Experimental Validation of a Dynamic Model (Equivalent Rigid Link System) on a Single-Link Flexible Manipulator

1989 ◽  
Vol 111 (4) ◽  
pp. 667-672 ◽  
Author(s):  
R. P. Petroka ◽  
Liang-Wey Chang
Keyword(s):  
Dynamic Model ◽  
Robot Manipulator ◽  
Flexible Manipulator ◽  
Flexible Manipulators ◽  
Rigid Link ◽  
Future Design ◽  
Single Link ◽  
Manipulator Design ◽  
And Control ◽  
Improved Accuracy

Flexibility effects on robot manipulator design and control are typically ignored which is justified when large, bulky robotic mechanisms are moved at slow speeds. However, when increased speed and improved accuracy are desired in robot system performance it is necessary to consider flexible manipulators. This paper simulates the motion of a single-link, flexible manipulator using the Equivalent Rigid Link System (ERLS) dynamic model and experimentally validates the computer simulation results. Validation of the flexible manipulator dynamic model is necessary to ensure confidence of the model for use in future design and control applications of flexible manipulators.

Dynamic Coupling and Control of Flexible Space Robots

2020 ◽  
Vol 20 (09) ◽  
pp. 2050103
Author(s):  
Yanfeng Du ◽  
Cong Wang
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Coupling Effect ◽  
Space Robot ◽  
Flexible Manipulator ◽  
Flexible Manipulators ◽  
Dynamic Coupling ◽  
Input Shaper ◽  
Flexible Panels ◽  
And Control

The dynamic modeling and coupling effect of a space robot are complex when the flexible manipulator and solar panels are considered. This paper investigates the dynamic coupling effect and control of a flexible space robot with flexible manipulators and flexible panels. The equations of motion are derived for the robot model both of the rigid-flexible type and flexible-flexible type. The flexible space robot dynamic model is verified by comparison with the results generated by the ADAMS software, for which good agreement has been obtained. The dynamic coupling matrix of the flexible space robot is derived based on the dynamic model. The effects of the central rigid body mass and the joints angle on the dynamic coupling are analyzed. A control method is proposed to manipulate the flexible space robot based on the system dynamic model. The multiple-impulse robust (MIR) input shaper is used to suppress the vibration of flexible structures in the proposed controller. Appropriate design parameter and frequency scaling factor are selected for the MIR input shaper to suppress the flexible vibration. The flexible space robot control is conducted to illustrate the effect of the proposed controller. It is shown that the proposed control method can realize the desired joints manipulation, while suppressing the vibration of the flexible manipulators and flexible panels.

Optimization in the Design and Control of Robotic Manipulators: A Survey

1989 ◽  
Vol 42 (4) ◽  
pp. 117-128 ◽  
Author(s):  
S. S. Rao ◽  
P. K. Bhatti
Keyword(s):  
Optimal Control ◽  
Robot Manipulator ◽  
Research Effort ◽  
Industrial Robot ◽  
Load Capacity ◽  
Robotic Manipulators ◽  
Optimization Techniques ◽  
Highly Nonlinear ◽  
Manipulator Design ◽  
And Control

Robotics is a relatively new and evolving technology being applied to manufacturing automation and is fast replacing the special-purpose machines or hard automation as it is often called. Demands for higher productivity, better and uniform quality products, and better working environments are primary reasons for its development. An industrial robot is a multifunctional and computer-controlled mechanical manipulator exhibiting a complex and highly nonlinear behavior. Even though most current robots have anthropomorphic configurations, they have far inferior manipulating abilities compared to humans. A great deal of research effort is presently being directed toward improving their overall performance by using optimal mechanical structures and control strategies. The optimal design of robot manipulators can include kinematic performance characteristics such as workspace, accuracy, repeatability, and redundancy. The static load capacity as well as dynamic criteria such as generalized inertia ellipsoid, dynamic manipulability, and vibratory response have also been considered in the design stages. The optimal control problems typically involve trajectory planning, time-optimal control, energy-optimal control, and mixed-optimal control. The constraints in a robot manipulator design problem usually involve link stresses, actuator torques, elastic deformation of links, and collision avoidance. This paper presents a review of the literature on the issues of optimum design and control of robotic manipulators and also the various optimization techniques currently available for application to robotics.

Neural-network-based adaptive fault-tolerant vibration control of single-link flexible manipulator

2019 ◽  
Vol 42 (3) ◽  
pp. 430-438 ◽  
Author(s):  
Le Li ◽  
Jinkun Liu
Keyword(s):  
Neural Network ◽  
Dynamic Model ◽  
Fault Tolerant ◽  
Rbf Neural Network ◽  
Direct Method ◽  
Fault Tolerant Control ◽  
Flexible Manipulator ◽  
Actuator Failure ◽  
Single Link ◽  
Boundary Disturbance

This paper proposes an adaptive fault-tolerant control scheme for a single-link flexible manipulator with actuator failure and uncertain boundary disturbance. The dynamic model of the flexible manipulator as-described by partial differential equations (PDEs) is derived under Hamilton’s principle. The dynamic model is then used to design an adaptive fault-tolerant control (FTC) scheme which tracks the given angle and regulates vibration in the case of actuator failure. The boundary disturbance is compensated by a radial basis function (RBF) neural network. The whole closed-loop system is proven asymptotically stable by Lyapunov direct method and LaSalle’s invariance principle. Simulation results indicate that the proposed controller is superior to the traditional PD controller.

