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Occurrence and Pollution-free Control of Apolygus lucorum in Winter Jujube
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作者 Linmao LI Xingyuan MEN +5 位作者 Baohua YE Yi YU Ansheng ZHANG Lili LI Sicong ZHANG Xianhong ZHOU 《Plant Diseases and Pests》 CAS 2012年第3期21-23,27,共4页
In recent years, Apolygus htcorum has become the main pest of winter jujube. It sucks juice of young parts of winter jujube and causes falling of buds and flowers, leaf perforations, deformities and fall- off of fruit... In recent years, Apolygus htcorum has become the main pest of winter jujube. It sucks juice of young parts of winter jujube and causes falling of buds and flowers, leaf perforations, deformities and fall- off of fruits, leading to serious economic loss. Considering the occurrence characteristics and control problems, the distribution, occurrence regularity, damage characteristics and outbreak reasons of A. lucorum are overviewed and analyzed in this paper, and the pollution-free control measures are also put forward. 展开更多
关键词 Winter jujube Apolygus lucorum OCCURRENCE Pollution-free control
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Regional selection of insecticides and fungal biopesticides to control aphids and thrips and improve the forage quality of alfalfa crops 被引量:1
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作者 PAN Fan GAO Li-jie +6 位作者 ZHU Kai-hui DU Gui-lin ZHU Meng-meng ZHAO Li GAO Yu-lin TU Xiong-bing ZHANG Ze-hua 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第1期185-194,共10页
The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of ... The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of the residues of chemical insecticides in alfalfa and their influence on the quality of alfalfa hay were examined.Efficacy varied among the different biological and chemical insecticides.The chemical insecticides were significantly more effective than biopesticides in a short time-frame.The efficacy period of biopesticides was significantly longer than that of chemical insecticides,and the corrected mortality rate of aphids in all regions was above 50%at 14 days after application.The analysis of pesticide residues showed that the residual doses of all the pesticides were within the allowed ranges after the safe period.The acid detergent fiber and neutral detergent fiber contents in alfalfa hay were higher and the protein content was lower in chemical insecticide treatments than in biopesticide treatments in Hebei.The relative feeding value of alfalfa hay treated with Metarhizium anisopliae IPP330189 was the highest among the treatments.Compared with chemical insecticides,the yield of alfalfa hay was higher in the biopesticides treatments.Biopesticides show a stronger control effect on insect populations and also a better improvement in the quality of alfalfa hay than chemical insecticides.This study provides a basis for exploring and developing a comprehensive control regime for alfalfa insect pests in the different alfalfa-growing regions in China,and for reducing chemical insecticide usage and improving forage quality. 展开更多
关键词 insect pest control pollution free control pesticide residue APHIDS THRIPS
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A Model-free Periodic Adaptive Control for Freeway Traffic Density via Ramp Metering 被引量:11
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作者 CHI Rong-Hu HOU Zhong-Sheng 《自动化学报》 EI CSCD 北大核心 2010年第7期1029-1032,共4页
关键词 交通系统 自适应匝道 自动化系统 交通管理
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Model Free Adaptive Predictive Control of Desulfurization Slurry pH Based on CPS Framework
