Frequency Response Identification and Dynamic Modeling of a Magnetic Levitation Device

Magnetic levitation is an emerging technology in applications such as MEMS production, high speed transportation and biomechanics. Due to the lack of mechanical contact, magnetically levitated devices are unimpeded by problems caused by friction, lubrication and sealing. This paper presents a dynamic model of a magnetic levitation device through the frequency response identification technique. Experimental results verify that the proposed model reasonably matches the actual system’s behavior. The magnetic levitator consists of a set of modules comprising the electromagnets, an iron yoke, a power amplifier, laser position sensors, and a controller. In order to obtain the total transfer function of the system, the dynamic model of each of these modules was obtained individually. The routine presented in this work is remarkable as it leads to the model of a highly nonlinear system through a modular approach that can be applied to a variety of systems.

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SIMPLIFIED DYNAMIC MODEL FOR HIGH-SPEED CHECKWEIGHER

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194513600367 ◽

2013 ◽

Vol 24 ◽

pp. 1360036 ◽

Cited By ~ 2

Author(s):

YUJI YAMAKAWA ◽

TAKANORI YAMAZAKI

Keyword(s):

Dynamic Model ◽

Measurement System ◽

High Speed ◽

Mass Measurement ◽

Conveyor Belt ◽

Open Loop ◽

Model Parameters ◽

Proposed Model ◽

Control Scheme ◽

Mass Damper

In this paper, we concern with the dynamic behaviors of a high speed mass measurement system with conveyor belt (a checkweigher). The goal of this paper is to construct a simple model of the measurement system so as to duplicate a response of the system. The checkweigher with electromagnetic force compensation can be approximated by the combined spring-mass-damper systems as the physical model, and the equation of motion is derived. The model parameters (a damping coefficient and a spring constant) can be obtained from the experimental data for open-loop system. Finally, the validity of the proposed model can be confirmed by comparison of the simulation results with the realistic responses. The simple dynamic model obtained offers practical and useful information to examine control scheme.

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Trajectory tracking control of delta parallel robot based on disturbance observer

Proceedings of the Institution of Mechanical Engineers Part I Journal of Systems and Control Engineering ◽

10.1177/0959651820974826 ◽

2020 ◽

pp. 095965182097482

Author(s):

Mingkun Wu ◽

Jiangping Mei ◽

Jinlu Ni ◽

Weizhong Hu

Keyword(s):

Dynamic Model ◽

Trajectory Tracking ◽

Disturbance Observer ◽

High Speed ◽

Parallel Robot ◽

Tracking Accuracy ◽

Trajectory Tracking Control ◽

Uncertain Dynamics ◽

High Acceleration ◽

Highly Nonlinear

Delta parallel robot is widely used in the manufacturing process of food, medicine, electronics and military industries, which is a highly nonlinear system with strongly uncertain dynamics. Therefore, there are many difficulties in the controller design of delta robot. Based on the simplified dynamic model, a nonlinear PD+ controller with nonlinear disturbance observer is proposed for Delta parallel robot in this article, which can realize high-precision trajectory tracking in high-speed and high-acceleration motion. Then, the asymptotic stability of the closed-loop system’s equilibrium point is proven by utilizing Lyapunov techniques and LaSalle’s invariance theorem. It is obvious that the proposed controller is significantly less dependent on the accuracy of the dynamic model. Besides, a disturbance observer based on the generalized momentum is constructed, which can effectively observe and compensate the disturbances. What’s more, the constructed disturbance observer avoids the calculation of the inverse of inertia matrix, which will greatly improve the response speed of the controller. The simulation results show that the proposed controller can assure better trajectory tracking accuracy in high-speed and high-acceleration motion. And the disturbance observer can effectively estimate the disturbance. The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article:This work was supported by the National Natural Science Foundation of China (grant number51474320).

