Linköping Studies in Science and TEchnology. Dissertations
No. 528

On Robot Feedback from Range Sensors:
Reliable Control by Active Reduction of Uncertainty and Ambiguities

Jonas Nygårds

Akademisk avhandling

som för avläggande av teknologie doktorsexamen vid Tekniska Högskolan i Linköping kommer att offentligt försvaras i sal T1, Linköpings Universitet, fredagen den 17 April 1998 kl. 10.15. Fakultetsopponent är Dr John Hallam, Department of Artificial Intelligence, The University of Edinburgh, Storbritannien.

Abstract

This thesis is on modelling and experimental tests when non contact sensing is used for feedback control in robotics. The motion of the robot is to be controlled relative to objects in the surrounding workspace during operations like gripping/docking, surface following, shape measuring etc.

On a system level three examples are studied in detail:

The long term goal is a framework where sub-operations can be assembled using model based feedback designed to fulfil the task tolerances with a pre-specified probability (close to unity). In essence, the tolerances and the required probability of success should be a model parameter of the feedback design.

Estimation is an important part of the presented feedback loops and implications are studied for four cases:

Keywords:
robot gripping and docking, LQG-feedback, posture estimation, Gaussian sum, optronic sensing, sheet of light range camera, time-of-flight laser, specular reflections, multiple scattering, range 'ghosts', active reduction of ambiguities, reliability, uncertainty, tolerances.

Robotics/Autonomous Mechanical Systems
Department of Mechanical Engineering
Linköping University, S-581 83 Linköping, Sweden
Linköping 1998

ISBN 91-7219-194-5 ISSN 0345-7524