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Postpartum Family Planning at the Timbuktu Hospital in Mali
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作者 Kassogué Djibril Samaké Alou +13 位作者 Dolo Akoro Sogoba Seydou Touré Lahaou Cissouma Assetou Kassogué Abdoulaye Maiga Mariam Mariko Souleymane Kantako Karamoko Ongoiba Oumar Sanogo Ooumar Traoré Bassirima Sidibé Idrissa Mandé Kassambara Youssouf Traoré Halima 《Open Journal of Obstetrics and Gynecology》 2024年第7期1074-1082,共9页
Introduction: Postpartum family planning is the prevention of pregnancies during the 12 months following childbirth. Few studies have been devoted to postpartum family planning in Mali. Our work will contribute to red... Introduction: Postpartum family planning is the prevention of pregnancies during the 12 months following childbirth. Few studies have been devoted to postpartum family planning in Mali. Our work will contribute to reducing unmet need for family planning. Objective: To study the use of contraceptive methods in the postpartum period in the obstetrics and gynecology unit of Timbuktu hospital. Materials and Methods: This was a descriptive and analytical cross-sectional study with prospective collection of data from January 1, 2022 to December 31, 2023. All women who gave birth having chosen and benefited from a contraceptive method were included. The statistical test used was the Fisher test with a significance threshold fixed at 5%. Results: The frequency of contraception in the postpartum period was 17.03%. The average age of clients was 26.14% with extremes of 14 and 45 years. They were paupiparous at 56.4% with an inter-birth interval of less than 12 months at 12.3%. More than half of the counseling (58.5%) was done during postnatal visits. The methods chosen were implants at 48.1%, injectable progestins at 21.3%, intrauterine device at 14.7%, miro-progestin pills at 13.5%, tubal ligation at 1 .4% and condoms at 1%. The regular follow-up rate was 51.1% of cases and 25.6% had no follow-up. Conclusion: The overall rate of postpartum family planning of 17.08% remains low. Improving FP staff skills will reduce unmet needs and contribute to increasing contraceptive prevalence in Timbuktu. 展开更多
关键词 Family planning POStpARTUM COUNSELING Contraceptive Methods Timbuktu Hospital
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TPS联合“PBL+CBL”双轨教学在肿瘤放疗住培中的应用
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作者 黄凤仙 曹席明 赵淑红 《延安职业技术学院学报》 2024年第5期43-47,共5页
目的 探讨放射治疗计划系统(Treatment Planning System,TPS)联合“问题教学法(problembased learning,PBL)+病例教学法(case-based learning,CBL)”双轨教学在肿瘤放射治疗(放疗)住院医师规范化培训(“住培”)中教学成果。方法 选取202... 目的 探讨放射治疗计划系统(Treatment Planning System,TPS)联合“问题教学法(problembased learning,PBL)+病例教学法(case-based learning,CBL)”双轨教学在肿瘤放射治疗(放疗)住院医师规范化培训(“住培”)中教学成果。方法 选取2020.9至2022.12在陕西省人民医院放疗科接受放疗“住培”的32名住院医师为研究对象,按随机数字表法分成试验组、对照组,每组16名。其中试验组接受TPS联合“PBL+CBL”双轨教学的教学模式,对照组接受传统教学模式。教学结束后对全部住院医师举行住院医师规范化培训考核及教学满意度问卷调查。结果 试验组住院医师的专业理论知识成绩(88.63±4.319)、临床实践能力成绩(4.19±5.256)及经典病例分析成绩(88.44±4.761)明显优于对照组住院医师(分别为:82.44±8.238、79.88±4.924、80.06±3.907),差异具有统计学意义(P<0.05)。试验组住院医师对教学的满意度明显高于对照组,具有统计学意义(P<0.05)。结论 采用TPS联合“PBL+CBL”双轨教学的教学模式进行肿瘤放疗住院医师规范化培训,有效提高肿瘤放疗住院医师的临床技能操作能力等,切实提高了“住培”教学质量。 展开更多
关键词 放射治疗 tps “PBL+CBL”双轨教学法 规范化培训
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茉莉JsMYB108和JsMYB305转录因子对萜烯合成酶基因TPS启动子的调控研究
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作者 张月 胡莉 +3 位作者 万超 胡双玲 尹秦婠 袁媛 《福建农业学报》 CAS CSCD 北大核心 2024年第8期927-937,共11页
【目的】探明茉莉香气合成相关转录因子JsMYB108和JsMYB305对3个萜烯合成酶基因JsTPS启动子的调控机制。【方法】以茉莉叶片DNA为模板,采用染色体步移法克隆3个JsTPS基因的启动子片段,预测启动子序列顺式作用元件,并在此基础上将3个JsTP... 【目的】探明茉莉香气合成相关转录因子JsMYB108和JsMYB305对3个萜烯合成酶基因JsTPS启动子的调控机制。【方法】以茉莉叶片DNA为模板,采用染色体步移法克隆3个JsTPS基因的启动子片段,预测启动子序列顺式作用元件,并在此基础上将3个JsTPS基因启动子片段分别构建到报告载体pGWB433,单独转化烟草叶片或与pK7FWG2.0-JsMYB108、pK7FWG2.0-JsMYB305效应载体共同转化烟草叶片以检测JsMYB108和JsMYB305对3个TPS基因启动子的激活作用;同时,通过酵母单杂交实验进一步检验JsMYB108和JsMYB305与3个TPS基因启动子的结合作用。【结果】克隆了3个JsTPS基因启动子片段,长度分别为1357、1849、1005 bp。这些序列中均含MYB识别位点,不同启动子序列包含不同顺式作用元件,如光反应元件、损伤响应元件、脱落酸诱导顺式作用元件等;叶片GUS染色和GUS活性检测结果显示3个JsTPS基因启动子片段均具有启动活性且JsMYB108和JsMYB305能不同程度地激活3个TPS基因启动子活性。JsMYB108使JsTPS1、JsTPS3、JsTPS4启动子活性增强至对照的1.96倍、6.47倍和4.15倍;JsMYB305使JsTPS1、JsTPS3、JsTPS4启动子活性增强至对照的1.57倍、15.18倍和3.12倍;酵母单杂交结果显示JsMYB108和JsMYB305能与JsTPS1、JsTPS3和JsTPS4启动子结合。【结论】JsMYB108和JsMYB305可以不同程度激活JsTPS基因启动子活性,推测这2个转录因子在茉莉花萜烯香气合成和代谢过程具有一定作用。 展开更多
