基于演化算法的带侧摆多星点目标调度算法

Scheduling algorithm for multi-satellite and point target task on swinging mode based on evolution algorithm

针对成像卫星观测效率较低的问题,提出了一种侧摆情况下的多星点目标调度方法。首先分析了卫星与地面目标的角度关系、正负侧摆角度以及时间窗口的计算方法。在此基础上,以最大化观测收益、最小化侧摆次数及最小化总的侧摆角度为优化目标,建立了带侧摆的多星点目标调度模型。并基于演化算法,提出了一种载荷侧摆情况下优化调度算法。算法中采用任务级别的单点交叉算子,通过时间窗口的选取进行变异操作,定义了基于冲突度的适应度计算函数,通过调整活动的实际开始时间来减少冲突,基于目标的优先顺序设计了个体的选择策略,基于冲突代价的概念设计了冲突消除方法。最后,针对一个具体的实例,给出了5星100个点目标在侧摆情况下的调度与仿真结果,并对侧摆角度分别为0°、10°、25°时的调度性能进行了分析。实验结果表明,当侧摆角度为25°时,其观测效率比无侧摆时提高18%,该方法在应急救灾及战时快速响应等应用上有着重要的价值。

Concerning the low efficiency of earth observation satellite, a scheduling method for multi-satellite and point target task on swinging mode was proposed. In this paper, the angle relation between satellites and ground targets and the computing method of the positive and negative swinging angle and time window were firstly analyzed. On the basis of these analyses, a scheduling model for multi-satellite and point target task on swinging mode was developed. In the model, the maximum observation was obtained, the minimum swinging number and the minimum total swinging angle were set as the optimization objectives. Based on evolution algorithm, an optimal scheduling algorithm on swinging mode was proposed. In the algorithm, the single point crossover operator and the mutation operation through the selection of time window were adopted. The fitness function based on conflict was defined. The conflicts were reduced by adjusting the actual start time of the activities. The selection strategy was designed according to the order of the optimization objectives. The conflicts were eliminated by defining the conflict cost. Finally, the scheduling result and the simulation of a practical example on 5 satellites and 100 point targets with swinging mode were given, and the scheduling performances were also analyzed with the swinging angle of 0~, 10~ and 25~. The experimental results show that the observation efficiency improves by 18% when the swinging angle is 25. The method has important application value in emergency relief and wartime rapid response.