Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Contributing to the Implementation of a Vision-Based Control Strategy for a Planar Parallel Manipulator
Submission Author:
Fernanda Thaís Colombo , SP
Co-Authors:
Fernanda Thaís Colombo, João Vitor de Carvalho Fontes, Maíra Martins da Silva
Presenter: João Vitor de Carvalho Fontes
doi://10.26678/ABCM.COBEM2017.COB17-0822
Abstract
The control of parallel manipulators require the use of complex strategies due to the coupling of the kinematic chains. Classical control strategies for robotic manipulators have to be revisited when dealing with the design of parallel kinematic manipulators. Among these strategies, two strategies should be considered: (i) joint space computed torque control and (ii) Cartesian space computed torque control. The first strategy (i) requires the calculation of inverse kinematics of the manipulator since the feedback control is performed by using the actual position of the active joints. This complexity imposes serious limitations for the control design. The second strategy (ii) requires the measurement of the end-effector’s pose since the feedback control strategy is based on this measurement. Thus, although mathematically simpler, this choice imposes a significant technical challenge: the measurement of the end-effector. In this work, two different aspects of strategy (ii) are treated for a 3RRR, a planar parallel manipulator. Firstly, the technical details of the measurement of the end-effector’s pose using servoing are given demonstrating the viability of the Cartesian space computed torque control. Secondly, an extensive numerical study is carried out for the evaluation of different control approaches: (a) joint space control, (b) Cartesian space control with servoing and (c) high-authority low-authority control considering feedback of joints’ position and end-effector’s pose values. The objective of this numerical study is to furnish insights for the experimental implementation of strategy (ii). The results of both studies demonstrate the potential of the exploiting visual servoing for controlling parallel manipulators.
Keywords
parallel planar manipulator, visual servoing, control strategies