关键词 茉莉 转录因子 tps 启动子 调控
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TPS与TBS分选粗煤泥对比研究
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作者 张丽明 段福山 +4 位作者 谢广元 伟强 苏东然 倪超 符向东 《选煤技术》 CAS 2024年第2期47-53,共7页
粗煤泥分选是选煤过程中的重要环节,传统的粗煤泥分选设备对难选粗煤泥难以实现有效分选,因此选煤厂通常采用两段分选来满足产品要求,但两段分选工艺比一段分选工艺复杂。为简化粗煤泥分选工艺流程,以TPS和TBS在回坡底矿选煤厂的工业应... 粗煤泥分选是选煤过程中的重要环节,传统的粗煤泥分选设备对难选粗煤泥难以实现有效分选,因此选煤厂通常采用两段分选来满足产品要求,但两段分选工艺比一段分选工艺复杂。为简化粗煤泥分选工艺流程,以TPS和TBS在回坡底矿选煤厂的工业应用为例,对比了两种设备在自身结构、产品结构和分选效果上的差异。在设备结构上,TPS通过在分选桶内增加一个内桶实现了两段分选,并通过顶水分配装置和内桶溢流导流槽等结构优化保证了两段分选的可靠性。在产品结构上,TBS可分选出精煤和研石两种产品,但无法同时获得合格精煤和高灰分尾煤;TPS不仅可获得精煤、中煤、石三种产品,而且可根据产品质量要求灵活调节出两产品或三产品,在精煤产品灰分合格的前提下TPS尾煤灰分为72.21%,同时可得到产率为36.62%、灰分为35.72%的中煤产品。在分选效果上,TPS的数量效率比TBS高2.82个百分点,可燃体回收率比TBS高24.53个百分点。TPS与TBS分选粗煤泥的对比研究可为TPS与TBS的合理选型提供有益参考。 展开更多
关键词 粗煤泥分选 tps TBS 设备结构 产品结构 分选效果 数量效率 可燃体回收率
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青钱柳萜烯合成酶TPS家族鉴定分析
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作者 黄太敏 叶茜 +4 位作者 杨自薇 张楠楠 陈丽 刘鑫 杨正婷 《贵州师范大学学报(自然科学版)》 CAS 北大核心 2024年第4期100-107,共8页
萜烯是植物中一类重要的化合物,不仅在细胞膜上扮演着电子传递的角色,还参与植物光合作用,并作为植物激素的主要成分。萜烯合成酶TPS是合成萜烯的关键酶,对于植物生长和抵御疾病具有重要意义。研究对青钱柳的TPS基因家族进行了全面的鉴... 萜烯是植物中一类重要的化合物,不仅在细胞膜上扮演着电子传递的角色,还参与植物光合作用,并作为植物激素的主要成分。萜烯合成酶TPS是合成萜烯的关键酶,对于植物生长和抵御疾病具有重要意义。研究对青钱柳的TPS基因家族进行了全面的鉴定和分析,发现青钱柳共有63个TPS基因家族成员,这些基因的蛋白质长度在260至854个氨基酸之间,并且分布在青钱柳的11条染色体上。通过启动子顺式作用元件分析,预测青钱柳的TPS基因家族可能参与了多种生物学反应。该研究为进一步探究青钱柳TPS的生理功能和应对环境胁迫的机制提供了理论支持。 展开更多
关键词 青钱柳 萜烯合成酶tps 基因家族 鉴定分析 顺式作用元件
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Evolutionary Decision-Making and Planning for Autonomous Driving Based on Safe and Rational Exploration and Exploitation 被引量:2
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作者 Kang Yuan Yanjun Huang +4 位作者 Shuo Yang Zewei Zhou Yulei Wang Dongpu Cao Hong Chen 《Engineering》 SCIE EI CAS CSCD 2024年第2期108-120,共13页
Decision-making and motion planning are extremely important in autonomous driving to ensure safe driving in a real-world environment.This study proposes an online evolutionary decision-making and motion planning frame... Decision-making and motion planning are extremely important in autonomous driving to ensure safe driving in a real-world environment.This study proposes an online evolutionary decision-making and motion planning framework for autonomous driving based on a hybrid data-and model-driven method.First,a data-driven decision-making module based on deep reinforcement learning(DRL)is developed to pursue a rational driving performance as much as possible.Then,model predictive control(MPC)is employed to execute both longitudinal and lateral motion planning tasks.Multiple constraints are defined according to the vehicle’s physical limit to meet the driving task requirements.Finally,two principles of safety and rationality for the self-evolution of autonomous driving are proposed.A motion envelope is established and embedded into a rational exploration and exploitation scheme,which filters out unreasonable experiences by masking unsafe actions so as to collect high-quality training data for the DRL agent.Experiments with a high-fidelity vehicle model and MATLAB/Simulink co-simulation environment are conducted,and the results show that the proposed online-evolution framework is able to generate safer,more rational,and more efficient driving action in a real-world environment. 展开更多
关键词 Autonomous driving DECISION-MAKING Motion planning Deep reinforcement learning Model predictive control
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Motion Planning for Autonomous Driving with Real Traffic Data Validation 被引量:1
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作者 Wenbo Chu Kai Yang +1 位作者 Shen Li Xiaolin Tang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第1期74-86,共13页