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Hybrid Dynamic Modeling and Analysis of High-speed Thin-rimmed Gears

Journal of Mechanical Design ◽

10.1115/1.4051137 ◽

2021 ◽

pp. 1-23

Author(s):

Changzhao Liu ◽

Yu Zhao ◽

Yong Wang ◽

Tie Zhang ◽

Hanjie Jia

Keyword(s):

Finite Element ◽

Dynamic Model ◽

High Speed ◽

Degrees Of Freedom ◽

Element Model ◽

Lumped Parameter Model ◽

Modeling And Analysis ◽

Lumped Parameter ◽

Proposed Model ◽

Angular Displacements

Abstract In this study, a hybrid dynamic model of high-speed thin-rimmed gears is developed. In this model, the translational and angular displacements (including the rigid and vibration displacements) with a total of six degrees of freedom (DOFs) are selected as the generalized coordinates for each gear, and the meshing force distributions along the contact line and between the teeth are considered. Thus, the model can be implemented under stationary and non-stationary conditions. The condensed finite element models are developed with the centrifugal and inertia forces for gear bodies. This paper proposes a novel method to couple the lumped parameter model and condensed finite element model for the hybrid dynamic model system, which considers the variation of the meshing tooth during the gear operation, namely, the variations of the acting point of meshing force. Based on the model, the dynamic analysis of high-speed thin-rimmed gears is conducted under stationary speed and acceleration processes. The effects of the flexible gear body, high speed, and tooth errors on the system dynamics and tooth load distribution are investigated. The analysis results are also compared with the current reference and pure finite element method to validate the proposed model.

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Thermo-mechanical behavior analysis of motorized spindle based on a coupled model

Advances in Mechanical Engineering ◽

10.1177/1687814017747144 ◽

2018 ◽

Vol 10 (1) ◽

pp. 168781401774714 ◽

Cited By ~ 3

Author(s):

Junfeng Liu ◽

Peng Zhang

Keyword(s):

Dynamic Model ◽

High Speed ◽

Dynamic Properties ◽

Dynamic Test ◽

Coupled Model ◽

Solution Procedure ◽

Motorized Spindle ◽

Proposed Model ◽

Motorized Spindles ◽

Rotor Dynamic

This article presents a thermo-mechanical coupled dynamic model for high-speed motorized spindles. The proposed model includes an angular ball bearing model, a thermal model, and a rotor dynamic model. The coupling relationship among these submodels is analyzed, and a solution procedure for the integrated model is designed. Based on the proposed model and solution procedure, the dynamic behaviors of the spindle system and the effects of the thermal displacement of the system on the behaviors are quantificationally discussed. Finally, an integrated dynamic test is carried out on a D62D24A-type motorized spindle, and the good agreement between the mathematical results and the experimental data indicates that the proposed model is capable of accurately predicting the dynamic properties of motorized spindles, and the accuracy of the model is improved when considering the thermo-mechanical coupled factor. The conclusions are useful for the dynamic design and the thermal compensation control of high-speed motorized spindles.

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Dynamic model for high-speed rotors based on their experimental characterization

Application and Theory of Computer Technology ◽

10.22496/atct.v2i4.108 ◽

2017 ◽

Vol 2 (4) ◽

pp. 25

Author(s):

L. A. Montoya ◽

E. E. Rodríguez ◽

H. J. Zúñiga ◽

I. Mejía

Keyword(s):

Dynamic Model ◽

High Speed ◽

Natural Frequencies ◽

Mode Shapes ◽

Experimental Characterization ◽

Rotating Systems ◽

Computing Performance ◽

The Impact ◽

Stiffness Distribution ◽

Good Agreement

Rotating systems components such as rotors, have dynamic characteristics that are of great importance to understand because they may cause failure of turbomachinery. Therefore, it is required to study a dynamic model to predict some vibration characteristics, in this case, the natural frequencies and mode shapes (both of free vibration) of a centrifugal compressor shaft. The peculiarity of the dynamic model proposed is that using frequency and displacements values obtained experimentally, it is possible to calculate the mass and stiffness distribution of the shaft, and then use these values to estimate the theoretical modal parameters. The natural frequencies and mode shapes of the shaft were obtained with experimental modal analysis by using the impact test. The results predicted by the model are in good agreement with the experimental test. The model is also flexible with other geometries and has a great time and computing performance, which can be evaluated with respect to other commercial software in the future.