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作者 Jian Liu Xiaoli Li +2 位作者 Kang Wang Fuqiang Wang Guimei Cui 《Journal of Beijing Institute of Technology》 EI CAS 2020年第4期544-555,共12页
In order to improve the slurry pH control accuracy of the absorption tower in the wet flue gas desulfurization process,a model free adaptive predictive control algorithm for the desulfurization slurry pH which is base... In order to improve the slurry pH control accuracy of the absorption tower in the wet flue gas desulfurization process,a model free adaptive predictive control algorithm for the desulfurization slurry pH which is based on a cyber physical systems framework is proposed.First,aiming to address system characteristics of non-linearity and pure hysteresis in slurry pH change process,a model free adaptive predictive control algorithm based on compact form dynamic linearization is proposed by combining model free adaptive control algorithm with model predictive control algorithm.Then,by integrating information resources with the physical resources in the absorption tower slurry pH control process,an absorption tower slurry pH optimization control system based on cyber physical systems is constructed.It is turned out that the model free adaptive predictive control algorithm under the framework of the cyber physical systems can effectively realize the high-precision tracking control of the slurry pH of the absorption tower,and it has strong robustness. 展开更多
关键词 wet flue gas desulfurization slurry pH cyber physical systems model free adaptive predictive control tracking control
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Free-matrix-based time-dependent discontinuous Lyapunov functional for synchronization of delayed neural networks with sampled-data control 被引量:1
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作者 王炜 曾红兵 Kok-Lay Teo 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第11期127-134,共8页
This paper is concerned with the synchronization of delayed neural networks via sampled-data control. A new technique, namely, the free-matrix-based time-dependent discontinuous Lyapunov functional approach, is adopte... This paper is concerned with the synchronization of delayed neural networks via sampled-data control. A new technique, namely, the free-matrix-based time-dependent discontinuous Lyapunov functional approach, is adopted in constructing the Lyapunov functional, which takes advantage of the sampling characteristic of sawtooth input delay. Based on this discontinuous Lyapunov functional, some less conservative synchronization criteria are established to ensure that the slave system is synchronous with the master system. The desired sampled-data controller can be obtained through the use of the linear matrix inequality(LMI) technique. Finally, two numerical examples are provided to demonstrate the effectiveness and the improvements of the proposed methods. 展开更多
关键词 neural networks synchronization sampled-data control free-matrix-based inequality
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Study of measurement and control of free loop of hot steel strip in twin-roll strip casting
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作者 YE Changhong FANG Yuan ZHANG Qing 《Baosteel Technical Research》 CAS 2018年第1期27-33,共7页
