基于磁流变减振器不确定半车悬架模型的半主动鲁棒控制研究

在分析半车悬架结构不确定性的基础上,建立了磁流变减振器半主动控制的半车模型,设计了鲁棒控制框图和鲁棒控制器.为了提高运行速度和便于工程实现,对所设计的高阶控制器进行了降阶处理,并进行了被动悬架、标准鲁棒控制半主动悬架和降阶控制器半主动悬架的频域分析.结合鲁棒控制器和半主动控制策略,在Simulink环境下构建了完成了被动悬架和降阶鲁棒控制器组成的半主动悬架时域仿真模型,对车辆在不同等级路面、不同行驶速度情况下的舒适性进行了全面的仿真研究和分析.仿真证明,所设计的鲁棒控制器和处理方法满足工程需要,相对于被动悬架车辆簧载质量垂向振动均方根值降低了14.1%以上,俯仰角架速度均方根值降低了31%以上,控制效果良好,乘坐舒适性得到提高.     

Robust control of nonlinear integrated ride and handling model using magnetorheological damper and differential braking system

The interaction of the ride and handling systems is one of the challenging topics in vehicle dynamics and control. In this study the dynamic behavior of a passenger car considering coupling among all the fourteen degrees of freedom is modeled using Boltzmann Hamel equations. In order to improve the ride quality and stability of the vehicle, a Magnetorheological damper and a differential braking system are used as control devices. Based on the nonlinear integrated ride and handling vehicle model, a nonlinear H-infinity controller is designed for an intermediate passenger car. The dynamic behavior of the controlled vehicle is simulated for single lane change and bump input, considering three different road conditions: Dry, rainy and snowy. The robustness of the designed controller is investigated when the vehicle is under these road conditions. The simulation results confirm the interactive nature of the ride and handling systems and the robustness of the designed control strategy.     

磁流变减振器原理

这里分析了一种磁流变减振器的原理,用粘度模型描述了磁流变液随外加磁场变化的流变特性,得到的阻尼力方程为这种减振器的设计提供了理论基础。研究结果表明:随着外加磁场的增加,磁流变液的表观粘度增加,减振器产生的阻尼力增大。     

采用磁流变阻尼器的人体座椅悬架系统模糊ANFIS-PID复合控制技术研究

对座椅悬架用单出杆式磁流变阻尼器进行阻尼特性试验,并借助MATLAB多项式拟合工具箱对改进多项式模型中未知参数进行辨识。分析人体振动特性,建立五自由度人体座椅悬架模型。综合模糊控制器与自适应模糊神经推理系统(Adaptive Neuro-Fuzzy Inference System,ANFIS)整定PID控制器的优点,提出一种模糊ANFIS-PID复合控制策略。采用正弦信号作为外界激励,分别对被动悬架、传统模糊控制、ANFIS-PID控制及模糊ANFIS-PID复合控制人体座椅悬架系统进行仿真分析。结果表明,辨识得出的参数和建立的改进多项式模型均可满足后续仿真要求;采用模糊ANFIS-PID复合控制策略的隔振效果明显优于传统模糊控制及ANFIS-PID控制,能有效改善人体座椅悬架系统的行驶平顺性及驾乘人员乘坐舒适性。     

馈能型磁流变减振器的设计与仿真研究

针对磁流变减振器需要外部供电限制其应用范围的问题,基于磁流变减振器的工作特点和振动能收集方法的探讨,提出了一种馈能型(自主供电)磁流变减振器。根据该馈能型磁流变减振器的功能模块分析,研究了集成馈能装置的磁流变减振器的设计方法并确定了其结构参数,并设计了与馈能装置相匹配的电能管理电路。特别地,在频率1 Hz~3 Hz、振幅10 mm振动条件下,利用有限元软件Ansoft对馈能装置进行了输出电能仿真,然后进一步仿真分析了其输出电能使磁流变减振器产生阻尼力的大小。仿真结果表明,该馈能型磁流变减振器产生阻尼力变化范围为1 072 N~2 028 N,说明在低频、小振幅振动条件下,该馈能型磁流变减振器可以在无需外部供电的情况下改变自身阻尼特性。     

轴向绕组磁路结构磁流变液阻尼器设计

给出轴向绕组磁路结构磁流变阻尼器的设计方法,通过判定线圈横截面积与线圈槽横截面积相等,将阻尼器结构设计与磁路设计联系起来,设计出结构合理紧凑的阻尼器。然后采用ANSYS软件对磁路结构进行电磁场有限元分析,分析表明阻尼器结构设计满足要求,轴向绕组磁路结构改善了阻尼间隙通道磁场分布。     

