机械式车高自动调平装置的研制

针对现有车高自动调平装置存在的不足,以某轻型客车非独立后悬架作为研制对象,对机械式车高自动调平装置进行了创新设计、样件试制和试验验证;为比较调平悬架和普通悬架的性能差异,在随机和脉冲路面激励下采用时域和频域分析法对两种悬架进行了数学建模和仿真分析,从而初步得出了自动调平悬架的主要性能特点。
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Investigation into Improvement for Anti-Rollover Propensity of SUV

Currently, many research from domestic and foreign on improving anti-rollover performance of vehicle mainly focus on the electronic control of auxiliary equipment, do not make full use of suspension layout to optimize anti-rollover performance of vehicle. This investigation into anti-rollover propensity improvement concentrates on the vehicle parameters greatly influencing on anti-rollover propensity of vehicle. A simulation based on fishhook procedure is used to perform design trials and evaluations aimed at ensuring an optimal balance between vehicle's design parameters and various engineering capacities, the anti-rollover propensity is optimized at the detailed design stage of a new SUV model. Firstly a four-DOF theoretical kinematic model is established, then a complete multi-body dynamics model built in ADAMS/car based on the whole vehicle parameters is correlated to the objective handing and stability test results of a mule car. Secondly, in fishhook test simulations, the Design of Experiments method is used to quantify the effect of the vehicle parameters on the anti-rollover performance. By means of the simulation, the roll center height of front suspension should be more than 30 mm, that of rear suspension less than 150 mm, and the HCG less than 620 mm for the SUV. The ratio of front to rear suspension roll stiffness should be ranged from 1.4 to 1.6 for the SUV. As a result, at the detailed design stage of product, the anti-rollover performance of vehicle can be improved by optimizing chassis and integrated vehicle parameters.     

非线性商用车仿生悬架等偏频等高度设计

针对商用车悬架基于满载设计存在的变簧载时车辆平顺性差的问题,提出了一种基于双菱形仿袋鼠腿悬架(简称“仿生悬架”)的等偏频等高度设计方案,并对该方案进行研究、分析与评价,以改善商用车的平顺性。通过静力学特性分析,得到了仿生悬架的弹性特性和刚度特性并开展了等偏频等高度设计研究。研究发现：仿生悬架具有较理想的非线性弹性特性和刚度特性,相比线性悬架,具有更多的动容量和更强的抗击穿能力;悬架的初始角度和刚度比对其特性和行程区间有重要影响;通过调节仿生悬架初始角度可实现不同簧载质量悬架的等偏频等高度设计,表明所提设计方案可行。仿真分析结果表明,在不同路面等级(B、C、D)、不同车速(40～100 km/h)下,商用车经仿生悬架等偏频等高度设计后,车身加速度均方根值较设计前明显减小,平顺性得到有效改善。搭建了仿生悬架实验测试模型,在不同路面条件下,等偏频等高度设计后,空载和半载垂向加速度均方根值较设计前分别减小20.6%～28.3%和12.1%～20.4%,验证了等偏频等高度设计方案的正确性和有效性。     

降低车辆振动的悬架参数多体动力仿真分析和优化

针对悬架结构参数对由于路面不平而产生的车辆振动的影响,通过在多体动力学分析工具AD-AMS环境下,综合运用参数化设计、单变量和多变量的筛选实验以及正交实验优化方法,对建立的车辆1/4悬架模型作了分析和研究;最后以降低车轮最大振动加速度为优化指标,在极差分析结果的指导下,得出了实验约束范围内悬架参数最优解。研究结果表明,该优化方法有助于降低类似悬架等复杂系统的优化求解的难度,且优化效果明显。     

汽车主动悬架的自适应控制研究

主要对汽车主动悬架自适应系统进行研究。根据悬架系统的模型,参数往往不确定,路面激励未知且可变,对主动悬架的非线性性能特点进行研究。采用增益调度控制、模型参考自适应控制和自校正控制等几类自适应控制策略应用于主动悬架的主动控制系统。通过自校正控制自适应系统,按照路面行驶工况进行最优控制,通过计算机对电液系统的阻尼、弹力和水平位置等进行调节,使悬架系统对不同运行工况具有最大程度的适应能力。确保主动悬架性能满足车辆行驶稳定性能与乘坐舒适性,实现对悬架的自我优化控制。     

磨床用自定心中心架的机构设计与优化

设计了一种磨床用自定心中心架的原型机构,建立了自定心中心架的参数组合和平动凸轮的参数化模型。通过对机构的设计参数组合筛选,提出了机构的优化设计目标和优化函数,设计了优化的计算程序。在保证中心架的传力性能、夹持稳定性和夹持精度的前提下,对机构中平动凸轮的两个重要参数进行了优化,为磨床用高精度自定心中心架的设计提供了完整的设计方案。     