Accurate trajectory prediction of surrounding road users is the fundamental input for motion planning,which enables safe autonomous driving on public roads.In this paper,a safe motion planning approach is proposed bas... Accurate trajectory prediction of surrounding road users is the fundamental input for motion planning,which enables safe autonomous driving on public roads.In this paper,a safe motion planning approach is proposed based on the deep learning-based trajectory prediction method.To begin with,a trajectory prediction model is established based on the graph neural network(GNN)that is trained utilizing the INTERACTION dataset.Then,the validated trajectory prediction model is used to predict the future trajectories of surrounding road users,including pedestrians and vehicles.In addition,a GNN prediction model-enabled motion planner is developed based on the model predictive control technique.Furthermore,two driving scenarios are extracted from the INTERACTION dataset to validate and evaluate the effectiveness of the proposed motion planning approach,i.e.,merging and roundabout scenarios.The results demonstrate that the proposed method can lower the risk and improve driving safety compared with the baseline method. 展开更多
关键词 Trajectory prediction Graph neural network Motion planning INTERACTION dataset
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Selection of media tools for community planning:A study from the perspective of communicative planning
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作者 Xiaotong Zhang Linjun Yu Yang Li 《Chinese Journal of Population,Resources and Environment》 2024年第3期305-311,共7页
In community planning,due to the lack of evidence regarding the selection of media tools,this study examines how a common but differentiated ideal speech situation can be created as well as how more appropriate media ... In community planning,due to the lack of evidence regarding the selection of media tools,this study examines how a common but differentiated ideal speech situation can be created as well as how more appropriate media tools can be defined and selected in the community planning process.First,this study describes the concept and theoretical basis of media used in community planning from the perspectives of the multiple effects of media evolution on communicative planning.Second,the classification criteria and typical characteristics of media tools used to support community planning are clarified from three dimensions:acceptability,cost effectiveness,and applicability.Third,strategies for applying media tools in the four phases of communicative planning-namely,state analysis,problem identification,contradictory solution and optimization-are described.Finally,trends in the development of media tools for community planning are explored in terms of multistakeholder engagement,supporting scientific decision-making and multiple-type media integration.The results provide a reference for developing more inclusive,effective,and appropriate media tools for enhancing decision-making capacity and modernizing governance in community planning and policy-making processes. 展开更多
关键词 Community planning Media tools Communicative planning
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Optimal search path planning of UUV in battlefeld ambush scene
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作者 Wei Feng Yan Ma +3 位作者 Heng Li Haixiao Liu Xiangyao Meng Mo Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期541-552,共12页
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
关键词 Battlefield ambush Optimal search path planning UUV path planning Probability of cooperative search
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Efficient Route Planning for Real-Time Demand-Responsive Transit
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作者 Hongle Li SeongKi Kim 《Computers, Materials & Continua》 SCIE EI 2024年第4期473-492,共20页
