基于平顺性的四轴重型商用车悬架参数优化

为提高车辆行驶平顺性,建立某四轴重型商用车悬架动力学模型,并对悬架参数进行优化。模型中,在车辆结构上考虑了平衡悬架和驾驶室,在悬架力学特性上考虑了阻尼非线性。采用遗传算法对车辆悬架的刚度特性和阻尼特性进行优化,优化综合考虑了车辆在不同路面等级下以不同车速行驶的平顺性。对优化前后驾驶室处垂直加速度均方值进行仿真对比,结果显示,优化后车辆行驶平顺性得到有效提高。     

电动汽车车身平顺性及车轮接地性分析与优化

以某分布式四轮驱动电动汽车为研究对象,在Adams/car中建立了整车模型,通过对前、后悬架参数进行灵敏度分析,探讨其对车身平顺性与车轮接地性的影响。基于α法建立评价车身平顺性与车轮接地性指标的多目标函数,对灵敏度较高的悬架参数进行优化设计。结果表明,优化后前、后悬架的刚度减小,前悬架的阻尼增大。与优化前相比,车身垂向加速度均方根值减小16%,左、右前轮动载荷的均方根值均减小11%。     

基于舒适性和轮胎动载的车辆悬架参数优化

为了改善汽车行驶的舒适性并减小轮胎对路面的动载，以某载货汽车为研究对象，建立了多目标优化模型，并采用统一目标函数法对车辆悬架参数进行优化。优化结果表明：优化后悬架刚度减小而阻尼增大，且前悬架参数变化较小，后悬架参数变化较大；相比于优化前，车身垂直方向加速度均方根值减小了20％，前轮动栽均方根值减小了40％，后轮变化更显著，减小了49％；采用多目标优化设计方法不仅可提高车辆自身的舒适性，而且可减小轮胎对路面的动载。     

基于径向基函数神经网络的半主动悬架滑模控制

采用天棚阻尼模型为参考模型,设计了1/4车辆悬架系统的滑模控制器,并用径向基函数神经网络对其进行了优化.研究了系统在随机激励条件下的车身加速度、悬架动行程和轮胎动位移等性能参数的控制效果,并对其功率谱密度进行了仿真分析.结果表明:该滑模控制器性能稳定,控制后悬架各性能参数在时域和频域中均得到明显改善.     

基于非线性空气弹簧模型的整车仿真与主客观评价

应用非线性空气弹簧模型,研究了空气悬架整车的动力学仿真和主观评价。结合空气弹簧频率、振幅相关性模型与Simulink仿真,给出了空气悬架整车7自由度模型,对比了不同路面情形下悬架动行程和簧上加速度的均方根值和功率谱密度。从时域和频率2个角度分析了不同速度、路面及减振器阻尼情形下空气悬架整车的动态特性。对装有不同空气弹簧的整车进行主、客观试验测试。结果表明：悬架动行程预测误差小于7%,簧上位置加速度共振峰值预测误差小于6%,共振频率预测误差小于6%;从而验证了所提模型的普适性和精确性;反映了带空气悬架整车的动态特性,解释了平顺性主客观试验的机理。     

遗传算法及在汽车悬架参数优化设计中的应用

为了探讨遗传算法在汽车悬架参数优化设计中应用的可行性,对遗传算法的基本概念、基本步骤以及常用的基于二进制编码的遗传算法的实现方法进行了研究。以1/4汽车两自由度振动模型为对象,运用遗传算法对悬架刚度和减振器阻尼系数进行了优化求解。研究结果表明,优化后得到的车身垂直振动加速度均方根值较优化前在整个频率范围内均有较大的减小,遗传算法应用于汽车悬架参数的优化设计具有较好的效果。     

被动天棚阻尼悬架降阶与优化

采用基于Routh稳定判据的Pade逼近法对被动天棚阻尼悬架系统进行降阶,寻找阶次低、元件少的ISD悬架结构。建立四分之一悬架模型,运用统一目标函数的遗传算法优化结构的参数,对比分析了传统被动、被动天棚阻尼和降阶ISD三种悬架系统的性能。结果表明,与被动天棚阻尼悬架相比,降阶ISD悬架的车身加速度、轮胎动载荷和悬架动行程均方根值都不同程度逼近被动天棚阻尼悬架,能够实现被动天棚阻尼悬架的主要性能,说明经降阶优化的ISD悬架综合性能可以接近被动天棚阻尼悬架,研究结果从理论上验证了基于Routh稳定判据的Pade逼近法的有效性。     

