Adaptive computed torque control for a parallel manipulator with redundant actuation

Robotica ◽  
2011 ◽  
Vol 30 (3) ◽  
pp. 457-466 ◽  
Author(s):  
Wei-Wei Shang ◽  
Shuang Cong ◽  
Yuan Ge
Keyword(s):  
Dynamic Model ◽  
Trajectory Tracking ◽  
Parallel Manipulator ◽  
Adaptive Dynamics ◽  
Tracking Error ◽  
Torque Control ◽  
Redundant Actuation ◽  
Task Space ◽  
Barbalat’S Lemma ◽  
Computed Torque

SUMMARYAn adaptive computed torque (ACT) controller in the task space is proposed for the trajectory tracking of a parallel manipulator with redundant actuation. The dynamic model, including the active joint friction, is established in the task space for the parallel manipulator, and the linear parameterization expression with respect to the dynamic and friction parameters is formulated. On the basis of the dynamic model, a new control law, which contains adaptive dynamics compensation, friction compensation, and tracking error elimination terms, is designed. After defining the state-space model of the error system, the parameter adaptation law is derived by using the Lyapunov method, and the convergence of the tracking error and the error rate is proved by using the Barbalat's lemma. The ACT controller is implemented in the trajectory tracking experiments of an actual 2-DOF parallel manipulator with redundant actuation, and the experiment results are compared with the computed torque controller.

Modeling and trajectory tracking control of 6-DOF RSS type parallel manipulator

Robotica ◽  
2013 ◽  
Vol 32 (4) ◽  
pp. 643-657 ◽  
Author(s):  
Ahmet Dumlu ◽  
Koksal Erenturk
Keyword(s):  
Dynamic Model ◽  
Trajectory Tracking ◽  
Tracking Control ◽  
Parallel Manipulator ◽  
Dynamic Models ◽  
Torque Control ◽  
Complete Model ◽  
Trajectory Tracking Control ◽  
Coupling System

SUMMARYIn this study, kinematic analysis of 6-DOF RSS parallel manipulator using Denavit Hartenbeng (D-H) method is investigated. In addition, in order to improve the proposed method, determination of all the active and passive angles, required to obtain Jacobian and complete dynamic model of manipulator, is also achieved. The effects of dynamic models of 6-DOF RSS parallel manipulator with its actuators on trajectory tracking control are studied in detail. Feedback dynamic compensation terms of motor-mechanism coupling system that is needed to compute torque control are obtained through both a single link approximation model and a complete dynamic model. The complete model is derived by taking account of the interaction between the input links and coupler links of the manipulator. Simulations showed that obtaining complete model of manipulator by means of D-H method and using computed control law could improve the quality of trajectory tracking control of parallel manipulator.

Model-based joint and task space control strategies for a kinematically redundant parallel manipulator

Robotica ◽  
2021 ◽  
pp. 1-17
Author(s):  
João Vitor de Carvalho Fontes ◽  
Fernanda Thaís Colombo ◽  
Natássya Barlate Floro da Silva ◽  
Maíra Martins da Silva
Keyword(s):  
Parallel Manipulator ◽  
Control Strategies ◽  
Parallel Manipulators ◽  
Torque Control ◽  
Redundancy Resolution ◽  
Task Space ◽  
Kinematic Redundancy ◽  
Model Based ◽  
The Impact ◽  
Computed Torque

Abstract One alternative to overcome the presence of singularities within Parallel Manipulators’ workspace is kinematic redundancy. This design alternative can be realized by adding an extra active joint to a kinematic chain. Due to this addition, the IKM presents an infinite number of solutions requiring a redundancy resolution scheme. Moreover, Parallel Manipulators’ control may require complex strategies due to their coupled and complex dynamic and kinematic relations. In this work, a model-free, a joint space computed torque, and a hybrid joint-task-space computed torque control strategies are experimentally compared for a kinematically redundant parallel manipulator. The latter is a novel strategy that requires the measurement of the end-effector’s pose, which is performed by an eye-to-hand limited frame rate camera. The impact of up to three kinematic redundancy levels is also experimentally evaluated using prepositioning and ongoing positioning redundancy resolution schemes. The data are assessed by evaluating a prescribed trajectory executed using a planar kinematically redundant parallel manipulator. These results indicate that kinematic redundancy can not only be used as an alternative design for reducing the presence of singular regions, as claimed in the literature, but also be used along with model-based control strategies for improving dynamic performance and accuracy of parallel manipulators.

