Visual Servoing from Lines

In this paper, we present a new approach to visual servoing using lines. It is based on a theoretical and geometrical study of the main line representations, which allows us to define a new representation, the so-called binormalized Plücker coordinates. These are particularly well suited for visual servoing. Indeed, they allow the definition of an image line alignment concept. Moreover, the control law which realizes such an alignment has several properties: partial decoupling between rotation and translation, analytical inversion of the motion equations and global asymptotic stability conditions. This control law was validated both in simulation and experimentally in the specific case of an orthogonal trihedron.

Laser steering using virtual trifocal visual servoing

This paper focuses on the development of a weakly calibrated three-view-based visual servoing control law applied to the laser steering process. It proposes to revisit the conventional trifocal constraints governing a three-view geometry for a more suitable use in the design of an efficient trifocal vision-based control. Thereby, an explicit control law is derived, without any matrix inversion, which allows to simply prove the global exponential stability of the control. Moreover, only ‘[Formula: see text]’ are necessary to design a fast trifocal control system. Thanks to the simplicity of the implementation, our control law is fast, accurate, robust to errors on the weak calibration and it exhibits good behavior in terms of convergence and decoupling. This was demonstrated by different experimental validations performed on a test-bench for the steering of laser spot on a 2D and 3D surface using a two degrees-of-freedom commercial piezoelectric mirror, as well as in preliminary cadaver trials using an endoluminal micromirror prototype.