In the twin-roll strip casting process, hot cast strips can be broken or tom if the casting speed does not match the rolling speed. Usually, a certain length of hot steel strip is hung freely between the caster and ro... In the twin-roll strip casting process, hot cast strips can be broken or tom if the casting speed does not match the rolling speed. Usually, a certain length of hot steel strip is hung freely between the caster and rolling mill to deal with the effect of this speed difference. In this paper,the freely hanging hot steel strip is referred to as the free loop of hot steel strip. Accurately measuring and controlling the height of this free loop is the key factor in maintaining a stable casting operation. Several methods for measuring the loop height of a steel strip are discussed and a method for accurately measuring and controlling the free loop height of hot steel strip is presented. Based on the results of the casting loop quantity change curve, this control method is confirmed to be effective and able to meet the requirements of continuous casting strip production. 展开更多
关键词 twin-roll strip casting free loop height of free loop measurement method measurement error control of free loop height
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THE ROBUST CONTROL SCHEME FOR FREE-FLOATING SPACE MANIPULATOR TO TRACK THE DESIRED TRAJECTORY IN JOINTSPACE 被引量:6
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作者 Chen Li (Department of Mechanical Engineering, Fuzhou University, Fuzhou 350002, China) Liu Yanzhu (Department of Engineering Mechanics,Shanghai Jiaotong University, Shanghai 200030, China) 《Acta Mechanica Solida Sinica》 SCIE EI 2001年第2期183-188,共6页
The control of a free-floating space manipulator system isdiscussed. With the augmentation approach, the nonlinearparameterization problem of the dynamic equations of the spacemanipulator system is overcome. Based on ... The control of a free-floating space manipulator system isdiscussed. With the augmentation approach, the nonlinearparameterization problem of the dynamic equations of the spacemanipulator system is overcome. Based on the results, the robustcontrol scheme for free-floating space manipulator with uncer- tainpayload parameters to track the desired trajectory in jointspace isproposed, and the global convergence of the tracking is verified byusing the Lyapunov method. 展开更多
关键词 free-floating space maniulator augmentation approach robust control
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Fuzzy Model Free Adaptive Control for Rotor Blade Full-Scale Static Testing
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作者 廖高华 乌建中 《Journal of Donghua University(English Edition)》 EI CAS 2015年第4期536-540,共5页
To eliminate the node traction coupling during wind turbine blade full-scale static testing,a model free adaptive control algorithm is presented based on fuzzy control performance function compensation. Based on the u... To eliminate the node traction coupling during wind turbine blade full-scale static testing,a model free adaptive control algorithm is presented based on fuzzy control performance function compensation. Based on the universal model theory,the fuzzy model free adaptive control( FMFAC) algorithm is designed by configuring the spot static testing experiences as compensation function F( ·). Then the algorithm implementation process is provided and its quick convergence is proved. Using software to establish static load coupling model of multi-nodes,simulate and verify the validity of FMFAC algorithm,which is applied to wind turbines blade full-scale static testing. The results show that the adaptive decoupling ability of FMFAC is better. The traction of four load points can stay steady and change coordinately. Process error is not over ± 6 k N. The error rate is lower than 1% in special phase.This algorithm effectively eliminates the traction coupling of the static testing process,and makes wind turbine blade testing steadily. 展开更多
