scholarly journals Application of predictive control techniques within parallel robot

2012 ◽  
Vol 23 (5) ◽  
pp. 530-540 ◽  
Author(s):  
Fabian Andres Lara-Molina ◽  
João Maurício Rosário ◽  
Didier Dumur ◽  
Philippe Wenger
Keyword(s):  
Predictive Control ◽  
Tracking Control ◽  
Parallel Robot ◽  
Torque Control ◽  
Control Techniques ◽  
Computed Torque Control ◽  
Youla Parameterization ◽  
Position Tracking Control ◽  
Control Application ◽  
Computed Torque

This paper addresses the position tracking control application of a parallel robot using predictive control techniques. A Generalized Predictive Control strategy (GPC), which considers the linear dynamic model, is used to enhance the tracking position accuracy. The robustification of GPC against measurement noise and neglected dynamics using Youla parameterization is performed. A simulation of the orthoglide robot considering uncertainties related to geometrical and dynamic parameters, sensors noise and frictions is performed on two different trajectories. Finally, it is compared the ro-bustified GPC controller with the classical Computed Torque Control (CTC). The robustified GPC controller shows a better performance for high accelerations and it also reduces the effect of the noise in the control signal of the parallel robot.

A PD Computed Torque Control Method with Online Self-gain Tuning for a 3UPS-PS Parallel Robot

Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Xiaogang Song ◽  
Yongjie Zhao ◽  
Chengwei Chen ◽  
Liang’an Zhang ◽  
Xinjian Lu
Keyword(s):  
Feedback Loop ◽  
Control Method ◽  
Virtual Work ◽  
Parallel Robot ◽  
Torque Control ◽  
Virtual Work Principle ◽  
Tuning Method ◽  
Computed Torque Control ◽  
Control Feedback ◽  
Computed Torque

SUMMARY In this paper, an online self-gain tuning method of a PD computed torque control (CTC) is used for a 3UPS-PS parallel robot. The CTC is applied to the 3UPS-PS parallel robot based on the robot dynamic model which is established via a virtual work principle. The control system of the robot comprises a nonlinear feed-forward loop and a PD control feedback loop. To implement real-time online self-gain tuning, an adjustment method based on the genetic algorithm (GA) is proposed. Compared with the traditional CTC, the simulation results indicate that the control algorithm proposed in this study can not only enhance the anti-interference ability of the system but also improve the trajectory tracking speed and the accuracy of the 3UPS-PS parallel robot.

Robust Computed Torque Schemes for Mechanical Manipulators: Nonadaptive Versus Adaptive

1991 ◽  
Vol 113 (2) ◽  
pp. 324-327 ◽  
Author(s):  
Y. H. Chen
Keyword(s):  
Finite Time ◽  
Tracking Control ◽  
Tracking Error ◽  
Statistical Information ◽  
Torque Control ◽  
Control Algorithms ◽  
Computed Torque Control ◽  
Control Schemes ◽  
Mechanical Manipulators ◽  
Computed Torque

We consider the tracking control problem of mechanical manipulators in the presence of uncertainty. Two classes of control algorithms are proposed. If the possible bound of the uncertainty is known, a class of nonadaptive robust computed torque control schemes is used. The control guarantees the tracking error to be confined within a specified region after a finite time. If the bound of uncertainty is unknown, a class of adaptive robust computed torque control schemes is used. The control guarantees the tracking error to converge to zero. Both classes of controls are continuous. No statistical information on the uncertainty is ever assumed.

scholarly journals Computed torque control of a 2-RR planar parallel robot // Control por par calculado de un robot paralelo planar 2-RR

Prospectiva ◽  
2017 ◽  
Vol 15 (2) ◽  
pp. 85-95 ◽  
Author(s):  
Eugenio Yime ◽  
Javier Roldán Mckenley ◽  
Jose Luis Villa Ramirez
Keyword(s):  
Robot Control ◽  
Parallel Robot ◽  
Torque Control ◽  
Computed Torque Control ◽  
Computed Torque

Se presentan el diseño, la construcción y el control de un mecanismo plano de cinco eslabones con cinco juntas de revoluta y dos grados de libertad. Se implementó el control por par calculado en el espacio articular para lograr una trayectoria deseada. Se desarrolló la cinemática de posición y de velocidad, tanto directa como inversa, y únicamente la cinemática inversa de aceleración como parámetro requerido en la ley de control. El enfoque escogido para este robot paralelo es ventajoso puesto que permite obtener una ecuación dinámica similar al modelamiento convencional de robots seriales, lo cual facilita la implementación de técnicas de control no lineal. La validez del enfoque planteado y la funcionalidad del controlador se verifican experimentalmente mediante la generación de una trayectoria circular por el efector. A pesar de la concordancia entre la simulación y los resultados experimentales, se sugiere como futuro trabajo el cambio en la estrategia de control para compensar efectos no modelados del sistema.

scholarly journals Robotic Comanipulation With Active Impedance Control

2009 ◽  
Author(s):  
Rui Cortesa˜o ◽  
Brian Zenowich ◽  
Rui Arau´jo ◽  
William Townsend
Keyword(s):  
Impedance Control ◽  
Torque Control ◽  
Task Space ◽  
Control Techniques ◽  
Time Control ◽  
Computed Torque Control ◽  
Position Data ◽  
Active Impedance ◽  
Design Experiments ◽  
Computed Torque

The paper presents active impedance control for robotic comanipulation tasks, enabling virtual contact interactions. Computed torque control in the task space powered by multiple-output active observers (AOBs) is proposed, enhancing haptic perception. Forces and force derivatives are artificially measured from position data around an equilibrium point that can move with time. Control techniques to deal with critical impedances are introduced, taking into account the noise distribution along the system. Stochastic design is discussed. A dynamic model of the redundant lightweight 7-DOF WAM™ arm is derived and evaluated, playing a key role in the control design. Experiments for small and high impedances are presented, highlighting merits and limitations of the approach. A comparative study between active and non-active impedance control is made.

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