In order to improve safety,economy efficiency and design automation degree of air route in terminal airspace,Three-dimensional(3D)planning of routes network is investigated.A waypoint probability search method is prop...In order to improve safety,economy efficiency and design automation degree of air route in terminal airspace,Three-dimensional(3D)planning of routes network is investigated.A waypoint probability search method is proposed to optimize individual flight path.Through updating horizontal pheromones by negative feedback factors,an antcolony algorithm of path searching in 3Dterminal airspace is implemented.The principle of optimization sequence of arrival and departure routes is analyzed.Each route is optimized successively,and the overall optimization of the whole route network is finally achieved.A case study shows that it takes about 63 sto optimize 8arrival and departure routes,and the operation efficiency can be significantly improved with desirable safety and economy.展开更多
Job planning (JP) systems shop oriented provide a basis for job shop scheduling and control in organizing short term production activities. This paper presents a method based on timed Petri net (TPN) method that is ...Job planning (JP) systems shop oriented provide a basis for job shop scheduling and control in organizing short term production activities. This paper presents a method based on timed Petri net (TPN) method that is used to program optimal JP for assembly shop. It includes three parts further. Firstly, an architecture of solutions to JP problems for any kind of shop oriented is presented to define a particular JP for a designated JP problem. Secondly, Petri net model is specified for aircraft part assembly processes. Finally, algorithms for optimizing generation of dynamic mechanism and a simulating case are then discussed. In comparison with traditional methods such as PERT or CPM, it is obviously convenient for planners or schedulers to schedule and manage assembly processes.展开更多
为解决低轨遥感星座协同任务规划面临的计算复杂度高、通信开销大、动态响应能力弱等问题,提出一种基于任务聚类与禁忌搜索的改进合同网算法(improved contract net protocol based on task clustering and tabu search,CN-TCTS).该算...为解决低轨遥感星座协同任务规划面临的计算复杂度高、通信开销大、动态响应能力弱等问题,提出一种基于任务聚类与禁忌搜索的改进合同网算法(improved contract net protocol based on task clustering and tabu search,CN-TCTS).该算法采用“单星调度-全局分配”的分层求解框架.首先,通过任务聚类合并元任务,有效缩减解空间;其次,设计了动态约束禁忌搜索算法(dynamic constraint tabu search,DCTS),通过价值导向的邻域搜索策略实现单星任务序列的快速规划;最后,在全局分配阶段,引入多种策略对传统合同网协议进行改进,实现任务的高效分配与冲突消解.仿真结果表明,本文所提CN-TCTS算法在400个任务的大规模场景下,任务完成率仍保持82.0%,且平均通信轮次仅为6.6轮.此外,在卫星突发失效的动态场景下,该算法表现出更强的鲁棒性,收益损失率更低.此外,局部规划算法仿真中验证了DCTS算法在收敛速度与解质量方面的优势.展开更多
Assembly model plans an important role in assembly sequence planning.Flexible assembly system (FAS) is a dis- crete event system (DES),so Petri net,as an important analytical tool for the DES,is used for modeling of a...Assembly model plans an important role in assembly sequence planning.Flexible assembly system (FAS) is a dis- crete event system (DES),so Petri net,as an important analytical tool for the DES,is used for modeling of an FAS.All of the feasible assembly sequences can be obtained by firing the Petri net model.In order to enhancing the efficiency of the assembly sequence planning,knowledge-based Petri net,combining an usual Petri net with expert’s knowledge and experiences,is proposed to con- struct the assembly model.So the feasible assembly sequences can be reduced greatly,and the optimum assembly sequence could be generated without the combinatorial explosion of solutions.展开更多
Aiming at the former formalized methods such as Strips, Situation Calculus and Fluent Calculus can not represent the action time and get the action sequence automatically, a novel method based on timed color Petri net...Aiming at the former formalized methods such as Strips, Situation Calculus and Fluent Calculus can not represent the action time and get the action sequence automatically, a novel method based on timed color Petri net—RPBTC was defined. The action time, the precondition and the post-condition of action are formalized in RPBTC based on the Fluent Calculus reasoning rules. An algorism for constructing the RPBTC net system based on bidirectional search strategy is proposed, and through executing the RPBTC net system, the action sequence for reaching the goal can be generated dynamically and the time for the robot reaching the goal also can be obtained. The experiment has proved the method RPBTC as a feasible method for robot planning.展开更多
基金supported by the National Natural Science Foundation of China(No.61039001)the State Technology Supporting Plan(No.2011BAH24B08)the Fundamental Research Funds for the Central Universities (No.ZXH2011A002)
文摘In order to improve safety,economy efficiency and design automation degree of air route in terminal airspace,Three-dimensional(3D)planning of routes network is investigated.A waypoint probability search method is proposed to optimize individual flight path.Through updating horizontal pheromones by negative feedback factors,an antcolony algorithm of path searching in 3Dterminal airspace is implemented.The principle of optimization sequence of arrival and departure routes is analyzed.Each route is optimized successively,and the overall optimization of the whole route network is finally achieved.A case study shows that it takes about 63 sto optimize 8arrival and departure routes,and the operation efficiency can be significantly improved with desirable safety and economy.
