共查询到20条相似文献,搜索用时 15 毫秒
1.
Sung-Ryong Hong Seung-Bok Choi Moon-Shik Han 《International Journal of Mechanical Sciences》2002,44(10):2027-2045
A squeeze-mode electro-rheological (ER) mount has been designed, manufactured, and applied to the vibration control of a frame structure subjected to external excitations. After verifying that the damping force of the ER mount can be controlled by controlling the applied voltage, a frame structure system supported by spring mounts and the proposed ER mounts has been assembled. The governing equation of the structural system is derived in the modal coordinate and is rewritten as a state-space control model. An optimal controller, which consists of the velocity feedback signal of the frame structure and the force feedback signal transmitted from the exciting point to the mount position, is formulated in order to attenuate the imposed excitations. The controller has been optimized experimentally and control responses such as the acceleration of the frame structure and the transmitted force at each mount position are presented in both time and frequency domains. 相似文献
2.
Optimal control of structural vibrations using a mixed-mode magnetorheological fluid mount 总被引:2,自引:0,他引:2
Seung-Bok Choi Sung-Ryong Hong Kum-Gil Sung Jung-Woo Sohn 《International Journal of Mechanical Sciences》2008,50(3):559-568
In this work, a mixed-mode magnetorheological (MR) mount is proposed and applied to the vibration control of a flexible beam structure subjected to external disturbances. On the basis of non-dimensional Bingham number, an appropriate size of the MR mount is designed and manufactured. After experimentally evaluating the field-dependent damping force of the MR mount, a structural system consisting of a flexible beam and vibrating rigid mass is established. The governing equation of motion of the system is derived and expressed as a state space control model. A linear quadratic Gaussian (LQG) controller is then designed in order to attenuate the vibration of the structural system. The controller is empirically realized and control responses such as acceleration and displacement of the structural system are evaluated and presented in frequency domain. 相似文献
3.
This paper presents vibration and noise control of flexible structures using squeeze mode electro-rheological mounts. After
verifying that the damping force of the ER mount can be controlled by the intensity of the electric fild, two different types
of ER squeeze mounts have been devised. Firstly, a small size ER mount to support 3 kg is manufactured and applied to the
frame structure to control the vibration. An optimal controller which consists of the velocity and the transmitted force feedback
signals is designed and implemented to attenuate both the vibration and the transmitted forces. Secondly, a large size of
ER mount to support 200 kg is devised and applied to the shell structure to reduce the radiated noise. Dynamic modeling and
controller design are undertaken in order to evaluate noise control performance as well as isolation performance of the transmitted
force. The radiated noise from the cylindrical shell is calculated by SYSNOISE using forces which are transmitted to the cylindrical
shell through two-stage mounting system. 相似文献
4.
基于磁流变技术的发动机隔振控制 总被引:7,自引:1,他引:6
悬置阻尼和刚度可调对发动机在宽频范围内实现积极隔振具有重要意义.在建立发动机3自由度隔振模型基础上,提出用可调阻尼的磁流变阻尼器和可调刚度的磁流变弹性体构成磁流变并联悬置系统,以降低发动机对基座的垂向传递力和抑制横向动反力矩为目标,设计出用仿人智能思想在线修改参数的垂直隔振模糊自适应控制器,并对各磁流变并联悬置的刚度和阻尼进行协调控制.用Matlab对发动机整机隔振进行仿真,搭建出发动机隔振台架试验系统,在宽频激励条件下对不同悬置的隔振效果进行对比研究.仿真表明基于磁流变并联悬置的发动机隔振控制具有明显的优势,台架试验结果表明相对于橡胶和液压悬置,磁流变液悬置能在较宽频范围把力和力矩的绝对传递率降低到约30%以内,可提高乘坐舒适性. 相似文献
5.
研究了具有可变刚度阻尼的发动机空气弹簧液压悬置的动特性和隔振特性。针对影响发动机空气弹簧液压悬置动特性的关键参数上液室等效体积刚度,采用理论和试验方法研究了上液室等效体积刚度的等效值,基于该等效值建立了空气弹簧液压悬置的理论模型,对空气腔开闭两种工况进行了空气弹簧液压悬置动特性的仿真和试验研究。搭建了发动机空气弹簧液压悬置系统试验台架,研究了台架各种激励频率下的空气弹簧液压悬置的隔振特性。结果表明:本研究采用的上液室等效体积刚度进行空气弹簧进行建模是正确、可行的,提高了空气弹簧建模效率和准确性;空气弹簧液压悬置在空气腔开启和关闭两种状态下,峰值动刚度增大幅值达78.5%,峰值阻尼角增大幅值达250%。台架试验表明:当台架激励频率小于25Hz时,悬置采用大刚度大阻尼;当台架激励频率大于等于25 Hz时,悬置采用小刚度小阻尼;悬置隔振率提升明显,不同频率下提升幅值达10%~67%。 相似文献
6.