关键词 wind turbines FUZZY control performance DECOUPLING model free adaptive control(MFAC) algorithm STATIC testing
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Rolling Control Characteristic Experimental Investigation of a Canard Missile with Free-Spinning Tail 被引量:1
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作者 雷娟棉 吴甲生 孟令涛 《Journal of Beijing Institute of Technology》 EI CAS 2006年第1期36-38,共3页
To study the rolling control characteristics of a canard-controlled missile, a series of wind tunnel experiment is conducted. The experimental method, the structure features of wind tunnel model and the experimental r... To study the rolling control characteristics of a canard-controlled missile, a series of wind tunnel experiment is conducted. The experimental method, the structure features of wind tunnel model and the experimental results are introduced in this paper. The experimental data show that the canard is an inefficient rolling control device for canard-controlled missile with fixed tail fins; but for the free-spinning tail fin configuration, the canard can conduct rolling control of the missile, and even have higher controlling efficiency under larger canard deflection angle. 展开更多
关键词 canard missile aerodynamic characteristics wind tunnel experiment free-spinning tail rolling control characteristics
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Model-free Adaptive Control for Spacecraft Attitude
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作者 Ran Xie Ting Song +1 位作者 Peng Shi Yushan Zhao 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2016年第6期61-66,共6页
A model-free adaptive control method is proposed for the spacecrafts whose dynamical parameters change over time and cannot be acquired accurately. The algorithm is based on full form dynamic linearization.A dimension... A model-free adaptive control method is proposed for the spacecrafts whose dynamical parameters change over time and cannot be acquired accurately. The algorithm is based on full form dynamic linearization.A dimension reduction matrix is introduced to construct an augmented system with the same dimension input and output. The design of the controller depends on the system input and output data rather than the knowledge of the controlled plant. The numerical simulation results show that the improved controller can deal with different models with the same set of controller parameters,and the controller performance is better than that of PD controller for the time-varying system with disturbance. 展开更多
关键词 model-free adaptive control spacecraft attitude control dimension reduction matrix time-varying system
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Stability of Networked Control Systems Based on Free-Weighting Matrices Method
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作者 袁智 王常虹 +1 位作者 李清华 闻帆 《Journal of Donghua University(English Edition)》 EI CAS 2009年第6期598-602,共5页
A new method of modeling discrete networked control systems with both the time-varying delay and packet loss was presented in this paper.The network-induced delay is time-varying and it can be smaller or larger than o... A new method of modeling discrete networked control systems with both the time-varying delay and packet loss was presented in this paper.The network-induced delay is time-varying and it can be smaller or larger than one sampling period.The feedback controller was designed by free-weighting matrices method and Lyapunov-Krasovskii functional to make the networked control system asymptotically stable.And sufficient conditions were derived.A numerical example is given to illustrate the effectiveness of the proposed approach. 展开更多
