Experimental Investigation and Semi-Active Control Design of A Magnetorheological Engine Mount

In this paper;the dynamic characteristics of a semi-active magnetorheological fluid(MRF)engine mount are studied.To do so,the performance of the MRF engine mount is experimentally examined in higher frequencies(50~170 Hz)and the various amplitudes(0.01~0.2 mm).In such an examination,an MRF engine mount along with its magnetically biased is fabricated and successfully measured.In addition,the natural frequencies of the system are obtained by standard hammer modal test.For modelling the behavior of the system,a mass-spring-damper model with tuned PID coefficients based on Pessen integral of absolute error method is used.The parameters of such a model including mass,damping ratio,and stiffness are identified with the help of experimental modal tests and the recursive least square method(RLS).It is shown that using PID controller leads to reducing the vibration transmissibility in the resonance frequency(=93.45 Hz)with respect to the typical passive engine mount by a factor of 58%.The average of the vibration transmissibility decreasing is also 43%within frequency bandwidth(50~170 Hz).

Performance analysis of semi-active cab’s hydraulic system of the vibratory roller using optimal fuzzy-PID control

In order to evaluate the performance of semi-active cab’s hydraulic mounts(SHM)of the off-road vibratory roller with the optimal fuzzy-PID(proportional integral derivative)control,a nonlinear dynamic model of the vehicle interacting with off-road terrains is established based on Matlab/Simulink software.The weighted root-mean-square(RMS)acceleration responses of the driver’s seat heave and the cab’s pitch angle are chosen as objective functions.The SHM is then optimized and analyzed via the optimal fuzzy-PID control under different operation conditions.The simulations results show that the driver’s ride comfort and the cab shaking are greatly affected by the off-road terrains under various operating conditions of the vehicle,especially at the speed from 8 to 12 km/h on a very poor terrain surface of Grenville soil ground under the vehicle travelling.With SHM using the optimal fuzzy-PID control,the driver’s ride comfort and the cab shaking are clearly improved under various operation conditions of the vehicle,particularly at the speed from 6 to 7 km/h of the vehicle traveling.

Ride quality evaluation of the soil compactor cab supplemented by auxiliary hydraulic mounts via simulation and experiment

In order to evaluate the ride quality of the soil compactor cab supplemented by the auxiliary hydraulic mounts (AHM), a nonlinear dynamic model of the soil compactor interacting with the off-road deformable terrain is established based on Matlab/Simulink sofware. The power spectral density (PSD) and the weighted root mean square (RMS) of acceleration responses of the vertical driver s seat, the cab s pitch and roll angle are chosen as objective functions in low-frequency range. Experimental investigation is also used to verify the accuracy of the model. The influence of the damping coefficients of the AHM on the cab s ride quality is analyzed, and damping coefficients are then optimized via a genetic algorithm program. The research results show that the cab s rubber mounts added by the AHM clearly improve the ride quality under various operating conditions. Particularly, with the optimal damping coefficients of the front-end mounts c a 1,2 = 1 500 N · s/m and of the rear-end mounts c a 3,4 =2 335 N · s/m, the weighted RMS values of the driver s seat, the cab s pitch and roll angle are reduced by 22.2%, 18.8%, 58.7%, respectively. Under the condition of the vehicle travelling, with the optimal damping coefficients of c a 1,2 = 1 500 N · s/m and c a 3,4 =1 882 N · s/m, the maximum PSD values of the driver s seat, the cab s pitch and roll angle are clearly decreased by 36.7%, 54.7% and 50.6% under the condition of the vehicle working.

驾驶室半主动悬置模糊PID控制策略研究

为了研究商用车驾驶室阻尼可调式半主动悬置对汽车乘坐舒适性的影响,在TruckSim中建立了整车模型与左右轮迹不平度模型,在MATLAB/Simulink中搭建了比例-积分-微分(PID)和模糊PID控制器模型,并且根据相关文献中的连续阻尼可调(CDC)减振器外特性试验结果建立了执行器模型,通过TruckSim和Simulink联合仿真的方式进行了研究。以商用车驾驶室垂向、俯仰和侧倾加速度的均方根值之和作为驾驶室的振动评价指标,对比了50 km/h和90 km/h车速下采用被动悬置和半主动悬置的驾驶室振动情况。仿真结果表明,相较于被动悬置,基于PID与模糊PID的半主动悬置均能够明显改善商用车驾驶室的平顺性,两种控制策略控制效果非常接近,在两种工况下使驾驶室整体振动情况改善约13.28%和14.02%。

Principle and Control of Active Engine Mount Based on Magnetostrictive Actuator

Engine mount system affects the automobile NVH performance.Active mounts would achieve excellent vibration isolation and relative displacement control performance in a broad frequency bandwidth by outputting controlled force to the mounting system.The actuator and control method of the active mounts determine the system performance.In this paper,an active mount based on the smart material,i.e.,Terfenol-D rod,is proposed,which mainly includes three parts:rubber spring,magnetostrictive actuator(MA),and hydraulic amplification mechanism(HAM).Dynamic model of the active mount is correspondingly established.A state feedback control method based on x-LMS(Least-Mean-Square)algorithm is proposed as well.Specifically,with the consideration of the unmeasurable state parameters in the active mounting system,an x-LMS state feedback controller with the system state as the reference signal is constructed by employing Sage-Husa Kalman filter to realize the state estimation of the active mounting system.Then a detailed analysis of the proposed control method is conducted,with deriving iterative formula of tap-weight vector.Sequentially,the problem of the dependence on the excitation signal in the x-LMS algorithm is addressed.The feasibility and capability of the proposed control method are verified and evaluated by simulation of a two-degree-offreedom active mounting system.

