Search for randomly moving targets II: Search path planning

The detection search problem is the identification of search paths for a specified time interval [0, T], so that the expected number of surviving targets at time T is minimized. The problem can be solved in real time only when the two major procedures: (1) estimation of target posterior distribution; and (2) evaluation of optimal controls (search path planning) based on this posterior target distribution can be done on line. The path planning problem is difficult since the state space is infinite dimensional. We introduce a discrete space-time model to which the Ordered Search Algorithm in AI Graph Search theory (with proper modifications) can be applied. The algorithm not only stops at the (an) optimal path but also expands far fewer nodes than an exhaustive search. The target estimation problem is treated in Part I[3].