一种磁流变阻尼器的分数阶微分模型

对磁流变阻尼器系统建立分数阶微分方程表征其非线性特征,将系统输出位移信号拟合磁流变阻尼器系统分数阶微分方程,以4个参数拟合这一黏弹性系统,其拟合精度明显高于整数阶微分方程.实验和分析表明,微分方程的阶数与磁流变阻尼器加载的电流有关,加电流时分数阶项阶数较不加电流时明显升高;加电流后分数阶项的阶数随电流强度的增加而增大;同时电流强度越大,系统惯性力的影响越小,黏、弹性力的影响程度也发生变化,控制电流强度越大,黏性力的影响越占优势;当磁流变液达到磁饱和时,模型不再随电流强度的变化发生改变.系统的黏弹特性和系统模型参数也受磁流变液性能和工作条件的影响.     

Modeling and testing of a field-controllable magnetorheological fluid damper

In this study, an experimental and a theoretical study were carried out to predict the dynamic performance of a linear magnetorheological (MR) fluid damper. After having designed and fabricated the MR damper, its dynamic testing was performed on a mechanical type shock machine under sinusoidal excitation. A theoretical flow analysis was done based on the Bingham plastic constitutive model to predict the behavior of the prototyped MR damper. The theoretical results were then validated by comparing them against experimental data, and it was shown that the flow model can accurately capture the dynamic force range of the MR damper. In addition to the flow model, a modified parametric algebraic model was proposed to capture the hysteretic behavior of the MR damper. The superiority of the proposed modified model was shown by comparing it with the Alg model as well as with a widely adopted modified Bouc-Wen model through an error analysis. It is observed that although all the three models are comparable at the excitation velocities of 0.05, 0.10, and 0.15 m/s, the mAlg model is remarkably successful at the highest excitation velocity of 0.2 m/s over the other two. The improvements in the predictions were found to be over 50%, relative to unmodified model especially at lower current inputs. Therefore, it was concluded that the present flow model can be successfully adopted to design and predict the dynamic behavior of MR dampers, while the mAlg model can be used to develop more effective control algorithms for such devices.     

Study on damping properties of magnetorheological damper

To research the properties of a new kind of smart controllable MR (magnetorheological) fluid, in this paper, the rheological models are discussed. On the basis of analyzing the structural forms of MR dampers, an improved structure of the MR damper is introduced; the properties of the novel MR damper are then tested. The experimental results reveal that the Herschel-Bulkley model predicts the force-velocity well; the damping properties of the ameliorated structure of the MR damper have improved; when the excitation is a trigonal signal, the MR damper reveals a thinning effect at high velocity; and when the excitation is a sinusoidal signal, the MR damper reveals a nonlinear hysteretic property between the damping force and relative velocity. Finally, the main unsolved problems have been put forward. __________ Translated from Ningxia Engineering Technology, 2005, 24 (4) (in Chinese)     

Vibration control of multi-story building structure by hybrid control using tuned liquid damper and active mass damper

This study proposes a hybrid control methodology that combines tuned liquid damper (TLD) and active mass damper (AMD) to suppress vibrations of multi-story building structure effectively. To this end, a dynamic model that can predict the vibration of multi-story building structure coupled with TLD and AMD is derived using the energy approach. The TLD that is mainly designed to suppress the main natural mode is developed with a multi-degree-of-freedom model to investigate the effect of the TLD on natural modes of structure numerically. The AMD is an active vibration controller that can suppress remaining resonant peaks, including ones resulting from the application of the TLD as well as other higher modes of interest. In this way, the proposed control can utilize the advantages of TLD and AMD simultaneously. We set up an experimental apparatus to verify the performance of the hybrid control methodology. The numerical and experimental results show that the proposed hybrid control method can successfully suppress the vibrations of multi-story building structure. The dynamic model derived in this study can also accurately predict the actual behavior of the system.

     

Research on magnetorheological damper suspension with permanent magnet and magnetic valve based on developed FOA-optimal control algorithm

Due to the fail safe problem, it was difficult for the existing Magnetorheological damper (MD) to be widely applied in automotive suspensions. Therefore, permanent magnets and magnetic valves were introduced to existing MDs so that fail safe problem could be solved by the magnets and damping force could be adjusted easily by the magnetic valve. Thus, a new Magnetorheological damper with permanent magnet and magnetic valve (MDPMMV) was developed and MDPMMV suspension was studied. First of all, mechanical structure of existing magnetorheological damper applied in automobile suspensions was redesigned, comprising a permanent magnet and a magnetic valve. In addition, prediction model of damping force was built based on electromagnetics theory and Bingham model. Experimental research was conducted on the newly designed damper and goodness of fit between experiment results and simulated ones by models was high. On this basis, a quarter suspension model was built. Then, fruit Fly optimization algorithm (FOA)-optimal control algorithm suitable for automobile suspension was designed based on developing normal FOA. Finally, simulation experiments and bench tests with input surface of pulse road and B road were carried out and the results indicated that working performance of MDPMMV suspension based on FOA-optimal control algorithm was good.     