Seung-Hwan Kim Seung-Bok Choi Sung-Ryong Hong M.-S.Moon-Sik Han 《International Journal of Mechanical Sciences》2004,46(1):269-157
This paper presents vibration control of a flexible beam structure using a hybrid mount which consists of elastic rubber and piezoelectric stack actuator. After identifying stiffness and damping properties of the rubber and piezoelectric elements, a mechanical model of the hybrid mount is established. The mount model is then incorporated with the beam structure, and the governing equation of motion is obtained in a state space. A sliding mode controller is designed in order to actively attenuate the vibration of the beam structure subjected to high-frequency and small magnitude excitations. The controller is experimentally realized and measured control responses such as acceleration of the beam structure and force transmission through the hybrid mount are evaluated and presented in both frequency and time domains. 相似文献
7.
理想的发动机悬架系统应隔离发动机工作转速范围内由发动机干扰力所引起的发动机振动,并阻止由冲击而激起的发动机弹跳,这意味着发动机悬架的动态刚度和阻尼是与频率和振幅有关的,改善依赖于频率和振幅特性的动态刚度与阻尼是发动机悬架系统发展的关键所在。传统的弹性悬架不能满足所有的要求,它仅能在静偏转和隔振之间进行折衷,特别在低频域,被动的液压悬架能比弹性悬架提供更好的特性,通常半主动技术,由于其可调性而被用来进一步改善液压悬架的特性,为了隔振、低频时主动发动机悬架系统非常硬,而在高频域内被调整的非常软,主动的发动机悬架已被认为是发动机悬架的新一代,发动机悬架系统的优化是相当可取的,但发动机悬架的优化工作出现一些局限性,文中综述国内,外发动机悬架技术的现状与进展。 相似文献
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Electro-rheological (ER) fluids undergo a phase change when subjected to an external electric field, and this phase change typically manifests itself as a many-order-of-magnitude change in the rheological behavior. This phenomenon permits the global stiffness and energy-dissipation properties of the beam structures to be tuned in order to synthesize the desired vibration characteristics. This paper reports on a proof-of-concept experimental investigation focused on evaluating the vibration properties of hollow cantilevered beams filled with an ER fluid and, consequently, deriving an empirical model for predicting field-dependent vibration characteristics. A hydrous-based ER fluid consisting of corn starch and silicone oil is employed. From the observation of modal characteristics, the beams are considered to be uniform viscoelastic materials and are modeled as a viscously-damped harmonic oscillator. Natural frequency, damping ratio and elastic modulus are evaluated with respect to the electric field and compared among three different beams: two types of different volume fraction of ER fluid and one type of different particle concentration of ER fluid by weight. Transient and forced vibration responses are examined in the time domain to demonstrate the validity of the proposed empirical model. 相似文献
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设计了一种基于圆盘挤压模式磁流变悬置,利用试验方法得出了不同激励频率条件下磁流变悬置的循环耗散功与励磁电流的关系.利用磁流变悬置,建立了发动机振动半主动控制的研究模型.提出了一种模糊控制方法,利用转速、加速度和动态拉压力传感器,借助美国国家仪器公司的数据采集和实时控制器,构建了发动机隔振模糊控制试验系统,并开展了怠速和常用工况条件下的发动机振动隔离控制试验研究.研究结果表明,与橡胶悬置相比,基于磁流变悬置的模糊控制系统,能够降低发动机动态激振力传递到支承,并且低转速条件下的振动隔离效果优于高转速条件下的. 相似文献
13.
Useful expressions are developed for the damping coefficient of two types of viscous dampers that contain electrorheological (ER) fluids. The damping action in the first type occurs in flow between stationary parallel plates; the second type has annular flow between two stationary concentric cylinders. For ER fluid control, an electric field is applied across the gap in which the fluid flow occurs. The solution for the concentric cylinder damper is based on a thin gap approximation. These solutions may facilitate solving mechanical systems problems, using ER fluids, and demonstrate the controllability of ER dampers. 相似文献
14.
