Topological navigation of mobile robot in a wireless sensor network

In this paper we present a novel navigation algorithm for a mobile robot to move across an open area covered by a pre-deployed wireless sensor network. The locations of the sensor nodes are unknown. We assume that from robot's starting position to the target location, there always exists a known path that the robot should move along. By using Lie derivative, we investigate the changing of signal strength difference along the vector field of robot's motion, and analytically prove that the signal strength differentiation can tell the correct direction the robot should move into. The proposed algorithm utilizes the wireless signal strength difference to guide the robot to move toward the desired sensor node at each step. The advantage of this algorithm is that the robot does not need to estimate the sensors' locations in order to topologically navigate through the unknown area and reach the target. Simulation results are included to demonstrate the proposed algorithm.