scholarly journals Dynamic Analysis and Experiment of 6-DOF Compliant Platform Based on Bridge-Type Amplifier

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1024
Author(s):  
Chao Lin ◽  
Shan Zheng ◽  
Mingdong Jiang
Keyword(s):  
Dynamic Model ◽  
Natural Frequency ◽  
Theoretical Calculations ◽  
Lagrange Equation ◽  
Damping Ratio ◽  
Elastic Beam ◽  
Analytical Models ◽  
Step Response ◽  
Element Analysis ◽  
Bridge Type

In this paper, we establish a dynamic model of a six-degrees-of-freedom (6-DOF) compliant positioning platform based on bridge-type amplifiers. Based on the elastic beam theory and energy relationship, we derived the bridge-type amplifier’s dynamic model using the Lagrange equation. Then, we established a dynamic model of the compliant platform based on the equivalent mass and equivalent stiffness of the bridge-type amplifier, and the analysis formula of the natural frequency was derived. Finally, the analytical models of natural frequencies of the bridge-type amplifier and the compliant platforms were verified using the finite element analysis (FEA) method. Through modal experiments, the damping ratio and natural frequency were identified. Step response experiments in the X/Y direction and Z direction were performed. The phenomenon that the experimental results appeared to match the theoretical calculations indicates that the dynamic model was accurate.

Vibration control of a servomotor-driven coupled elastic shaft-elastic beam system

2004 ◽  
Vol 218 (10) ◽  
pp. 1115-1124
Author(s):  
H Diken ◽  
A Ankarali
Keyword(s):  
Control System ◽  
Natural Frequency ◽  
Frequency Ratio ◽  
Damping Ratio ◽  
Elastic Beam ◽  
Step Response ◽  
Elastic Shaft ◽  
Disc Rotation ◽  
Frequency Ratios ◽  
System Frequency

In this study an elastodynamic control system consisting of servomotor, elastic shaft, disc and elastic beam, which is attached to the disc, is considered. Non-dimensional parametric equations of motions are obtained. The control system damping ratio, the frequency ratio of the torsional natural frequency to the beam natural frequency and also the frequency ratio of the beam natural frequency to the control system frequency are used as parameters. Simulation results are obtained for the step response of the disc rotation and for the beam tip vibration for different frequency ratios. Results show that even for highly flexible systems the effect of flexibility on the control system behaviour can be substantially reduced by proper selection of the control system frequency.

scholarly journals Multi-Physical Design and Resonant Controller Based Trajectory Tracking of the Electromagnetically Driven Fast Tool Servo

Actuators ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 28
Author(s):  
Imran Hussain ◽  
Wei Xia ◽  
Dongpo Zhao ◽  
Peng Huang ◽  
Zhiwei Zhu
Keyword(s):  
Natural Frequency ◽  
Trajectory Tracking ◽  
Voice Coil Motor ◽  
Diamond Turning ◽  
Analytical Models ◽  
Physical Parameters ◽  
Fast Tool Servo ◽  
Element Analysis ◽  
Loop Control ◽  
Resonant Controller

In this paper, a voice coil motor (VCM) actuated fast tool servo (FTS) system is developed for diamond turning. To guide motions of the VCM actuator, a crossed double parallelogram flexure mechanism is selected featuring totally symmetric structure with high lateral stiffness. To facilitate the determination of the multi-physical parameters, analytical models of both electromagnetic and mechanical systems are developed. The designed FTS with balanced stroke and natural frequency is then verified through the finite element analysis. Finally, the prototype of the VCM actuated FTS is fabricated and experimentally demonstrated to achieve a stroke of ±59.02 μm and a first natural frequency of 253 Hz. By constructing a closed-loop control using proportional–integral–derivative (PID) controller with the internal-model based resonant controller, the error for tracking a harmonic trajectory with ±10 μm amplitude and 120 Hz frequency is obtained to be ±0.2 μm, demonstrating the capability of the FTS for high accuracy trajectory tracking.

scholarly journals Multi-Physical Design and Resonant Controller Based Trajectory Tracking of the Electromagnetically Driven Fast Tool Servo

2020 ◽  
Author(s):  
Imran Hussain ◽  
Wei Xia ◽  
Dongpo Zhao ◽  
Peng Huang ◽  
Zhiwei Zhu
Keyword(s):  
Natural Frequency ◽  
Trajectory Tracking ◽  
Voice Coil Motor ◽  
Diamond Turning ◽  
Analytical Models ◽  
Physical Parameters ◽  
Fast Tool Servo ◽  
Element Analysis ◽  
Loop Control ◽  
Resonant Controller