Demand Responsive Transit (DRT) responds to the dynamic users’ requests without any fixed routes and timetablesand determines the stop and the start according to the demands. This study explores the optimization of d... Demand Responsive Transit (DRT) responds to the dynamic users’ requests without any fixed routes and timetablesand determines the stop and the start according to the demands. This study explores the optimization of dynamicvehicle scheduling and real-time route planning in urban public transportation systems, with a focus on busservices. It addresses the limitations of current shared mobility routing algorithms, which are primarily designedfor simpler, single origin/destination scenarios, and do not meet the complex demands of bus transit systems. Theresearch introduces an route planning algorithm designed to dynamically accommodate passenger travel needsand enable real-time route modifications. Unlike traditional methods, this algorithm leverages a queue-based,multi-objective heuristic A∗ approach, offering a solution to the inflexibility and limited coverage of suburbanbus routes. Also, this study conducts a comparative analysis of the proposed algorithm with solutions based onGenetic Algorithm (GA) and Ant Colony Optimization Algorithm (ACO), focusing on calculation time, routelength, passenger waiting time, boarding time, and detour rate. The findings demonstrate that the proposedalgorithmsignificantly enhances route planning speed, achieving an 80–100-fold increase in efficiency over existingmodels, thereby supporting the real-time demands of Demand-Responsive Transportation (DRT) systems. Thestudy concludes that this algorithm not only optimizes route planning in bus transit but also presents a scalablesolution for improving urban mobility. 展开更多
关键词 Autonomous bus route planning real-time dynamic route planning path finding DRT bus route optimization sustainable public transport
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Exploration of Detailed Planning Practice of Chemical Industrial Parks under the Background of Territorial Space Planning
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作者 CHENG Xi 《Journal of Landscape Research》 2024年第4期51-54,共4页
With the gradual completion of the overall planning of city and county land space,the detailed planning will be prepared according to the requirements of transmitting and refining the upper planning.Industrial parks a... With the gradual completion of the overall planning of city and county land space,the detailed planning will be prepared according to the requirements of transmitting and refining the upper planning.Industrial parks are one of the“main forces”of local economic development,and the preparation of their detailed planning will escort their development.The key points of the Control Indicators of Construction Land in Industrial Projectsissued in 2008 and 2023 were compared,and the new requirements for detailed planning under the background of territorial space and the contradictions between the detailed planning of industrial parks and the overall planning of the upper territorial space were sorted out based on the summary of the existing problems in the development of chemical parks.It provides some ideas for the practice of detailed planning of chemical industrial parks under the background of territorial space. 展开更多
关键词 Detailed planning Chemical industrial parks PRACTICE Territorial spatial planning
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Stochastic programming based coordinated expansion planning of generation,transmission,demand side resources,and energy storage considering the DC transmission system
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作者 Liang Lu Mingkui Wei +4 位作者 Yuxuan Tao Qing Wang Yuxiao Yang Chuan He Haonan Zhang 《Global Energy Interconnection》 EI CSCD 2024年第1期25-37,共13页
With the increasing penetration of wind and solar energies,the accompanying uncertainty that propagates in the system places higher requirements on the expansion planning of power systems.A source-grid-load-storage co... With the increasing penetration of wind and solar energies,the accompanying uncertainty that propagates in the system places higher requirements on the expansion planning of power systems.A source-grid-load-storage coordinated expansion planning model based on stochastic programming was proposed to suppress the impact of wind and solar energy fluctuations.Multiple types of system components,including demand response service entities,converter stations,DC transmission systems,cascade hydropower stations,and other traditional components,have been extensively modeled.Moreover,energy storage systems are considered to improve the accommodation level of renewable energy and alleviate the influence of intermittence.Demand-response service entities from the load side are used to reduce and move the demand during peak load periods.The uncertainties in wind,solar energy,and loads were simulated using stochastic programming.Finally,the effectiveness of the proposed model is verified through numerical simulations. 展开更多
