Vehicle Routing Problem Instances: Application to Multi-UAV Mission Planning

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83659/1/AIAA-2010-8435-207.pd

Task assignment algorithms for teams of UAVs in dynamic environments

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics; and, (S.M.)--Massachusetts Institute of Technology, Operations Research Center, 2004.Includes bibliographical references (p. 113-118).For many vehicles, obstacles, and targets, coordination of a fleet of Unmanned Aerial Vehicles (UAVs) is a very complicated optimization problem, and the computation time typically increases very rapidly with the problem size. Previous research proposed an approach to decompose this large problem into task assignment and trajectory problems, while capturing key features of the coupling between them. This enabled the control architecture to solve an assignment problem first to determine a sequence of waypoints for each vehicle to visit, and then concentrate on designing paths to visit these pre-assigned waypoints. Although this approach greatly simplifies the problem, the task assignment optimization was still too slow for real-time UAV operations. This thesis presents a new approach to the task assignment problem that is much better suited for replanning in a dynamic battlefield. The approach, called the Receding Horizon Task Assignment (RHTA) algorithm, is shown to achieve near-optimal performance with computational times that are feasible for real-time implementation. Further, this thesis extends the RHTA algorithm to account for the risk, noise, and uncertainty typically associated with the UAV environment. This work also provides new insights on the distinction between UAV coordination and cooperation. The benefits of these improvements to the UAV task assignment algorithms are demonstrated in several simulations and on two hardware platforms.by Mehdi Alighanbari.S.M

Optimal scheduling for refueling multiple autonomous aerial vehicles

The scheduling, for autonomous refueling, of multiple unmanned aerial vehicles (UAVs) is posed as a combinatorial optimization problem. An efficient dynamic programming (DP) algorithm is introduced for finding the optimal initial refueling sequence. The optimal sequence needs to be recalculated when conditions change, such as when UAVs join or leave the queue unexpectedly. We develop a systematic shuffle scheme to reconfigure the UAV sequence using the least amount of shuffle steps. A similarity metric over UAV sequences is introduced to quantify the reconfiguration effort which is treated as an additional cost and is integrated into the DP algorithm. Feasibility and limitations of this novel approach are also discussed

Adaptive fault-tolerant control of uncertain nonlinear systems under Actuator failure of unmanned aerial vehicles

With the increasingly extensive application of UAV technology, UAV accidents are increasing, and the safety problem is becoming more and more serious. Therefore, it is urgent to ensure the safety and reliability of UAV. This paper fi rstly introduces the application requirements and research signifi cance of the fault-tolerant control system of UAV; Secondly, the classifi cation of fault-tolerant control system of UAV is introduced. Finally, taking the nonlinear system of UAV as an example, the controller and its parameters are derived, and Simulink simulation model is established with MATLAB software to verify that the designed adaptive fault-tolerant controller can eff ectively maintain the stability and reliability of the system