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Mechanical systems and signal processing 27건

  1. [해외논문]   Distributed microscopic actuation analysis of paraboloidal membrane shells of different geometric parameters   SCIE

    Yue, Honghao (School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, Heilongjiang Province 150001, PR China ) , Lu, Yifan (School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, Heilongjiang Province 150001, PR China ) , Deng, Zongquan (School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, Heilongjiang Province 150001, PR China ) , Tzou, Hornsen (College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR China)
    Mechanical systems and signal processing v.103 ,pp. 1 - 22 , 2018 , 0888-3270 ,

    초록

    Abstract Paraboloidal membrane shells of revolution are commonly used as key components for advanced aerospace structures and aviation mechanical systems. Due to their high flexibility and low damping property, active vibration control is of significant importance for these in-orbit membrane structures. To explore the dynamic control behavior of space flexible paraboloidal membrane shells, precision distributed actuation and control effectiveness of free-floating paraboloidal membrane shells with piezoelectric actuators are investigated. Governing equations of the shell structronic system are presented first. Then, distributed control forces and control actions are formulated. A transverse mode shape function of the paraboloidal shell based on the membrane approximation theory and specified boundary condition is assumed in the modal control force analysis. The actuator induced modal control forces on the paraboloidal shell are derived. The expressions of microscopic local modal control forces are obtained by shrinking the actuator area into infinitesimal and the four control components are investigated respectively to predict the spatial microscopic actuation behavior. Geometric parameter (height-radius ratio and shell thickness) effects on the modal actuation behavior are explored when evaluating the micro-control efficiency. Four different cases are discussed and the results reveal the fact that shallow (e.g., antennas/reflectors) and deep (e.g., rocket/missile fairing) paraboloidal shells exhibit totally different modal actuation behaviors due to their curvature differences. Analytical results in this paper can serve as guidelines for optimal actuator placement for vibration control of different paraboloidal structures. Highlights Paraboloidal membrane shells of different geometric parameters are investigated and compared. Modal microscopic control effect and the contributing components are explored. Curvature and flexural rigidity effects on modal actuation behavior of the paraboloidal shells are investigated. Analyses provide guidelines for optimal actuator placement on different paraboloidal shells.

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  2. [해외논문]   Optimal control of the gear shifting process for shift smoothness in dual-clutch transmissions   SCIE

    Li, Guoqiang (Corresponding author.) , Gö , rges, Daniel
    Mechanical systems and signal processing v.103 ,pp. 23 - 38 , 2018 , 0888-3270 ,

    초록

    Abstract The control of the transmission system in vehicles is significant for the driving comfort. In order to design a controller for smooth shifting and comfortable driving, a dynamic model of a dual-clutch transmission is presented in this paper. A finite-time linear quadratic regulator is proposed for the optimal control of the two friction clutches in the torque phase for the upshift process. An integral linear quadratic regulator is introduced to regulate the relative speed difference between the engine and the slipping clutch under the optimization of the input torque during the inertia phase. The control objective focuses on smoothing the upshift process so as to improve the driving comfort. Considering the available sensors in vehicles for feedback control, an observer design is presented to track the immeasurable variables. Simulation results show that the jerk can be reduced both in the torque phase and inertia phase, indicating good shift performance. Furthermore, compared with conventional controllers for the upshift process, the proposed control method can reduce shift jerk and improve shift quality. Highlights An optimal control strategy for dual-clutch transmissions is proposed. The torque phase and the inertia phase are covered by the optimal control strategy. The driving comfort is improved by reducing the jerk. A comprehensive simulation study is provided. A comparison with conventional control strategies is given.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  3. [해외논문]   Identification of cutting force coefficients in machining process considering cutter vibration   SCIE

    Yao, Qi (Corresponding author.) , Luo, Ming , Zhang, Dinghua , Wu, Baohai
    Mechanical systems and signal processing v.103 ,pp. 39 - 59 , 2018 , 0888-3270 ,

