  We consider the challenging problem of online planning for a team of agents
to autonomously search and track a time-varying number of mobile objects under
the practical constraint of detection range limited onboard sensors. A standard
POMDP with a value function that either encourages discovery or accurate
tracking of mobile objects is inadequate to simultaneously meet the conflicting
goals of searching for undiscovered mobile objects whilst keeping track of
discovered objects. The planning problem is further complicated by
misdetections or false detections of objects caused by range limited sensors
and noise inherent to sensor measurements. We formulate a novel multi-objective
POMDP based on information theoretic criteria, and an online multi-object
tracking filter for the problem. Since controlling multi-agent is a well known
combinatorial optimization problem, assigning control actions to agents
necessitates a greedy algorithm. We prove that our proposed multi-objective
value function is a monotone submodular set function; consequently, the greedy
algorithm can achieve a (1-1/e) approximation for maximizing the submodular
multi-objective function.