液压减振器散热性能研究

液压减振器是通过消耗机械能实现减振目的的装置,但目前其散热效果并不理想,温度升高导致了减振器整体性能下降。利用路面不平度激励模型、悬架系统振动模型、热量传递模型,通过能量守恒定律建立了液压减振器的热力学平衡数学模型。综合考虑油液泄漏特性、密封特性以及液压减振器阻尼性能界定其许用油温。对液压减振器散热参数进行了分析研究,且试验结果表明分析模型与设计方法正确,为减振器的设计提供参考。     

Optimization of suspension parameters to improve impact harshness of road vehicles

This paper illustrates the development and implementation of a parameter optimization methodology to improve impact harshness (IH) of road vehicles. A full ADAMS model of a small commercial vehicle is used as the IH test vehicle. The methodology involves the use of design of experiments methods together with response surface methodology. Significant design parameters affecting IH of the vehicle are first determined by the screening experiments. Once the critical parameters are identified, they are optimized to achieve improvement in the IH by constructing response surface. The optimization results indicate that the selected suspension parameters are capable of improving IH performance of the full vehicle ADAMS model by minimizing longitudinal and vertical acceleration responses. The results also show that considerable improvement can be obtained by using the proposed parameter optimization methodology.     

基于MATLAB的菱形客车平顺性研究

建立了菱形客车十一自由度整车模型,分析各设计因素对整车平顺性的影响,并以随机路面下各个乘员的垂直加速度为优化目标,各个悬架的动行程和各个车轮的相对动载为约束条件,运用遗传算法NSGA-Ⅱ对悬架参数进行优化设计。优化后菱形客车平顺性得到了提高,以此时的悬架参数为基础分析了菱形客车在脉冲路面下平顺性的变化规律。     

基于主动悬架系统车辆的道路友好性

为分析悬架系统对车辆道路友好性的影响,设计出可提高道路友好性的主动悬架系统最优控制器,及可分析基于最优控制策略的主动悬架系统,以及被动悬架系统的道路友好性动态仿真模型,仿真分析得出车辆在两种典型的A、B级路面行驶时,基于最优控制策略的主动悬架系统及被动悬架系统车辆对路面造成的动载荷.利用动态载荷系数、动态载荷应力因子及95百分位综合四次幂力三种典型道路友好性评价指标对两种悬架系统的道路友好性进行分析比较.结果表明,采用动态载荷系数、动态载荷应力因子对悬架系统的道路友好性进行评价时,在A级路面上,主动悬架系统的道路友好性分别是被动悬架系统的1.5、1.6倍;在B级路面上主动悬架系统的道路友好性是被动悬架系统的1.5、2.5倍;采用95百分位综合四次幂力指标评价两种悬架系统的道路友好性时,在A级路面上,两种悬架系统的道路友好性相差无几;在B级路面上主动悬架系统的道路友好性比被动悬架系统提高2.5倍.因此,具有合理控制参数的基于最优控制策略的主动悬架系统可提高重型车辆的道路友好性.     

悬架参数多目标性能优化

以多体动力学理论为基础,利用机械动力学分析软件ADAMS建立某轿车的整车虚拟样机模型。研究悬架系统对乘员舒适性及车辆对道路破坏程度的影响规律。根据行驶平顺性和道路友好性各自评价指标进行了数值计算,分析了行驶车速、悬架弹簧刚度和减振器阻尼对车辆平顺性和道路友好性的影响,最后得到了优化的悬架参数。通过比较优化前后的车辆对道路的动载荷,提出了对车辆悬架设计与使用方面的有益建议。     

基于CATIA/ADAMS的麦弗逊悬架运动分析

悬架是汽车的车架与车桥或车轮之间的传力连接装置,汽车悬架类型的选择和悬架参数的差异对汽车的操纵稳定性和行驶平顺性具有重要的影响。主要分析了麦弗逊悬架的结构特点,并通过CATIA软件建立麦弗逊悬架的三维立体简化模型,并运用ADAMS软件对其进行仿真分析,了解悬架的运动状态和过程,并得出相关结论,确定车轮定位参数的选择范围,以及悬架的优化设计方法。     

基于粒子群算法的汽车ABS控制器参数的优化设计

提出了基于粒子群算法的汽车ABS控制器参数的优化设计方法。该方法将ABS控制器的参数编码为粒子群中粒子的向量,通过粒子群在参数空间的寻优得到优化的控制参数。然后分别以未优化的参数和优化的参数作为控制参数进行了仿真试验,仿真结果证实了该算法的有效性。最后以优化的参数作为控制参数进行路试,取得了比较满意的制动效果。     

基于MATLAB的链斗卸船机挖料阻力的研究

以散货力学理论为基础，以MATLAB为工具，建立了悬链式链斗卸船机挖料阻力的数学模型并进行数值仿真，得出的结论对悬链式链斗卸船机的优化设计有一定的帮助。     

液压挖掘机工作装置综合优化研究

液压挖掘机反铲工作装置是一个典型的开链四杆机构,其铰点的布局对于作业性能以及使用寿命至关重要.采用常规优化方法对反铲工作装置进行优化,往往难以得到满意的结果.因此,建立了反铲工作装置的综合优化模型,并采用遗传算法进行了优化.仿真及实验结果表明:相对于传统方法,遗传优化更为快捷有效;优化后工作装置的综合性能有了较大的提高.     