关键词 Hydro-wind-solar complementary Expansion planning Demand response Energy storage system Source-network-demand-storage coordination
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Correlates of Mistimed Pregnancy and Unmet Need for Family Planning among Women of Reproductive Age in Sandema, Ghana
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作者 Elvis Junior Dun-Dery Elijah Yendaw +2 位作者 Frederick Dun-Dery Lawrence Bagrmwin Menaal Kaushal 《Advances in Reproductive Sciences》 CAS 2024年第2期125-140,共16页
Background: Globally, an estimated 80 million unintended pregnancies comprising both mistimed and unwanted pregnancies are recorded yearly. Yet only half of the women at risk of mistimed pregnancy use contraceptives. ... Background: Globally, an estimated 80 million unintended pregnancies comprising both mistimed and unwanted pregnancies are recorded yearly. Yet only half of the women at risk of mistimed pregnancy use contraceptives. In developing countries, over 100 million females have unmet need, and national surveys in Ghana indicate 23% unmet need rate. Methods: Using a cross-sectional community-based approach, a sample size of 300 women of reproductive age were selected using multi-step cluster sampling techniques. The study was quantitative, using structured interviewer-administered questionnaires. Results: Two-third (66%) of the women in reproductive age still had unmet need, 71% were currently pregnant, and more than a third (36%) confirmed ever having a mistimed pregnancy. Fifty-three percent (53%) of the women confirmed never communicating with their partners on family planning issues, a little below half (45%) took their own health care decisions. Seventy nine percent (79%) ever received family planning services from a health professional. Factors related to unmet needs included mistimed pregnancy, level of education, preferred birth/pregnancy interval, communication between partners and the autonomy to spend self-earnings. Conclusion: Considering that high rates of unmet need results in mistimed pregnancy, improved policies around the influence of unmet need on mistimed pregnancies are needed. 展开更多
关键词 CONTRACEPTION Family planning Mistimed Pregnancy Ghana Unintended Pregnancy
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A Planning Method for Operational Test of UAV Swarm Based on Mission Reliability
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作者 Jingyu Wang Ping Jiang Jianjun Qi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1889-1918,共30页
The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV swarm.Due to the... The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV swarm.Due to the high cost and long duration of operational tests,it is essential to plan the test in advance.To solve the problem of planning UAV swarm operational test,this study considers the multi-stage feature of a UAV swarm mission,composed of launch,flight and combat stages,and proposes a method to find test plans that can maximize mission reliability.Therefore,a multi-stage mission reliability model for a UAV swarm is proposed to ensure successful implementation of the mission.A multi-objective integer optimization method that considers both mission reliability and cost is then formulated to obtain the optimal test plans.This study first constructs a mission reliability model for the UAV swarm in the combat stage.Then,the launch stage and flight stage are integrated to develop a complete PMS(Phased Mission Systems)reliability model.Finally,the Binary Decision Diagrams(BDD)and Multi Objective Quantum Particle Swarm Optimization(MOQPSO)methods are proposed to solve the model.The optimal plans considering both reliability and cost are obtained.The proposed model supports the planning of UAV swarm operational tests and represents a meaningful exploration of UAV swarm test planning. 展开更多
