HLA/RTI下周期与非周期任务调度的实时性改进

为了把高层体系结构的标准应用到实时系统中,必须确保运行时支撑环境的实时性.联邦成员间相关的任务之间有优先顺序约束关系,在联邦成员内调度运行时较难提供可预测的响应,因而难以保证所有任务尤其是非周期任务的实时性.以任务调度理论的角度在联邦成员内部综合调度周期与非周期任务运行的D-EDF（Double-Earliest Deadline First）策略,既能舍弃部分冗余数据使周期性任务在截止时间前高效完成,又能调度非周期性任务规则的运行提高实时响应速度,使得联邦成员可以高效地处理有优先顺序约束关系的任务,进而改进了运行时支撑环境的实时性.最后证明了D-EDF调度策略的可行性.      

Study on TT&C resources scheduling technique based on inter-satellite link

The navigation constellation will have the capability of supporting Tracking Telemetry and Command (TT&C) operations by inter-satellite link (ISL). The ISL will become an important solution to reduce the shortage of ground TT&C resources. The problems need to be studied urgently in the field of space TT&C network resources scheduling management are how to determine the availability of ISL and how to allocate TT&C resources of ISL. The performance and scheduling constraints of navigation constellation?s ISL are analyzed, and three utilization strategies of ISL to perform TT&C operations are proposed. The allocation of TT&C resources based on ISL falls into two successive phases. Firstly, master satellite determination equation is established by using 0–1 Programming model based on the availability matrix. Mathematical method is used to solve the equation to determine the master satellite and the topology of ISL. Secondly, Constraint Programming (CP) model is used to describe the ground TT&C resources scheduling problem with special requirements of TT&C operations based on master satellite, and a heuristic algorithm is designed to solve the CP model. The equations and algorithm are verified by simulation examples. The algorithm of TT&C resources scheduling based on ISL has realized the synthesized usage of both the ISL and ground resources on TT&C field. This algorithm can improve TT&C supports of territorial ground TT&C network for global navigation constellation, and provides technical reference for the TT&C mission planning of global constellation by using ISL.     

基于CCR带并行腔双集束型设备调度方法

为有效解决450mm晶圆制造中带有并行处理腔的集束型设备群调度问题,提出了基于产能约束资源（CCR）的调度方法。首先,综合考虑多品种加工、晶圆驻留和资源约束等特征,以系统总完工时间最小作为目标,建立带并行腔双集束型设备调度数学模型;其次,为优化机械手作业顺序,对CCR实施锁定-收紧-松弛（LTL）策略,构建了一种以CCR为界的分段调度算法;最后,进行了仿真实验分析。结果表明本文提出的算法是有效和有竞争性的。      

基于改进算法的工艺规划与车间调度的双目标优化模型

针对工艺规划与车间调度的集成问题,一般考虑以加工时间、加工成本和加工质量为优化性能指标,而对能量消耗等环境影响因素考虑不足。本文建立了工艺规划与车间调度的数学模型,以完工时间和能量消耗为优化目标,通过设置权重系数来调节优化目标倾向。采用改进的混合模拟退火与遗传算法对问题进行求解,利用遗传算法的全局搜索速度快和模拟退火的突跳性强的特点,结合回火机制,有效地得到了完工时间和能量优化结果。最后,通过实例仿真表明该方法具有可行性。     

卫星有效载荷的规划与调度

卫星有效载荷的规划与调度要求是指卫星根据自身资源情况合理安排各个载荷的工作状态，在满足各种资源约束的条件下实现资源的优化配置。有效载荷的规划与调度可以归结为典型的资源受限的规划与调度问题。本文以对地观测卫星的有效载荷系统为例，分析了卫星的资源特点和载荷的工作特性，在此基础上提出了一种有效载荷规划与调度的方法。仿真实例表明了算法的可行性。     

基于调度预测的星载混合相关任务调度算法及其仿真的研究

为解决星载计算机系统中具有相关性任务的调度和临界资源的分配问题，提出了一种星载混合相关任务调度算法。首先，对星载计算机系统中的任务给出了形式化的描述。其次，具体阐述了这种星载多任务调度算法并给出了可调度性预测分析条件。最后，通过仿真实验对这个调度算法的性能进行了验证并给出了结论。     

改进差分进化算法求解多成像卫星调度问题

针对多成像卫星联合调度规划建模难度大和求解复杂度高等问题,通过分析成像卫星的成像过程和工作原理,将成像卫星调度过程分为调度预处理、任务规划和调度优化3个阶段。在调度规划过程中,建立了多星联合调度约束满足最优化模型,采用启发式算法思想,定义了个体适应度评估函数,设计了任务冲突消解方法,提出了一种改进的差分进化算法。在此基础上,采用一些确定性规则对调度规划方案可行解进行了评估和二次优化。结果表明:提出的成像卫星调度问题求解方法能够有效地分配卫星资源,生成优化的调度方案。设计结果也能够为卫星系统最优化设计和效能评估提供必要的决策支持。     

Comparative analysis of global optical observability of satellites in LEO

With a growing number of resident space objects (RSOs), the facilities for near-Earth space surveillance have to cope with increasing workload. It also applies to low-cost small optical surveillance facilities which may present regional, national and global networks. Improved methods of planning and scheduling optical telescopes are required to use these instruments efficiently. Today, optical observations are only feasible if the following quite stringent requirements are met: the object should be illuminated by sunlight, and it should be above while the Sun is below the observer’s horizon. For different orbits, these preconditions result in varying degrees of the space object observability at various ground-based sites. Certainly, satellites in low Earth orbit (LEO) are particularly difficult to observe. This study aims at developing a new technique for assessing observability of a satellite in different types of orbits – namely, low, medium and high Earth orbits, imaging of the opportunity for its visibility in respective diagrams and their analysing for the existing near-Earth population of RSOs. Unlike other researches, wherein one or several observational stations have been chosen as target sites for in-depth analyses of visibility of all the satellites or just the selected ones, the present study focuses on examining the probability of optical surveillance of satellites in a certain orbit from any locations worldwide. It offers considerable scope for automation of surveillance planning and scheduling optical surveillance networks.     

面向数字化装配生产过程的动态调度方法

针对数字化装配实际生产过程中动态扰动因素造成静态调度失效问题,建立面向数字化装配生产过程的动态调度模型。模型考虑了机器故障、人员流失和不合格产品等动态扰动对装配过程的影响,建立飞机大部件数字化装配工艺流程描述模型。在此基础上计算预调度方案,扰动产生时刻重新计算调整预调度方案。将资源利用率、平均生产率和作业平衡系数等指标作为优化目标,结合多目标优化遗传算法求解模型的Pareto最优解,得到多目标优化的装配作业调度方案。     

基于改进AHP的低轨星座传感器调度方法

针对低轨星座传感器调度,分析了影响调度的因素,用改进判断矩阵的构造方法建立相应的调度准则,提出了一种基于改进层次分析的传感器调度方法,有效克服了传统层次分析方法需要一致性检验的缺点。典型场景仿真结果表明：改进层次分析法的性能明显优于传统层次分析法。