This paper introduces a unified planning framework for composite hybrid aerial/terrestrial precision manipulators(CHAT-PM),enabling energy-efficient trimodal navigation in complex environments.The proposed path search...This paper introduces a unified planning framework for composite hybrid aerial/terrestrial precision manipulators(CHAT-PM),enabling energy-efficient trimodal navigation in complex environments.The proposed path search algorithm leverages terrain-specific heuristics and motion primitives to prioritize energy-saving terrestrial/inclined paths while dynamically selecting optimal motion modes.To address the computational complexity of trimodal dynamics,a unified nonlinear model predictive control(NMPC)approach is developed by integrating complementary constraints,thereby eliminating mixed-integer optimization and unifying aerial-terrestrial-inclined dynamics under a single framework.The dynamics model further incorporates disturbances from robotic arm operations,ground/slope contact forces,and aerodynamic effects,enhancing trajectory accuracy.Finally,the effectiveness and superiority of the proposed method are demonstrated by simulation results and real-world experiments.展开更多
Aiming at the practical application of Unmanned Underwater Vehicle(UUV)in underwater combat,this paper proposes a battlefield ambush scene with UUV considering ocean current.Firstly,by establishing these mathematical ...Aiming at the practical application of Unmanned Underwater Vehicle(UUV)in underwater combat,this paper proposes a battlefield ambush scene with UUV considering ocean current.Firstly,by establishing these mathematical models of ocean current environment,target movement,and sonar detection,the probability calculation methods of single UUV searching target and multiple UUV cooperatively searching target are given respectively.Then,based on the Hybrid Quantum-behaved Particle Swarm Optimization(HQPSO)algorithm,the path with the highest target search probability is found.Finally,through simulation calculations,the influence of different UUV parameters and target parameters on the target search probability is analyzed,and the minimum number of UUVs that need to be deployed to complete the ambush task is demonstrated,and the optimal search path scheme is obtained.The method proposed in this paper provides a theoretical basis for the practical application of UUV in the future combat.展开更多
In view of the structure and action behavior of mechatronic systems,a method of searching fault propagation paths called maximum-probability path search(MPPS)is proposed,aiming to determine all possible failure propag...In view of the structure and action behavior of mechatronic systems,a method of searching fault propagation paths called maximum-probability path search(MPPS)is proposed,aiming to determine all possible failure propagation paths with their lengths if faults occur.First,the physical structure system,function behavior,and complex network theory are integrated to define a system structural-action network(SSAN).Second,based on the concept of SSAN,two properties of nodes and edges,i.e.,the topological property and reliability property,are combined to define the failure propagation property.Third,the proposed MPPS model provides all fault propagation paths and possible failure rates of nodes on these paths.Finally,numerical experiments have been implemented to show the accuracy and advancement compared with the methods of Function Space Iteration(FSI)and the algorithm of Ant Colony Optimization(ACO).展开更多