关键词 UAV swarm PMS MOQPSO BDD mission reliability operational test planning
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A Reverse Path Planning Approach for Enhanced Performance of Multi-Degree-of-Freedom Industrial Manipulators
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作者 Zhiwei Lin Hui Wang +3 位作者 Tianding Chen Yingtao Jiang Jianmei Jiang Yingpin Chen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1357-1379,共23页
In the domain of autonomous industrial manipulators,precise positioning and appropriate posture selection in path planning are pivotal for tasks involving obstacle avoidance,such as handling,heat sealing,and stacking.... In the domain of autonomous industrial manipulators,precise positioning and appropriate posture selection in path planning are pivotal for tasks involving obstacle avoidance,such as handling,heat sealing,and stacking.While Multi-Degree-of-Freedom(MDOF)manipulators offer kinematic redundancy,aiding in the derivation of optimal inverse kinematic solutions to meet position and posture requisites,their path planning entails intricate multiobjective optimization,encompassing path,posture,and joint motion optimization.Achieving satisfactory results in practical scenarios remains challenging.In response,this study introduces a novel Reverse Path Planning(RPP)methodology tailored for industrial manipulators.The approach commences by conceptualizing the manipulator’s end-effector as an agent within a reinforcement learning(RL)framework,wherein the state space,action set,and reward function are precisely defined to expedite the search for an initial collision-free path.To enhance convergence speed,the Q-learning algorithm in RL is augmented with Dyna-Q.Additionally,we formulate the cylindrical bounding box of the manipulator based on its Denavit-Hartenberg(DH)parameters and propose a swift collision detection technique.Furthermore,the motion performance of the end-effector is refined through a bidirectional search,and joint weighting coefficients are introduced to mitigate motion in high-power joints.The efficacy of the proposed RPP methodology is rigorously examined through extensive simulations conducted on a six-degree-of-freedom(6-DOF)manipulator encountering two distinct obstacle configurations and target positions.Experimental results substantiate that the RPP method adeptly orchestrates the computation of the shortest collision-free path while adhering to specific posture constraints at the target point.Moreover,itminimizes both posture angle deviations and joint motion,showcasing its prowess in enhancing the operational performance of MDOF industrial manipulators. 展开更多
关键词 Reverse path planning Dyna-Q bidirectional search posture angle joint motion
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Heuristic Expanding Disconnected Graph:A Rapid Path Planning Method for Mobile Robots
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作者 Yong Tao Lian Duan +3 位作者 He Gao Yufan Zhang Yian Song Tianmiao Wang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期68-82,共15页
Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of th... Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of the neighborhood search strategy,the robots could hardly obtain the most optimal global path.A global path planning algorithm,denoted as EDG*,is proposed by expanding nodes using a well-designed expanding disconnected graph operator(EDG)in this paper.Firstly,all obstacles are marked and their corners are located through the map pre-processing.Then,the EDG operator is designed to find points in non-obstruction areas to complete the rapid expansion of disconnected nodes.Finally,the EDG*heuristic iterative algorithm is proposed.It selects the candidate node through a specific valuation function and realizes the node expansion while avoiding collision with a minimum offset.Path planning experiments were conducted in a typical indoor environment and on the public dataset CSM.The result shows that the proposed EDG*reduced the planning time by more than 90%and total length of paths reduced by more than 4.6%.Compared to A*,Dijkstra and JPS,EDG*does not show an exponential explosion effect in map size.The EDG*showed better performance in terms of path smoothness,and collision avoidance.This shows that the EDG*algorithm proposed in this paper can improve the efficiency of path planning and enhance path quality. 展开更多
