scholarly journals Dynamic modelling and vibration suppression of a single-link flexible manipulator with two cables

2021 ◽  
Vol 162 ◽  
pp. 104347
Author(s):  
Lewei Tang ◽  
Marc Gouttefarde ◽  
Haining Sun ◽  
Lairong Yin ◽  
Changjiang Zhou
Keyword(s):  
Vibration Suppression ◽  
Dynamic Modelling ◽  
Flexible Manipulator ◽  
Single Link

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.

Finite difference and finite element approaches to dynamic modelling of a flexible manipulator

1997 ◽  
Vol 211 (2) ◽  
pp. 145-156 ◽  
Author(s):  
M O Tokhi ◽  
Z Mohamed ◽  
A K M Azad
Keyword(s):  
Finite Element ◽  
Finite Difference ◽  
Computational Efficiency ◽  
Dynamic Modelling ◽  
Comparative Investigation ◽  
Flexible Manipulator ◽  
Dynamic Characterization ◽  
Finite Dimensional ◽  
Single Link

This paper presents a comparative investigation of the dynamic characterization of flexible manipulators on the basis of accuracy, computational efficiency and computational requirements using finite difference (FD) and finite element (FE) methods. A constrained planar single-link flexible manipulator is considered. Finite-dimensional simulations of the manipulator are developed using FD and FE methods. The simulation algorithms thus developed are implemented on two computing domains and their performances, on the basis of accuracy in characterizing the behaviour of the manipulator and computational efficiency, are assessed.

scholarly journals Dynamic characterisation of a flexible manipulator system

Robotica ◽  
2001 ◽  
Vol 19 (5) ◽  
pp. 571-580 ◽  
Author(s):  
M.O. Tokhi ◽  
Z. Mohamed ◽  
M.H. Shaheed
Keyword(s):  
Finite Element ◽  
Dynamic Modelling ◽  
Model Performance ◽  
Element Model ◽  
Flexible Manipulator ◽  
Experimental Investigations ◽  
Inertia Effects ◽  
System A ◽  
Frequency Domains ◽  
Single Link

This paper presents theoretical and experimental investigations into the dynamic modelling and characterisation of a flexible manipulator system. A constrained planar single-link flexible manipulator is considered. A dynamic model of the system is developed based on finite element methods. The flexural and rigid dynamics of the system as well as inertia effects and structural damping are accounted in the model. Performance of the algorithm in describing the dynamic behaviour of the system is assessed in comparison to an experimental test-rig. Experimental results are presented for validation of the developed finite element model in the time and frequency domains.

scholarly journals Dynamic modelling of a single-link flexible manipulator: parametric and non-parametric approaches

Robotica ◽  
2002 ◽  
Vol 20 (1) ◽  
pp. 93-109 ◽  
Author(s):  
M.H. Shaheed ◽  
M.O. Tokhi
Keyword(s):  
Dynamic Modelling ◽  
Autoregressive Process ◽  
Parametric Models ◽  
Flexible Manipulator ◽  
Recursive Least Squares ◽  
Single Link ◽  
Input Model ◽  
Validation Tests ◽  
Input Torque ◽  
Non Parametric

This paper presents an investigation into the development of parametric and non-parametric approaches for dynamic modelling of a flexible manipulator system. The least mean squares, recursive least squares and genetic algorithms are used to obtain linear parametric models of the system. Moreover, non-parametric models of the system are developed using a non-linear AutoRegressive process with eXogeneous input model structure with multi-layered perceptron and radial basis function neural networks. The system is in each case modelled from the input torque to hub-angle, hub-velocity and end-point acceleration outputs. The models are validated using several validation tests. Finally, a comparative assessment of the approaches used is presented and discussed in terms of accuracy, efficiency and estimation of the vibration modes of the system.

Modal Identification and Nonlinear Vibration of Flexible Manipulator With Revolute Pair Incorporating Generic Payload

2018 ◽  
Author(s):  
Pravesh Kumar ◽  
Barun Pratiher
Keyword(s):  
Dynamic Modelling ◽  
Primary Resonance ◽  
Free Vibration Analysis ◽  
Modal Identification ◽  
Flexible Manipulator ◽  
Nonlinear Behaviour ◽  
Nonlinear Characteristics ◽  
Rotating Speed ◽  
Single Link ◽  
Modes Of Vibration

The effect of all-inclusive generic offset payload characteristics on the modes of vibration and nonlinear characteristics of a rotating flexible manipulator with a revolute pair has been accomplished in the present article. A brief dynamic modelling and free vibration analysis to obtain the eigenspectrums of the system, whereafter nonlinear analysis of a manipulator with a general offset payload undergoing overall motion has been accomplished. Dynamic equation of motion and associated boundary conditions have been developed where the payload is considered as a mass whose center of gravity doesn’t coincide with the point of attachment with the manipulator. The effect of various system parameters such as offset mass, offset inertia, offset length, hub mass, actuated inertia and hub stiffness on eigenfrequency is well tabulated and the same effect on eigenspectrums is presented graphically. Further, MMS is employed to investigate the effect of parametric variation on the nonlinear behaviour and associated bifurcation of the rotating single-link flexible manipulator being harmonically driven at the joint under primary resonance considering the centrifugal forces acting on the link and payload as well. The present analysis indicated the pronounced effect of system mass, inertia, stiffness and rotating speed on the eigencharacteristics and bifurcations of a flexible manipulator with a rotating joint.

scholarly journals The Study of Dynamic Modeling and Multivariable Feedback Control for Flexible Manipulators with Friction Effect and Terminal Load

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1522
Author(s):  
Fuli Zhang ◽  
Zhaohui Yuan
Keyword(s):  
Dynamic Model ◽  
Vibration Suppression ◽  
Control Method ◽  
Coupling Effect ◽  
Flexible Manipulator ◽  
Flexible Beam ◽  
Robot Dynamics ◽  
Joint Friction ◽  
Balance Principle ◽  
Multivariable Feedback

The flexible manipulato is widely used in the aerospace industry and various other special fields. Control accuracy is affected by the flexibility, joint friction, and terminal load. Therefore, this paper establishes a robot dynamics model under the coupling effect of flexibility, friction, and terminal load, and analyzes and studies its control. First of all, taking the structure of the central rigid body, the flexible beam, and load as the research object, the dynamic model of a flexible manipulator with terminal load is established by using the hypothesis mode and the Lagrange method. Based on the balance principle of the force and moment, the friction under the influence of flexibility and load is recalculated, and the dynamic model of the manipulator is further improved. Secondly, the coupled dynamic system is decomposed and the controller is designed by the multivariable feedback controller. Finally, using MATLAB as the simulation platform, the feasibility of dynamic simulation is verified through simulation comparison. The results show that the vibration amplitude can be reduced with the increase of friction coefficient. As the load increases, the vibration can increase further. The trajectory tracking and vibration suppression of the manipulator are effective under the control method of multi-feedback moment calculation. The research is of great significance to the control of flexible robots under the influence of multiple factors.

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