Kinematics and Dynamics Modeling of a New 4-DOF Cable-Driven Parallel Manipulator

2013 ◽  
pp. 249-265
Author(s):  
Hamoon Hadian ◽  
Yasser Amooshahi ◽  
Abbas Fattah
Keyword(s):  
Dynamic Model ◽  
Parallel Manipulator ◽  
Joint Space ◽  
Kinematics And Dynamics ◽  
Dynamics Modeling ◽  
Kinematic Constraint ◽  
Control Scheme ◽  
Minimum Number ◽  
Dynamical Properties ◽  
Computed Torque

This paper addresses the kinematics and dynamics modeling of a 4-DOF cable-driven parallel manipulator with new architecture and a typical Computed Torque Method (CTM) controller is developed for dynamic model in SimMechanics. The novelty of kinematic architecture and the closed loop formulation is presented. The workspace model of mechanism’s dynamic is obtained in an efficient and compact form by means of natural orthogonal complement (NOC) method which leads to the elimination of the nonworking kinematic-constraint wrenches and also to the derivation of the minimum number of equations. To verify the dynamic model and analyze the dynamical properties of novel 4-DOF cable-driven parallel manipulator, a typical CTM control scheme in joint-space is designed for dynamic model in SimMechanics.

scholarly journals Mechatronic Model Based Computed Torque Control of a Parallel Manipulator

10.5772/5650 ◽  
2008 ◽  
Vol 5 (1) ◽  
pp. 14 ◽  
Author(s):  
Zhiyong Yang ◽  
Jiang Wu ◽  
Jiangping Mei ◽  
Jian Gao ◽  
Tian Huang
Keyword(s):  
Parallel Manipulator ◽  
Torque Control ◽  
Model Based ◽  
Computed Torque Control ◽  
Computed Torque

Computed Torque Control of a Caterpillar Robot Manipulator Using Neural Network

2016 ◽  
Vol 15 ◽  
pp. 106-118 ◽  
Author(s):  
Mehran Rahmani ◽  
Ahmad Ghanbari
Keyword(s):  
Neural Network ◽  
Trajectory Tracking ◽  
Control Method ◽  
Robot Manipulator ◽  
Setting Time ◽  
Torque Control ◽  
Learning Ability ◽  
Control Effort ◽  
Better Than ◽  
Computed Torque

This paper presents a neural computed torque controller, which employs to a Caterpillar robot manipulator. A description to exert a control method application neural network for nonlinear PD computed torque controller to a two sub-mechanisms Caterpillar robot manipulator. A nonlinear PD computed torque controller is obtained via utilizing a popular computed torque controller and using neural networks. The proposed controller has some advantages such as low control effort, high trajectory tracking and learning ability. The joint angles of two sub-mechanisms have been obtained by using the numerical simulations. The discovered figures show that the performance of the neural computed torque controller is better than a conventional computed torque controller in trajectory tracking and reduction of setting time. Finally, snapshots of gain sequences are demonstrated.

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 Trajectory Tracking Control for Uncertain Robot Manipulators with Repetitive Motions in Task Space

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Jiutai Liu ◽  
Xiucheng Dong ◽  
Yong Yang ◽  
Hongyu Chen
Keyword(s):  
Trajectory Tracking ◽  
Robot Manipulators ◽  
Tracking Error ◽  
Task Space ◽  
Learning Gain ◽  
Trajectory Tracking Control ◽  
Adaptive Iterative Learning Control ◽  
Tracking Tasks ◽  
Control Schemes ◽  
Composite Energy

This paper aims at the trajectory tracking problem of robot manipulators performing repetitive tasks in task space. Two control schemes are presented to conduct trajectory tracking tasks under uncertain conditions including unmodeled dynamics of robot and additional disturbances. The first controller, pure adaptive iterative learning control (AILC), is based upon the use of a proportional-derivative-like (PD-like) feedback structure, and its design seems very simple in the sense that the only requirement on the learning gain and control parameters is the positive definiteness condition. The second controller is designed with a combination of AILC and neural networks (NNs) where the AILC is adopted to learn the periodic uncertainties that attribute to the repetitive motion of robot manipulators while the add-on NNs are used to approximate and compensate all nonperiodic ones. Moreover, a combined error factor (CEF), which is composed of the weighted sum of tracking error and its derivative, is designed for network updating law to improve the learning speed as well as tracking accuracy of the system. Stabilities of the controllers and convergence are proved rigorously by a Lyapunov-like composite energy function. The simulations performed on two-link manipulator are provided to verify the effectiveness of the proposed controllers. The results of compared simulations illustrate that our proposed control schemes can significantly conduct trajectory tracking tasks.

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