State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China.
University of Chinese Academy of Sciences, Beijing 100101, China.
Sensors (Basel). 2019 Mar 23;19(6):1430. doi: 10.3390/s19061430.
Emergency observations are missions executed by Earth observation satellites to support urgent ground operations. Emergency observations become more important for meeting the requirements of highly dynamic and highly time-sensitive observation missions, such as disaster monitoring and early warning. Considering the complex scheduling problem of Earth observation satellites under emergency conditions, a multi-satellite dynamic mission scheduling model based on mission priority is proposed in this paper. A calculation model of mission priority is designed for emergency missions based on seven impact factors. In the satellite mission scheduling, the resource constraints of scheduling are analyzed in detail, and the optimization objective function is built to maximize the observation mission priority and mission revenues, and minimize the waiting time for missions that require urgency for execution time. Then, the hybrid genetic tabu search algorithm is used to obtain the initial satellite scheduling plan. In case of the dynamic arrival of new emergency missions before scheduling plan releases, a dynamic scheduling algorithm based on mission priority is proposed to solve the scheduling problem caused by newly arrived missions and to obtain the scheduling plan of newly arrived missions. A simulation experiment was conducted for different numbers of initial missions and newly arrived missions, and the scheduling results were evaluated with a model performance evaluation function. The results show that the execution probability of high-priority missions increased because the mission priority was taken into account in the model. In the case of more satellite resources, when new missions dynamically arrived, the satellite resources can be reasonably allocated to these missions based on the mission priority. Overall, this approach reduces the complexity of the dynamic adjustment and maintains the stability of the initial scheduling plan.
应急观测是地球观测卫星执行的任务,旨在支持紧急地面作业。应急观测对于满足高度动态和高度时间敏感观测任务的要求变得更加重要,如灾害监测和预警。考虑到紧急情况下地球观测卫星的复杂调度问题,本文提出了一种基于任务优先级的多星动态任务调度模型。基于七个影响因素,为应急任务设计了任务优先级的计算模型。在卫星任务调度中,详细分析了调度的资源约束,并建立了优化目标函数,以最大化观测任务优先级和任务收入,最小化需要紧急执行时间的任务的等待时间。然后,采用混合遗传禁忌搜索算法得到初始卫星调度计划。在调度计划发布之前有新的紧急任务动态到达的情况下,提出了一种基于任务优先级的动态调度算法来解决新到达任务引起的调度问题,并得到新到达任务的调度计划。针对不同数量的初始任务和新到达任务进行了仿真实验,并使用模型性能评估函数对调度结果进行了评估。结果表明,由于模型中考虑了任务优先级,高优先级任务的执行概率增加了。在卫星资源较多的情况下,当新任务动态到达时,可以根据任务优先级合理分配卫星资源给这些任务。总体而言,这种方法降低了动态调整的复杂性,并保持了初始调度计划的稳定性。