Beyond Geometric Mapping

Henrik I Christensen

Centre for Autonomous Systems
Royal Institute of Technology
SE-100 44 Stockholm, Sweden
hic (at) kth.se

Abstract

Autonomy for mobile systems inherently requires localisation of a system to ensure that it is not getting lost. In addition localisation is also an important service for goal achievement. For operation in natural environments -- be it domestic houses or outdoors -- there is often a need to perform concurrent localisation and mapping. The problem is typically referred to as Simultaneous Localisation and Mapping (SLAM). So far most of the research in SLAM has emphasized a purely geometric approach to mapping. Such an approach is well suited for fully autonomous systems, but when a system cooperates with a human there is a need to provide a common representation for the mapping. Euclidean geometry (SE(3)) is not necessarily the best possible basis for such a representation. People typically refer to places and locations in terms of their location relatively to landmarks or relatively to local topological regions. In addition such places and locations are referred to through a semantic label -- "the kitchen", "Henrik's office", etc. Such representations might not be suitable for robot localisation. There is consequently a need to establish a common basis in which both objectives can be accommodated. We will refer the overall process as Human Augmented Mapping. Neither the robot, not the human operator is perfect, and there is thus a need for a dialogue between the user and the robot to resolve ambiguities.

The presentation will discuss a SLAM based representation using graphical models, associated topical information and annotated semantic information. Inference and uncertainty modelling within the representation is briefly outlined. In addition integration of a language model for description of spatial references is introduced to allow "discussion" of ambiguous situations. The system has been tested across a number of different environments and users. In addition to a model of the overall system and its architecture, empirical results are also presented for three different robots, in four environments across 10 users.

Biography

Henrik I Christensen is the director of the Centre for Autonomous Systems at the Royal Institute of Technology, and a chaired professor of computer science specialising in autonomous systems, with the Department of Computer Science and Numerical Analysis.

His research is on mobile robotics, autonomous systems, computer vision, and biologically inspired robot systems. The overall emphasis is on a holistic approach to design of systems, including mathematically well defined methods for design, analysis and implementation of systems. A fundamental idea is that methods should be evaluated in realistic settings which involves an interesting scenario and a full systems context.

He is a co-founder of the company Intelligent Machines and serve as a scientific advisor to Evolution Robotics. In addition he is actively involved in a number of community efforts in particular as the coordinator of the EU network of excellence in Robotics - EURON, that coordinates research, education, industrial links and publishing across Europe. He is a fellow of the International Foundation of Robotics Research and serves as an     IEEE RAS distinguished lecturer (2004-2006).