Coordinated Planning Transmission Tasks in Heterogeneous Space Networks:A Semi-Distributed Approach

This paper studies the coordinated planning of transmission tasks in the heterogeneous space networks to enable efficient sharing of ground stations cross satellite systems.Specifically,we first formulate the coordinated planning problem into a mixed integer liner programming(MILP)problem based on time expanded graph.Then,the problem is transferred and reformulated into a consensus optimization framework which can be solved by satellite systems parallelly.With alternating direction method of multipliers(ADMM),a semi-distributed coordinated transmission task planning algorithm is proposed,in which each satellite system plans its own tasks based on local information and limited communication with the coordination center.Simulation results demonstrate that compared with the centralized and fully-distributed methods,the proposed semi-distributed coordinated method can strike a better balance among task complete rate,complexity,and the amount of information required to be exchanged.

An Integrated Image Task Planning in Satellite Networks:From Instruction Release and Observation Perspective

The unreasonable observation arrangements in the satellite operation control center(SOCC)may result in the observation data cannot be downloaded as scheduled.Meanwhile,if the operation instructions released by the satellite telemetry tracking center(STTC)for the on-board payloads are not injected on the specific satellites in time,the corresponding satellites cannot perform the observation operations as planned.Therefore,there is an urgent need to design an integrated instruction release,and observation task planning(I-IRO-TP)scheme by efficiently collaborating the SOCC and STTC.Motivated by this fact,we design an interaction mechanism between the SOCC and the STTC,where we first formulate the I-IRO-TP problem as a constraint satisfaction problem aiming at maximizing the number of completed tasks.Furthermore,we propose an interactive imaging task planning algorithm based on the analysis of resource distribution in the STTC during the previous planning periods to preferentially select the observation arcs that not only satisfy the requirements in the observation resource allocation phase but also facilitate the arrangement of measurement and control instruction release.We conduct extensive simulations to demonstrate the effectiveness of the proposed algorithm in terms of the number of completed tasks.

Complex task planning method of space-aeronautics cooperative observation based on multi-layer interaction

With the new development trend of multi-resource coordinated Earth observation and the new goal of Earth observation application of“short response time,high observation accuracy,and wide coverage”,space-aeronautics cooperative complex task planning problem has become an urgent problem to be solved.The focus of this problem is to use multiple resources to perform collaborative observations on complex tasks.By analyzing the process from task assignment to receiving task observation results,we propose a multi-layer interactive task planning framework which is composed of a preprocessing method for complex tasks,a task allocation layer,a task planning layer,and a task coordination layer.According to the characteristics of the framework,a hybrid genetic parallel tabu(HGPT)algorithm is proposed on this basis.The algorithm uses genetic annealing algorithm(GAA),parallel tabu(PT)algorithm,and heuristic rules to achieve task allocation,task planning,and task coordination.At the same time,coding improvements,operator design,annealing operations,and parallel calculations are added to the algorithm.In order to verify the effectiveness of the algorithm,simulation experiments under complex task scenarios of different scales are carried out.Experimental results show that this method can effectively solve the problems of observing complex tasks.Meanwhile,the optimization effect and convergence speed of the HGPT is better than that of the related algorithms.

Overall plan and design of the task management system of ternary optical computer

t In this paper an overall scheme of the task management system of ternary optical computer （TOC） is proposed, and the software architecture chart is given. The function and accomplishment of each module in the system are described in general. In addition, according to the aforementioned scheme a prototype of TOC task management system is implemented, and the feasibility, rationality and completeness of the scheme are verified via running and testing the prototype.

Research on Model and Algorithm of Task Allocation and Path Planning for Multi-Robot

Based on the modeling of robot working environment, the shortest distance matrix between points is solved by Floyd algorithm. With the objective of minimizing the sum of the fixed cost of robot and the cost of robot operation, an integer programming model is established and a genetic algorithm for solving the model is designed. In order to make coordination to accomplish their respective tasks for each robot with high efficiency, this paper uses natural number encoding way. The objective function is based on penalty term constructed with the total number of collisions in the running path of robots. The fitness function is constructed by using the objective function with penalty term. Based on elitist retention strategy, a genetic algorithm with collision detection is designed. Using this algorithm for task allocation and path planning of multi-robot, it can effectively avoid or reduce the number of collisions in the process of multi-robot performing tasks. Finally, an example is used to validate the method.

