Control Solution for a Cable-Driven Parallel Robot With Highly Variable Payload

Volume 5B: 42nd Mechanisms and Robotics Conference ◽

10.1115/detc2018-85304 ◽

2018 ◽

Cited By ~ 2

Author(s):

Etienne Picard ◽

Stéphane Caro ◽

Franck Plestan ◽

Fabien Claveau

Keyword(s):

Real Time ◽

Parallel Robot ◽

Pd Controller ◽

Control Solution ◽

Total Load ◽

Heterogeneous Objects ◽

Control Scheme ◽

Pick And Place ◽

Payload Mass ◽

Moving Platform

This paper deals with the design of a robust control scheme for a suspended Cable-Driven Parallel Robot (CDPR), composed of eight cables and a moving platform (MP), suitable for pick-and-place operations of heterogeneous objects with different shapes, sizes and masses, up to a total load of 700 kg. Dynamometers measure the force applied by each cable onto the moving-platform and are used to assess the payload mass at any time. In the proposed control solution, each motor of the CDPR is directly driven by a PD torque controller, which takes benefit of the real-time payload estimation in a feedforward term. In order to evaluate its performance, experiments on a typical pick and place trajectory are realized for different payloads. As a result, three control schemes: (i) a Proportional-Derivative (PD) torque controller; (ii) a PD controller with compensation of the MP mass only and (iii) a PD controller with real-time mass estimation and compensation are experimentally compared with respect to their positioning accuracy. It turns out that a good estimation of the payload is obtained in real-time thanks to the dynamometers. Moreover, the higher the payload mass, the more accurate the proposed controller with respect to its two counterparts.

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Optimal Kinematic Redundancy Planning for Planar Mobile Cable-Driven Parallel Robots

Volume 5B: 42nd Mechanisms and Robotics Conference ◽

10.1115/detc2018-86182 ◽

2018 ◽

Cited By ~ 2

Author(s):

Tahir Rasheed ◽

Philip Long ◽

David Marquez-Gamez ◽

Stéphane Caro

Keyword(s):

Parallel Robot ◽

Parallel Robots ◽

Degree Of Freedom ◽

Static Equilibrium ◽

Kinematic Redundancy ◽

Pick And Place ◽

Moving Platform ◽

Three Degree Of Freedom

Mobile Cable-Driven Parallel Robots (MCDPRs) are special type of Reconfigurable Cable Driven Parallel Robots (RCDPRs) with the ability of undergoing an autonomous change in their geometric architecture. MCDPRs consists of a classical Cable-Driven Parallel Robot (CDPR) carried by multiple Mobile Bases (MBs). Generally MCDPRs are kinematically redundant due to the additional mobilities generated by the motion of the MBs. As a consequence, this paper introduces a methodology that aims to determine the best kinematic redundancy scheme of Planar MCDPRs (PMCDPRs) with one degree of kinematic redundancy for pick-and-place operations. This paper also discusses the Static Equilibrium (SE) constraints of the PMCDPR MBs that are needed to be respected during the task. A case study of a PMCDPR with two MBs, four cables and a three degree-of-freedom (DoF) Moving Platform (MP) is considered.

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Trajectory-Planning and Normalized-Variable Control for Parallel Pick-and-Place Robots

Journal of Mechanisms and Robotics ◽

10.1115/1.4042631 ◽

2019 ◽

Vol 11 (3) ◽

Cited By ~ 6

Author(s):

Peyman Karimi Eskandary ◽

Bruno Belzile ◽

Jorge Angeles

Keyword(s):

Trajectory Planning ◽

Cycle Time ◽

Kinematic Chain ◽

Linear Quadratic Regulator ◽

Parallel Robot ◽

Linear Quadratic ◽

Trajectory Tracking Control ◽

Moving Plate ◽

Control Scheme ◽

Pick And Place

Trajectory planning and an efficient control scheme play a crucial role in improving the performance of pick-and-place robots. This paper introduces a novel method of trajectory planning with cycle time and path constraints. Assuming that a smooth trajectory is given, to be followed within a prescribed cycle time, the newly proposed method of trajectory planning removes the torque peaks of the actuators by a suitable scheduling of the velocity of the moving plate. Since pick-and-place robots are usually expected to meet the end poses in a certain time span, while disregarding the intermediate poses, the velocity can be tuned properly around the critical points of the trajectory by means of a time-scaling function. Moreover, the authors report the formulation of a linear quadratic regulator (LQR) controller with normalized variables to be used in conjunction with our trajectory-tracking control scheme for an in-house-developed Schönflies-motion generator. This parallel robot offers a functionally symmetric, single-loop architecture, with an isostatic kinematic chain, and virtually unlimited rotatability of its gripper. A comparison between two actuation systems developed by the authors is conducted via simulation results.

