Adaptive Inverse-Dynamic and Neuro-Inverse-Dynamic Active Vibration Control of a Single-Link Flexible Manipulator

2005 ◽  
Vol 219 (6) ◽  
pp. 431-448 ◽  
Author(s):  
M H Shaheed ◽  
H Poerwanto ◽  
M O Tokhi
Keyword(s):  
Position Control ◽  
Control Strategies ◽  
Inverse Model ◽  
Flexible Manipulator ◽  
Recursive Least Squares ◽  
Structural Vibration ◽  
Control Loop ◽  
Inverse Dynamic ◽  
Single Link ◽  
Collocated Control

This paper presents investigations into the development of adaptive inverse-dynamic and neuro-inverse-dynamic control strategies for a flexible manipulator system employing a combined collocated and non-collocated control structure. Collocated control is utilized to track the position of the system while the non-collocated inverse and neuro-inverse control are utilized to reduce the vibration of the system. The controllers are developed in two phases: a collocated position control loop using proportional-derivative feedback control is developed and combined first with an adaptive inverse non-collocated control loop using a recursive least-squares algorithm and then with a neuro-inverse model using a multi-layered perceptron neural network. The problem of instability of the non-collocated control loop arising from the non-minimum phase characteristics of the plant is solved in the former case by reflecting the non-invertible plant zeros into the stability region. In the case of the neuro-inverse model, the problem of instability of the control loop is accounted for through the neuro-inverse learning process. The performances of both the proposed control strategies are assessed within a simulation environment of a single-link flexible manipulator and it is demonstrated that a significant reduction in the level of structural vibration of the system is achieved with both techniques. The significance of the neuro-inverse model approach in achieving stable control is demonstrated.

A Time-Domain Inverse Dynamic Tracking Control of a Single-Link Flexible Manipulator

1994 ◽  
Vol 116 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Dong-Soo Kwon ◽  
Wayne J. Book
Keyword(s):  
Time Domain ◽  
Dynamic Method ◽  
Position Control ◽  
Industrial Robots ◽  
Flexible Manipulator ◽  
System Control ◽  
State Variables ◽  
Inverse Dynamic ◽  
Single Link ◽  
Link Flexibility

A manipulator system with a large workspace volume and high payload capacity has greater link flexibility than do typical industrial robots and teleoperators. If link flexibility is significant, position control of the manipulator’s end-effector exhibits nonminimum-phase, noncollocated, and flexible-structure system control problems. This paper addresses inverse dynamic trajectory planning issues of a single-link flexible manipulator. The inverse dynamic equation of a single-link flexible manipulator was solved in the time-domain. By dividing the inverse system equation into its causal part and anticausal part, the inverse dynamic method calculates the feed-forward torque and the trajectories of all state variables that do not excite structural vibrations for a given end-point trajectory. Through simulation and experiment with a single-link manipulator, the effectiveness of the inverse dynamic method in producing fast and vibration-free motion has been demonstrated.

Resonant Control of a Single-Link Flexible Manipulator

2014 ◽  
Vol 67 (5) ◽  
Author(s):  
Auwalu M. Abdullahi ◽  
Z. Mohamed ◽  
Marwan Nafea M.
Keyword(s):  
Feedback Control ◽  
Flexible Manipulator ◽  
Control Loop ◽  
Vibration Effect ◽  
System A ◽  
Resonant Modes ◽  
Single Link ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Resonant Control

This paper presents resonant control of a single-link flexible manipulator based on the resonant modes frequencies of the system. A flexible manipulator system is a single-input multi-output (SIMO) system with motor torque as an input and hub angle and the tip deflection as outputs. The previous system which is modeled using the finite element method is considered, and the resonant modes of the system are determined. Two negative feedback controllers are used to control the system. The inner feedback control loop designed using the resonant frequencies adds damping to the system and suppress the vibration effect around the hub angle. For the outer feedback control loop, a proportional integral controller is designed to achieve a zero steady state error so that a precise tip positioning can be achieved. Simulation results are presented and discussed to show the effectiveness of the resonant control scheme. 