关键词 网络控制系统 矩阵方法 稳定性 自由 LYAPUNOV 网络诱导时延 时变时延 反馈控制器
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Trajectory Control of Scale-Free Dynamical Networks with Exogenous Disturbances
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作者 杨洪勇 张顺 宗广灯 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第1期185-192,共8页
在这份报纸,多代理人的轨道控制有外长的骚乱的动态系统被学习。建议没有规模的网络拓扑学创作的多重代理人,为低度节点拒绝骚乱的表演和高度节点被分析。第一,没有骚乱的多代理人系统的一致被在代理人的部分上设计卡住的控制策略学... 在这份报纸,多代理人的轨道控制有外长的骚乱的动态系统被学习。建议没有规模的网络拓扑学创作的多重代理人,为低度节点拒绝骚乱的表演和高度节点被分析。第一,没有骚乱的多代理人系统的一致被在代理人的部分上设计卡住的控制策略学习,在这卡住的控制能把多重代理人的状态带到期望的一致课程的地方。然后,骚乱的影响被开发骚乱观察员考虑,并且骚乱观察员基于控制(DOBC ) 为一个外长的系统产生估计骚乱的骚乱被开发。有在合成控制器下面的骚乱的多代理人系统的 Asymptotical 一致能为没有规模的网络拓扑学被完成。由与没有规模的网络拓扑学和外长的骚乱分析多代理人系统的例子,最后,结果的真理被证明。在有设计参数的 DOBC 下面,多代理人系统的轨道集中被卡住节点的二个类研究。我们发现了它为比卡住的低度节点的卡住的高度节点有更更强壮的坚韧性到外长的骚乱。 展开更多
关键词 外部扰动 弹道控制 无尺度网络 多代理系统 无标度网络 干扰性能 拓扑结构 多智能体系统
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Effects of Scale-Free Topological Properties on Dynamical Synchronization and Control in Coupled Map Lattices 被引量:1
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作者 CHEN Wei FANG Jin-Qing KANG Ge-Wen 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2期361-368,共8页
在纸,我们学习效果没有规模(SF ) 在联合地图格子(电流型逻辑) 的动态同步和控制上的拓扑学。我们的策略是使用三个反馈控制方法,包括经常的反馈和推迟时间的反馈的二种类型,到到达需要的同步状态的网络节点的小部分。二控制分叉图... 在纸,我们学习效果没有规模(SF ) 在联合地图格子(电流型逻辑) 的动态同步和控制上的拓扑学。我们的策略是使用三个反馈控制方法,包括经常的反馈和推迟时间的反馈的二种类型,到到达需要的同步状态的网络节点的小部分。二控制分叉图诗句反馈力量分别地被获得。当£线性地被增加,为第一推迟时间的反馈控制的批评反馈力量γ _ c 的值线性地被增加,这被发现。有 SF 的电流型逻辑失去同步,如果γ 】 γ _ c.Numerical 例子被举表明所有结果, intermittency 发生。 展开更多
关键词 无标度网络 拓扑性质 耦合图矩阵 动态同步 反馈控制 时滞反馈
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位移无拖曳控制的动力学协调条件研究
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作者 苟兴宇 王丽娇 +2 位作者 许现民 邹奎 蒋庆华 《宇航学报》 EI CAS CSCD 北大核心 2024年第4期540-549,共10页
针对位移无拖曳控制的可实现性问题及避免推力饱和问题,首先基于位移无拖曳控制动力学方程,推导出位移无拖曳控制系统中连续可变推力推进子系统的最大推力需要满足的基本动力学协调条件。进一步由位移无拖曳控制动力学方程退化得到的切... 针对位移无拖曳控制的可实现性问题及避免推力饱和问题,首先基于位移无拖曳控制动力学方程,推导出位移无拖曳控制系统中连续可变推力推进子系统的最大推力需要满足的基本动力学协调条件。进一步由位移无拖曳控制动力学方程退化得到的切换动力学方程,推导出负刚度加速度函数为线性及非线性函数两种情形下的让步动力学协调条件。针对让步动力学协调条件开展了仿真比对,结果表明,强非线性情形下的让步动力学协调条件比退化的线性情形更加严苛。最后通过分析给出位移无拖曳控制避免推力饱和的、定性的动力学协调条件,并得到仿真校验,即:检验质量初始状态及指令状态应在让步动力学协调条件区域内靠近负刚度力零位,开环系统时间延迟尽可能短,并且控制带宽应折中选择。 展开更多
关键词 位移无拖曳控制 动力学协调条件 切换动力学方程 HAMILTON函数 检验质量状态初值
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一种永磁同步电机模型失配容错控制算法
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作者 黄刚 张雨涵 +2 位作者 龚事引 于惠钧 李祥飞 《组合机床与自动化加工技术》 北大核心 2024年第2期103-109,共7页
针对高精度永磁同步电机驱动系统因转动惯量、摩擦系数与磁链参数失配造成其控制精度和稳定性降低的问题,提出了一种基于有限时间收敛扩张状态观测器的无模型滑模容错控制方法。首先,建立了考虑内外不确定性的永磁同步电机转速环超局部... 针对高精度永磁同步电机驱动系统因转动惯量、摩擦系数与磁链参数失配造成其控制精度和稳定性降低的问题,提出了一种基于有限时间收敛扩张状态观测器的无模型滑模容错控制方法。首先,建立了考虑内外不确定性的永磁同步电机转速环超局部模型,并设计了无模型全局积分终端滑模控制器;其次,设计了有限时间收敛扩张状态观测器来降低模型失配带来的影响;最后,通过与其他方法的仿真和实验对比,验证了所提方法能够在不获取精确模型的情况下实现了对多种模型失配与外部扰动工况的容错控制,并提高了电机的控制精度。 展开更多
关键词 永磁同步电机 无模型控制 模型失配 容错控制
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Research on PCC Control Method for Ribbon-free Random Winding 被引量:1
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作者 魏建 王明红 +2 位作者 汤以范 陆文华 吴文英 《Journal of Donghua University(English Edition)》 EI CAS 2004年第5期106-110,共5页
Based on analyzing the overlap appearance of random winding, basic principles of ribbon-free random winding and parametric selections for anti-overlap are discussed. The ribbon-free random winding control system and i... Based on analyzing the overlap appearance of random winding, basic principles of ribbon-free random winding and parametric selections for anti-overlap are discussed. The ribbon-free random winding control system and its related hardware construction as well as its software design are introduced by applying PCC technology to high speed spinning machine of synthetic filament. 展开更多
