Combined Discrete-Distributed Control of a Single-Link Flexible Manipulator Using a Lyapunov Approach

1999 ◽  
Vol 121 (3) ◽  
pp. 448-456 ◽  
Author(s):  
Min Gu ◽  
Samuel F. Asokanthan
Keyword(s):  
Hybrid Control ◽  
Control Strategies ◽  
Direct Method ◽  
Equations Of Motion ◽  
Design Procedure ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Single Link ◽  
And Performance ◽  
Good Agreement

This paper presents a development of hybrid control strategies for a single-link flexible manipulator. The control system consists of two actuators; a DC servo motor at the joint and a distributed piezoelectric film actuator bonded to the surfaces of the flexible link. Equations of motion considering two control inputs were developed using the generalized Hamilton’s principle. A feedback control law has been developed based on Lyapunov’s direct method and global stability of closed-loop system is guaranteed. A loop-closure technique was introduced to simplify the design procedure for choosing the feedback gains. Simulation and the experimental results were found to be in good agreement and performance improvement obtained using the hybrid control strategy has been demonstrated.

A Finite Element Approach for Single-Link Flexible Manipulator

2013 ◽  
Vol 347-350 ◽  
pp. 453-456
Author(s):  
Jing Yuan Shi ◽  
Kai Jun Ji ◽  
Yan Kun Tang ◽  
Kun Yang
Keyword(s):  
Finite Element ◽  
Equations Of Motion ◽  
Energy Approach ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Finite Element Approach ◽  
Single Link ◽  
Element Approach

Many researchers have studied the dynamics of the single-link flexible manipulator. A finite element approach is used in this study to describe the dynamics of the flexible link. The displacement of any point on the link is described in terms of modal displacements. Energy approach is used to formulate the equations of motion.

Vibration Control of a Flexible Link Manipulator Using an Array of Fiber-Optic Curvature Sensors and Piezoelectric Actuators

2007 ◽  
Author(s):  
Kerem Gurses ◽  
Bradley J. Buckman ◽  
Edward J. Park
Keyword(s):  
Motion Control ◽  
Sensor Array ◽  
Fiber Optic ◽  
Element Model ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Velocity Feedback ◽  
Lyapunov Approach ◽  
Single Link ◽  
Actuator Control

This paper presents a novel feedback sensing approach for actively suppressing vibrations of a single-link flexible manipulator. Slewing of the flexible link by a rotating hub induces vibrations in the link that persist long after the hub stops rotating. These vibrations are suppressed through a combined scheme of PD-based hub motion control and proposed piezoelectric (PZT) actuator control, which is a composite linear and velocity feedback controller. Lyapunov approach was used to synthesize the controller based on a finite element model of the system. Its realization was possible due to the availability of both linear and angular velocity feedback provided by a unique, commercially-available fiber optic curvature sensor array, called ShapeTape™. It is comprised of an array of fiber optic curvature sensors, laminated on a long, thin ribbon tape, geometrically arranged in such a way that, when it is embedded into the flexible link, the bend and twist of the link’s centerline can be measured. Experimental results show the effectiveness of the proposed approach.

On the Properties of a Dynamic Model of Flexible Robot Manipulators

1998 ◽  
Vol 120 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Marco A. Arteaga
Keyword(s):  
Dynamic Model ◽  
Structural Properties ◽  
Robot Manipulators ◽  
Equations Of Motion ◽  
Mechanical Systems ◽  
Control Design ◽  
Flexible Manipulator ◽  
Robot Dynamics ◽  
Flexible Link ◽  
Flexible Robot

Control design of flexible robot manipulators can take advantage of the structural properties of the model used to describe the robot dynamics. Many of these properties are physical characteristics of mechanical systems whereas others arise from the method employed to model the flexible manipulator. In this paper, the modeling of flexible-link robot manipulators on the basis of the Lagrange’s equations of motion combined with the assumed modes method is briefly discussed. Several notable properties of the dynamic model are presented and their impact on control design is underlined.

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.

Point Control of a One-Link Flexible Manipulator

1986 ◽  
Vol 53 (1) ◽  
pp. 23-27 ◽  
Author(s):  
S. B. Skaar ◽  
D. Tucker
Keyword(s):  
Transfer Functions ◽  
Control Strategies ◽  
Open Loop ◽  
Flexible Manipulator ◽  
Distributed Parameter ◽  
Loop Control ◽  
Control Approach ◽  
Alternative Approach ◽  
Single Link ◽  
Point Control

An alternative approach to the control of nonrigid, distributed parameter systems is presented. Transfer functions that relate the response of points on the system to a controlling force or torque are used in place of ordinary differential equations, which represent an approximation to the system dynamics. The implications of this “point control” approach are discussed with regard to plant modeling accuracy, uncontrolled regions, open-loop and closed-loop control strategies, system identification, and feedback estimation. Sample optimal control histories are illustrated for a single-link manipulator member with end load.

