大规模无线传感网中的无人机携能通信航迹规划研究

The use of unmanned aerial vehicles (UAV) as communication platforms has attracted many interests in recent years. In order to resolve the energy harvesting and data collection problem in large-scale wireless sensor networks (WSNs), this project studis a UAV-enabled wireless powered communication platform by exploiting the high maneuverability and the advantage of line-of-sight(LoS) communication link of UAV. At the theoretical layer, the project research focuses on the rechargeable time allocation scheme during the flight time of UAV. At the same time, a concept of region-dependent charging strategy based on the residual energy is proposed. Furthermore, the project establishes the charging mathematical model aiming to balance the energy harvesting and throughput maximization target. Finally, at the algorithmic layer, the project proposes a low-complexity algorithm with higher performance than the existing methods by exploiting the hybrid convex property as well as the distributed computing structure in the original problem，which enables the FPGA platform implementation. The research results of the project is expected to prolong the network life time, promote the convergence development and complement for UAV-enabled wireless powered communication and WSN.

本项目针对大规模无线传感网数据收集与能量补充面临的技术挑战问题，充分利用无人机自由移动及视距通信的优势，令无人机搭载无线能量发射装置与sink节点，为地面节点实时补充能量、传输数据。理论创新之处在于考虑了无人机自充电模式，通过航迹规划中无人机自充电的时间分配设计，实现无人机通信平台在无线传感网中执行任务的可延续性，避免频繁人工干预；另外，根据传感网节点剩余能量将传感网进行区域划分，并据此提出能量补充与数据传输均衡考虑的充电策略。算法创新之处在于本项目通过对现有算法的改进，发掘原非凸问题中隐藏的凸性，并在求解中引入并行分步式计算思想，在实现系统性能提高的同时，将航迹规划中心集成于FPGA芯片。本项目产出的无线携能通信技术可望实现无线传感网长期稳定运行，推动无人机携能通信技术和无线传感网的融合发展和优势互补。

部署于野外环境的无线传感网节点，无法进行器件更换，往往缺少稳定持续的能量补充来源。利用无人机配置无线能量充电及通信设备，可以借助无人机的无障碍快速移动，视距通信等特性，建立空地无线携能通信平台，从而一方面使网络中节点的通信尽量限制在局部区域内，有效降低网络传输能量消耗，另一方面可以利用无线充电，进一步提升无线传感网络的生命周期。本课题重点研究以下三个内容：1）根据传感网节点剩余能量储备的不同，提出灵活的按需充电策略；2）研究无人机在机载能量受限时的轨迹优化与功率分配问题；3）改进传统的SCA算法对无人机航迹的规划，提出了无人机轨迹的闭式解。本研究通过优化无人机的飞行轨迹，与地面传感节点的充电功率及通信功率，实现了无人机对无线传感网的数据收集及能量补充。项目研究成果能突破无线传感网节点无法更换电池的限制，为大规模无线传感网在偏远地区、无人地带的部署提供解决方案。本研究资助发表的SCI文章6篇，专利5篇。