me

Philipp Althaus

PhD

Phone: +46-707348105
Email: philipp@nada.kth.se

Address:
Fleminggatan 70
S - 112 45 Stockholm
Sweden

Additional Information:
CV


I just recently got my PhD in robotics from the Centre for Autonomous Systems at the Royal Institute of Technology (KTH) in Stockholm, Sweden


[scout robot]

Research

My research deals with various aspects of indoor navigation for mobile robots. For a system that moves around in a household or office environment, two major problems must be tackled. First, an appropriate control scheme has to be designed in order to navigate the platform. Second, the form of representations of the environment must be chosen.
Behaviour based approaches have become the dominant methodologies for designing control schemes for robot navigation. One of them is the dynamical systems approach, which is based on the mathematical theory of nonlinear dynamics. It provides a sound theoretical framework for both behaviour design and behaviour coordination. In the work presented in my thesis, the approach has been used for the first time to construct a navigation system for realistic tasks in large-scale real-world environments. In particular, the coordination scheme was exploited in order to combine continuous sensory signals and discrete events for decision making processes. In addition, this coordination framework assures a continuous control signal at all times and permits the robot to deal with unexpected events.
In order to act in the real world, the control system makes use of representations of the environment. On the one hand, local geometrical representations parameterise the behaviours. On the other hand, context information and a predefined world model enable the coordination scheme to switch between subtasks. These representations constitute symbols, on the basis of which the system makes decisions. These symbols must be anchored in the real world, requiring the capability of relating to sensory data. A general framework for these anchoring processes in hybrid deliberative architectures is proposed. A distinction of anchoring on two different levels of abstraction reduces the complexity of the problem significantly.
A topological map was chosen as a world model. Through the advanced behaviour coordination system and a proper choice of representations, the complexity of this map can be kept at a minimum. This allows the development of simple algorithms for automatic map acquisition. When the robot is guided through the environment, it creates such a map of the area online. The resulting map is precise enough for subsequent use in navigation.
In addition, initial studies on navigation in human-robot interaction tasks are presented in my thesis. These kinds of tasks pose different constraints on a robotic system than, for example, delivery missions. It is shown that the methods developed can easily be applied to interactive navigation. Results show a personal robot maintaining formations with a group of persons during social interaction.


Publications


Philipp Althaus
Last modified: Tue Apr 6 11:13:03 MEST 2004