Abstract: Aiming at the problem of information freshness in the process of massive data processing in wireless sensor networks, based on the constraints of UAV flight speed, altitude, collision avoidance, and reliable transmission, this paper uses Age of Information (AoI) as the assessment parameter to propose a non-convex optimization strategy for AoI minimization that combines collection point selection, trajectory optimization, and UAV working time trade-off. Taking multiple UAVs' transmitting energy to multiple sensor nodes and collecting sensor data under the same frequency band as a scenario, the information collection process of multiple UAVs in three-dimensional space is simulated and verified. Through the Successive Convex Approximation (SCA) optimization algorithm, the established non-convex problem is transformed into a convex optimization problem for solution. Finally, the optimal collection point, optimal flight strategy, allocation trade-off index of energy delivery time and transmission time during the UAV flight are obtained. The experimental results show that the optimal solution obtained by the scheme can effectively minimize the system AoI.

Key words: UAV, wireless sensor network, AoI, convex optimization