Semi-active engine mount design using auxiliary magneto-rheological fluid compliance chamber

Engine mounts are used in the automotive industry to isolate engine and chassis by reducing the noise and vibration imposed from one to the other. This paper describes modelling, simulation and design of a semi-active engine mount that is designed specifically to address the complicated vibration pattern of variable displacement engines (VDE). The ideal isolation for VDE requires the stiffness to be switchable upon cylinder activation/deactivation operating modes. In order to have a modular design, the same hydraulic engine mount components are maintained and a novel auxiliary magneto-rheological (MR) fluid chamber is developed and retrofitted inside the pumping chamber. The new compliance chamber is a controllable pressure regulator, which can effectively alter the dynamic performance of the mount. Switching between different modes happens by turning the electrical current to the MR chamber magnetic coil on and off. A model has been developed for the passive hydraulic mount and then it is extended to include the MR auxiliary chamber as well. A proof-of-concept prototype of the design has been fabricated which validates the mathematical model. The results demonstrate unique capability of the developed semi-active mount to be used for VDE application.     

基于磁处理法的隧道永磁体排水管防结晶试验

为预防隧道排水管结晶堵塞，提出永磁体排水管关键技术指标，通过自制的永磁体排水管开展室内试验和现场试验，研究磁场强度、流量、磁体布置间距对永磁体排水管内结晶的影响，根据不同条件下结晶物的质量变化和SEM图像进行试验分析。结果表明： 1）磁场强度为0.1~0.3 T时永磁体排水管具有较好的防结晶效果，磁场强度超过0.2 T后防结晶效果逐渐降低，当磁场强度为0.4 T时永磁体排水管内结晶量反而大于普通排水管； 2）随着试验管段内溶液流量增大，永磁体排水管的防结晶效果增强，但当流量超过450 mL/s之后，防结晶效果不再随流量增大而增强； 3）经永磁体处理后，管道内的结晶物由规则的立方体形状转变为粗糙松散的不规则体，由硬质块状转变为粉末状，有从方解石向文石、球霞石转化的趋势； 4）随着管道永磁体布置间距减小，管道内最终结晶量呈下降趋势，在10、40、70 cm 3种永磁体布置间距中，最佳布置间距为40 cm。     

Fault detection and isolation for a nonlinear railway vehicle suspension with a Hybrid Extended Kalman filter

Fault detection is considered to be one way to improve system reliability and dependability for railway vehicles. The secondary lateral and anti-yaw dampers are the most critical parts in railway suspension systems. So far, the dampers have been modelled as linear components in the fault detection and isolation observer design. In this work, a Hybrid Extended Kalman filter is used to capture the nonlinear characteristics of the dampers. In order to detect and isolate faults, a nonlinear residual generator is developed, which can distinguish clearly between different types of faults. A lateral half train model serves as an example for the proposed technique. The results show that failures in the nonlinear suspension system can be detected and isolated accurately.     

磁流变阻尼器动力学特性研究

从材料流变特性和动力学、机械学、电磁学的角度出发，建立了磁流阻尼器的动力学模型。应用该模型可由磁流变阻尼器设计参数得到其动力学特性，如力—速度曲线，并与试验结果相吻合，为磁流阻尼器设计和性能预测提供了参考。     

Passive Repulsive MagLev: Concept and Experimental Demonstration

A simple demonstrator for a magnetic levitation vehicle (MagLev) based on repulsive suspension forces generated by permanent magnets is presented. The lateral and yaw motions are stabilized using controlled electromagnets. A mathematical model, aimed mainly at defining the control strategy, has been developed and then experimentally validated using the demonstrator. Two different control strategies have been tested, namely a zero position error and a zero average current control strategy. Both proved to grant a stable behaviour and to effectively counteract external force disturbances. This demonstrator will be used in future research on MagLev vehicles but also on magnetic suspensions in general.     

Passive Repulsive MagLev: Concept and Experimental Demonstration

A simple demonstrator for a magnetic levitation vehicle (MagLev) based on repulsive suspension forces generated by permanent magnets is presented. The lateral and yaw motions are stabilized using controlled electromagnets. A mathematical model, aimed mainly at defining the control strategy, has been developed and then experimentally validated using the demonstrator. Two different control strategies have been tested, namely a zero position error and a zero average current control strategy. Both proved to grant a stable behaviour and to effectively counteract external force disturbances. This demonstrator will be used in future research on MagLev vehicles but also on magnetic suspensions in general.     

