Vehicle Size and Orientation Estimation Using Geometric Fitting
2000 (English)Licentiate thesis, monograph (Other academic)
Over the years imaging laser radar systems have been developed for both military and civilian applications. Among the applications we note collection of 3D data for terrain modelling and object recognition. One part of the object recognition process is to estimate the size and orientation of the object.
This thesis concerns a vehicle size and orientation estimation process based on scanning laser radar data. Methods for estimation of length and width of vehicles are proposed. The work is based on the assumption that from a top view mos tvehicles’ edges are approximately of rectangular shape. Thus, we have a rectangle fitting problem.
The first step in the process is sorting of data into different lists containing object data and data from the ground closest to the object. Then a rectangle with minimal area is estimated based on object data only. We propose an algorithm for estimation of the minimum rectangle area containing the convex hull of the object data. From the rectangle estimate, estimates of the length and width of the objectcan be retrieved.
The first rectangle estimate is then improved using least squares methods based on both object and ground data. Both linear and nonlinear least squares methods are described. These improved estimates of the length and width are less biased compared to the initial estimates.
Three algorithms are evaluated; a minimum rectangle estimator proposed by the author, the mixed LS-TLS algorithm and a quasi-Newton algorithm. The algorithms are applied to both simulated and real laser radar data.
The thesis ends with a discussion of the assumptions that this work is based on and some suggestions of future work.
Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2000. , 83 p.
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 840
IdentifiersURN: urn:nbn:se:liu:diva-98135ISBN: 91-7219-790-0OAI: oai:DiVA.org:liu-98135DiVA: diva2:652259
Millnert, Mille, Professor