ISIS project: Sensor Fusion

This project is carried out by Division of Automatic Control and Communication Systems in cooperation with SAAB Aerospace, SAAB Bofors Dynamics and NIRA Dynamics.

Selected publications

F. Gustafsson, F. Gunnarsson, N. Bergman, U. Forssell, J. Jansson, R. Karlsson, and P-J. Nordlund. Particle filters for positioning, navigation and tracking. IEEE Transactions on Signal Processing, Vol. 50, Nr. 2, 2002. pdf-file.
N. Persson, F. Gustafsson and M. Drevö. Indirect tire pressure monitoring using sensor fusion. In SAE 2002, Detroit, 2002. Report number 2002-01-1250. pdf-file.
P-J. Nordlund and F. Gustafsson. Recursive estimation of three-dimensional aircraft position using terrain-aided positioning. Proc. of ICASSP, Orlando, May, 2002. pdf-file
P-J. Nordlund, F. Gunnarsson and F. Gustafsson. Particle filters for positioning in wireless networks. Proc. of EUSIPCO (invited paper), Toulouse, France, September, 2002. pdf-file.

Urban Forssell, Peter Hall, Stefan Ahlqvist, Fredrik Gustafsson. Novel Map-Aided Positioning System. Proc. of FISITA, Helsinki, Finland, 2002. pdf-file.
Positioning using time-difference of arrival measurements. Fredrik Gustafsson and Fredrik Gunnarsson. ICASSP, Hongkong, PRC, 2003. pdf-file or ps-file.
Particle filter and Cramer-Rao lower bound for underwater navigation. Rickard Karlsson, Fredrik Gustafsson and Tobias Karlsson. ICASSP, Hongkong, PRC, 2003. pdf-file or ps-file.

Highlights 2002

Three licentiate theses were presented:

A project survey paper appeared, describing most of the projects above and a general framework for the particle filter. The author of the master thesis received an award (nonexisting link removed). The project was successfully continued in a student project and another master thesis. The result is a complete navigator including voice guidance implemented on a Compaq iPAQ handheld computer. This is probably the world's first demonstrator of a real application based on a particle filter.

A new company, NIRA Dynamics, entered ISIS and the sensor fusion project.

A workshop was organized on particle filters for navigation, including a plenary talk and three master thesis presentations at our three industrial partners. The workshop was attended by about 50 people.


Terrain aided navigation Mobile phone positioning from time-difference of arrival measurements
Underwater terrain aided navigation

The research in the area of sensor fusion is focused on target tracking, navigation and positioning applications. The common denominator here is that these problems can be written as non-linear state space models with non-Gaussian noise:

where the state vector contains position, velocity and other dynamical states, and the measurements come form sensors as gyroscopes, accelerometers, GPS, radar, etc. The filtering problem is to estimate the states given the measurements. The classical approach is to linearize the state space model, to assume Gaussian noise and then applying the Kalman filter. The particle filter provides a general algorithm for approximating a posteriori distirbution of the states with arbitrary accuracy. The framework is particular suitable for sensor fusion, where sensor information of different kind is mixed with e.g. information from digital maps.

We have the last few years developed efficient and robust particle filter algorithms to approximate the a posteriori distribution of the state vector, and applied the algorithms to a number of applications: