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Estimation of the Free Space in Front of a Moving Vehicle
Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
2009 (English)In: Proceedings of the '09 SAE World Congress & Exhibition, 2009Conference paper (Refereed)
Abstract [en]

There are more and more systems emerging making use of measurements from a forward looking radar and a forward looking camera. It is by now well known how to exploit this data in order to compute estimates of the road geometry, tracking leading vehicles, etc. However, there is valuable information present in the radar concerning stationary objects, that is typically not used. The present work shows how radar measurements of stationary objects can be used to obtain a reliable estimate of the free space in front of a moving vehicle. The approach has been evaluated on real data from highways and rural roads in Sweden.

Place, publisher, year, edition, pages
Keyword [en]
Road geometry, Weighted least squares, Quadratic program, Road borders, Free space estimation, Automotive radar, Road mapping
National Category
Engineering and Technology Control Engineering
URN: urn:nbn:se:liu:diva-44998DOI: 10.4271/2009-01-1288Local ID: 79290ISBN: 978-0-7680-2126-4OAI: diva2:265860
SAE World Congress & Exhibition, April 2009, Detroit, MI, USA
Available from: 2011-12-16 Created: 2009-10-10 Last updated: 2013-02-21Bibliographically approved
In thesis
1. Automotive Sensor Fusion for Situation Awareness
Open this publication in new window or tab >>Automotive Sensor Fusion for Situation Awareness
2009 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The use of radar and camera for situation awareness is gaining popularity in automotivesafety applications. In this thesis situation awareness consists of accurate estimates of theego vehicle’s motion, the position of the other vehicles and the road geometry. By fusinginformation from different types of sensors, such as radar, camera and inertial sensor, theaccuracy and robustness of those estimates can be increased.

Sensor fusion is the process of using information from several different sensors tocompute an estimate of the state of a dynamic system, that in some sense is better thanit would be if the sensors were used individually. Furthermore, the resulting estimate isin some cases only obtainable through the use of data from different types of sensors. Asystematic approach to handle sensor fusion problems is provided by model based stateestimation theory. The systems discussed in this thesis are primarily dynamic and they aremodeled using state space models. A measurement model is used to describe the relationbetween the state variables and the measurements from the different sensors. Within thestate estimation framework a process model is used to describe how the state variablespropagate in time. These two models are of major importance for the resulting stateestimate and are therefore given much attention in this thesis. One example of a processmodel is the single track vehicle model, which is used to model the ego vehicle’s motion.In this thesis it is shown how the estimate of the road geometry obtained directly from thecamera information can be improved by fusing it with the estimates of the other vehicles’positions on the road and the estimate of the radius of the ego vehicle’s currently drivenpath.

The positions of stationary objects, such as guardrails, lampposts and delineators aremeasured by the radar. These measurements can be used to estimate the border of theroad. Three conceptually different methods to represent and derive the road borders arepresented in this thesis. Occupancy grid mapping discretizes the map surrounding theego vehicle and the probability of occupancy is estimated for each grid cell. The secondmethod applies a constrained quadratic program in order to estimate the road borders,which are represented by two polynomials. The third method associates the radar measurementsto extended stationary objects and tracks them as extended targets.

The approaches presented in this thesis have all been evaluated on real data from bothfreeways and rural roads in Sweden.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2009. 76 p.
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1422
National Category
Information Science
urn:nbn:se:liu:diva-51226 (URN)LiU-TEK-LIC-2009:30 (Local ID)978-91-7393-492-3 (ISBN)LiU-TEK-LIC-2009:30 (Archive number)LiU-TEK-LIC-2009:30 (OAI)
2009-11-20, Visionen, B-building, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Available from: 2009-10-23 Created: 2009-10-22 Last updated: 2009-10-23Bibliographically approved

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