Machining quality of clean-up region has a strong influence on the performances of the impeller. In order to plan clean-up tool paths rapidly and obtain good finish surface quality, an efficient and robust tool path g...Machining quality of clean-up region has a strong influence on the performances of the impeller. In order to plan clean-up tool paths rapidly and obtain good finish surface quality, an efficient and robust tool path generation method is presented, which employs an approach based on point-searching. The clean-up machining mentioned in this paper is pencil-cut and multilayer fillet-cut for a free-form model with a ball-end cutter. For pencil-cut, the cutter center position can be determined via judging whether it satisfies the distance requirement. After the searching direction and the tracing direction have been determined, by employing the point-searching algorithm with the idea of dichotomy, all the cutter contact （CC） points and cutter location （CL） points can be found and the clean-up boundaries can also be defined rapidly. Then the tool path is generated. Based on the main concept of pencil-cut, a multilayer fillet-cut method is proposed, which utilizes a ball-end cutter with its radius less than the design radius of clean-up region. Using a sequence of intermediate virtual cutters to divide the clean-up region into several layers and given a cusp-height tolerance for the final layer, then the tool paths for all layers are calculated. Finally, computer implementation is also presented in this paper, and the result shows that the proposed method is feasible.展开更多
目的:基于专利引文网络探索类器官领域的技术发展主路径。方法:本研究通过构建类器官领域的专利引文网络,采用搜索路径连接数算法(search path link count,SPLC)计算遍历权重,对类器官领域开展主路径分析,探索该领域的技术发展轨迹。结...目的:基于专利引文网络探索类器官领域的技术发展主路径。方法:本研究通过构建类器官领域的专利引文网络,采用搜索路径连接数算法(search path link count,SPLC)计算遍历权重,对类器官领域开展主路径分析,探索该领域的技术发展轨迹。结果:类器官领域共有专利申请2 250项,包含专利引文12 722件;专利申请数量逐年增长,技术开发聚焦于疾病模型、药物筛选、细胞培养及器官芯片等方向。主路径分析显示,全局主路径上专利数量最多,有12件,包含1条技术路线,全局关键路径主路径与全局主路径一致;局部前向主路径上有10件专利,包含1条技术路线;这2条技术路线反映出中国类器官领域的技术发展轨迹,中国技术创新聚焦于基于肿瘤类器官技术的疾病机制研究、基于肺癌类器官模型的疾病机制研究、肺癌类器官模型的开发与优化。局部后向主路径上有9件专利,包含2条技术路线,局部关键路径主路径与局部后向主路径一致;这2条技术路线反映出美国类器官领域的技术发展轨迹,技术创新聚焦于胃肠道类器官培养与疾病模型研究、干细胞驱动的器官功能修复技术、细胞移植与器官再生。结论:本研究通过类器官领域的专利主路径分析,识别技术发展轨迹,从情报学角度为类器官研发提供信息支撑。展开更多
针对跳点搜索(jump point search,JPS)算法路径存在斜向穿越障碍物、搜索过程中存在较多冗余跳点、路径拐点多且靠近障碍物的问题,提出一种安全快速的跳点搜索(safe fast jump point search,SFJPS)算法。该算法重新定义跳点判断规则,使...针对跳点搜索(jump point search,JPS)算法路径存在斜向穿越障碍物、搜索过程中存在较多冗余跳点、路径拐点多且靠近障碍物的问题,提出一种安全快速的跳点搜索(safe fast jump point search,SFJPS)算法。该算法重新定义跳点判断规则,使生成的跳点均为安全跳点,解决了路径中斜向穿越障碍物的情况;加入基于角度的搜索方向优先级判断,有效减少了搜索过程中的冗余节点,加快了搜索速度;基于Bresenham算法对路径上的跳点进行关键跳点筛选,关键跳点生成的路径拐点明显减少,贴近障碍物的路径长度大幅减小,整体路径长度也有所减小。结果表明在不同场景下本文算法相较于A*算法和JPS算法,路径长度分别最大减小了5.42%和4.48%,搜索时间分别最大缩短了98.33%和67.83%,搜索节点数最大减少了99.08%和56.72%,路径拐点数分别最大减少了90.91%和83.33%。相较于Theta*算法路径长度增加了1.17%,搜索时间缩短了91.07%,搜索节点数减少了98.9%。仿真试验证明本文算法规划速度快,路径安全且拐点更少,更加适用于移动机器人路径规划问题。展开更多
针对跳点搜索算法(jump point search,JPS)在路径规划过程中出现的穿越墙角的不安全行为,提出了一种基于蜂窝栅格地图的跳点搜索算法(honeycomb raster map-JPS,H-JPS)。构建蜂窝栅格地图代替传统栅格地图,在JPS算法的基础上结合蜂窝栅...针对跳点搜索算法(jump point search,JPS)在路径规划过程中出现的穿越墙角的不安全行为,提出了一种基于蜂窝栅格地图的跳点搜索算法(honeycomb raster map-JPS,H-JPS)。构建蜂窝栅格地图代替传统栅格地图,在JPS算法的基础上结合蜂窝栅格修改了剪枝规则与跳点判断规则,再利用蜂窝栅格特点设计了新的启发式函数来提高搜索效率,通过找寻最远节点的节点更新规则来优化生成的轨迹。利用Matlab仿真平台验证算法的搜索效率和安全性,结果表明,相较于传统JPS算法,采用H-JPS算法进行路径规划能够完全消除危险节点,路径规划时间和长度分别缩短了41.9%和11.1%,显著提高了搜索效率。展开更多
