Method and system for tracking multiple regional objects by multi-dimensional relaxation

Abstract

A method and system for real-time tracking of objects isare disclosed. A region is repeatedly scanned providing a plurality of images or data sets having points corresponding to ojbectsobjects in the region to be tracked. Given a previously determined track for each object in the region, an M-dimensional combinatorial optimization assignment problem is formulated using the points from M-1 of the images or data sets, wherein each point is preferably used in extending at most one track. The M-dimensional problem is subsequently solved for an optimal or near-optimal assignment of the points to the tracks, extending the tracking of the objects so that a response to each object can be initiated by the system in real-time. Speed and accuracy is provided by an iterative Lagrangian Relaxation technique wherein a plurality of constraint dimensions are relaxed simultaneously to yield a reduced dimensional optimization problem whose solution is used to formulate an assignment problem of dimensionality less than M. The iterative reducing of dimensions terminates when exact solutions are determined for two-dimensional cases. A recovery procedure is used for determining a higher dimensional assignment problem solution from a problem having one less dimension. The procedure is useful when the reduced dimensional optimizational problem has two constraint dimensions.

Description

RELATED APPLICATIONSU.S. APPLICATION DATA [0001]This application is a reissue of U.S. Pat. No. 5,959,574 which is a continuation-in-part of U.S. patent application Ser. No. 08 / 404,024, filed Mar. 14, 1995 and issued Jul. 16, 1996 as U.S. Pat. No. 5,537,119, which is a continuation-in-part of U.S. patent application Ser. No. 08 / 171,327 filed Dec. 21, 1993, now U.S. Pat. No. 5,406,289.STATEMENT REGARDING FEDERAL RIGHTS [0002]This invention was made with government support under Grant Nos. F49620-00-1-0108, F49620-93-1-0133, F49620-95-1-0136, and F49620-97-1-0273 awarded by the U.S. Air Force Office of Scientific Research to Colorado State University Research Foundation. The government has certain rights in the invention. FIELD OF THE INVENTION[0003]The invention relates generally to computerized techniques for processing data obtained from radiation reflections used to track multiple discrete object.BACKGROUND OF THE INVENTION[0004]a. Field of the Invention [0005]The invention relates...

AI Technical Summary

Benefits of technology

The patent describes a method for optimizing the assignment of observations to different tracks using a combination of constraints. The problem is solved by reducing the complexity of the original problem by generating lower dimension optimizations and solving them iteratively. This process allows for more flexibility in assigning points to the tracks, but adds penalties to the cost of an assignment. A preliminary auxiliary function is defined for each dimension and the gradient of the function is determined to determine the penalty factors. The procedure is iterated until an acceptable solution is reached. In an alternative embodiment, multiple dimensions can be relaxed simultaneously. A technical effect of this method is to improve the efficiency of the assignment process by solving the problem more efficiently using a combination of constraints and relaxing dimensions.

Problems solved by technology

In relaxing the constraints, terms having penalty factors are added into the objective function thereby increasing the total cost of an assignment when one or more points are assigned to more than one track.

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