Distributed cooperative task planning algorithm for multiple satellites in delayed communication environment

Multiple earth observing satellites need to communicate with each other to observe plenty of targets on the Earth together. The factors, such as external interference, result in satellite information interaction delays, which is unable to ensure the integrity and timeliness of the information on decision making for satellites. And the optimization of the planning result is affected. Therefore, the effect of communication delay is considered during the multi-satel ite coordinating process. For this problem, firstly, a distributed cooperative optimization problem for multiple satellites in the delayed communication environment is formulized. Secondly, based on both the analysis of the temporal sequence of tasks in a single satellite and the dynamically decoupled characteristics of the multi-satellite system, the environment information of multi-satellite distributed cooperative optimization is constructed on the basis of the directed acyclic graph（DAG）. Then, both a cooperative optimization decision making framework and a model are built according to the decentralized partial observable Markov decision process（DEC-POMDP）. After that, a satellite coordinating strategy aimed at different conditions of communication delay is mainly analyzed, and a unified processing strategy on communication delay is designed. An approximate cooperative optimization algorithm based on simulated annealing is proposed. Finally, the effectiveness and robustness of the method presented in this paper are verified via the simulation.

Emergency Tasks Planning Based on Formal Modeling of Emergency Plan and HTN Planning System SHOP2

A theoretical approach of ordered emergency tasks generation is proposed for dealing with a specific emergency event rapidly, exactly and effectively. According to the general principles of an emergency plan developed to response to an emergency management, a workflow model is employed to complete the formal modeling of concrete emergency plan firstly. Then the HTN planning system SHOP2 is introduced, the transformation method of domain knowledge from emergency domain to SHOP2 domain is studied. At last, the general procedure to solve the emergency decision prob-lems and to generate executive emergency tasks is set up drawing support from SHOP2 planning system, which will combine the principles (or knowledge) of emergency plan and the real emergency situations.

Study on DSM-based task planning of product cooperative development

The results of analyzing the managerial characteristics and complexity of product cooperative development suggest that task planning is an important aspect for process management of product cooperative development and the method for planning tasks should be able to model the dependency between tasks and iterations during the development process. In this paper, a DSM-based method and its corresponding optimization algorithms are developed. At first the coupled task sets and uncoupled task sets are identified, and the tasks are then optimized by the corresponding algorithms. The optimal tasks plan will reduce the development time and cost. Considering the practical requirements in real world, a Multilayer DSM is proposed, and its information communication techniques between DSM and traversing principle are described in details.

Collaborative task planning for an internet based multi-operator multi-robot system

In an Internet based multi-operator and multi-robot system (IMOMR), operators have to work collaboratively to overcome the constraints of space and time. Inherently, the activities among them can be defined as a computer-supported cooperative work (CSCW). As a practical application of CSCW, a collaborative task planning system (CTPS) for IMOMR is proposed in this paper on the basis of Petri nets. Its definition, components design, and concrete implementation are given in detail, respectively. As a result, a clear collaboration mechanism of multiple operators in an IMOMR is obtained to guarantee their task planning.

Research on Task Planning Algorithm of Retrieving Invalid Satellite for Free-Flying Space Robot

A free-flying space robot will accomplish manufacturing, assembling and repair instead of astronauts in the future unmanned space flight hbecause of its flexible maneuverability in space. This paper presents a task planning algorithm of retrieving invalid satellite for free-fiving space robot. First we discuss kinematics model and deduct cinematics equations of dual-arm space robot. Then the process of retrieving an invalid satellite, which is divided into eleven motion procedures. At the same time, we have developed a free-flying space robot task planning simulation system and the experimental results show that this algorithm is feasible and correct.

