造过程中零部件偏差与装配过程进行分析。确定了各影响因素对外倾角的影响范围,为整车制造过程中控制外倾角偏差以及提高整车质量提供了参考。     

基于遗传算法的汽车麦弗逊悬架的优化

遗传算法是一种基于生物自然选择与遗传机理的随机搜索算法。文章利用遗传算法对麦弗逊悬架进行了优化。结果表明,该算法使悬架设计工作更为精确、有效。优化后,悬架系统的运动学特性得到了改善。     

麦式悬架系统运动分析

本文介绍了麦式悬架的结构形式、特点。根据该悬架实际的结构，在没有简化的情况下对其运动规律进行了精确分析；阐述了在车轮跳动及转向过程中悬架运动特性参数变化情况的计算方法，介绍了麦式悬架及转向系统的运动分析程序。     

麦弗逊悬架侧载螺旋弹簧优化设计

以某轿车为例,建立了麦弗逊悬架多体动力学模型,将减振器侧向力仿真结果作为侧载弹簧设计目标,应用有限元方法进行结构优化设计,并进行了试验验证。研究结果表明,采用优化设计的侧载螺旋弹簧后可显著降低悬架侧载,为悬架系统及其元件的优化提供了一种参考方法。     

车身后减振器安装点改进设计

车身后减振器安装点钣金侧开裂是乘用车耐久试验常见故障之一.本文回顾了某七座SUV后减振器安装点开裂问题,并从载荷和结构设计角度给出了发生此问题的原因.同时,结合力学设计基本原则,设计了一种减振器安装点结构,在后视图上减振器安装点落在减振器中心轴线上,钣金安装平面竖直向上.通过仿真验证,此结构可以显著降低车身侧钣金应力水...     

含非线性轮胎模型的汽车四轮转向与主动悬架集成控制

在建立汽车四轮转向与主动悬架统一动力学模型的基础上,分别对2个子系统进行控制器的设计研究.在四轮转向控制器的设计方面,提出了修正后的理想参考模型,采取前馈加反馈的跟踪控制策略,在主动悬架的控制器设计中则采用最优控制方法.结合非线性轮胎模型,在MAT-LAB/Simulink环境下对被动系统、四轮转向系统、主动悬架系统以及四轮转向与主动悬架集成控制系统进行了仿真分析.结果表明:集成控制系统除了能改善车辆在转弯过程中的质心侧偏角响应、横摆角速度响应以及在不平路面上的行驶平顺性外,还能有效抑制由不平路面等外界干扰对车辆转向性能带来的影响.     

High Frequency Characteristics of a Front Wheel Suspension

This paper presents a modeling method to analyze the frequency characteristics of a suspension system. The method employs the superelement and lumped methods for structural modeling of flexible bodies, and it is incorporated with a multibidy dynamics formulation in which joint nonlinearities can be considered effectively. To verify the accuracy of the results obtained by the modeling method, a quarter car test was made. Test results showed that the computational model provided fairly accurate frequency characteristics for the suspension system. Other useful conclusions were also drawn from this study.     

High Frequency Characteristics of a Front Wheel Suspension

SUMMARY

This paper presents a modeling method to analyze the frequency characteristics of a suspension system. The method employs the superelement and lumped methods for structural modeling of flexible bodies, and it is incorporated with a multibidy dynamics formulation in which joint nonlinearities can be considered effectively. To verify the accuracy of the results obtained by the modeling method, a quarter car test was made. Test results showed that the computational model provided fairly accurate frequency characteristics for the suspension system. Other useful conclusions were also drawn from this study.     

麦弗逊式前悬架液力减振器阻尼特性仿真与试验

分析了某轿车麦弗逊式前悬架液力减振器的结构特点,建立了该减振器阻尼特性的数学模型,分别采用钱氏摄动法和有限元法计算减振器节流阀片的挠曲变形,通过仿真计算得到了相应的减振器阻尼特性,通过台架试验进行了减振器样件的阻尼性能测试。对比分析表明:仿真结果与试验结果基本一致,验证了减振器阻尼特性数学模型的有效性;根据有限元法计算的阀片变形所预测的减振器阻尼特性更接近试验值,研究结果有利于提高液力减振器阻尼特性的计算精度。     

基于ve-DYNA的麦弗逊悬架系统构建方法分析

ve—DYNA是基于Matlab／Simulink开发的、具有模块化结构的整车动力学分析软件。以红旗轿车的前悬架模型为例，介绍了ve—DYNA悬架模型，给出了在ve—DYNA中建立前悬架模型所需的参数，讨论了通过其它工具软件和试验获取刚性器件转动惯量参数和轮胎动力学参数的方法。通过与ADAMS软件中麦弗逊悬架特性曲线的对比，定性说明了所配置模型的正确性和所给出模型参数获取方法的可行性。     

空间悬索结构的几何非线性分析

以某空间悬索结构在使用阶段的状态评估及维护项目为依托,结合有限元方法,采用节点刚结和抗弯刚度较小的梁单元来模拟索模型,用增量法与Newton-Raphson迭代法相结合的方法求解几何非线性问题.通过现场静载实验数据与计算结果进行对比分析.     

非线性弹簧悬架及其实现的方法

详细论述非线性弹簧汽车悬架系统对汽车舒适性的贡献。非线性弹簧悬架可以兼顾空载和满载等不同的工况，保证汽车在不同的载荷下具有相同的固有频率。详尽论述了适用于轿车螺旋弹簧等实现非线性的原理以及非线性弹簧的设计途径。着重介绍了多用于轿车滚筒式空气弹簧结构和弹簧刚度形成的构成，从而给出非线性设计的主要途径。