油气弹簧非线性特性对车辆平顺性的影响分析

推导并建立了某工程车辆油气弹簧的非线性刚度和阻尼特性的数学模型，并将其导入到车辆模型中。根据汽车悬架质量分配特点．将汽车简化为两自由度的舣质量振动系统，对此两自由度模型的车轮加速度、车身加速度和悬架动行程进行了仿真从仿真结果可以看出，非线性油气弹簧能很好地衰减由路面传递来的振动。分析了刚度和阻尼的变化对车辆平顺性的影响。     

随机路面激励下车辆系统参数对汽车行驶平顺性的影响研究

基于汽车系统动力学和随机振动理论，建立了简化的人体-座椅、车身及车轮3-DOF车辆振动模型，采用线性滤波白噪声法建立了路面激励模型，并仿真分析了常见C级路面的不平度特性。以C级随机路面激励为车辆振动系统输入，运用变步长四阶Runge-Kutta法求解了车辆系统数学模型。在时域和频域两方面，仿真分析了座椅刚度、阻尼，悬架刚度、阻尼及轮胎刚度对座椅、悬架性能的影响，以及路面不平度和车速对座椅垂向加权加速度的影响。得出了座椅加速度、悬架动挠度、轮胎动载荷功率谱密度随座椅刚度、阻尼系数，悬架刚度、阻尼系数及轮胎刚度变化的规律。     

基于ADAMS和响应面法的汽车悬架阻尼优化与试验

基于响应面法和ADAMS/Car虚拟样机模型,在不改变悬架刚度前提下,根据不同的行驶条件对前、后悬架阻尼参数进行了优化匹配.设计了前、后悬架可调阻尼减振器并进行台架性能测试.将可调阻尼减振器装车进行随机路面平顺性试验的结果表明,采用优化后悬架阻尼参数的整车行驶平顺性得到改善,验证了响应面法和阻尼优化匹配方案的有效性.     

大跨悬索桥MTMD抖振控制的参数优化

针对悬索桥抖振控制问题,建立有限元模型,应用神经网络和遗传算法对多重调频质量阻尼器(MTMD)进行双参数优化。以某大跨悬索桥为例,利用神经网络改进的谐波合成模拟方法(RBF-WAWS法)对脉动风速进行模拟,并换算成抖振力作用主梁上,通过时程分析及后处理获取主跨跨中横桥向响应值。将响应值的均方差作为优化目标函数,以MTMD总质量、个数及阻尼比作为优化变量和约束条件,采用神经网络拟合目标函数并应用改进的自适应遗传算法进行寻优。结果表明,优化后的MTMD能有效控制悬索桥在脉动风作用下的抖振响应,减振率达48%。提出的理论与计算方法对悬索桥中MTMD的设置及参数选取具有实际工程意义。     

Suspension parameter estimation in the frequency domain using a matrix inversion approach

The dynamic lumped parameter models used to optimise the ride and handling of a vehicle require base values of the suspension parameters. These parameters are generally experimentally identified. The accuracy of identified parameters can depend on the measurement noise and the validity of the model used. The existing publications on suspension parameter identification are generally based on the time domain and use a limited degree of freedom. Further, the data used are either from a simulated ‘experiment’ or from a laboratory test on an idealised quarter or a half-car model. In this paper, a method is developed in the frequency domain which effectively accounts for the measurement noise. Additional dynamic constraining equations are incorporated and the proposed formulation results in a matrix inversion approach. The nonlinearities in damping are estimated, however, using a time-domain approach. Full-scale 4-post rig test data of a vehicle are used. The variations in the results are discussed using the modal resonant behaviour. Further, a method is implemented to show how the results can be improved when the matrix inverted is ill-conditioned. The case study shows a good agreement between the estimates based on the proposed frequency-domain approach and measurable physical parameters.     

双横臂扭杆弹簧悬架系统空间结构非线性特性的建模与分析

利用空问解析几何方法,建立了考虑导向杆件、弹性元件和阻尼元件的空间结构、空间姿态和空间尺寸的具有三维空间结构的转向轮的双横臂扭杆弹簧悬架系统的数学模型,研究该悬架的空间结构非线性阻尼和非线性刚度特性.分析结果表明:该悬架系统的等效阻尼和等效刚度具有明显的空间结构非线性特征.     