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On the Design of a 4 Degrees-of-freedom Pick and Place Cable Suspended Parallel Manipulator

IAES International Journal of Robotics and Automation (IJRA) ◽

10.11591/ijra.v6i4.pp286-302 ◽

2017 ◽

Vol 6 (4) ◽

pp. 286

Author(s):

F. J. Castillo-Garcia ◽

P. Rea ◽

A. Gonzalez-Rodriguez ◽

E. Ottaviano

Keyword(s):

Control Strategy ◽

Parallel Manipulator ◽

Degrees Of Freedom ◽

Parallel Robot ◽

Medium Size ◽

Pd Controller ◽

Positioning Accuracy ◽

Pick And Place ◽

And Control ◽

4 Degrees Of Freedom

This paper proposes the design and control strategy for a four degrees-of-freedom spatial cable-suspended parallel robot for pick and place operations. Pick and place is a repetitive task requiring payload changes for the movement to pick-up the object, and the movement to the nal pose to release the manipulated object. In this paper, a new robust control strategy has been proposed, together with proper trajectories for the required operation. The control strategy consists on the system decoupling and linearization by means of a feedforward term and a cascade PD controller. The main advantage of the proposed solution is that its design can be scalable in size spanning from centimeters to meters with a relatively good positioning accuracy. Finally, simulations are reported to show the overall performances of the proposed con guration for pick and place operations with a medium size manipulator.

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Design and implementation of decoupled periodic control scheme for a laboratory-based quadruple-tank process

Proceedings of the Institution of Mechanical Engineers Part I Journal of Systems and Control Engineering ◽

10.1177/09596518211022897 ◽

2021 ◽

pp. 095965182110228

Author(s):

Jatin K Pradhan ◽

Arun Ghosh

Keyword(s):

Real Time ◽

High Frequency ◽

Linear Time ◽

Disturbance Attenuation ◽

Minimum Phase ◽

Periodic Control ◽

Linear Time Invariant ◽

Control Scheme ◽

Gain Margin ◽

Time Invariant

It is well known that linear time-invariant controllers fail to provide desired robustness margins (e.g. gain margin, phase margin) for plants with non-minimum phase zeros. Attempts have been made in literature to alleviate this problem using high-frequency periodic controllers. But because of high frequency in nature, real-time implementation of these controllers is very challenging. In fact, no practical applications of such controllers for multivariable plants have been reported in literature till date. This article considers a laboratory-based, two-input–two-output, quadruple-tank process with a non-minimum phase zero for real-time implementation of the above periodic controller. To design the controller, first, a minimal pre-compensator is used to decouple the plant in open loop. Then the resulting single-input–single-output units are compensated using periodic controllers. It is shown through simulations and real-time experiments that owing to arbitrary loop-zero placement capability of periodic controllers, the above decoupled periodic control scheme provides much improved robustness against multi-channel output gain variations as compared to its linear time-invariant counterpart. It is also shown that in spite of this improved robustness, the nominal performances such as tracking and disturbance attenuation remain almost the same. A comparison with [Formula: see text]-linear time-invariant controllers is also carried out to show superiority of the proposed scheme.

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Observer-based robust integral of the sign of the error control of class I of underactuated mechanical systems: Theory and real-time experiments

Transactions of the Institute of Measurement and Control ◽

10.1177/01423312211031396 ◽

2021 ◽

pp. 014233122110313

Author(s):

Afef Hfaiedh ◽

Ahmed Chemori ◽

Afef Abdelkrim

Keyword(s):

