Optimal motion and communication for persistent information collection using a mobile robot

In this paper, we study the problem of persistent information collection using a mobile robot. We consider the scenario where information bits are generated with certain rates at a given set of points of interest (POIs) in a workspace. A mobile robot is then tasked with moving along a periodic trajectory, collecting the information bits from the POIs, and transmitting them to a fixed remote station over realistic fading communication channels. The goal is to minimize the total energy (the summation of motion and communication energies) consumed in one period, while guarantying the following: 1) the number of generated information bits at each POI remains bounded at all the times, 2) the collected information bits in one period are transmitted to the remote station, in the same period, with an acceptable reception quality, and 3) the number of collected information bits in one period is less than the memory size of the robot at all the times. Assuming that the trajectory of the robot defines a Hamiltonian cycle on the POIs, we propose a novel mixed-integer linear program (MILP) to design the optimal trajectory of the robot as well as its motion (velocity profile) and communication (transmission power and rate profiles) along its trajectory. The solution of the MILP is analyzed through several simulations. Our results show the effectiveness of the proposed MILP approach for persistent information collection in fading communication environments.