拖拉机驾驶室悬置系统振动特性分析

建立了拖拉机驾驶室悬置系统的动力学模型,通过模态分析得到驾驶室悬置系统模态频率和模态振型,发动机怠速激励频率与悬置系统最高模态频率比值达到2.3,满足隔离发动机振动的要求。完成了拖拉机在原地怠速、田间耕作、土路转场三个典型工况下驾驶室悬置系统振动测试。通过计算隔振率发现,悬置系统对发动机激励衰减效果较好,对路面不平引起的低频振动衰减效果较差。本文通过模态分析和典型工况下的隔振率分析,为驾驶室悬置系统的分析和优化提供了方向。

商用车驾驶室悬置隔振仿真研究

采用多刚体系统动力学理论研究商用车驾驶室悬置隔振系统的平顺性问题,提出了基于多刚体动力学的现代虚拟样机技术进行驾驶室悬置隔振系统设计和计算分析方法,运用ADAMS软件建立了整车系统的参数化振动模型,结合实际参数对典型货车进行了随机振动分析,以驾驶室座椅处加速度均方根值为评价对象对原车驾驶室悬置系统和底盘主悬架系统进行了参数匹配和改进设计,解决了原车隔振效果差的问题。

商用车驾驶室悬置仿真与隔振性能优化

针对某款商用车驾驶室悬置的开发,采用ADAMS/View软件建立其标杆车的全浮式空气弹簧悬置模型。研制了动力学等效驾驶室并进行了台架振动测试,验证了模型的正确性。在此基础上,建立了该商用车开发车型的悬置动力学模型,对其进行模态分析。以隔振性能为优化目标,采用广义简约梯度法对开发车型空气弹簧的参数进行了优化。结果表明:优化后的主驾驶座椅垂向加速度功率谱密度下降了27.6%,改善了驾驶室的隔振性能。

驾驶室悬置系统的振动传递率匹配研究

针对某型装载机在发动机怠速及较低转速时驾驶室振动剧烈这一问题,分析其发动机至驾驶室振动传递路径,初步判断驾驶室悬置系统是影响驾驶室舒适性的可能因素。对其驾驶室悬置隔振性能进行测试,结果显示悬置传递率较低,尤其是前悬置,没有起到隔振的作用。在ADAMS/View中建立了该驾驶室悬置系统的多体动力学模型,并对悬置刚度进行了灵敏度分析,再根据灵敏度分析结果,对前悬置刚度进行了重新匹配设计,并对改进效果进行了仿真验证。最后,对改进后的悬置系统进行了实车测试,验证了改进的有效性。

重卡驾驶室半主动悬置控制方法

为了抑制在路面激励下某型重卡驾驶室的振动加速度响应,研究基于磁流变阻尼器驾驶室半主动悬置系统的控制方法。建立了重卡驾驶室半主动悬置集中质量动力学模型,分别采用比例积分微分(proportion integration differentiation,简称PID)控制理论和模糊最优控制理论设计控制器,并利用磁流变阻尼器动力特性实验数据对模糊最优控制器的参数进行优化。以驾驶室质心垂直、侧倾及俯仰3个方向加速度为控制目标,利用ADAMS/Simulink联合仿真方法,对比分析PID控制和模糊最优两种控制策略与被动状态下重卡驾驶室悬置振动控制效果。针对实际重卡进行不同速度路面激励下的振动控制实验。仿真和实验结果表明,采用PID和模糊最优控制方法均能有效抑制重卡驾驶室半主动悬置的振动加速度响应,其中模糊最优控制效果总体优于PID控制。

基于液固耦合有限元分析的驾驶室液压悬置结构参数

通过材料试验确定了所研究驾驶室液压悬置橡胶材料的本构模型。分别建立了液压悬置的固体模型和液体模型,将其导入有限元分析软件中建立了液固耦合模型。利用准静态分析方法计算了液压悬置的静刚度,并与试验数据进行了比较。在动刚度分析中,液体流动参数采用K-Epsilon RNG紊流模型,计算了液压悬置的动刚度和相位角,并与试验数据比较。经过试验验证,表明所建立的驾驶室悬置液固耦合有限元模型是正确的。利用所建立的有限元模型分析了悬置主要结构参数对其动特性的影响。