针对传统蚁群算法在农机导航路径规划中存在前期搜索盲目、死锁、收敛速度慢、收敛路径质量低的问题,本文提出基于跳点优化蚁群算法(Jump point optimized ant colony algorithm,JPOACO)的路径规划方法。首先,使用优化跳点搜索算法对地...针对传统蚁群算法在农机导航路径规划中存在前期搜索盲目、死锁、收敛速度慢、收敛路径质量低的问题,本文提出基于跳点优化蚁群算法(Jump point optimized ant colony algorithm,JPOACO)的路径规划方法。首先,使用优化跳点搜索算法对地图进行预处理,获得简化跳点;其次,通过简化跳点对栅格地图进行信息素初始化,以加强简化跳点的引导能力和减少前期盲目搜索;接着,设计蚂蚁死亡惩罚机制,以降低陷入死锁蚂蚁走过路径的信息素,减少死锁问题的发生;再者,通过重新设计启发式信息函数并引入分级式信息素因子改进状态转移概率函数,以提高收敛速度,缩短路径长度;最后,采用路径优化策略删减不必要路径节点,以进一步缩短路径长度、提升平滑度,提高路径质量。仿真结果表明,在简单环境中,JPOACO算法求得的路径长度较传统蚁群算法和另一种优化蚁群算法短约22.6%和2.0%,收敛迭代次数、收敛时间分别减少约77.0%、77.5%和49.3%、87.8%,零死亡迭代次数和零死亡时间较后者减少约19.5%和80.5%;在复杂菠萝种植环境中,JPOACO算法较传统蚁群算法和另一种优化蚁群算法求得的路径长度短16.6%和4.7%,收敛迭代次数、收敛时间分别减少约77.1%、17.4%和73.7%、47.4%,零死亡迭代次数和零死亡时间较后者减少约34.3%和58.2%,表明本文算法具有较高的适用性和可行性。展开更多
基金supported in part by the National Natural Science Foundation of China(Grant Nos.62225305,62403169,623B2029,52025054,52435001,623B2029)the State Key Laboratory of Robotics and System(HIT)。
文摘This paper introduces a unified planning framework for composite hybrid aerial/terrestrial precision manipulators(CHAT-PM),enabling energy-efficient trimodal navigation in complex environments.The proposed path search algorithm leverages terrain-specific heuristics and motion primitives to prioritize energy-saving terrestrial/inclined paths while dynamically selecting optimal motion modes.To address the computational complexity of trimodal dynamics,a unified nonlinear model predictive control(NMPC)approach is developed by integrating complementary constraints,thereby eliminating mixed-integer optimization and unifying aerial-terrestrial-inclined dynamics under a single framework.The dynamics model further incorporates disturbances from robotic arm operations,ground/slope contact forces,and aerodynamic effects,enhancing trajectory accuracy.Finally,the effectiveness and superiority of the proposed method are demonstrated by simulation results and real-world experiments.
文摘Aiming at the practical application of Unmanned Underwater Vehicle(UUV)in underwater combat,this paper proposes a battlefield ambush scene with UUV considering ocean current.Firstly,by establishing these mathematical models of ocean current environment,target movement,and sonar detection,the probability calculation methods of single UUV searching target and multiple UUV cooperatively searching target are given respectively.Then,based on the Hybrid Quantum-behaved Particle Swarm Optimization(HQPSO)algorithm,the path with the highest target search probability is found.Finally,through simulation calculations,the influence of different UUV parameters and target parameters on the target search probability is analyzed,and the minimum number of UUVs that need to be deployed to complete the ambush task is demonstrated,and the optimal search path scheme is obtained.The method proposed in this paper provides a theoretical basis for the practical application of UUV in the future combat.
基金Project(2017JBZ103)supported by the Fundamental Research Funds for the Central Universities,China
文摘In view of the structure and action behavior of mechatronic systems,a method of searching fault propagation paths called maximum-probability path search(MPPS)is proposed,aiming to determine all possible failure propagation paths with their lengths if faults occur.First,the physical structure system,function behavior,and complex network theory are integrated to define a system structural-action network(SSAN).Second,based on the concept of SSAN,two properties of nodes and edges,i.e.,the topological property and reliability property,are combined to define the failure propagation property.Third,the proposed MPPS model provides all fault propagation paths and possible failure rates of nodes on these paths.Finally,numerical experiments have been implemented to show the accuracy and advancement compared with the methods of Function Space Iteration(FSI)and the algorithm of Ant Colony Optimization(ACO).
