Adaptive Interaction Control of a Very Flexible Parallel Robot Manipulator

2020 ◽  
pp. 133-150
Author(s):  
Fatemeh Ansarieshlaghi ◽  
Peter Eberhard
Keyword(s):  
Robot Manipulator ◽  
Parallel Robot ◽  
Interaction Control ◽  
Adaptive Interaction

scholarly journals A Novel Kinematically Redundant Planar Parallel Robot Manipulator With Full Rotatability

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicholas Baron ◽  
Andrew Philippides ◽  
Nicolas Rojas
Keyword(s):  
Potential Application ◽  
Robot Manipulator ◽  
Video Recording ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Geometric Method ◽  
Forward Kinematics ◽  
Online Video ◽  
End Effector ◽  
Moving Platform

This paper presents a novel kinematically redundant planar parallel robot manipulator, which has full rotatability. The proposed robot manipulator has an architecture that corresponds to a fundamental truss, meaning that it does not contain internal rigid structures when the actuators are locked. This also implies that its rigidity is not inherited from more general architectures or resulting from the combination of other fundamental structures. The introduced topology is a departure from the standard 3-RPR (or 3-RRR) mechanism on which most kinematically redundant planar parallel robot manipulators are based. The robot manipulator consists of a moving platform that is connected to the base via two RRR legs and connected to a ternary link, which is joined to the base by a passive revolute joint, via two other RRR legs. The resulting robot mechanism is kinematically redundant, being able to avoid the production of singularities and having unlimited rotational capability. The inverse and forward kinematics analyses of this novel robot manipulator are derived using distance-based techniques, and the singularity analysis is performed using a geometric method based on the properties of instantaneous centers of rotation. An example robot mechanism is analyzed numerically and physically tested; and a test trajectory where the end effector completes a full cycle rotation is reported. A link to an online video recording of such a capability, along with the avoidance of singularities and a potential application, is also provided.

Adaptive backstepping control for parallel robot with uncertainties in dynamics and kinematics

Robotica ◽  
2014 ◽  
Vol 32 (6) ◽  
Author(s):  
Jing Zou ◽  
John K. Schueller
Keyword(s):  
Measurement Errors ◽  
Robot Manipulator ◽  
Kinematic Model ◽  
Parallel Robot ◽  
Joint Space ◽  
Backstepping Control ◽  
Adaptive Backstepping ◽  
Robot Tracking ◽  
Robot Systems ◽  
Backstepping Controller

SUMMARYIt is common in robot tracking control that controllers are designed based on the exact kinematic model of the robot manipulator. However, because of measurement errors and changes of states in practice, the original kinematic model is often no longer accurate and will degrade the control result. An adaptive backstepping controller is designed here for parallel robot systems with kinematics and dynamics uncertainties. Backstepping control is used to manage the transformation between the errors in task space and joint space. Adaptive control is utilized to compensate for uncertainties in both dynamics and kinematics. The controller demonstrated good performance in simulation.

scholarly journals Robotic Measurement and Control for Chiropractic Research

2006 ◽  
Vol 3 (1) ◽  
pp. 43-48 ◽  
Author(s):  
P. Goldsmith ◽  
S. Wynd ◽  
G. Kawchuk
Keyword(s):  
Robot Manipulator ◽  
Vision System ◽  
Parallel Robot ◽  
Calibration Procedure ◽  
Positional Accuracy ◽  
Experimental Procedure ◽  
Control Scheme ◽  
And Control ◽  
Measurement And Control ◽  
Chiropractic Research

The precision and programmability of robotic manipulators makes them suitable for biomechanics research, particularly when an experimental procedure must be accurately repeated multiple times. This paper describes a robotic system used to investigate biomechanical mechanisms of stroke in humans. A parallel robot manipulator is used to reproduce chiropractic manipulations on animal subjects using a 3-D vision system. An algorithm for calibrating the system is proposed and tested on the robot. An iterative learning control scheme is then introduced to improve positional accuracy. Experimental results demonstrate that the calibration procedure and learning scheme are both effective.

Computer-aided-symbolic dynamic modeling for Stewart-platform manipulator

Robotica ◽  
2009 ◽  
Vol 27 (3) ◽  
pp. 331-341 ◽  
Author(s):  
J. Lin ◽  
C.-W. Chen
Keyword(s):  
Robot Manipulator ◽  
Weight Ratio ◽  
Parallel Robot ◽  
Stewart Platform ◽  
Torque Control ◽  
Dynamic Equations ◽  
Robot Arm ◽  
Serial Link ◽  
Axis Parallel ◽  
Control Methodology

SUMMARYThe Stewart platform manipulator is a fully kinematic linkage system that has major mechanical differences from typical serial link robots. It is a six-axis parallel robot manipulator with a high force-to-weight ratio and good positioning accuracy that exceeds that of a conventional serial link robot arm. This study examines the dynamic equations and control methodology for a Stewart platform. Because manual symbolic expansion of Stewart platform robot dynamic equations is tedious, time-consuming, and prone to errors, an automated derivation process is highly desired. The main goal of this work is to present an efficient procedure for computer generation of dynamic equations for a Stewart platform manipulator. As MATLAB has a powerful signal processing toolbox along with symbolic processing capabilities and is widely used as a common technical computing environment in many universities and research laboratories, the objective of this study was to develop a MATLAB-based approach for symbolic computation for a parallel linked robot. Additionally, a computed-torque control methodology is utilized for such a structure. Simulation results demonstrate the effectiveness of the proposed control methodology.

scholarly journals Load Parameter Identification for Parallel Robot Manipulator Based on Extended Kalman Filter

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shijie Song ◽  
Xiaolin Dai ◽  
Zhangchao Huang ◽  
Dawei Gong
Keyword(s):  
Kalman Filter ◽  
Dynamic Model ◽  
Extended Kalman Filter ◽  
Robot Manipulator ◽  
External Disturbance ◽  
Parallel Robot ◽  
Load Parameter ◽  
Identification Algorithm ◽  
Dynamic Parameters ◽  
Dynamic Coupling

Load is the main external disturbance of a parallel robot manipulator. This disturbance will cause dynamic coupling among different degrees of freedom and make heaps of model-based control methods difficult to apply. In order to compensate this disturbance, it is crucial to obtain an accurate dynamic model of load. However, in practice, the load is always uncertain and its dynamic parameters are arduous to know a priori. To cope with this problem, this paper proposes a novel and simple approach to identify the dynamic parameters of load. Firstly, the dynamic model of the parallel robot manipulator with uncertain load is established and the dynamic coupling caused by load is also analyzed. Then, according to the dynamic model, the excitation signal is designed and a weak nonlinear dynamic model is derived. Furthermore, the identification model is presented and the identification algorithm based on the extended Kalman filter is designed. Lastly, numerical simulation results, obtained using a six-degree-of-freedom Gough–Stewart parallel manipulator, demonstrate the good estimation performance of the proposed method.

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