Design of a Stroke Dependent Damper for the Front Axle Suspension of a Truck Using Multibody System Dynamics and Numerical Optimization

Summary A stroke dependent damper is designed for the front axle suspension of a truck. The damper supplies extra damping for inward deflections rising above 4 cm. In this way the damper should reduce extreme suspension deflections without deteriorating the comfort of the truck. But the question is which stroke dependent damping curve yields the best compromise between suspension deflection working space and comfort. Therefore an optimization problem is defined to minimize the maximum inward suspension deflection subject to constraints on the chassis acceleration for three typical road undulations. The optimization problem is solved using sequential linear programming (SLP) and multibody dynamics simulation software. Several optimization runs have been carried out for a small two degree of freedom vehicle model and a large full-scale model of the truck semi-trailer combination. The results show that the stroke dependent damping can reduce large deflections at incidental road disturbances, but that the optimum stroke dependent damping curve is related to the acceleration bound. By means of vehicle model simulation and numerical optimization we have been able to quantify this trade-off between suspension deflection working space and truck comfort.     

基于多体系统动力学的微型客车操纵稳定性DOE优化设计

利用多体系统动力学软件ADAMS建立了某微型客车动力学模型,并应用该模型对整车操纵稳定性进行了仿真分析.结合仿真数据利用ADAMS/Insight模块对前、后悬架系统中的刚度和阻尼进行了正交DOE优化,通过对优化结果的分析提出前、后悬架系统刚度值和阻尼值的3组合理匹配组合,最后通过3种组合在试验样车上的主观评价结果确定了前、后悬架刚度值和阻尼值.     

载货汽车驾驶室乘坐舒适性研究

通过计算机仿真模拟了在路面随机输入下驾驶室底板的振动响应;利用Nastran软件对车身的有限元模型进行模态抽取,建立了刚弹耦合模型;对多刚体模型、刚弹耦合振动模型的计算结果与试验进行了对比,验证了模型的正确性;以驾驶室悬置的弹簧刚度、减振器阻尼为影响因素,通过虚拟DOE正交试验分析,显著改善了驾驶室的乘坐舒适性。     

Roll and pitch independently tuned interconnected suspension: modelling and dynamic analysis

In this paper, a roll and pitch independently tuned hydraulically interconnected passive suspension is presented. Due to decoupling of vibration modes and the improved lateral and longitudinal stability, the stiffness of individual suspension spring can be reduced for improving ride comfort and road grip. A generalised 14 degree-of-freedom nonlinear vehicle model with anti-roll bars is established to investigate the vehicle ride and handling dynamic responses. The nonlinear fluidic model of the hydraulically interconnected suspension is developed and integrated with the full vehicle model to investigate the anti-roll and anti-pitch characteristics. Time domain analysis of the vehicle model with the proposed suspension is conducted under different road excitations and steering/braking manoeuvres. The dynamic responses are compared with conventional suspensions to demonstrate the potential of enhanced ride and handling performance. The results illustrate the model-decoupling property of the hydraulically interconnected system. The anti-roll and anti-pitch performance could be tuned independently by the interconnected systems. With the improved anti-roll and anti-pitch characteristics, the bounce stiffness and ride damping can be optimised for better ride comfort and tyre grip.     

非线性汽车行驶平顺性模型的神经网络优化

本文运用离散生成随机路面输入的方法，在时城上对11自由度非线性整车行驶平顺性模型进行了分析研究，并在此 以径向基函数神经网络对悬架参数进行了优化计算。模型及算法合理准确，为汽车行驶平顺性的进一步研究提供了有价值的参考方法。     

Hybrid modelling and damping collaborative optimisation of Five-suspensions for coupling driver-seat-cab system

For the complex structure and vibration characteristics of coupling driver-seat-cab system of trucks, there is no damping optimisation theory for its suspensions at present, which seriously restricts the improvement of vehicle ride comfort. Thus, in this paper, the seat suspension was regarded as ‘the fifth suspension’ of cab, the ‘Five-suspensions’ for this system was proposed. Based on this, using the mechanism modelling method, a 4 degree-of-freedom coupling driver-seat-cab system model was presented; then, by the tested cab suspensions excitation and seat acceleration response, its parameters identification mathematical model was established. Based on this, taking optimal ride comfort as target, its damping collaborative optimisation mathematical model was built. Combining the tested signals and a simulation model with the mathematical models of parameters identification and damping collaborative optimisation, a complete flow of hybrid modelling and damping collaborative optimisation of Five-suspensions was presented. With a practical example of seat and cab system, the damping parameters were optimised and validated by simulation and bench test. The results show that the model and method proposed are correct and reliable, providing a valuable reference for the design of seat suspension and cab suspensions.