斜拉桥拉索磁流变阻尼器减振技术研究

采用数值仿真和现场试验对磁流变阻尼器的减振性能进行了研究。数值仿真计算评估了磁流变阻尼器安装高度、外部激励、阻尼器输入电压等参数对拉索系统模态阻尼比的影响 ,结果表明磁流变阻尼器具有良好的阻尼可调特性 ,调节阻尼器的输入电压可以获得拉索系统的最佳模态阻尼比 ;现场试验表明 ,安装该阻尼器后 ,拉索系统的模态阻尼比提高 3～ 6倍 ,并存在一优化电压 ,在该电压下模态阻尼比达到最大 ;实际风雨振时的现场观测结果显示 ,磁流变阻尼器具有很好的减振效果 ;拉索磁流变阻尼器减振技术已在岳阳洞庭湖大桥全桥实施 ,解决了该桥的风雨振问题     

Adaptive Suspension Concepts for Road Vehicles

Most vehicle suspensions are composed of passive spring and damper devices, although improved suspension performance is possible if an active system is used to control forces or relative velocities. The complexity, power requirements, and cost of fully active suspensions have restricted their use. Various partially active suspensions have been proposed and suspensions with slow load levelers and variable dampers are in widespread use. Here we analyze a class of basically passive suspensions the parameters of which can be varied actively in response to various measured signals on the vehicle. These suspensions can come close to optimal performance with simpler means than many of the active or semi-active schemes previously proposed.     

Adaptive Suspension Concepts for Road Vehicles

SUMMARY

Most vehicle suspensions are composed of passive spring and damper devices, although improved suspension performance is possible if an active system is used to control forces or relative velocities. The complexity, power requirements, and cost of fully active suspensions have restricted their use. Various partially active suspensions have been proposed and suspensions with slow load levelers and variable dampers are in widespread use. Here we analyze a class of basically passive suspensions the parameters of which can be varied actively in response to various measured signals on the vehicle. These suspensions can come close to optimal performance with simpler means than many of the active or semi-active schemes previously proposed.     

磁动力在新能源汽车上的应用

电磁汽车发动机是一款,利用永磁铁和电磁铁同磁极之间,相互排斥的原理,设计出来的一款全新理念的汽车发动机。     

洞庭湖大桥拉索风雨振控制新技术

随着大跨径斜拉桥的不断建设，斜拉索的减振特别是风雨振的控制已成为该类桥梁急需解决的关键问题之一。岳阳洞庭湖大桥建成通车后已发生多次强烈风雨振，在对应用磁流变智能阻尼减振技术控制风雨振研究的基础上，全面评估了该技术控制拉索振动的实际效果，证明该阻尼器是拉索风雨振控制的有效手段。岳阳洞庭湖大桥全桥安装磁流变阴尼器后，加速度响应降低为原加速度的1/20-1/30。     

大跨连续刚构桥箱梁抗震分析与减震措施研究

高烈度地震区大跨连续刚构桥箱梁在地震作用下会发生弯曲变形,产生较大弯矩和剪力,对箱梁抗裂及承载能力产生不利影响。为减小连续刚构桥箱梁在地震作用下的内力,以(90+190+228+123+60)m刚构+连续梁协作体系桥为例,采用有限元软件Midas Civil建模,对主墩墩型和支座类型的影响进行抗震分析并提出减震措施。研究结果表明:①主墩采用双薄壁墩比独柱式空心薄壁墩对箱梁抗震有利;②在辅助墩、交界墩或桥台处设置高阻尼隔震橡胶支座,可以减小箱梁和主墩受力;③在主桥梁端纵桥向设置粘滞阻尼器可以显著降低箱梁和主墩的弯矩;④组合使用高阻尼隔震橡胶支座+粘滞阻尼器减震措施,可以在不中断交通的情况下显著提升连续刚构桥的抗震性能。     

Vehicle Dynamic Analysis and Evaluation of Continuously Controlled Semi-Active Suspensions Using Hardware-in-the-loop Simulation

A semi-active suspension system with continuously variable damper is greatly expected to be used mainly in the future as a high-performance suspension system due to its cost-effectiveness, light weight, and low energy consumption. In this paper, to develop a suitable control logic for the semi-active suspension system, the hardware-in-the-loop simulation is performed for the experimental continuously variable damper combined with a quarter-car model, and the simulation results are compared for passive, on/off controlled, and continuously controlled dampers in the aspects of ride comfort and driving safety, assuming each damper to be installed on the vehicle.     