Effectiveness of Task Sharing and Task Shifting on the Uptake of Family Planning in Kenya

Background: Contraception is an inexpensive and cost-effective intervention, but health workforce shortages and restrictive policies on the roles of mid and lower-level cadres limit access to effective contraceptive methods in many settings. Task sharing and task shifting are strategies that can be adopted to increase uptake of health services including family planning. Methods: We collected data through online survey, key informant interviews and focused grouped discussions with an intervention group and that implemented the task sharing and task shifting policy guidelines and a control group that did not implement the policy. A total of 434 questionnaires were filled by health workers’ in primary health care facilities to assess effectiveness of task sharing and task shifting on the uptake of family planning services including its strengths and challenges. The questionnaire was designed with the aim of getting data on services provided by the cadres on effectiveness (number of clients, increase in use of methods, access to services), how they perceive these tasks, the bottlenecks and facilitating factors associated with the practice of task sharing and task shifting. Results: We found out that the task sharing and task shifting can expand and increase access to services as stated by 95% of the respondents. Most community health workers provided more of the family planning services at 45% with only 5% of the services of family planning being provided by medical officers. 98% of family planning services were integrated with other services. Task shifting was beneficial to the health care providers as well as the clients and the success of task sharing and task shifting depended on training, supportive supervision and a regulated environment through policies. Conclusion: The study shows that formalized task sharing and task shifting can increase health service uptake especially when community health workers are involved to provide services in the community. This leads to increased service provision, equivalent health professional performance across cadres and patient outcomes in the provision of family planning services.

多机协同自主任务规划系统研究综述

针对多机协同自主任务规划显著提升无人机任务感知效能、提高任务执行能力的现状,对其关键技术进行阐述,主要包括知识表示、通感一体化、任务调度及航迹规划等技术。针对知识表示技术,阐述基于任务环境上下文感知的知识库构建方法,进而对多域融合知识图谱构建、动态知识图谱更新与共享方法进行分析总结;针对通感一体化技术,分析了环境适变、灵活可扩的多机协同通感一体化架构,进而揭示多机协同通感一体化理论能限,阐述面向任务差异性需求的资源共享方法;针对任务调度及航迹规划技术,阐述资源适配的多机协同自主任务调度方案,并对基于动力学模型的航迹控制策略及不完美环境下的鲁棒控制机制进行分析总结。

陆地生态系统碳监测卫星自主任务规划研究

低轨遥感卫星往往以全球或全国范围内的特定地物为探测目标。为提高卫星在轨运行的自主性,文章提出了一种面向地物目标属性的遥感卫星自主任务规划方法。首先外推出预报点90 min后的星下点经纬度,并根据星载地图和太阳高度角,得到预报点的阳照/阴影、陆地/海洋、境内/境外属性。对地物目标属性信息进行平滑处理后,根据各载荷的地物目标属性,识别出各载荷的工作任务时间段,可实时实现提前约1个轨道圈的载荷自主任务规划。

一种动态锁定式多星协同任务规划的A2C算法

提出了一种基于强化学习算法的多星协同任务规划方法。该方法将多星协同任务规划视为多个双星协同规划,采用相邻双星锁定的方式来共享双星任务规划结果信息,基于A2C(优势动作评价)强化学习算法对双星任务规划的结果进行再调整。针对多星协同任务规划状态空间复杂且变化的问题,设计了两级状态空间和价值评价函数决策的方法,对强化学习所依赖的状态空间进行维度限制,确保智能体对任务进行调整的过程不影响状态空间维度。算法设计过程考虑了多种约束条件,设置了天气、成像质量和成像优先级等可调参数作为强化学习A2C算法的评价参数,这些可调参数有助于用户自定义决策评价体系。最后,通过仿真验证了算法的可行性。仿真结果表明,该算法多星协同任务规划的组合任务抛弃率小于10%。

基于FreeRTOS的桶装水搬运机器人控制系统研究

针对工业机器人运动控制装置二次开发难度大、专业应用性差,设计一款以STM32F4系列单片机为核心,基于FreeRTOS操作系统的桶装水搬运机器人的控制系统。根据现场总线、实时操作要求、伺服控制方式等要素,设计运动控制器硬件和控制系统软件的整体方案;根据最短任务时间调度设计优化FreeRTOS操作系统任务调度算法;根据机器人结构、桶装水搬运路径和码垛方式,通过分析常用行进轨迹算法,优化5次多项式的轨迹方程,并通过MATLAB进行仿真,验证轨迹算法的准确性,对于工业搬运机器人系统设计具有一定参考意义。