The effect of damper leakage and fire size on the performance of smoke control system in high-rise building

Journal of Mechanical Science and Technology - The major function of smoke control system is to prevent smoke from penetrating to vertical shaft or stairwell by pressurizing vestibule where is...     

剪切阀式磁流变液减振器磁路设计方法

激流变液减振器是新型的智能化减振装置，在汽车、机械以及土木工程减振领域具有广泛的应用前景。设计磁路是设计此类减振器一个关键技术。这里研究了在土木及汽车减振领域最具应用潜力的剪切阀式磁流变液减振器的磁路设计计算方法。发现了磁路最小断面面积是影响磁场强度的的关键因素之一，进而提出了磁路设计中应该注意的几个基本问题。     

非线性系统的模糊建模及仿真

以一个非线性模型为研究对象、通过对自适应神经模糊推理系统（ANFIS）建模机理的研究,建立了非线性实例模糊模型,并且在不同的输入下进行仿真实验,结果表明利用ANFIS进行非线性系统建模和辨识是可行的,其辩识精度很高.     

Parameter identification of the Bouc-Wen model for the magnetorheological damper using fireworks algorithm

Journal of Mechanical Science and Technology - To solve the problems of low identification accuracy and complex identification methods in the Bouc-Wen model of the magnetorheological (MR) damper, a...     

新型磁流变阻尼器设计及磁场有限元分析

磁流变液是一种新型的智能材料,在外加磁场作用下其流变学特性如屈服强度能够在毫秒级时间内发生连续可逆的变化.利用磁流变液的这种特殊性能,针对力觉再现技术的要求,设计了一种新型的磁流变阻尼器结构.详细阐述了该阻尼器的工作原理和力矩模型,并完成了有限元模型的建立.运用磁场有限元分析软件Ansoft对阻尼器进行了磁场强度检验并进行了相应的结构改进.仿真结果表明该阻尼器设计结构合理,为磁流变阻尼器的准确设计提供了保证.     

一类不确定非线性系统的自适应模糊控制

自适应模糊控制理论是模糊控制理论与自适应控制理论相互交叉、相互渗透而形成的一个研究领域.针对一类带有扰动的SISO不确定非线性系统,本文提出了一种综合型自适应模糊控制方案.该方案充分利用了被控对象信息和模糊控制规则,保证了闭环系统的稳定性和跟踪误差的收敛性,仿真结果表明本方法比单纯的直接型或间接型模糊控制方法具有更好的跟踪性能.     

基于递归神经网络的大滞后非线性系统预测控制

针对带有大滞后的非线性系统，提出了在迭代多步预测的基础上，将系统多步预测输出值进行线性化，在多步预测目标函数下实现系统控制的方法。采用适合于动态系统实时控制的扩展Elman网络，利用训练速度快的阻尼最小二乘法学习网络权值。仿真实验表明了该方法的有效性。     

Vibration control of a structure using Magneto-Rheological grease damper

This paper describes an application study of Magneto-Rheological (MR) grease damper to a structure with three stories. MR fluid is known as one of successful smart materials whose rheological properties can be varied by magnetic field strength, and has been applied to various kinds of device such as dampers, clutches, engine mounts, etc. However, ferromagnetic particles dispersed in MR fluid settle out of the suspension after a certain interval due to the density difference between the particles and their career fluid. To overcome this defect, we have developed a new type of controllable working fluid using grease as the career of magnetic particles. Network of thickener in grease is expected to hold the magnetic particles and prevent them from settled down. No or little sedimentation was observed in MR grease whose characteristics could be controlled by the magnetic field strength. MR grease was introduced into a cylindrical damper and its performance was studied. As a result, it was confirmed that the damping force of MR grease damper could be controlled by the applied electric current to the coil in the cylinder of damper. Furthermore, vibration response of a three-story model structure equipped with MR grease damper was investigated experimentally, and it was shown that MR grease damper worked effectively as a semi-active damper.     

带陀螺阻尼器的起重机吊重防摆控制装置研究

由于起重机吊钩缺乏旋转动力装置,在强风作用下会导致其悬挂载荷发生旋转,针对这一问题,提出了一种带陀螺阻尼器的起重机悬挂载荷防摆控制装置.首先,采用由伺服电机驱动的吊钩对悬挂载荷进行旋转定位,采用了单轴机械陀螺的被动控制方式,对悬挂载荷旋转时产生的反作用力矩进行了抑制;然后,从两个方面对该装置进行了优化(在机械陀螺仪的万...