A New Approach to Control Single-Link Flexible Arms. Part 2. Control of the Tip Position in the Presence of Joint Friction

1989 ◽  
Author(s):  
Vicente Feliu ◽  
Kuldip S. Rattan ◽  
Jr Brown ◽  
H. B.
Keyword(s):  
New Approach ◽  
Joint Friction ◽  
Single Link ◽  
Tip Position ◽  
Flexible Arms

Feedforward Control of Single-Link Flexible Manipulators by Discrete Model Inversion

1999 ◽  
Vol 121 (4) ◽  
pp. 713-721 ◽  
Author(s):  
V. Feliu ◽  
K. S. Rattan
Keyword(s):  
Transfer Function ◽  
Feedforward Control ◽  
Point Of View ◽  
Model Inversion ◽  
Single Link ◽  
Feedforward Controller ◽  
Tip Position ◽  
Flexible Arms ◽  
System Transfer Function ◽  
General Method

The design of feedforward controllers to control the position of single-link flexible arms is developed in this paper. The objective is to drive the tip position along a commanded trajectory without any oscillations at the tip. The method is based on the well-known dynamics model inversion technique. Since the controllers are implemented on a computer, the dynamic inversion of the single-link flexible arm is studied from a discrete point of view. A general method to obtain a feedforward controller is developed, even in the case when the system transfer function is of nonminimum phase. The method is general in the sense that it removes oscillation in the arm with any number of vibration modes. A method to modify the transfer function of these controllers to improve the robustness is also proposed in this paper. It is shown that the input preshaping scheme developed by Singer and Seering is a special case of this method. The design technique is illustrated with numerical examples and a comparison with the input preshaping method is carried out.

Modeling and Control of Single-Link Flexible Arms With Lumped Masses

1992 ◽  
Vol 114 (1) ◽  
pp. 59-69 ◽  
Author(s):  
V. Feliu ◽  
K. S. Rattan ◽  
H. B. Brown
Keyword(s):  
Control Method ◽  
Flexible Beam ◽  
Outer Loop ◽  
Modeling And Control ◽  
Control Scheme ◽  
Single Link ◽  
Tip Position ◽  
Flexible Arms ◽  
Lumped Masses ◽  
And Control

This paper deals with the modeling and control of a special class of single-link flexible arms. These arms consist of flexible massless structures having some masses concentrated at certain points of the beam. In this paper, the dynamic model of such flexible arms is developed and some of the control properties are deduced. A robust control scheme to remove the effects of friction in the joins is proposed. The control scheme consists of two nested feedback loops, an inner loop to control the position of the motor and an outer loop to control the tip position. The inner loop is described in other publications. A simple feedforward-feedback controller is designed for the outer loop to drive the beam accurately along a desired trajectory. Effects of the changes in the tip’s mass are studied. This modeling and control method is then generalized to the distributed-mass flexible beam case. Finally, experimental results are presented.

Study on the Effect of Link Flexibility on Tip Position of a Single Link Robotic Arm

2021 ◽  
pp. 142-151
Author(s):  
E. Madhusudan Raju ◽  
L. Siva Rama Krishna ◽  
Y. Sharath Chandra Mouli ◽  
V. Nageswara Rao
Keyword(s):  
Robotic Arm ◽  
Single Link ◽  
Link Flexibility ◽  
Tip Position

Design of Trajectories With Physical Constraints for Very Lightweight Single Link Flexible Arms

2006 ◽  
Author(s):  
Francisco Ramos ◽  
Vicente Feliu ◽  
Ismael Payo
Keyword(s):  
Design Process ◽  
Internal Control ◽  
Elastic Limit ◽  
Feedforward Control ◽  
Objective Method ◽  
Maximum Deflection ◽  
Robotic Arms ◽  
Physical Constraints ◽  
Single Link ◽  
Flexible Arms

This communication deals with feedforward control of light, flexible robotic arms. In particular we develop a new, objective method to design a family of trajectories that can be used as modified inputs which cancel the tip vibrations during the robot manoeuvres. This method takes into account the constraints encountered in real actuators (motors), such as a maximum motor torque, and those due to the mechanical limits of the link, such as the maximum deflection before reaching the elastic limit of the link. Parameters of the internal control of the actuators are also derived from the design process, gaining the fastest performance without saturating the motor. Lastly, we show some experimental results which clearly demonstrate the benefits of the new trajectories by comparing them to a linear one.

Vision-Based Tip Position Control of a Single-Link Robot Manipulator

2019 ◽  
Author(s):  
Umesh Kumar Sahu ◽  
Arun Mishra ◽  
Biswajeet Sahu ◽  
Prateek Priyaranjan Pradhan ◽  
Dipti Patra ◽  
...  
Keyword(s):  
Position Control ◽  
Robot Manipulator ◽  
Single Link ◽  
Tip Position

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.

RELATIVE POSITIONING OF STROKE-BASED CLUSTERING: A NEW APPROACH TO ONLINE HANDWRITTEN DEVANAGARI CHARACTER RECOGNITION

2012 ◽  
Vol 12 (02) ◽  
pp. 1250016 ◽  
Author(s):  
K. C. SANTOSH ◽  
CHOLWICH NATTEE ◽  
BART LAMIROY
Keyword(s):  
Character Recognition ◽  
Dynamic Time Warping ◽  
Large Range ◽  
Recognition Rate ◽  
Relative Positioning ◽  
Writing Style ◽  
Time Warping ◽  
New Approach ◽  
Tip Position ◽  
Dynamic Time

In this paper, we propose a new scheme for Devanagari natural handwritten character recognition. It is primarily based on spatial similarity-based stroke clustering. A feature of a stroke consists of a string of pen-tip positions and directions at every pen-tip position along the trajectory. It uses the dynamic time warping algorithm to align handwritten strokes with stored stroke templates and determine their similarity. Experiments are carried out with the help of 25 native writers and a recognition rate of approximately 95% is achieved. Our recognizer is robust to a large range of writing style and handles variation in the number of strokes, their order, shapes and sizes and similarities among classes.

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