面向超低空物流场景的多机协同航迹规划算法

无人机产业的迅猛发展促进了低空开放,形成了国内外城市超低空物流运输的浪潮,然而,现有的航迹规划算法没有考虑空域的划分方式与运行规则,不适用于城市超低空物流场景下多无人机的协同航迹规划,桎梏了超低空物流行业的发展。针对该问题,从实际需求出发,在空域高度层架构的基础上探索适用于城市超低空物流场景的多无人机协同航迹规划方法。将原问题分解为无人机-高度层任务分配与多无人机单高度层协同航迹规划两个相互耦合的子问题,并分别运用基于知识图谱的任务分配解法与基于粒子群算法的改进人工势场法对两个子问题进行求解。仿真实验表明,该方法在求解单高度层协同航迹规划子问题中不但能够避免传统方法的固有缺陷,平均迭代次数相较于对比方法也减少了62.09%;同时,仿真结果也表明所提方法可以快速鲁棒的解决原问题,为城市超低空物流场景提供了切实可行的多机航迹规划方法。

重大装备制造多机器人任务分配与运动规划技术研究综述

飞机蒙皮、船舶舱体、高铁车身等大型复杂部件高效高品质制造是航空航天、海洋舰船、轨道交通等领域重大装备发展的根基.大型复杂部件具有尺寸超大、型面复杂等特点,传统的人工、单机制造面临着效率低、一致性差、空间有限等问题,多机器人具有高鲁棒性、高效性等优点,为大型复杂部件制造提供了良好的制造基础.任务分配与运动规划是多机器人制造系统的决策中枢,其性能影响整个系统的运行效率.考虑到重大装备部件制造任务分配与运动规划过程中任务工序多、冲突干涉多、精度需求高等挑战,本文首先对复杂环境下多机器人任务分配与运动规划的重要性进行了说明;然后阐述了目前主要的任务分配与运动规划方法,包括其在智能制造领域下的应用;在此基础上,对现阶段复杂场景下任务分配和运动规划存在的问题进行了分析,并使用强化学习与混合优化算法等方法提出了解决思路;最后对重大装备大型复杂部件制造过程多机器人任务分配和动态规划技术及应用的发展进行了总结与展望.

面向重访周期需求的敏捷成像卫星任务规划方法

为满足敏捷成像星座观测目标的重访周期需求,提出一种混合编码差分进化算法.分析敏捷成像卫星的工作特点,构造评价重访周期需求满足情况的目标函数,建立成像任务约束满足模型.针对观测任务选择与否、执行顺序和成像时间的优化需求,提出一种二进制-实数混合编码差分进化算法,实现了成像任务在时间轴上的分布优化.通过工程实例进行仿真校验,仿真结果表明相比于基于二进制编码的遗传算法,本文算法在优化时间和优化效果方面都有较大优势.

小天体多节点着陆器强化学习任务规划方法

针对中国提出的小天体多节点着陆器节点运动强耦合,着陆规划过程复杂、执行易偏差、重新规划速度慢特点,提出一种多节点着陆器强化学习任务规划方法。该方法首先将状态空间规划逻辑模型描述为矩阵,利用模型矩阵将任务规划建模为马尔科夫过程,之后通过状态哈希的广度优先搜索算法筛选随机生成状态,生成有效多节点着陆器状态空间始末状态,构建虚拟状态空间训练环境,随机切换始末状态训练强化学习智能体,提升节点的规划适应能力,实现多种条件下的任务规划。对着陆任务进行仿真,实验表明训练后智能体成功完成所有测试任务,且规划效率比POPF3规划器更高,在方案频繁调整的短序列任务上规划速度优势更大,可以更好地应用于多节点着陆器的任务规划。

无人机蜂群作战任务规划研究现状与展望

无人机具有低成本、无伤亡、操作简便、灵活可靠等作战优势,在多次局部冲突中大放异彩,而无人机蜂群是一种以大量无人机为基础节点的新型作战样式,近年来受到各军事强国的持续关注。任务规划作为无人机蜂群遂行作战任务的核心,也是其发挥作战能力的关键之一。阐述了无人机蜂群作战任务规划的基本概念和流程,着重从任务分配和航迹规划两个方面,分析了任务规划模型和约束条件,对比了各类典型方法的优缺点,并从场景构设、规划模型、规划要素、推演评估、规划模式等5方面阐述了无人机蜂群作战任务规划的关键问题及发展趋势,对无人机蜂群的作战样式探索和任务规划研究具有参考借鉴意义。