Target localization in unknown environments using static wireless sensors and mobile robots

This paper proposes a novel scheme for target localization in unknown environments using a prior-deployed static wireless sensor network (WSN). The goal is to have multiple mobile autonomous robots navigate from any point in a region to the closest identified target location just by interacting with the sensors. This is achieved in two ways: (i) by producing a pseudogradient in the region having its peak closest to the target, and (ii) by having the sensors assist the robots, guiding them to the target efficiently. Such a scheme makes use of the topology of the network to create a navigation path as the robot follows this pseudo-gradient in the network to reach the global maxima. It is assumed that there is no global coordinate frame for the region i.e. the WSN and robots are not aware of their position globally, and only make use of the relative localization based on neighborhood information. The performance of the scheme is analyzed in simulation with different node-densities and obstaclefilled regions.