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Frequency response of an internal amplifier in a high-speed integrated circuit measured by electro-optic sampling

Electronics Letters ◽

10.1049/el:19880070 ◽

1988 ◽

Vol 24 (2) ◽

pp. 106 ◽

Cited By ~ 11

Author(s):

J.M. Wiesenfeld ◽

M.S. Heutmaker

Keyword(s):

Frequency Response ◽

Integrated Circuit ◽

High Speed ◽

Electro Optic

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Modeling the Excess Velocity of Low-Viscous Taylor Droplets in Square Microchannels

Fluids ◽

10.3390/fluids4030162 ◽

2019 ◽

Vol 4 (3) ◽

pp. 162 ◽

Cited By ~ 2

Author(s):

Thorben Helmers ◽

Philip Kemper ◽

Jorg Thöming ◽

Ulrich Mießner

Keyword(s):

High Speed ◽

Process Intensification ◽

Continuous Phase ◽

Channel Cross Section ◽

Optimization Approach ◽

Mean Flow ◽

Bypass Flow ◽

Wall Film ◽

Proposed Model ◽

The Mean

Microscopic multiphase flows have gained broad interest due to their capability to transfer processes into new operational windows and achieving significant process intensification. However, the hydrodynamic behavior of Taylor droplets is not yet entirely understood. In this work, we introduce a model to determine the excess velocity of Taylor droplets in square microchannels. This velocity difference between the droplet and the total superficial velocity of the flow has a direct influence on the droplet residence time and is linked to the pressure drop. Since the droplet does not occupy the entire channel cross-section, it enables the continuous phase to bypass the droplet through the corners. A consideration of the continuity equation generally relates the excess velocity to the mean flow velocity. We base the quantification of the bypass flow on a correlation for the droplet cap deformation from its static shape. The cap deformation reveals the forces of the flowing liquids exerted onto the interface and allows estimating the local driving pressure gradient for the bypass flow. The characterizing parameters are identified as the bypass length, the wall film thickness, the viscosity ratio between both phases and the C a number. The proposed model is adapted with a stochastic, metaheuristic optimization approach based on genetic algorithms. In addition, our model was successfully verified with high-speed camera measurements and published empirical data.

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Investigating the Trackability of Silicon Microprobes in High-Speed Surface Measurements

Sensors ◽

10.3390/s21051557 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1557

Author(s):

Min Xu ◽

Zhi Li ◽

Michael Fahrbach ◽

Erwin Peiner ◽

Uwe Brand

Keyword(s):

Dynamic Model ◽

High Speed ◽

High Signal ◽

Resonant Response ◽

High Demand ◽

Surface Measurements ◽

Tactile Roughness ◽

Low Mass ◽

Roughness Measurements

High-speed tactile roughness measurements set high demand on the trackability of the stylus probe. Because of the features of low mass, low probing force, and high signal linearity, the piezoresistive silicon microprobe is a hopeful candidate for high-speed roughness measurements. This paper investigates the trackability of these microprobes through building a theoretical dynamic model, measuring their resonant response, and performing tip-flight experiments on surfaces with sharp variations. Two microprobes are investigated and compared: one with an integrated silicon tip and one with a diamond tip glued to the end of the cantilever. The result indicates that the microprobe with the silicon tip has high trackability for measurements up to traverse speeds of 10 mm/s, while the resonant response of the microprobe with diamond tip needs to be improved for the application in high-speed topography measurements.

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