In this paper, a voice coil motor (VCM) actuated fast tool servo (FTS) system is developed for diamond turning. To guide motions of the VCM actuator, a crossed double parallelogram flexure mechanism is selected featuring totally symmetric structure with high lateral stiffness. To facilitate the determination of the multi-physical parameters, analytical models of both electromagnetic and mechanical systems are developed. The designed FTS with balanced stroke and natural frequency is then verified through the finite element analysis. Finally, the prototype of the VCM actuated FTS is fabricated and experimentally demonstrated to have a stroke of ±59.02 μm and a first natural frequency of 253 Hz. By constructing a closed-loop control using PID controller with the internal-model based resonant controller, the error for tracking a harmonic trajectory with ±10 μm amplitude and 120 Hz frequency is obtained to be ±0.2 μm, demonstrating the capability of the FTS for high accuracy trajectory tracking.

scholarly journals Displacement amplification ratio modeling of bridge-type nano-positioners with input displacement loss

2019 ◽  
Vol 10 (1) ◽  
pp. 299-307
Author(s):  
Jinyin Li ◽  
Peng Yan ◽  
Jianming Li
Keyword(s):  
Experimental Testing ◽  
Elastic Beam ◽  
Beam Theory ◽  
Element Analysis ◽  
Compliance Matrix ◽  
Amplification Ratio ◽  
Practical Applications ◽  
Analysis And Design ◽  
Proposed Model ◽  
Bridge Type

Abstract. This paper presents an improved modeling method for bridge-type mechanism by taking the input displacement loss into consideration, and establishes an amplification ratio model of bridge-type mechanism according to compliance matrix method and elastic beam theory. Moreover, the amplification ratio of the designed bridge-type nano-positioner is obtained by taking the guiding mechanism as the external load of bridge-type mechanism. Comparing with existing methods, the proposed model is more accurate, which is further verified by finite element analysis(FEA) and experimental test. The consistency of the results obtained from theoretical model, FEA and experimental testing indicates that the proposed model can accurately predict the amplification characteristics of nano-positioners, which helps the analysis and design of bridge-type nano-positioners in practical applications.

Analysis of Bridge-Type Nano-Positioning Stage

2010 ◽  
Vol 44-47 ◽  
pp. 3828-3832
Author(s):  
Li Ma ◽  
Zheng Feng He ◽  
Hang Kong Ouyang
Keyword(s):  
Natural Frequency ◽  
Tilt Angle ◽  
Elastic Beam ◽  
Beam Theory ◽  
Theory Analysis ◽  
Frequency Model ◽  
Amplification Ratio ◽  
Positioning Stage ◽  
Bridge Type ◽  
The Ideal

A piezoelectric nanostage using bridge-type flexure hinge mechanisms is developed. Elastic beam theory was used to analyze the ideal and theoretic displacement amplification ratio and find that their value is mainly influenced by the length of the tilt rod and tilt angle of bridge-type. A multilayer S-type hinge is designed as the prismatic of moving platform. Stiffness and natural frequency model of the whole stage is built and find out that their value is mainly relevant to hinge thickness, tilt angle of bridge-type hinge and length of S-type hinge. Finally, finite element method (FEM) is used to verify the drived model. The errors of the total stiffness and the natural frequency of the stage between FEM and theory analysis are 3.8% and 6.6% respectively, which confirm the predictions of theory analysis.

Rapid calculation method for estimating static and dynamic performances of closed hydrostatic guideways

2017 ◽  
Vol 69 (6) ◽  
pp. 1040-1048 ◽  
Author(s):  
Zhiwei Wang ◽  
Yi Liu ◽  
Feng Wang
Keyword(s):  
Dynamic Model ◽  
Lagrange Equation ◽  
Dynamic Stiffness ◽  
Step Response ◽  
Nonlinear Spring ◽  
Content Type ◽  
New Model ◽  
Linear Spring ◽  
Spring Coefficient ◽  
Better Than

Purpose The purpose of this paper is to establish a simplified model of the closed hydrostatic guideway for the rapid analysis of static and dynamic characteristics. Further, the influence of compressibility and dynamic frequency are taken into consideration in the new dynamic model. Design/methodology/approach The new model is based on the second kind of Lagrange equation. In this model, the closed hydrostatic guideway is supported by 12 pads, and each oil pad is equivalent to a nonlinear spring-damper system. The equivalent spring coefficient and damper coefficient of the oil pad are extracted by the three different equivalent methods. Finally, the validation experiments of step load response and dynamic stiffness are conducted on a hydrostatic guideway. Findings For solving the step response, the linear spring-damper model and the nonlinear spring-damper Model 1 are better than the nonlinear spring-damper Model 2. The accuracy of the three methods are very high for static stiffness calculation. For the calculation of dynamic stiffness, the nonlinear spring-damper Model 2 is better than the nonlinear spring-damper Model 1. The linear spring-damper model has low precision for dynamic stiffness calculation, especially at high frequency. The accuracy of the new model is validated by experiments. Originality/value The equivalent method of nonlinear spring-damper system has higher accuracy. Different equivalent methods should be adopted for different load types. The computational speeds of the new dynamic model with the three methods are much better than finite element method (about ten times).

scholarly journals Detection of Friction Stir Welding Defects of AA1060 Aluminum Alloy Using Specific Damping Capacity

