Position control of very lightweight single-link flexible arms with large payload variations by using disturbance observers

2012 ◽  
Vol 60 (4) ◽  
pp. 532-547 ◽  
Author(s):  
R. Morales ◽  
V. Feliu ◽  
V. Jaramillo
Keyword(s):  
Position Control ◽  
Single Link ◽  
Flexible Arms

Adaptive Sliding Mode Impedance Control of Single-Link Flexible Manipulators interacting with the Environment at an Unknown Intermediate Point

Robotica ◽  
2019 ◽  
Vol 38 (9) ◽  
pp. 1642-1664 ◽  
Author(s):  
Ali Fayazi ◽  
Naser Pariz ◽  
Ali Karimpour ◽  
V. Feliu-Batlle ◽  
S. Hassan HosseinNia
Keyword(s):  
Position Control ◽  
Sliding Mode ◽  
Impedance Control ◽  
Detection Algorithm ◽  
Reference Trajectory ◽  
Constrained Motion ◽  
Intermediate Point ◽  
Control Scheme ◽  
Single Link ◽  
Motion Mode

SUMMARYThis paper proposes an adaptive robust impedance control for a single-link flexible arm when it encounters an environment at an unknown intermediate point. First, the intermediate collision point is estimated using a collision detection algorithm. The controller, then, switches from free to constrained motion mode. In the unconstrained motion mode, the exerted force to environment is nearly zero. Thus, the reference trajectory is a prescribed desired trajectory in position control. In the constrained motion mode, the reference trajectory is determined by the desired target dynamic impedance. The simulation results demonstrate the efficiency of proposed control scheme.

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.

Position Control of Direct-Drive Robot Manipulators with PMAC Motors Using Enhanced Fuzzy PD Control

2004 ◽  
Vol 8 (3) ◽  
pp. 324-331
Author(s):  
Dong Sun ◽  
◽  
Y. X. Su ◽  
James K. Mills ◽  
Keyword(s):  
Position Control ◽  
Robot Manipulators ◽  
Pd Controller ◽  
Control Performance ◽  
Direct Drive ◽  
Control Approach ◽  
Single Link ◽  
Nonlinear Tracking ◽  
Control Methodology ◽  
Fuzzy Pd

A position control approach for direct-drive robot manipulators with permanent magnet AC (PMAC) motors is proposed. The conventional vector control architecture has been simplified by specifying the motor stator phase so that the rotating d-axis current is zero. The position control is designed to be an enhanced fuzzy PD controller, by incorporating two nonlinear tracking differentiators into a conventional fuzzy PD controller. The proposed control methodology is easy to implement, and exhibits better control performance than conventional control methods. Experiments conducted on a single-link manipulator directly driven by a PMAC motor demonstrate the validity of the proposed approach.

scholarly journals Robust position-based impedance control of lightweight single-link flexible robots interacting with the unknown environment via a fractional-order sliding mode controller

Robotica ◽  
2018 ◽  
Vol 36 (12) ◽  
pp. 1920-1942 ◽  
Author(s):  
Ali Fayazi ◽  
Naser Pariz ◽  
Ali Karimpour ◽  
Seyed Hassan Hosseinnia
Keyword(s):  
Fractional Order ◽  
Position Control ◽  
Sliding Mode ◽  
Impedance Control ◽  
Lyapunov Theory ◽  
Reference Trajectory ◽  
Constrained Motion ◽  
Unknown Environment ◽  
Control Scheme ◽  
Single Link

SUMMARYThis paper presents a fractional-order sliding mode control scheme equipped with a disturbance observer for robust impedance control of a single-link flexible robot arm when it comes into contact with an unknown environment. In this research, the impedance control problem is studied for both unconstrained and constrained maneuvers. The proposed control strategy is robust with respect to the changes of the environment parameters (such as stiffness and damping coefficient), the unknown Coulomb friction disturbances, payload, and viscous friction variations. The proposed control scheme is also valid for both unconstrained and constrained motions. Our novel approach automatically switches from the free to the constrained motion mode using a simple algorithm of contact detection. In this regard, an impedance control scheme is proposed with the inner loop position control. This means that in the free motion, the applied force to the environment is zero and the reference trajectory for the inner loop position control is the desired trajectory. However, in the constrained motion the reference trajectory for the inner loop is determined by the desired impedance dynamics. Stability of the closed loop control system is proved by Lyapunov theory. Several numerical simulations are carried out to indicate the capability and the effectiveness of the proposed control scheme.

End-point position control of a single-link arm using shape memory alloy actuators

2003 ◽  
Vol 217 (8) ◽  
pp. 871-882 ◽  
Author(s):  
Y M Han ◽  
C J Park ◽  
S B Choi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Governing Equation ◽  
Position Control ◽  
Sliding Mode ◽  
Point Position ◽  
End Point ◽  
Single Link ◽  
Point Trajectories ◽  
Sma Spring

This article presents a novel type of actuating mechanism for the end-point trajectory control of a single-link system. The actuating mechanism consists of two sets of shape memory alloy (SMA) springs to generate a desired link motion of the system. The governing equation of motion is derived using the Lagrangian equation and Jacobian matrix. The actuator dynamic of the SMA spring is then empirically identified and incorporated into the governing equation. A sliding mode controller that is robust to parameter variations such as the time constant of the SMA actuator is formulated to achieve desired end-point trajectories of the single-link system. The controller is experimentally realized and tracking control performances for various end-point position trajectories are presented. In addition, the simulated control results are compared with the measured ones in order to validate the proposed control model.

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