关键词 Global path planning Mobile robot Expanding disconnected graph Edge node OFFSET
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Trajectory planning for multi-robot coordinated towing system based on stability
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作者 赵志刚 ZHAO Xiangtang +2 位作者 WEI Qizhe SU Cheng MENG Jiadong 《High Technology Letters》 EI CAS 2024年第1期43-51,共9页
Given the unconstrained characteristics of the multi-robot coordinated towing system,the rope can only provide a unidirectional constraint force to the suspended object,which leads to the weak ability of the system to... Given the unconstrained characteristics of the multi-robot coordinated towing system,the rope can only provide a unidirectional constraint force to the suspended object,which leads to the weak ability of the system to resist external disturbances and makes it difficult to control the trajectory of the suspended object.Based on the kinematics and statics of the multi-robot coordinated towing system with fixed base,the dynamic model of the system is established by using the Newton-Euler equations and the Udwadia-Kalaba equations.To plan the trajectories with high stability and strong control,trajectory planning is performed by combining the dynamics and stability of the towing system.Based on the dynamic stability of the motion trajectory of the suspended object,the stability of the suspended object is effectively improved through online real-time planning and offline manual adjustment.The effectiveness of the proposed method is verified by comparing the motion stability of the suspended object before and after planning.The results provide a foundation for the motion planning and coordinated control of the towing system. 展开更多
关键词 towing system unconstrained system trajectory planning dynamic stability
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Ground threat prediction-based path planning of unmanned autonomous helicopter using hybrid enhanced artificial bee colony algorithm
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作者 Zengliang Han Mou Chen +1 位作者 Haojie Zhu Qingxian Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期1-22,共22页
Unmanned autonomous helicopter(UAH)path planning problem is an important component of the UAH mission planning system.Aiming to reduce the influence of non-complete ground threat information on UAH path planning,a gro... Unmanned autonomous helicopter(UAH)path planning problem is an important component of the UAH mission planning system.Aiming to reduce the influence of non-complete ground threat information on UAH path planning,a ground threat prediction-based path planning method is proposed based on artificial bee colony(ABC)algorithm by collaborative thinking strategy.Firstly,a dynamic threat distribution probability model is developed based on the characteristics of typical ground threats.The dynamic no-fly zone of the UAH is simulated and established by calculating the distribution probability of ground threats in real time.Then,a dynamic path planning method for UAH is designed in complex environment based on the real-time prediction of ground threats.By adding the collision warning mechanism to the path planning model,the flight path could be dynamically adjusted according to changing no-fly zones.Furthermore,a hybrid enhanced ABC algorithm is proposed based on collaborative thinking strategy.The proposed algorithm applies the leader-member thinking mechanism to guide the direction of population evolution,and reduces the negative impact of local optimal solutions caused by collaborative learning update strategy,which makes the optimization performance of ABC algorithm more controllable and efficient.Finally,simulation results verify the feasibility and effectiveness of the proposed ground threat prediction path planning method. 展开更多
关键词 UAH Path planning Ground threat prediction Hybrid enhanced Collaborative thinking
