Visual servoing

Visual servoing module overview

ViSP visual servoing module allows to build tasks to control a robotic system using vision. This module may use some features that are implemented in the visual features module.

This module doesn’t require any third-party library.

The source code documentation shows which are the corresponding classes part of visual servoing module.

Below you will find videos that illustrate very simple examples of visual-servoing applications done with ViSP.

Robot positioning wrt an object

The first three videos show the behavior of an IBVS, a 2D 1/2 and a PBVS visual-servoing scheme during a positioning task achieved on an ADEPT Viper s850 arm.

This video shows the behavior of an image based visual servoing (IBVS) scheme in order to position the robot with respect to a simple target. In the image, the trajectories of the points are straight lines. [source code]  This video shows the behavior of a 2D half visual servoing (2D 1/2) scheme. In the image, the trajectory of the reference point is a straight line. [source code]
 This video shows the bahavior of a position-based visual servoing (PBVS) scheme. The 3D trajectory of the camera frame is a straight line. [source code]
These two videos show how it is possible with ViSP to build a visual servoing scheme from four line features in order to position a robot with respect to a postcard. On the left the camera is fixed on an Afma robotics gantry robot. On the right the camera is fixed on an ADEPT Viper s850 six dof arm. After convergence, the target is moved by hand. [source code]

Joint limit avoidance

These two videos show examples of coupling visual servoing and joint-limits avoidance. The control scheme combines the regulation at zero of the selected vision-based task to gaze a target with the minimization of a secondary cost function. This cost function reflect the manipulability of the robot in the vicinity of the joint limits. The [source code] is an implementation of the paper E. Marchand, F. Chaumette, A. Rizzo. Using the task function approach to avoid robot joint limits and kinematic singularities in visual servoing. In IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, IROS’96, Volume 3, Pages 1083-1090, Osaka, Japan, November 1996. details pdf

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