车辆电液主动悬架智能控制研究

建立悬架系统和电液伺服作动器数学模型,分别在正弦信号激励和随机路面激励下,设计最优控制器,在MATLAB/simulink里搭建仿真模型进行数值仿真。仿真结果表明:最优控制的电液主动悬架系统对由路面输入引起的振动能有效抑制,车身加速度、悬架动挠度和轮胎动载荷与被动悬架相比分别降低20%~55%、25%~44%、0%~54%,车辆行驶平顺性和操纵稳定性得到很大改善,验证了控制器的性能。     

Hierarchical Control of Ride Height System for Electronically Controlled Air Suspension Based on Variable Structure and Fuzzy Control Theory

The current research of air suspension mainly focuses on the characteristics and design of the air spring. In fact, electronically controlled air suspension(ECAS) has excellent performance in flexible height adjustment during different driving conditions. However, the nonlinearity of the ride height adjusting system and the uneven distribution of payload affect the control accuracy of ride height and the body attitude. Firstly, the three-point measurement system of three height sensors is used to establish the mathematical model of the ride height adjusting system. The decentralized control of ride height and the centralized control of body attitude are presented to design the ride height control system for ECAS. The exact feedback linearization method is adopted for the nonlinear mathematical model of the ride height system. Secondly, according to the hierarchical control theory, the variable structure control(VSC) technique is used to design a controller that is able to adjust the ride height for the quarter-vehicle anywhere, and each quarter-vehicle height control system is independent. Meanwhile, the three-point height signals obtained by three height sensors are tracked to calculate the body pitch and roll attitude over time, and then by calculating the deviation of pitch and roll and its rates, the height control correction is reassigned based on the fuzzy algorithm. Finally, to verify the effectiveness and performance of the proposed combined control strategy, a validating test of ride height control system with and without road disturbance is carried out. Testing results show that the height adjusting time of both lifting and lowering is over 5 s, and the pitch angle and the roll angle of body attitude are less than 0.15?. This research proposes a hierarchical control method that can guarantee the attitude stability, as well as satisfy the ride height tracking system.     

非确定性参数对油气悬架系统性能的影响

建立了油气悬架系统2自由度1/4车辆模型的数学模型,应用Matlab6.5/Simulink5.0建立了相应的仿真模型。研究了节流孔流量系数、油液动力粘度和气体多变指数等非确定性参数对平顺性、悬架动行程和轮胎接地性等悬架系统性能的影响。研究结果表明非确定性参数对悬架系统性能的影响是单调的,因此,设计油气悬架时,它们的取值应使悬架系统性能在最恶劣的工况下满足设计要求,从而保证悬架系统性能始终满足要求。     

Optimization of secondary suspension of piecewise linear vibration isolation systems

A comprehensive optimal design solution is presented for piecewise-linear vibration isolation systems. First, primary suspension optimum parameters are established, followed by an investigation of jump-avoidance conditions for the secondary suspension. Within the no-jump zones, an optimal design solution is then obtained for the secondary system and overall results are discussed.Averaging method is employed to obtain an implicit function for frequency response of a bilinear system under steady-state conditions. This function is examined for jump-avoidance and a condition is derived which when met ensures that the undesirable phenomenon of ‘jump’ does not occur and the system response is functional and unique. Optimal stiffness and damping parameters for the primary suspension are extracted from a recently established work for passive linear vibration systems. For each point of the primary suspension optimal curve, jump-free zones are identified. Iterating this process, a boundary surface between no-jump (unique response) and jump (multiple-response) areas is established. Keeping optimal parameters for the primary suspension system fixed, the secondary suspension stiffness and damping parameters are varied inside the no-jump zones to explore optimum solutions for the secondary.The root mean square (RMS) of the absolute acceleration is minimized against the RMS of the relative displacement (η). It is observed that there is a certain band of parameters defined by primary damping, within which a valid frequency response can be obtained. An optimum numerical solution is sought within this band of parameters. Optimal solution curves are achieved for the secondary suspension. These can be used in conjunction with the optimal curve for the primary suspension to select design parameter values for the best possible vibration isolation performance in a given application.     

自适应悬架对车辆性能改进的潜力

研究主动悬架自适应于路面输入和车辆参数变化,从而进一步改进车辆性能的潜力,以及车辆参数变化对车辆系统输出的影响,仿真结果表明了在主动悬架的最优控制设计中,其控制律参数自适应于路面输入的有效性,以及控制器设计中车辆参数估计的必要性。