    초록

    Abstract Among current cutting force models, cutting force coefficients still are the foundation of predicting calculation combined with consideration of geometry engagement variation, equipment characteristics, material properties and so on. Attached with unimpeachable significance, the traditional and some novel identification methods of cutting force coefficient are still faced with trouble, including repeated onerous work, over ideal measuring condition, variation of value due to material divergence, interference from measuring units. To utilize the large amount of data from real manufacturing section, enlarge data sources and enrich cutting data base for former prediction task, a novel identification method is proposed by considering stiffness properties of the cutter-holder-spindle system in this paper. According to previously proposed studies, the direct result of cutter vibration is the form of dynamic undeformed chip thickness. This fluctuation is considered in two stages of this investigation. Firstly, a cutting force model combined with cutter vibration is established in detailed way. Then, on the foundation of modeling, a novel identification method is developed, in which the dynamic undeformed chip thickness could be obtained by using collected data. In a carefully designed experiment procedure, the reliability of model is validated by comparing predicted and measured results. Under different cutting condition and cutter stiffness, data is collected for the justification of identification method. The results showed divergence in calculated coefficients is acceptable confirming the possibility of accomplishing targets by applying this new method. In discussion, the potential directions of improvement are proposed. Highlights Stiffness property of cutter is considered by using a two-degree freedom model. Real-time cutting force coefficients determination using vibrational forces signals. The method proposed is applicable in varied stiffness conditions. Quick output of abundant cutting force coefficients for further analysis.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  4. [해외논문]   Time–frequency analysis based on ensemble local mean decomposition and fast kurtogram for rotating machinery fault diagnosis   SCIE

    Wang, Lei (Corresponding author.) , Liu, Zhiwen , Miao, Qiang , Zhang, Xin
    Mechanical systems and signal processing v.103 ,pp. 60 - 75 , 2018 , 0888-3270 ,

    초록

    Abstract A time–frequency analysis method based on ensemble local mean decomposition (ELMD) and fast kurtogram (FK) is proposed for rotating machinery fault diagnosis. Local mean decomposition (LMD), as an adaptive non-stationary and nonlinear signal processing method, provides the capability to decompose multicomponent modulation signal into a series of demodulated mono-components. However, the occurring mode mixing is a serious drawback. To alleviate this, ELMD based on noise-assisted method was developed. Still, the existing environmental noise in the raw signal remains in corresponding PF with the component of interest. FK has good performance in impulse detection while strong environmental noise exists. But it is susceptible to non-Gaussian noise. The proposed method combines the merits of ELMD and FK to detect the fault for rotating machinery. Primarily, by applying ELMD the raw signal is decomposed into a set of product functions (PFs). Then, the PF which mostly characterizes fault information is selected according to kurtosis index. Finally, the selected PF signal is further filtered by an optimal band-pass filter based on FK to extract impulse signal. Fault identification can be deduced by the appearance of fault characteristic frequencies in the squared envelope spectrum of the filtered signal. The advantages of ELMD over LMD and EEMD are illustrated in the simulation analyses. Furthermore, the efficiency of the proposed method in fault diagnosis for rotating machinery is demonstrated on gearbox case and rolling bearing case analyses. Highlights This paper proposes a novel time–frequency analysis method based on ELMD and FK. The ELMD is used to decompose non-stationary signal and obtain PF components. The FK is used to detect impact components from the sensitive PF component. The proposed method proves to be highly efficient by experiments.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  5. [해외논문]   Amplitude-cyclic frequency decomposition of vibration signals for bearing fault diagnosis based on phase editing   SCIE

    Barbini, L. (The University of Bath Department of Mechanical Engineering, Claverton Down, Bath BA2 7AY, UK ) , Eltabach, M. (Centre Technique des Industries Mécaniques, Félix-Louât, Senlis 60300, France ) , Hillis, A.J. (The University of Bath Department of Mechanical Engineering, Claverton Down, Bath BA2 7AY, UK ) , du Bois, J.L. (The University of Bath Department of Mechanical Engineering, Claverton Down, Bath BA2 7AY, UK)
    Mechanical systems and signal processing v.103 ,pp. 76 - 88 , 2018 , 0888-3270 ,

    초록

    Abstract In rotating machine diagnosis different spectral tools are used to analyse vibration signals. Despite the good diagnostic performance such tools are usually refined, computationally complex to implement and require oversight of an expert user. This paper introduces an intuitive and easy to implement method for vibration analysis: amplitude cyclic frequency decomposition. This method firstly separates vibration signals accordingly to their spectral amplitudes and secondly uses the squared envelope spectrum to reveal the presence of cyclostationarity in each amplitude level. The intuitive idea is that in a rotating machine different components contribute vibrations at different amplitudes, for instance defective bearings contribute a very weak signal in contrast to gears. This paper also introduces a new quantity, the decomposition squared envelope spectrum, which enables separation between the components of a rotating machine. The amplitude cyclic frequency decomposition and the decomposition squared envelope spectrum are tested on real word signals, both at stationary and varying speeds, using data from a wind turbine gearbox and an aircraft engine. In addition a benchmark comparison to the spectral correlation method is presented. Highlights Method for analysis of vibration data. Separation bearing/gear signals. Only one parameter has to be selected by the user and the algorithm is computationally fast. Good candidate for industrial applications. Tested on not trivial experimental data and compared with spectral correlation.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