首先对燃料电池车电机悬置系统进行初步设计,得出各支点的刚度和阻尼参数;然后对燃料电池车电机悬置系统的刚度和阻尼进行优化设计;在优化设计中,通过改变悬置系统的刚度和阻尼,达到了减小电机质心三个自由度上峰值的效果,可以验证优化是有效的,思路方法是合理的。 相似文献
15.
Optimal design of nonlinear hydraulic engine mount 总被引:1,自引:0,他引:1
Young Kong Ahn Jin Dae Song Bo-Suk Yang Kyoung Kwan Ahn Shin Morishita 《Journal of Mechanical Science and Technology》2005,19(3):768-777
This paper shows that the performance of a nonlinear fluid engine mount can be improved by an optimal design process The property
of a hydraulic mount with inertia track and decouplen differs according to the disturbance frequency range. Since the excitation
amplitude is large at low excitation frequency range and is small at high excitation frequency range, mathematical model of
the mount can be divided into two linear models One is a low frequency model and the other is a high frequency model The combination
of the two models is very useful in the analysis of the mount and is used for the first time in the optimization of an engine
mount in this paper Normally, the design of a fluid mount is based on a trial and error approach in industry because there
are many design parameters In this study, a nonlinear mount was optimized to minimize the transmissibilities of the mount
at the notch and the resonance frequencies for low and high-frequency models by a popular optimization technique of sequential
quadratic programming (SQP) supported by MATLAB(r) subroutine. The results show that the performance of the mount can be greatly improved for the low and high frequencies ranges
by the optimization method 相似文献
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T. Ramachandran K. P. Padmanaban 《The International Journal of Advanced Manufacturing Technology》2013,67(1-4):887-898
Though many computationally expensive internal combustion engine vibration models are available, simple and computationally efficient tools are required for preliminary design work. The unbalanced forces of rotating and reciprocating parts are the primary sources for the engine vibrations which in turn reduce the durability and reliability of consumer and commercial automotives. So, a significant vibration isolation is needed for both engine and interface between the engine mounts, and it could be obtained with the help of rotating balancing disks attached at both ends of the crank shaft. The masses of the balancing disks and their lead angles influence the effectiveness of vibration isolation that can be measured by the engine mount displacement caused due to engine vibrations. The optimized masses of balancing disks and their lead angles minimize the engine mount displacements that ensure the effective vibration isolation. In this paper, the genetic algorithm is employed to optimize the masses of the balancing disks and their lead angles with an objective of minimizing the engine mount displacements. 相似文献
19.
Feng Qishan Zhang Jianwu Yin Chengliang School of Mechanical Engineering Shanghai Jiaotong University Shanghai China 《机械工程学报(英文版)》2005,18(4):603-608
A speed control analysis for an in-line gasoline fueled internal combustion (IC) engine is presented for the purpose of alleviation of high frequency oscillations in engine revolutions.A dynamic cylinder-by-cylinder model is proposed,base on slider-crank mechanism,which is extended to develop a digital governor providing a high fidelity estimation of rotary speed oscillation for hybrid vehicle engines.A modified PID controller that P and I gain is placed in feedback path is also described for hybrid electric vehicle (HEV) engine speed regulation.By comparison between measured and estimated signals,it is demonstrated that a good agreement has been achieved and the governor behaves an excellent damping speed ripple. 相似文献
20.
ZHANG Yunxia ZHANG Jianwu SHANGGUAN Wenbin FENG Qishan 《机械工程学报(英文版)》2008,21(3):31-35
To investigate the dynamic characteristics and damping theory of the passive hydraulic engine mount (PHEM), numerical prediction is performed through lumped parameter model. System parameters, including volume compliance of the decoupler chamber, effective piston area, fluid inertia and resistance of inertia track and direct-decoupler, are identified by means of experiments and finite element method (FEM). Dynamic behaviors are tested with elastomer test system for purpose of validating PHEM. With incorporation of inertia track and direct-decoupler, PHEM behaves effective and efficient vibration isolation in range of both low and high frequencies. The comparison of the numerical results with the experimental observations shows that the present PHEM achieves fairly good performance for the engine vibration isolation. 相似文献