基于试验验证的商用车驾驶室悬置参数优化研究

针对目前中国商用车驾驶室舒适性问题,以整车刚柔耦合多体动力学理论基础,采用ADAMS软件建立某典型商用车驾驶室及其悬置系统动力学模型,并对该模型进行了准确性验证。设计了DOE优化试验,经过仿真分析,对驾驶室悬置的刚度和阻尼进行优化,并对试验车辆按照优化参数进行改进。最后,通过道路试验表明,优化后的商用车行驶平顺性较优化前提升了9.6%,改善了驾驶室的隔振性能。

轻型卡车驾驶室悬置系统优化匹配设计

为了解决某轻型卡车驾驶室在62 km/h左右时存在比较严重的振动,对乘坐舒适性影响较大的问题,对该车型驾驶室悬置进行了匹配优化.采用频响函数方法,利用LMS Test-Lab测试系统对驾驶室质心、转动惯量等惯性参数进行了识别,并用称重法对所获得的质心数据进行了验证.在所获惯性参数基础上,采用遗传算法,在Matlab软件中编写优化程序,对驾驶室悬置3向刚度进行了优化.试制样件并装车进行了路试.实验结果表明:悬置系统优化后的驾驶室在该速度下振动加速度幅值被消减了32%,振动情况得到了明显改善.

基于响应面法的驾驶室悬置系统平顺性优化

针对某厂商自主研制的自卸车存在乘坐舒适性较差的问题,采用试验设计技术与响应面法相结合的方法对其驾驶室悬置系统参数进行优化。首先,在有限元软件HyperWorks中对驾驶室进行模态分析,采用ADAMS软件建立驾驶室悬置系统的刚柔耦合多体动力学模型;接着,对实车工地路试采集的振动数据进行分析;最后,以驾驶室悬置系统的弹簧刚度和减振阻尼为试验因子,以驾驶室座椅地板处的振动加速度的最大幅值的最小化为优化目标,运用响应面法对悬置系统的参数进行优化。结果表明,优化后驾驶室的振动明显减弱,提高了车辆的乘坐舒适性。

重型车驾驶室翻转液压缸最优安装位置研究

重型车驾驶室翻转主要是通过液压泵驱动布置在驾驶室前部下方的液压缸来实现,液压缸的安装位置对驾驶室翻转的轻便性、可靠性影响较大。文章通过理论推导,找到了液压缸下支点的最佳安装位置的确定方法,求得最大工作力臂;通过实例并运用CAE软件ABAQUS,对液压缸安装位置优化前后的底板纵梁进行有限元分析。结果表明,优化后的安装位置改善了底板纵梁处的应力状况,对重型车驾驶室翻转液压缸最优安装位置的研究方法是正确有效的。

悬置支架结构的有限元分析与拓扑优化设计

卡车驾驶室悬置支架是重要的连接构件之一,为了在产品设计阶段寻求最佳设计方案,利用通用有限元分析和优化软件Hyperworks7.0,以柔度为目标,以体积作为约束条件,结合零件的结构、约束、受力等特点,对驾驶室悬置支架进行了有限元分析和结构拓扑优化,并在优化基础上进行了二次设计.与传统设计支架相比,优化设计支架最大应力减小50.6%,质量减少14.6%.基于有限元法的结构分析和拓扑优化,能在产品开发阶段主动寻求最优方案,对提高产品质量、缩短设计周期有重要作用.

半挂牵引车驾驶室悬置隔振仿真研究

介绍了全浮式驾驶室半挂列车的悬置隔振的仿真研究。在ADAMS中建立了基于整车的驾驶室悬置系统的多刚体动力学模型,并进行了仿真分析。

商用车驾驶室柔性限位结构的仿真分析

分析了商用车全浮式驾驶室悬置柔性限位结构的原理,利用现代多刚体动力学仿真系统建立了基于整车的柔性限位模型,并进行了仿真计算,分析了特定结构下的限位能力和冲击加速度,为我国驾驶室悬置系统的设计开发人员提供了良好参考。

重型货车全浮式驾驶室悬置的建模分析及改进

针对重型货车全浮式驾驶室在路况较差时振动剧烈的情况,利用UG软件对全浮式驾驶室悬置进行建模,将模型导入ADAMS中作仿真分析,找出问题所在。在此基础上根据生产厂家实际情况选择半浮式驾驶室悬置为改进方案,进行建模、运动仿真分析,主要比较全浮式、半浮式驾驶室悬置的仿真输出曲线。仿真结果表明,改进方案满足了厂家要求。

驾驶室悬置结构对载货汽车平顺性的影响

为了提高重型载货汽车的平顺性,对其驾驶室悬置结构进行优化设计。选取具有不同驾驶室悬置结构形式的重型载货汽车为研究对象,进行整车随机输入平顺性试验及悬置隔振率试验,采用总加权加速度均方根值及振动传递率评价驾驶室悬置的优劣。试验研究表明:在不改变其他参数情况下,改变驾驶室悬置结构能有效提高其平顺性;在结构空间允许的条件下,增加横向减振器是提高车辆平顺性最有效的方法。