关键词 可编程控制器 自由扰动线圈 参数选择 软件设计 纺纱设备
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基于无模型自适应控制的半潜式平台运动性能研究
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作者 余杨 张鹏辉 +2 位作者 成司元 张文豪 余建星 《振动与冲击》 EI CSCD 北大核心 2024年第2期88-96,共9页
南海海域油气资源极其丰富,半潜式平台在该海域工作时常常面临着系泊失效这一重大危险情况。该研究以一艘装配有悬链式系泊系统和DP-3动力定位系统的半潜式平台为研究对象,利用AQWA软件开展系泊失效前后半潜式平台运动性能研究。同时,... 南海海域油气资源极其丰富,半潜式平台在该海域工作时常常面临着系泊失效这一重大危险情况。该研究以一艘装配有悬链式系泊系统和DP-3动力定位系统的半潜式平台为研究对象,利用AQWA软件开展系泊失效前后半潜式平台运动性能研究。同时,借助于AQWA软件二次开发功能,将无模型自适应控制作为动力定位系统控制理论,以研究半潜式平台系泊失效后运动性能恢复。数值仿真模拟结果表明,采用无模型自适应控制作为动力定位系统控制理论的半潜式平台能很好地恢复系泊失效后的运动性能,有效地减小系泊失效带来的危害;基于偏格式动态线性化和全格式动态线性化的无模型自适应控制比基于紧格式动态线性化的无模型自适应控制能让半潜式平台更快地恢复运动性能。 展开更多
关键词 半潜式平台 系泊失效 无模型自适应控制 动力定位系统 运动性能
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基于自抗扰的感应电机无模型预测电流控制
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作者 贺虎成 徐景哲 +3 位作者 谭阜琛 刘洵文 张杰 翟恒 《电力系统保护与控制》 EI CSCD 北大核心 2024年第13期149-160,共12页
针对采用传统比例积分(proportional integral,PI)控制算法的感应电机在面对复杂扰动时控制性能降低的问题,基于矢量控制系统,提出了感应电机的自抗扰(active disturbance rejection control,ADRC)无模型预测控制(model-free predictive... 针对采用传统比例积分(proportional integral,PI)控制算法的感应电机在面对复杂扰动时控制性能降低的问题,基于矢量控制系统,提出了感应电机的自抗扰(active disturbance rejection control,ADRC)无模型预测控制(model-free predictive control,MFPC)方法。首先,结合转速环和磁链环数学模型,设计了转速环和磁链环的ADRC控制器,对负载变化和内参摄动产生的内外扰动进行观测并补偿。其次,为避免内环控制器对电机参数的依赖,基于无模型控制原理,建立了dq电流环的超局部方程,将控制量之外的变量视为干扰量,并引入非线性扩张状态观测器估计干扰量。最后,结合预测控制思想设计了电流环控制器,得到开关状态作用于逆变器。仿真与实验结果表明提出的算法相对PI算法有更好的抗扰性和鲁棒性,可以有效提高感应电机的动态和稳态性能。 展开更多
关键词 感应电机 自抗扰控制 无模型控制 超局部方程 预测控制
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Optimal control of nonholonomic motion planning for a free-falling cat
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作者 戈新生 陈立群 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第5期601-607,共7页
The nonholonomic motion planning of a free-falling cat is investigated. Nonholonomicity arises in a free-falling cat subject to nonintegrable angle velocity constraints or nonintegrable conservation laws. When the tot... The nonholonomic motion planning of a free-falling cat is investigated. Nonholonomicity arises in a free-falling cat subject to nonintegrable angle velocity constraints or nonintegrable conservation laws. When the total angular momentum is zero, the motion equation of a free-falling cat is established based on the model of two symmetric rigid bodies and conservation of angular momentum. The control of system can be converted to the problem of nonholonomic motion planning for a free-falling cat. Based on Ritz approximation theory, the Gauss-Newton method for motion planning by a falling cat is proposed. The effectiveness of the numerical algorithm is demonstrated through simulation on model of a free-falling cat. 展开更多
关键词 free-falling cat nonholonomic constraint motion planning optimal control
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基于无人机PPK技术在免像控条件下山区光伏地形图的生产
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作者 黄小兵 牛仁义 +5 位作者 王炫懿 程万君 杨健 张社轩 赵三星 刘宇 《北京测绘》 2024年第6期846-850,共5页
针对光伏场区高差大、部分区域植被覆盖、通信信号弱的特点,本文提出了一种基于动态后处理技术(PPK)在免像控条件下航测光伏地形图生产的方法。该方法首先在免像控的条件下对航测获取的无人机影像定位测姿系统(POS)数据和点云数据进行PP... 针对光伏场区高差大、部分区域植被覆盖、通信信号弱的特点,本文提出了一种基于动态后处理技术(PPK)在免像控条件下航测光伏地形图生产的方法。该方法首先在免像控的条件下对航测获取的无人机影像定位测姿系统(POS)数据和点云数据进行PPK解算;然后利用点云后处理、影像空中三角测量、数字微分纠正等技术生成高精度数字高程模型(DEM)和数字正射影像(DOM)成果;最后利用DEM和DOM成果构建三维模型,实现地形图生产。利用两个典型应用实例,验证了该方法可完全满足光伏地形图的精度要求。 展开更多
关键词 光伏地形图 后处理运动学定位技术 三维模型 免像控
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