tailieunhanh - Báo cáo hóa học: " Research Article Tracking Objects with Networked Scattered Directional Sensors"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Tracking Objects with Networked Scattered Directional Sensors | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 360912 10 pages doi 2008 360912 Research Article Tracking Objects with Networked Scattered Directional Sensors Kurt Plarre1 and P. R. Kumar2 1 Department of Mechanical Engineering and Center for Control Dynamical Systems and Computation University of California Santa Barbara CA 93106 USA 2 Department of Electrical and Computer Engineering and Coordinated Science Laboratory University of Illinois at Urbana-Champaign 1308 w Main St. Urbana IL 61801 USA Correspondence should be addressed to P. R. Kumar plarre@ Received 19 April 2007 Accepted 4 August 2007 Recommended by Damien B. Jourdan We study the problem of object tracking using highly directional sensors sensors whose field of vision is a line or a line segment. A network of such sensors monitors a certain region of the plane. Sporadically objects moving in straight lines and at a constant speed cross the region. A sensor detects an object when it crosses its line of sight and records the time of the detection. No distance or angle measurements are available. The task of the sensors is to estimate the directions and speeds of the objects and the sensor lines which are unknown a priori. This estimation problem involves the minimization of a highly nonconvex cost function. To overcome this difficulty we introduce an algorithm which we call adaptive basis algorithm. This algorithm is divided into three phases in the first phase the algorithm is initialized using data from six sensors and four objects in the second phase the estimates are updated as data from more sensors and objects are incorporated. The third phase is an optional coordinated transformation. The estimation is done in an ad-hoc coordinate system which we call adaptive coordinate system. When more information is available for example the location of six sensors the estimates can be transformed to the real-world coordinate