scholarly journals Evolutionary computing approaches to optimum design of fuzzy logic controller for a flexible robot system

2013 ◽  
Vol 23 (4) ◽  
pp. 395-412 ◽  
Author(s):  
Bidyadhar Subudhi ◽  
Subhakanta Ranasingh
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Position Control ◽  
Fitness Function ◽  
Flexible Manipulator ◽  
Position Tracking ◽  
Flexible Robot ◽  
Robot System ◽  
Single Link ◽  
Tip Position

Abstract This paper presents the design of a Fuzzy Logic Controller (FLC) whose parameters are optimized by using Genetic Algorithm (GA) and Bacteria Foraging Optimization (BFO) for tip position control of a single link flexible manipulator. The proposed FLC is designed by minimizing the fitness function, which is defined as a function of tip position error, through GA and BFO optimization algorithms achieving perfect tip position tracking of the single link flexible manipulator. Then the tip position responses obtained by using both the above controllers are compared to suggest the best controller for the tip position tracking.

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.

scholarly journals Control of Flexible Manipulator Systems

1996 ◽  
Vol 210 (2) ◽  
pp. 113-130 ◽  
Author(s):  
M O Tokhi ◽  
A K M Azad
Keyword(s):  
Closed Loop ◽  
Control Strategies ◽  
Open Loop ◽  
Flexible Manipulator ◽  
Closed Loop Control ◽  
Loop Control ◽  
Acceleration Feedback ◽  
Low Pass ◽  
Input Torque ◽  
Collocated Control

This paper presents an investigation into the development of open-loop and closed-loop control strategies for flexible manipulator systems. Shaped torque inputs, including Gaussian-shaped and low-pass (Butter-worth and elliptic) filtered input torque functions, are developed and used in an open-loop configuration and their performance studied in comparison to a bang-bang input torque through experimentation on a single-link flexible manipulator system. Closed-loop control strategies that use both collocated (hub angle and hub velocity) and non-collocated (end-point acceleration) feedback are then proposed. A collocated proportional and derivative (PD) control is first developed and its performance studied through experimentation. The collocated control is then extended to incorporate, additionally, non-collocated feedback through a proportional integral derivative (PID) configuration. The performance of the hybrid collocated and non-collocated control strategy thus developed is studied through experimentation. Experimental results verifying the performance of the developed control strategies are presented and discussed.

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.

scholarly journals Development of an experimental single-link flexible manipulator system

2018 ◽  
Vol 7 (2.29) ◽  
pp. 7
Author(s):  
Hanim Mohd Yatim ◽  
Intan Zaurah Mat Darus
Keyword(s):  
Impact Test ◽  
Industrial Sector ◽  
Dominant Mode ◽  
Flexible Manipulator ◽  
Structural Vibration ◽  
Experimental Result ◽  
Sensors And Actuators ◽  
Single Link ◽  
The Impact ◽  
Experimental Rig

Demand for the applications of flexible manipulator due to their benefits has received attention from the industries. However, the flexibility of flexible manipulator has resulted in structural vibration and needs to be studied accordingly. This paper presents the development of a laboratory facility constituting of single-link flexible manipulator system. A new experimental rig flexible manipulator system constrained to move horizontally was designed, developed and fabricated. The experimental equipment setup and method of capturing data are presented. Experimental works have been done to highlight the effect of forces on hub-angle and end-point vibration of the flexible manipulator. Impact test was carried out to identify the dominant mode of vibration of the flexible manipulator. Result from the impact test was compared with the experimental data recorded for model validation and verification. The experimental result demonstrated that the reasonable accuracy with only 1.31% of error was obtained for the dominant mode of vibration. The experimental rig developed incorporating the sensors and actuators deployed may direct future researchers towards significant applications of flexible manipulator in the industrial sector and to promote better productivity. 

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.

Sign in / Sign up

Export Citation Format

Share Document