Nonlinear modeling and vibration analysis of a two-link flexible manipulator coupled with harmonically driven flexible joints

2019 ◽  
Vol 131 ◽  
pp. 278-299 ◽  
Author(s):  
Pravesh Kumar ◽  
Barun Pratiher
Keyword(s):  
Vibration Analysis ◽  
Nonlinear Modeling ◽  
Flexible Manipulator ◽  
Flexible Joints

Nonlinear modeling of d33-mode piezoelectric actuators using experimental vibration analysis

2021 ◽  
Vol 505 ◽  
pp. 116151
Author(s):  
P. Shivashankar ◽  
S. Gopalakrishnan ◽  
S.B. Kandagal
Keyword(s):  
Vibration Analysis ◽  
Nonlinear Modeling ◽  
Piezoelectric Actuators

Equivalent micropolar beam model for spatial vibration analysis of planar repetitive truss structure with flexible joints

2020 ◽  
Vol 165 ◽  
pp. 105202 ◽  
Author(s):  
Fushou Liu ◽  
Libin Wang ◽  
Dongping Jin ◽  
Xiangdong Liu ◽  
Pingli Lu
Keyword(s):  
Vibration Analysis ◽  
Truss Structure ◽  
Beam Model ◽  
Flexible Joints ◽  
Spatial Vibration

Design of the tip state estimator for hybrid-structured flexible manipulator based on SDFT and FLAKF

2018 ◽  
Vol 38 (5) ◽  
pp. 576-586
Author(s):  
Teng Long ◽  
En Li ◽  
Junfeng Fan ◽  
Lei Yang ◽  
Zize Liang
Keyword(s):  
State Estimation ◽  
Vibration Analysis ◽  
Vertical Plane ◽  
Estimation Method ◽  
Flexible Manipulator ◽  
Frequency Noise ◽  
Static Deflection ◽  
State Estimator ◽  
Content Type ◽  
Vibration Model

PurposeThis paper aims to design a tip state estimation method for a hybrid-structured flexible manipulator (HSFM) with one rotating joint and one telescopic joint in the vertical plane.Design/methodology/approachThe HSFM model is decomposed into a static deflection model and a vibration model. The sliding discrete Fourier transform (SDFT) is used to filter the high frequency noise and obtain main vibration components to represent the vibration model. Then, a novel fuzzy logic adaptive Kalman filter (FLAKF) is designed to estimate the state of a vibrational equilibrium position. The complete tip state of the HSFM is obtained by superimposing the FLAKF filter results with the SDFT vibration analysis results.FindingsBoth the simulation results and physical experimental results verify the effectiveness of the proposed tip state estimation method. The vibration analysis based on SDFT is used to represent the vibration model and reduce the computational complexity in the process of solving differential equation. The proposed FLAKF can effectively increase the stability and robustness of the estimator.Originality/valueIn this paper, the tip state estimation problem of the HSFM in vertical plane is first proposed. The effect of gravity on the HSFM is considered by the static deflection model. A precise tip state estimator is designed by a closed loop SDFT and a novel FLAKF, which can provide an accurate feedback for the vibration control controller and make an accurate evaluation of the control effect.

Vibration control of coupled Duffing oscillators in flexible single-link manipulators

2020 ◽  
pp. 107754632095259
Author(s):  
Jie Huang ◽  
Jinchen Ji
Keyword(s):  
High Speed ◽  
Vibration Suppression ◽  
Control Method ◽  
Negative Impact ◽  
Nonlinear Modeling ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Structural Nonlinearity ◽  
Single Link ◽  
Coupled Duffing Oscillators

Motion-induced oscillations of the flexible single link and its payload at the tip have negative impact on the anticipated performance of the flexible manipulators and thus should be suppressed to achieve tip positioning accuracy and high-speed operation. Because of the structural flexibility, the dynamics of the flexible manipulator can be described by coupled Duffing oscillators when considering the inherent structural nonlinearity of the flexible link into the dynamic modeling. However, little research has been focused on addressing the dynamic coupling issue in the nonlinear modeling of flexible-link manipulators using coupled Duffing oscillators. This article presents coupled Duffing oscillators for the nonlinear modeling of flexible single-link manipulators and then proposes a control method for suppressing the nonlinear vibrations of the coupled Duffing oscillators. Simulated and experimental results obtained from a flexible single-link manipulator test bench are in good agreement with the proposed nonlinear modeling and also demonstrate the effectiveness of the proposed control techniques for vibration suppression of the flexible manipulator.