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2437 ◽  
Author(s):  
Waheed AbuShanab ◽  
Essam Moustafa
Keyword(s):  
Finite Element ◽  
Friction Stir Welding ◽  
Natural Frequency ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Impact Testing ◽  
Damping Capacity ◽  
Element Analysis ◽  
Friction Stir ◽  
Specific Damping Capacity

The demand for nondestructive testing has increased, especially in welding testing. In the current study, AA1060 aluminum plates were jointed using the friction stir welding (FSW) process. The fabricated joints were subjected to free vibration impact testing in order to investigate the dynamic properties of the welded joint. Damping capacity and dynamic modulus were used in the new prediction method to detect FSW defects. The data acquired were processed and analyzed using a dynamic pulse analyzer lab shop and ME’Scope’s post-processing software, respectively. A finite element analysis using ANSYS software was conducted on different types of designed defects to predict the natural frequency. The results revealed that defective welded joints significantly affect the specific damping capacity. As the damping ratio increased, so did the indication of opportunities to increase the presence of defects. The finite element simulation model was consistent with experimental work. It was therefore revealed that natural frequency was insufficient to predict smaller defects.

scholarly journals Investigation of the Damping Capacity of CFRP Raft Frames

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 653
Author(s):  
Jinguang Zhang ◽  
Jun Rao ◽  
Lei Ma ◽  
Xianglong Wen
Keyword(s):  
Natural Frequency ◽  
Simulation Analysis ◽  
Plate Theory ◽  
Damping Ratio ◽  
Great Influence ◽  
Maximum Error ◽  
Bottom Plate ◽  
Damping Capacity ◽  
Element Analysis ◽  
First Order

In this paper, based on the composite laminated plate theory and a strain energy model, the damping capacity of a Carbon Fiber Reinforced Plastics (CFRP) raft frame was studied. According to the finite element analysis (FEA) and damping ratio prediction model, the influences of different layups on the damping capacity of the raft frame and its components (top/bottom plate and I-support) were discussed. Comparing the FEA results with the test results, it can be figured out that the CFRP laminate layup has a great influence on the damping ratio of the raft frame, and the maximum error of the first-order natural frequency and damping ratio of the top/bottom plate were 5.6% and 15.1%, respectively. The maximum error of the first-order natural frequency of the I-support between the FEA result and the test result was 7.5%, suggesting that because of the stress concentration, the error of the damping ratio was relatively large. As for the raft frame, the damping performance was affected by the I-support arrangement and the simulation analysis was in good agreement with the experimental results. This study can provide a useful reference for improving the damping performance of CFRP raft frames.

Determination of frequency response from step response: application to fluid-filled catheters

1979 ◽  
Vol 236 (2) ◽  
pp. H376-H378 ◽  
Author(s):  
S. A. Glantz ◽  
J. V. Tyberg
Keyword(s):  
Decay Rate ◽  
Frequency Response ◽  
Natural Frequency ◽  
Damping Ratio ◽  
Step Change ◽  
Step Response ◽  
Undamped Natural Frequency

The performance of a fluid-filled catheter can be described by reporting its undamped natural frequency and damping ratio. These parameters can be measured by subjecting the catheter to sinusoidally varying pressures at a wide variety of frequencies to obtain the frequency response. They can also be computed from the response to a step change in pressure, which is often easier to produce. This paper derives the required equations and includes a graph which permits one to look up the undamped natural frequency after measuring the period and decay rate of the oscillation following a step change in pressure.

Effects of Core Height, Cell Angle and Face Thickness on Vibration Behavior of Aircraft Sandwich Structure with Honeycomb Core: An Experimental and Numerical Investigations

2021 ◽  
Vol 1039 ◽  
pp. 65-85
Author(s):  
Muhsin Jaber Jweeg ◽  
S.H. Bakhy ◽  
S.E. Sadiq
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Natural Frequency ◽  
Sandwich Structure ◽  
Damping Ratio ◽  
Design Parameters ◽  
Honeycomb Core ◽  
Element Analysis ◽  
Vibration Behavior ◽  
Core Height

The aim of the present paper is to study the vibration behavior of a sandwich structure with honeycomb core experimentally and numerically with different design parameters. The natural frequency and damping ratio were obtained. Core height, cell angle and face thickness were considered as design parameters. Finite element models for the honeycomb sandwich were developed and analyzed via ANSYS finite element analysis (FEA) software. Response Surface Method (RSM) is used to establish numerical methodology to simulate the effect of the design parameters on natural frequency and damping ration. The employment of (RSM) provides a study of the effect of design parameters on natural frequency and damping ratio, numerical modeling of them in term of design parameters and specifying optimization condition. The experimental tests were conducted on sandwich specimens for the validity goal of the previous models created via the finite element analysis. The obtained results show that the natural frequency is directly proportional to the core height and face thickness, while it is inversely proportional to cell angle, Vice versa for damping ratio. Moreover, the optimum value of natural frequency (209.031 Hz) as minimum and damping ratio (0.0320) as maximum were found at 4.8855 mm of core height, 26.770 cell angle and 0.0614 mm face thickness.

Sign in / Sign up

Export Citation Format

Share Document