STARS: Static Relays for Remote Sensing in Multirobot Real-Time Search and Monitoring

Mobile surveillance and sensing systems need a networking infrastructure that enables the mobile systems to transmit information gathered to a base station. We consider the problem of an efficient use of mobile robots to sense not only the region but also deploy relays to build the networking infrastructure. To develop an efficient solution to the above problem, we first present a problem called precedence constrained two traveling salesman (PC2TSP). We propose a near-optimal heuristic to PC2TSP to generate tours by clustering points, generating optimal single-traveler tours, and tour pruning and balance. By modeling in part by PC2TSP, we then solve the problem of minimum time two-robot real-time search with online relay deployment. We call the solution STAtic Relay aided Search (STARS), which identifies visiting positions, assigns the precedence constraint, and finally generates tours by PC2TSP. STARS enables solutions for remote robotic sensing and control. In addition, STARS substantially reduces cost compared to a homogeneous mobile robot system and enables constant monitoring of suspicious areas. STARS and our solution to PC2TSP are extensible to deal with more than two travelers. Extensive simulations show that our solution to PC2TSP achieves near-optimal performance with less than 2 percent average difference from optimal.