基金National Natural Science Foundation of China （51005183） National Science and Technology Major Project （2011X04016-031）
文摘Machining quality of clean-up region has a strong influence on the performances of the impeller. In order to plan clean-up tool paths rapidly and obtain good finish surface quality, an efficient and robust tool path generation method is presented, which employs an approach based on point-searching. The clean-up machining mentioned in this paper is pencil-cut and multilayer fillet-cut for a free-form model with a ball-end cutter. For pencil-cut, the cutter center position can be determined via judging whether it satisfies the distance requirement. After the searching direction and the tracing direction have been determined, by employing the point-searching algorithm with the idea of dichotomy, all the cutter contact （CC） points and cutter location （CL） points can be found and the clean-up boundaries can also be defined rapidly. Then the tool path is generated. Based on the main concept of pencil-cut, a multilayer fillet-cut method is proposed, which utilizes a ball-end cutter with its radius less than the design radius of clean-up region. Using a sequence of intermediate virtual cutters to divide the clean-up region into several layers and given a cusp-height tolerance for the final layer, then the tool paths for all layers are calculated. Finally, computer implementation is also presented in this paper, and the result shows that the proposed method is feasible.
文摘针对跳点搜索(jump point search,JPS)算法路径存在斜向穿越障碍物、搜索过程中存在较多冗余跳点、路径拐点多且靠近障碍物的问题,提出一种安全快速的跳点搜索(safe fast jump point search,SFJPS)算法。该算法重新定义跳点判断规则,使生成的跳点均为安全跳点,解决了路径中斜向穿越障碍物的情况;加入基于角度的搜索方向优先级判断,有效减少了搜索过程中的冗余节点,加快了搜索速度;基于Bresenham算法对路径上的跳点进行关键跳点筛选,关键跳点生成的路径拐点明显减少,贴近障碍物的路径长度大幅减小,整体路径长度也有所减小。结果表明在不同场景下本文算法相较于A*算法和JPS算法,路径长度分别最大减小了5.42%和4.48%,搜索时间分别最大缩短了98.33%和67.83%,搜索节点数最大减少了99.08%和56.72%,路径拐点数分别最大减少了90.91%和83.33%。相较于Theta*算法路径长度增加了1.17%,搜索时间缩短了91.07%,搜索节点数减少了98.9%。仿真试验证明本文算法规划速度快,路径安全且拐点更少,更加适用于移动机器人路径规划问题。
文摘针对跳点搜索算法(jump point search,JPS)在路径规划过程中出现的穿越墙角的不安全行为,提出了一种基于蜂窝栅格地图的跳点搜索算法(honeycomb raster map-JPS,H-JPS)。构建蜂窝栅格地图代替传统栅格地图,在JPS算法的基础上结合蜂窝栅格修改了剪枝规则与跳点判断规则,再利用蜂窝栅格特点设计了新的启发式函数来提高搜索效率,通过找寻最远节点的节点更新规则来优化生成的轨迹。利用Matlab仿真平台验证算法的搜索效率和安全性,结果表明,相较于传统JPS算法,采用H-JPS算法进行路径规划能够完全消除危险节点,路径规划时间和长度分别缩短了41.9%和11.1%,显著提高了搜索效率。
文摘针对传统蚁群算法在农机导航路径规划中存在前期搜索盲目、死锁、收敛速度慢、收敛路径质量低的问题,本文提出基于跳点优化蚁群算法(Jump point optimized ant colony algorithm,JPOACO)的路径规划方法。首先,使用优化跳点搜索算法对地图进行预处理,获得简化跳点;其次,通过简化跳点对栅格地图进行信息素初始化,以加强简化跳点的引导能力和减少前期盲目搜索;接着,设计蚂蚁死亡惩罚机制,以降低陷入死锁蚂蚁走过路径的信息素,减少死锁问题的发生;再者,通过重新设计启发式信息函数并引入分级式信息素因子改进状态转移概率函数,以提高收敛速度,缩短路径长度;最后,采用路径优化策略删减不必要路径节点,以进一步缩短路径长度、提升平滑度,提高路径质量。仿真结果表明,在简单环境中,JPOACO算法求得的路径长度较传统蚁群算法和另一种优化蚁群算法短约22.6%和2.0%,收敛迭代次数、收敛时间分别减少约77.0%、77.5%和49.3%、87.8%,零死亡迭代次数和零死亡时间较后者减少约19.5%和80.5%;在复杂菠萝种植环境中,JPOACO算法较传统蚁群算法和另一种优化蚁群算法求得的路径长度短16.6%和4.7%,收敛迭代次数、收敛时间分别减少约77.1%、17.4%和73.7%、47.4%,零死亡迭代次数和零死亡时间较后者减少约34.3%和58.2%,表明本文算法具有较高的适用性和可行性。