    이미지

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  6. [해외논문]   A guided wave dispersion compensation method based on compressed sensing   SCIE

    Xu, Cai-bin (School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China ) , Yang, Zhi-bo (School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China ) , Chen, Xue-feng (School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China ) , Tian, Shao-hua (Collaborative Innovation Center of High-end Manufacturing Equipment, Xi'an Jiaotong University, Xi'an 710049, China ) , Xie, Yong (School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, China)
    Mechanical systems and signal processing v.103 ,pp. 89 - 104 , 2018 , 0888-3270 ,

    초록

    Abstract The ultrasonic guided wave has emerged as a promising tool for structural health monitoring (SHM) and nondestructive testing (NDT) due to their capability to propagate over long distances with minimal loss and sensitivity to both surface and subsurface defects. The dispersion effect degrades the temporal and spatial resolution of guided waves. A novel ultrasonic guided wave processing method for both single mode and multi-mode guided waves dispersion compensation is proposed in this work based on compressed sensing, in which a dispersion signal dictionary is built by utilizing the dispersion curves of the guided wave modes in order to sparsely decompose the recorded dispersive guided waves. Dispersion-compensated guided waves are obtained by utilizing a non-dispersion signal dictionary and the results of sparse decomposition. Numerical simulations and experiments are implemented to verify the effectiveness of the developed method for both single mode and multi-mode guided waves. Highlights A guided wave dispersion compensation based on compressed sensing method is proposed. The dispersive signal can be compensated to the waveform of the excitation. Both single mode and multi-mode dispersive guided waves can be compensated.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  7. [해외논문]   Sliding-mode control combined with improved adaptive feedforward for wafer scanner   SCIE

    Li, Xiaojie (Electronic Engineering College, Heilongjiang University, No. 74 Xuefu Road, Nangang District, 150080 Harbin, Heilongjiang, China ) , Wang, Yiguang (Electronic Engineering College, Heilongjiang University, No. 74 Xuefu Road, Nangang District, 150080 Harbin, Heilongjiang, China)
    Mechanical systems and signal processing v.103 ,pp. 105 - 116 , 2018 , 0888-3270 ,

    초록

    Abstract In this paper, a sliding-mode control method combined with improved adaptive feedforward is proposed for wafer scanner to improve the tracking performance of the closed-loop system. Particularly, In addition to the inverse model, the nonlinear force ripple effect which may degrade the tracking accuracy of permanent magnet linear motor (PMLM) is considered in the proposed method. The dominant position periodicity of force ripple is determined by using the Fast Fourier Transform (FFT) analysis for experimental data and the improved feedforward control is achieved by the online recursive least-squares (RLS) estimation of the inverse model and the force ripple. The improved adaptive feedforward is given in a general form of nth-order model with force ripple effect. This proposed method is motivated by the motion controller design of the long-stroke PMLM and short-stroke voice coil motor for wafer scanner. The stability of the closed-loop control system and the convergence of the motion tracking are guaranteed by the proposed sliding-mode feedback and adaptive feedforward methods theoretically. Comparative experiments on a precision linear motion platform can verify the correctness and effectiveness of the proposed method. The experimental results show that comparing to traditional method the proposed one has better performance of rapidity and robustness, especially for high speed motion trajectory. And, the improvements on both tracking accuracy and settling time can be achieved. Highlights The general form of an improved adaptive feedforward is proposed for nth-order systems with force ripple. The dominant frequency components of the force ripple are obtained by experimental analysis based on FFT. A sliding-mode control method combined with the improved adaptive feedforward is established for precision control of wafer scanner. The feasibility and effectiveness of the proposed methods are demonstrated by comparative experiments in real application.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  8. [해외논문]   Measurement of instantaneous rotational speed using double-sine-varying-density fringe pattern   SCIE

    Zhong, Jianfeng (Laboratory of Optics, Terahertz and Non-Destructive Testing, School of Mechanical Engineering and Automation, Fuzhou University, 350108, PR China ) , Zhong, Shuncong (Department of Precision Mechanical Engineering, School of Mechatronic Engineering and Automation, Shanghai University, 200072, PR China ) , Zhang, Qiukun (Department of Precision Mechanical Engineering, School of Mechatronic Engineering and Automation, Shanghai University, 200072, PR China ) , Peng, Zhike (State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiaotong University, 200240, PR China)
    Mechanical systems and signal processing v.103 ,pp. 117 - 130 , 2018 , 0888-3270 ,