A Dynamic Model on a Single-Link Flexible Manipulator

1990 ◽  
Vol 112 (1) ◽  
pp. 138-143 ◽  
Author(s):  
Liang-Wey Chang ◽  
K. P. Gannon
Keyword(s):  
Experimental Validation ◽  
Shape Function ◽  
Equations Of Motion ◽  
Flexible Manipulator ◽  
Natural Mode ◽  
Lagrangian Dynamics ◽  
The Finite Element Method ◽  
Single Link ◽  
Robust Motion Control ◽  
Nodal Displacements

An enhanced Equivalent Rigid Link System (ERLS) model using natural-mode shape function for flexible manipulators is developed. An experimental validation of the model is performed on a single-link manipulator. The Lagrangian dynamics and the Finite Element Method are used to derive the equations of motion. Joint variables and nodal displacements are chosen being generalized coordinates. The model well describes the dynamic behavior of manipulator systems and allows for applications to design a robust motion control.

Hybrid control of piezoelectric flexible manipulator based on Volterra filtered-xLMS algorithm

2021 ◽  
pp. 107754632110459
Author(s):  
Yuxue Pu ◽  
Xiaobao Li ◽  
Fang Zhang
Keyword(s):  
Vibration Control ◽  
Nonlinear Vibration ◽  
Lead Zirconate Titanate ◽  
Control Strategy ◽  
Hybrid Control ◽  
Vibration Response ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Volterra Filter ◽  
Derivative Control

To suppress the nonlinear vibration of the flexible manipulator during motion, this article presents a hybrid control strategy based on a servo motor and a piezoelectric actuator. The dynamic model of the piezoelectric flexible manipulator is established first. To realize the trajectory tracking, a proportional derivative control method is used to schedule the control torque. Because the Volterra filter can approximate the nonlinear system model, a Volterra filtered-xLMS algorithm based on a second-order Volterra filter structure is proposed, by which the active nonlinear vibration control of flexible link is realized. Simulation results show that the proposed Volterra filtered-xLMS algorithm can not only make use of the advantages of the classical filtered-xLMS algorithm but also solve the problem of effective modeling of nonlinear secondary path. The proposed hybrid control strategy based on Volterra filtered-xLMS algorithm and proportional derivative control algorithm can improve the position accuracy of joint and effectively suppress the vibration response of the nonlinear flexible link. A piezoelectric flexible manipulator with PZT (lead zirconate titanate) sensor and actuator is designed to demonstrate the validity and efficiency of the proposed method by experiments. Experiment results demonstrate that the attenuation time of vibration response is reduced from 5 s to 1.5 s, the vibration response at the first-order frequency is reduced by 60%, and the proposed methodology has an important advantage in application of active vibration control of piezoelectric flexible manipulator.

A force observation method for tracking control of flexible-link manipulators

Robotica ◽  
2012 ◽  
Vol 31 (4) ◽  
pp. 669-677 ◽  
Author(s):  
S. Farokh Atashzar ◽  
M. Shahbazi ◽  
H. A. Talebi ◽  
F. Towhidkhah
Keyword(s):  
Tracking Control ◽  
Flexible Manipulator ◽  
Control Technique ◽  
Flexible Link ◽  
Robust Controller ◽  
Estimation Errors ◽  
Control Scheme ◽  
Lyapunov Redesign ◽  
Single Link ◽  
Observation Method

SUMMARYIn this paper, a composite controller is proposed for single-link flexible manipulators exposed to external tip force disturbances. In the proposed scheme, the extended Kalman filter is utilized to observe the environmental forces and the Lyapunov redesign robust controller is applied to control the destabilizing effect of the observation errors in noisy situations. The observed force can be utilized in different applications (such as tele-surgical robotics) in order to eliminate the necessity of additional force sensors. This fact is important for structural miniaturization and cost reduction. The main contributions of this paper are (1) proposing a disturbance observation technique for in-contact flexible link manipulators (note that the challenge of Jacobian singularity is studied as a possible diverging factor of the observation) and (2) proposing the composite robust controller to eliminate the destabilizing effect of estimation errors. The advantages of the proposed control scheme over the conventional techniques are analyzed. Simulation results are given for a single-link flexible manipulator to illustrate the effectiveness of the composite control technique and experimental results are given to validate the performance of the observation method.

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.

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