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Safe Motion Planning and Control Framework for Automated Vehicles with Zonotopic TRMPC
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作者 Hao Zheng Yinong Li +1 位作者 Ling Zheng Ehsan Hashemi 《Engineering》 SCIE EI CAS CSCD 2024年第2期146-159,共14页
Model mismatches can cause multi-dimensional uncertainties for the receding horizon control strategies of automated vehicles(AVs).The uncertainties may lead to potentially hazardous behaviors when the AV tracks ideal ... Model mismatches can cause multi-dimensional uncertainties for the receding horizon control strategies of automated vehicles(AVs).The uncertainties may lead to potentially hazardous behaviors when the AV tracks ideal trajectories that are individually optimized by the AV's planning layer.To address this issue,this study proposes a safe motion planning and control(SMPAC)framework for AVs.For the control layer,a dynamic model including multi-dimensional uncertainties is established.A zonotopic tube-based robust model predictive control scheme is proposed to constrain the uncertain system in a bounded minimum robust positive invariant set.A flexible tube with varying cross-sections is constructed to reduce the controller conservatism.For the planning layer,a concept of safety sets,representing the geometric boundaries of the ego vehicle and obstacles under uncertainties,is proposed.The safety sets provide the basis for the subsequent evaluation and ranking of the generated trajectories.An efficient collision avoidance algorithm decides the desired trajectory through the intersection detection of the safety sets between the ego vehicle and obstacles.A numerical simulation and hardware-in-the-loop experiment validate the effectiveness and real-time performance of the SMPAC.The result of two driving scenarios indicates that the SMPAC can guarantee the safety of automated driving under multi-dimensional uncertainties. 展开更多
关键词 Automated vehicles Automated driving Motion planning Motion control Tube MPC ZONOTOPE
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General Optimal Trajectory Planning:Enabling Autonomous Vehicles with the Principle of Least Action
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作者 Heye Huang Yicong Liu +4 位作者 Jinxin Liu Qisong Yang Jianqiang Wang David Abbink Arkady Zgonnikov 《Engineering》 SCIE EI CAS CSCD 2024年第2期63-76,共14页
This study presents a general optimal trajectory planning(GOTP)framework for autonomous vehicles(AVs)that can effectively avoid obstacles and guide AVs to complete driving tasks safely and efficiently.Firstly,we emplo... This study presents a general optimal trajectory planning(GOTP)framework for autonomous vehicles(AVs)that can effectively avoid obstacles and guide AVs to complete driving tasks safely and efficiently.Firstly,we employ the fifth-order Bezier curve to generate and smooth the reference path along the road centerline.Cartesian coordinates are then transformed to achieve the curvature continuity of the generated curve.Considering the road constraints and vehicle dynamics,limited polynomial candidate trajectories are generated and smoothed in a curvilinear coordinate system.Furthermore,in selecting the optimal trajectory,we develop a unified and auto-tune objective function based on the principle of least action by employing AVs to simulate drivers’behavior and summarizing their manipulation characteristics of“seeking benefits and avoiding losses.”Finally,by integrating the idea of receding-horizon optimization,the proposed framework is achieved by considering dynamic multi-performance objectives and selecting trajectories that satisfy feasibility,optimality,and adaptability.Extensive simulations and experiments are performed,and the results demonstrate the framework’s feasibility and effectiveness,which avoids both dynamic and static obstacles and applies to various scenarios with multi-source interactive traffic participants.Moreover,we prove that the proposed method can guarantee real-time planning and safety requirements compared to drivers’manipulation. 展开更多
关键词 Autonomous vehicle Trajectory planning Multi-performance objectives Principle of least action
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