    초록

    Abstract Fast and accurate rotational speed measurement is required both for condition monitoring and faults diagnose of rotating machineries. A vision- and fringe pattern-based rotational speed measurement system was proposed to measure the instantaneous rotational speed (IRS) with high accuracy and reliability. A special double-sine-varying-density fringe pattern (DSVD-FP) was designed and pasted around the shaft surface completely and worked as primary angular sensor. The rotational angle could be correctly obtained from the left and right fringe period densities (FPDs) of the DSVD-FP image sequence recorded by a high-speed camera. The instantaneous angular speed (IAS) between two adjacent frames could be calculated from the real-time rotational angle curves, thus, the IRS also could be obtained accurately and efficiently. Both the measurement principle and system design of the novel method have been presented. The influence factors on the sensing characteristics and measurement accuracy of the novel system, including the spectral centrobaric correction method (SCCM) on the FPD calculation, the noise sources introduce by the image sensor, the exposure time and the vibration of the shaft, were investigated through simulations and experiments. The sampling rate of the high speed camera could be up to 5000 Hz, thus, the measurement becomes very fast and the change in rotational speed was sensed within 0.2 ms. The experimental results for different IRS measurements and characterization of the response property of a servo motor demonstrated the high accuracy and fast measurement of the proposed technique, making it attractive for condition monitoring and faults diagnosis of rotating machineries. Highlights A DSVD fringe pattern-based system was proposed to measure IRS with high reliability. The influence factors on the performance of the proposed system was investigated. The fundamental design and measurement principle of the system have been presented.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  9. [해외논문]   Reduced-order modeling approach for frictional stick-slip behaviors of joint interface   SCIE

    Wang, Dong (Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang 621999, China ) , Xu, Chao (School of Astronautics, Northwestern Polytechnical University, Xi'an 710072, China ) , Fan, Xuanhua (Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang 621999, China ) , Wan, Qiang (Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang 621999, China)
    Mechanical systems and signal processing v.103 ,pp. 131 - 138 , 2018 , 0888-3270 ,

    초록

    Abstract The complex frictional stick-slip behaviors of mechanical joint interface have a great effect on the dynamic properties of assembled structures. In this paper, a reduced-order modeling approach based on the constitutive Iwan model is proposed to describe the stick-slip behaviors of joint interface. An improved Iwan model is developed to describe the non-zero residual stiffness at macro-slip regime and smooth transition of joint stiffness from micro-slip to macro-slip regime, and the power-law relationship of energy dissipation during the micro-slip regime. In allusion to these nonlinear behaviors, the finite element method is used to calculate the recycle force under monolithic loading and the energy dissipation per cycle under oscillatory loading. The proposed model is then used to predict the nonlinear stick-slip behaviors of joint interface by curve-fitting to the results of finite element analysis, and the results show good agreements with the finite element analysis. A comparison with the experiment results in literature is also made. The proposed model agrees very well with the experiment results.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  10. [해외논문]   A new surface fractal dimension for displacement mode shape-based damage identification of plate-type structures   SCIE

    Shi, Binkai (School of Mechanics and Materials, Hohai University, Nanjing 210098, PR China ) , Qiao, Pizhong (Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USA)
    Mechanical systems and signal processing v.103 ,pp. 139 - 161 , 2018 , 0888-3270 ,

    초록

    Abstract Vibration-based nondestructive testing is an area of growing interest and worthy of exploring new and innovative approaches. The displacement mode shape is often chosen to identify damage due to its local detailed characteristic and less sensitivity to surrounding noise. Requirement for baseline mode shape in most vibration-based damage identification limits application of such a strategy. In this study, a new surface fractal dimension called edge perimeter dimension (EPD) is formulated, from which an EPD-based window dimension locus (EPD-WDL) algorithm for irregularity or damage identification of plate-type structures is established. An analytical notch-type damage model of simply-supported plates is proposed to evaluate notch effect on plate vibration performance; while a sub-domain of notch cases with less effect is selected to investigate robustness of the proposed damage identification algorithm. Then, fundamental aspects of EPD-WDL algorithm in term of notch localization, notch quantification, and noise immunity are assessed. A mathematical solution called isomorphism is implemented to remove false peaks caused by inflexions of mode shapes when applying the EPD-WDL algorithm to higher mode shapes. The effectiveness and practicability of the EPD-WDL algorithm are demonstrated by an experimental procedure on damage identification of an artificially-induced notched aluminum cantilever plate using a measurement system of piezoelectric lead-zirconate (PZT) actuator and scanning laser Doppler vibrometer (SLDV). As demonstrated in both the analytical and experimental evaluations, the new surface fractal dimension technique developed is capable of effectively identifying damage in plate-type structures. Highlights New edge perimeter dimension (EPD) for localization and quantification of damage is proposed. An EPD-based window dimension locus (EPD-WDL) algorithm is developed. The fundamental aspects of EPD-WDL algorithm are assessed.

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