简支箱梁桥地震反应半主动控制分析

为提高某简支梁桥的抗震能力,采取适当的减震控制措施能够有效地减小桥梁的地震反应。建立了某简支箱梁桥的有限元模型,将板式橡胶支座与磁流变阻尼器组合使用,在桥梁的支座和伸缩缝处共设置8组磁流变阻尼器,分析了不同地震动输入下的简支箱梁桥主动控制、半主动控制和被动控制的减震效果。结果表明,半主动控制对简支梁桥的减震效果非常显著,并且能够很好地接近主动控制的减震效果。半主动控制对于桥梁整体地震反应的减震效果优于始终提供最大阻尼力的被动控制。这为半主动控制阻尼器在简支梁桥抗震中的实际应用提供了理论上的指导。     

Design of electromagnetic shock absorbers for automotive suspensions

Electromechanical dampers seem to be a valid alternative to conventional shock absorbers for automotive suspensions. They are based on linear or rotative electric motors. If they are of the DC-brushless type, the shock absorber can be devised by shunting its electric terminals with a resistive load. The damping force can be modified by acting on the added resistance. To supply the required damping force without exceeding in size and weight, a mechanical or hydraulic system that amplifies the speed is required. This paper illustrates the modelling and design of such electromechanical shock absorbers. This paper is devoted to describe an integrated design procedure of the electrical and mechanical parameters with the objective of optimising the device performance. The application to a C class front suspension car has shown promising results in terms of size, weight and performance.     

粘滞阻尼器在斜拉桥减震设计中的应用

介绍了斜拉桥减震设计的思想以及粘滞阻尼器在斜拉桥减震设计中的应用,并以一座斜拉桥为例,在相同的地震波作用下,对飘浮体系、弹性约束体系和加粘滞阻尼器的半漂浮体系分别进行时程分析,比较了3种体系梁端及桥塔的水平位移、水平惯性力和桥塔的受力情况。研究表明:粘滞阻尼器能够改善斜拉桥的动力特性,不仅使得结构的位移和受力都是最小,而且提高了斜拉桥的抗震能力和耐久性,这种体系最能符合斜拉桥的减震设计思想。     

CAMRY与PRIUS永磁同步电动机比较

首先分析CAMRY与PRIUS的动力系统,接着对两车电动机的转子结构、空载磁场、钕铁硼磁钢和效率图进行比较,最后给出CAMRY和PRIUS永磁同步电动机主要参数的计算结果,并做对比分析。     

Non-linear modelling and control of semi-active suspensions with variable damping

Electro-hydraulic dampers can provide variable damping force that is modulated by varying the command current; furthermore, they offer advantages such as lower power, rapid response, lower cost, and simple hardware. However, accurate characterisation of non-linear f–v properties in pre-yield and force saturation in post-yield is still required. Meanwhile, traditional linear or quarter vehicle models contain various non-linearities. The development of a multi-body dynamics model is very complex, and therefore, SIMPACK was used with suitable improvements for model development and numerical simulations. A semi-active suspension was built based on a belief–desire–intention (BDI)-agent model framework. Vehicle handling dynamics were analysed, and a co-simulation analysis was conducted in SIMPACK and MATLAB to evaluate the BDI-agent controller. The design effectively improved ride comfort, handling stability, and driving safety. A rapid control prototype was built based on dSPACE to conduct a real vehicle test. The test and simulation results were consistent, which verified the simulation.     

Shape design optimization of interior permanent magnet motor for vibration mitigation using level set method

This paper presents a new optimization method to obtain the structural design of permanent magnet motor which can reduce the mechanical vibration. The optimization problem is formulated to minimize a multi-objective function including the mean compliance of the whole stator for maximizing the stiffness under the magnetic force and the torque ripple by aligning torque profiles to a constant target value for maximizing the magnetic performance, with constraint for material usage. The level set function is introduced for representing the structural boundaries and calculating the material properties. A coupled magneto-mechanical analysis is performed to verify the vibration characteristic of the motor system and obtain the design sensitivities. To confirm the usefulness of the proposed design method and to obtain the optimum structural design for low vibration motor, a design example of 20 kW interior permanent magnet motor developed for the power train of a hybrid electric vehicle is provided.     

汽车磁流变减振器设计中值得注意的若干技术问题

汽车磁流变减振器利用磁流变液的流变特性可受外加磁场控制的特性，实现减振器的阻尼系数的可控，从而实现阻尼力的控制，基于磁流变换的磁流变减振器的特性是由多种因素所决定的，如磁流变液、工作模式、磁路结构、导磁材料、线圈和机械结构等。对磁流变液的性能、阻尼通道的设计、磁路中磁芯材料的选用以及磁流变减振器的体积补偿等在磁流变减振器设计中值得注意的一些问题进行了探讨。