scholarly journals Vibration Analysis of Multilink Manipulators Based on Timoshenko Beam Theory

2011 ◽  
Vol 2011 ◽  
pp. 1-21
Author(s):  
Carmelo di Castri ◽  
Arcangelo Messina
Keyword(s):  
Finite Elements ◽  
Timoshenko Beam ◽  
Vibration Analysis ◽  
Beam Theory ◽  
Point Of View ◽  
Flexible Manipulator ◽  
Closed Formula ◽  
Refined Model ◽  
Matrix Formulation ◽  
Analytical Point

Timoshenko's theory is adopted in order to accurately describe the freely vibrating dynamics of a multilink flexible manipulator. It is herein presented an analytical modelling strategy that extends previous works through a more refined model which accounts for elastic complicating effects along with lumped inertial loads which are typically mounted on joints of manipulators; in this regard, more accurate results are provided. The eigenproblem is presented from an analytical point of view through a matrix formulation, thus providing an essentially closed formula. Apart from the limitations of the implementing calculator, the formulation can take into account an arbitrary number of links in an arbitrary settled configuration, thus allowing relevant analytical analysis and avoiding the need to recur to nonimmediate numerical schemes. Once the analytical model is introduced, solutions are compared to both those achieved by previous models and those obtained by a finite elements method.

Nonlinear Modeling of Flexible Manipulators Using Nondimensional Variables

2005 ◽  
Vol 1 (2) ◽  
pp. 123-134 ◽  
Author(s):  
M. Chandra Shaker ◽  
Ashitava Ghosal
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Frequencies ◽  
Nonlinear Modeling ◽  
Equations Of Motion ◽  
Flexible Manipulator ◽  
Flexural Stiffness ◽  
Flexible Manipulators ◽  
Linear Strain ◽  
Linear Manner

This paper deals with nonlinear modeling of planar one- and two-link, flexible manipulators with rotary joints using finite element method (FEM) based approaches. The equations of motion are derived taking into account the nonlinear strain-displacement relationship and two characteristic velocities, Ua and Ug, representing material and geometric properties (also axial and flexural stiffness) respectively, are used to nondimensionalize the equations of motion. The effect of variation of Ua and Ug on the dynamics of a planar flexible manipulator is brought out using numerical simulations. It is shown that above a certain Ug value (approximately ⩾45m∕s), a linear model (using a linear strain-displacement relationship) and the nonlinear model give approximately the same tip deflection. Likewise, it was found that the effect of Ua is prominent only if Ug is small. The natural frequencies are seen to be varying in a nonlinear manner with Ua and in a linear manner with Ug.

Nonlinear Modeling of Kinematic and Flexibility Effects in Manipulator Design

1988 ◽  
Vol 110 (3) ◽  
pp. 243-254 ◽  
Author(s):  
G. Naganathan ◽  
A. H. Soni
Keyword(s):  
Finite Element ◽  
Nonlinear Modeling ◽  
Beam Theory ◽  
Flexible Manipulator ◽  
Nonlinear Coupling ◽  
Coupling Effects ◽  
End Effector ◽  
Positioning Errors ◽  
Planar Manipulators ◽  
Manipulator Design

This paper presents a finite-element-based, nonlinear model to predict the dynamic response of spatial manipulators with flexible links. The methodology takes into account the complete nonlinear coupling effects between the nonlinear gross motion of the links and their deformations due to distributed elasticity. The end-effector performance is predicted for commanded joint motion profiles, when the above nonlinear coupling is taken into account. A simple and efficient finite-element scheme has been developed using a Newton–Euler formulation and Timoshenko Beam Theory. In addition to the spatial manipulators, a particularized methodology is developed for the analysis of planar manipulators. Case studies of both planar and spatial manipulators are presented. Nonlinear kinematic coupling effects are observed to contribute significantly to end-effector positioning errors in flexible manipulator configurations.

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