Influence of backlash in gear reducer on dynamic of single-link manipulator arm

Robotica ◽  
2014 ◽  
Vol 33 (08) ◽  
pp. 1671-1685 ◽  
Author(s):  
Jian-Wei Lu ◽  
Xiao-Ming Sun ◽  
Alexander F. Vakakis ◽  
Lawrence A. Bergman
Keyword(s):  
Dynamic Response ◽  
Dynamic Modeling ◽  
Excitation Frequency ◽  
Planetary Gear ◽  
Flexible Manipulator ◽  
Lumped Mass ◽  
Modeling And Control ◽  
Single Link ◽  
Manipulator Arm ◽  
And Control

SUMMARYThe dynamic modeling of a flexible single-link manipulator arm with consideration of backlash in the planetary gear reducer at the joint is presented, and the influence of backlash on the dynamic response of the system is evaluated. A 2K-H planetary gear reducer with backlash was employed as an example to discuss the dynamic modeling of the sub-model of the planetary gear reducer, and the sub-model of the planetary gear reducer was established based on the lumped mass method. The flexible manipulator was regarded as an Euler--Bernoulli beam, and the dynamic model of the flexible manipulator arm with backlash in the planetary gear reducer was determined from Lagrange's equations. Based on the this model, the influence of the backlash in the planetary gear reducer and excitation frequency on the dynamic response of the system were evaluated through simulation, and the results showed that the dynamic response of the system is sensitive to the backlash and the excitation frequency simultaneously, which provides a theoretical foundation for improvement of dynamic modeling and control of the flexible manipulator arm.

On Dynamics and Control of Multi-Link Flexible Manipulators

1995 ◽  
Vol 117 (2) ◽  
pp. 134-142 ◽  
Author(s):  
W. Gawronski ◽  
C.-H. C. Ih ◽  
S. J. Wang
Keyword(s):  
Rigid Body ◽  
Inverse Dynamics ◽  
Linear Time ◽  
Flexible Manipulator ◽  
Flexible Manipulators ◽  
Link Length ◽  
Joint Torques ◽  
Control Approach ◽  
Dynamics And Control ◽  
And Control

This paper presents solutions of dynamics, inverse dynamics, and control problems of multi-link flexible manipulators. In deriving the manipulator dynamics, flexible deformations are assumed to be small in relation to the link length, angular rates of the links are assumed to be much smaller than their fundamental frequencies, and nonlinear terms (centrifugal and Coriolis forces) in the flexible manipulator model are assumed to be the same as those in the rigid body model. Flexible displacements are measured with respect to the rigid body configuration, obtained from its rigid body inverse kinematics. As a result, a linear time-varying system is obtained. The inverse dynamics problem consists of determination of joint torques for a given tip trajectory such that joint angles in the flexible configuration are equal to the angles in the rigid body configuration. The manipulator control system consists of the feedforward compensation and feedback control loops. Simulation results of a two-link space crane with a large payload show that the performance of this linearized dynamics and control approach is accurate, and at the same time is robust when subjected to parameter variations during slew operations.

Dynamics and Motion Control of Flexible Manipulators With Multi-Degree of Kinematic Redundancy

2005 ◽  
Author(s):  
Yue-Qing Yu ◽  
Ji-Yun Yang
Keyword(s):  
Motion Control ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
Flexible Manipulator ◽  
Flexible Manipulators ◽  
Kinematic Redundancy ◽  
Flexible Robot ◽  
Flexible Robots ◽  
Dynamic Performances ◽  
Self Motion

The dynamics and motion control of flexible robot manipulators is an advanced topic in the study of robotics. The precise tracking of the end-effector trajectory of flexible robots can be improved by the self-motion of redundant manipulators. The flexible manipulator with single-degree of kinematic redundancy has been considered only at present. This study addresses on the dynamics and motion control of flexible robots with multi-degree of kinematic redundancy. Compared with the robot with one-degree of redundancy, the optimal motion programming of a flexible robot manipulator with two-degree of redundancy has been obtained successfully based on pseudo-inverse solution. The numerical results of planar three-link and four-link flexible manipulators show the advantage of multi-degree of redundancy in improving the kinematic and dynamic performances of flexible robot manipulators.

Vibration Control of a Space Flexible Robot Manipulator Using PZT Actuators

2011 ◽  
Vol 66-68 ◽  
pp. 1142-1148 ◽  
Author(s):  
Jun Qiang Lou ◽  
Yan Ding Wei
Keyword(s):  
Control Strategy ◽  
Vibration Suppression ◽  
Robot Manipulator ◽  
Equations Of Motion ◽  
System Stability ◽  
Flexible Manipulator ◽  
Flexible Robot ◽  
Simulation Results ◽  
And Control ◽  
And Robotics

The dynamic analysis and control of flexible robot manipulators have been the main concerns of many recent studies in aeronautics and robotics. Moreover, the complexity of this problem increases when a flexible manipulator carries a payload. In this paper, we proposed a space two-link flexible manipulator with tip payload featuring surface-bonded piezoelectric torsional actuator and shear actuator. The equations of motion for the system are obtained using Hamilton’s principle. A Lyapunov-based controller is proposed to suppress the vibration of the system. Stability of the system is also investigated. The simulation results demonstrate the proposed control strategy is well suited for active control of vibration suppression on flexible manipulators.

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