Real Time ◽

Error Control ◽

Degrees Of Freedom ◽

Sliding Mode ◽

Mechanical Systems ◽

Class I ◽

Control Input ◽

Underactuated Mechanical Systems ◽

Control Scheme ◽

And Performance

In this paper, the control problem of a class I of underactuated mechanical systems (UMSs) is addressed. The considered class includes nonlinear UMSs with two degrees of freedom and one control input. Firstly, we propose the design of a robust integral of the sign of the error (RISE) control law, adequate for this special class. Based on a change of coordinates, the dynamics is transformed into a strict-feedback (SF) form. A Lyapunov-based technique is then employed to prove the asymptotic stability of the resulting closed-loop system. Numerical simulation results show the robustness and performance of the original RISE toward parametric uncertainties and disturbance rejection. A comparative study with a conventional sliding mode control reveals a significant robustness improvement with the proposed original RISE controller. However, in real-time experiments, the amplification of the measurement noise is a major problem. It has an impact on the behaviour of the motor and reduces the performance of the system. To deal with this issue, we propose to estimate the velocity using the robust Levant differentiator instead of the numerical derivative. Real-time experiments were performed on the testbed of the inertia wheel inverted pendulum to demonstrate the relevance of the proposed observer-based RISE control scheme. The obtained real-time experimental results and the obtained evaluation indices show clearly a better performance of the proposed observer-based RISE approach compared to the sliding mode and the original RISE controllers.

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Practical Real-Time Implementation of a Disturbance Rejection Control Scheme for a Twin-Rotor Helicopter System Using Intelligent Active Force Control

IEEE Access ◽

10.1109/access.2020.3046728 ◽

2020 ◽

pp. 1-1

Author(s):

Sherif I. Abdelmaksoud ◽

Musa Mailah ◽

Ayman M. Abdallah

Keyword(s):

Real Time ◽

Force Control ◽

Disturbance Rejection ◽

Active Force ◽

Active Force Control ◽

Disturbance Rejection Control ◽

Control Scheme ◽

Twin Rotor

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Implementation and intelligent gain tuning feedback–based optimal torque control of a rotary parallel robot

Journal of Vibration and Control ◽

10.1177/10775463211019177 ◽

2021 ◽

pp. 107754632110191

Author(s):

Farzam Tajdari ◽

Naeim Ebrahimi Toulkani

Keyword(s):

Real Time ◽

Tracking Error ◽

Parallel Robot ◽

Torque Control ◽

Test Bed ◽

Linear Quadratic ◽

Control Effort ◽

The Real ◽

Unknown Disturbances ◽

Quadratic Integral

Aiming at operating optimally minimizing error of tracking and designing control effort, this study presents a novel generalizable methodology of an optimal torque control for a 6-degree-of-freedom Stewart platform with rotary actuators. In the proposed approach, a linear quadratic integral regulator with the least sensitivity to controller parameter choices is designed, associated with an online artificial neural network gain tuning. The nonlinear system is implemented in ADAMS, and the controller is formulated in MATLAB to minimize the real-time tracking error robustly. To validate the controller performance, MATLAB and ADAMS are linked together and the performance of the controller on the simulated system is validated as real time. Practically, the Stewart robot is fabricated and the proposed controller is implemented. The method is assessed by simulation experiments, exhibiting the viability of the developed methodology and highlighting an improvement of 45% averagely, from the optimum and zero-error convergence points of view. Consequently, the experiment results allow demonstrating the robustness of the controller method, in the presence of the motor torque saturation, the uncertainties, and unknown disturbances such as intrinsic properties of the real test bed.

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ETCC: a congestion control scheme for real-time multimedia streaming

Fifth World Congress on Intelligent Control and Automation (IEEE Cat. No.04EX788) ◽

10.1109/wcica.2004.1340872 ◽

2004 ◽

Author(s):

Li Wang ◽

Shuxin Du

Keyword(s):

Congestion Control ◽

Real Time ◽

Multimedia Streaming ◽

Control Scheme

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Speed Synchronization System of Master-Slave Motor Based on Repetitive Control

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.644-650.523 ◽

2014 ◽

Vol 644-650 ◽

pp. 523-526

Author(s):

Yun Ling ◽

Huan Chen ◽

Fei Li

Keyword(s):

Real Time ◽

Spectrum Analysis ◽

Repetitive Control ◽

Speed Control ◽

Time Spectrum ◽

Mechanical Resonance ◽

Synchronization System ◽

Speed Controller ◽

Control Scheme ◽

Magnet Wire

In the wrapping process of magnet wire, as the haulage speed of master motor varies periodically, it is difficult for slave wrapping motor to track master motor due to the mechanical resonance, which destabilizes the wrapping pitch. In the proposed system, the synchronization speed control scheme of master-slave motor based on repetitive control compensation is employed. In the process of control, real-time spectrum analysis of the haulage speed is given, which can be used to adjust the parameters of wrapping speed controller adaptively with the acquired characteristic information of the mechanical resonant. Simulation shows that wrapping speed can track haulage speed well in the proposed system, and the maximum tracking synchronous deviation can be reduced to 56% of that in the system without repetitive control.

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