文摘Job planning (JP) systems shop oriented provide a basis for job shop scheduling and control in organizing short term production activities. This paper presents a method based on timed Petri net (TPN) method that is used to program optimal JP for assembly shop. It includes three parts further. Firstly, an architecture of solutions to JP problems for any kind of shop oriented is presented to define a particular JP for a designated JP problem. Secondly, Petri net model is specified for aircraft part assembly processes. Finally, algorithms for optimizing generation of dynamic mechanism and a simulating case are then discussed. In comparison with traditional methods such as PERT or CPM, it is obviously convenient for planners or schedulers to schedule and manage assembly processes.
文摘为解决低轨遥感星座协同任务规划面临的计算复杂度高、通信开销大、动态响应能力弱等问题,提出一种基于任务聚类与禁忌搜索的改进合同网算法(improved contract net protocol based on task clustering and tabu search,CN-TCTS).该算法采用“单星调度-全局分配”的分层求解框架.首先,通过任务聚类合并元任务,有效缩减解空间;其次,设计了动态约束禁忌搜索算法(dynamic constraint tabu search,DCTS),通过价值导向的邻域搜索策略实现单星任务序列的快速规划;最后,在全局分配阶段,引入多种策略对传统合同网协议进行改进,实现任务的高效分配与冲突消解.仿真结果表明,本文所提CN-TCTS算法在400个任务的大规模场景下,任务完成率仍保持82.0%,且平均通信轮次仅为6.6轮.此外,在卫星突发失效的动态场景下,该算法表现出更强的鲁棒性,收益损失率更低.此外,局部规划算法仿真中验证了DCTS算法在收敛速度与解质量方面的优势.
文摘Assembly model plans an important role in assembly sequence planning.Flexible assembly system (FAS) is a dis- crete event system (DES),so Petri net,as an important analytical tool for the DES,is used for modeling of an FAS.All of the feasible assembly sequences can be obtained by firing the Petri net model.In order to enhancing the efficiency of the assembly sequence planning,knowledge-based Petri net,combining an usual Petri net with expert’s knowledge and experiences,is proposed to con- struct the assembly model.So the feasible assembly sequences can be reduced greatly,and the optimum assembly sequence could be generated without the combinatorial explosion of solutions.
文摘Aiming at the former formalized methods such as Strips, Situation Calculus and Fluent Calculus can not represent the action time and get the action sequence automatically, a novel method based on timed color Petri net—RPBTC was defined. The action time, the precondition and the post-condition of action are formalized in RPBTC based on the Fluent Calculus reasoning rules. An algorism for constructing the RPBTC net system based on bidirectional search strategy is proposed, and through executing the RPBTC net system, the action sequence for reaching the goal can be generated dynamically and the time for the robot reaching the goal also can be obtained. The experiment has proved the method RPBTC as a feasible method for robot planning.
