Multi-UAV Resource Constrained Online Monitoring of Large-scale Spatio-temporal Environment with Homing Guarantee

We propose a homing constrained bi-objective optimization variant of budget-limited informative path planning for monitoring a spatio-temporal environment. The objective function consists of weighted combination of two components: model performance which must be maximized and travel distance which must be bounded by the maximum operational range. Besides this, we have additional constraints that guarantee that the robots will return to home (base station) upon completion of their respective missions. Optimizing over this objective function is essentially NP-hard owing to the conflicting constituents. Moreover, the appropriate choice of weights and additional homing guarantees further adds to complications. We employ Gaussian Process (GP) model [1] which is highly data driven i.e., the larger the amount of training data, the better the model performance. However, owing to limited resources, a robot can only collect a limited amount of training samples. Thus, with the introduction of our bi-objective cost function, it becomes possible to plan budget-limited (e.g., battery, flight time, travel distance etc.) informative tours using autonomous mobile robots to effectively select only the most informative (uncertain) locations from the environment. In this work, we develop an algorithm to autonomously choose the appropriate weights for the components based on available resources while ensuring homing and maintaining model quality. We perform simulations to verify the effectiveness of our proposed objective function on the publicly available Ozone Concentration dataset gathered from USA.