Energy-Constrained Delivery of Goods with Drones Under Varying Wind Conditions

In this paper, we study the feasibility of sending drones to deliver goods from a depot to a customer by solving what we call the Mission-Feasibility Problem (MFP). Due to payload constraints, the drone can serve only one customer at a time. To this end, we propose a novel framework based on time-dependent cost graphs to properly model the MFP and tackle the delivery dynamics. When the drone moves in the delivery area, the global wind may change thereby affecting the drone's energy consumption, which in turn can increase or decrease. This issue is addressed by designing three algorithms, namely: (i) compute the route of minimum energy once, at the beginning of the mission, (ii) dynamically reconsider the most convenient trip towards the destination, and (iii) dynamically select only the best local choice. We evaluate the performance of our algorithms on both synthetic and real-world data. The changes in the drone's energy consumption are reflected by changes in the cost of the edges of the graphs. The algorithms receive the new costs every time the drone flies over a new vertex, and they have no full knowledge in advance of the weights. We compare them in terms of the percentage of missions that are completed with success (the drone delivers the goods and comes back to the depot), with delivered (the drone delivers the goods but cannot come back to the depot), and with failure (the drone neither delivers the goods nor comes back to the depot).Comment: typo author's nam

Design and evaluation of a new multi-path incremental routing algorithm on software routers

In this paper we analyze intra-domain routing protocols improvements to support new features required by realtime services. In particular we introduce OSPF Fast Convergence and highlight the advantage of using a dynamic algorithm instead of the Dijkstra one to compute the shortest paths. Then we propose a new multi-path dynamic algorithm which uses multipath information to make a fast determination about the new shortest paths when a link failure occurs, reducing this way the network re-convergence time. To evaluate the proposed algorithm performance we have implemented it in the OSPF code of the Quagga open-source routing software. We compare our own algorithm with three different dynamic algorithms, like the one implemented in Cisco routers and the two others, well known in literature, proposed by Narvaez and Ramalingam-Reps. We show how, by exploiting multi-path information, our algorithm performs, in many case studies, better than the above algorithms, especially in a link failure scenario. © 2009 IEEE