Image-Based Visual Servoing of the I4R parallel robot without Proprioceptive Sensors

Abstract

This paper proposes a method to control an I4R parallel robot by the observation of its legs with a calibrated camera. We show that the control law depends only on the edges of its forearms extracted from the image and that no proprioceptive sensors are used. Indeed, the variables needed for control (namely, the directions of the arms and forearms as well as the positions of the wrists ) can be reconstructed from the forearms edges. Experimental validation of the reconstruction is given and simulation of the control with realistic noises is performed showing the validity of the approach.

Vector-based dynamic modeling and control of the Quattro parallel robot by means of leg orientations

“…We would like to point out that this estimation is performed in a single image. Note that this result was already verified in [13] on a real I4R robot, and is adapted here for the end-effector of the Quattro robot.…”

Dynamic visual servoing from sequential regions of interest acquisition

“…Another research topic is to design dynamic vision-based control laws that take into account and compensate for more dynamic phenomena such as flexibilities, backlashes and other mechanical defects. Considering parallel robot control problem, it appears that it is also relevant to control this class of robots from leg observation (Dallej et al 2007;Özgür et al 2011). One interesting perspective is thus to generalize this concept into dynamic control of a parallel robot from leg observation.…”

Contribution to generic modeling and vision-based control of a broad class of fully parallel robots

“…It has been shown in ref. [48] that these parameters can be measured using only vision in the case of the I4R robot. Moreover, it was shown that one can get rid of the joint values in the same movement.…”