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Heading control method and experiments for an unmanned wave glider 被引量:3
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作者 LIAO Yu-lei LI Yi-ming +2 位作者 WANG Lei-feng LI Ye JIANG Quan-quan 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第11期2504-2512,共9页
The control system designing of unmanned wave glider(UWG) is challenging since the control system is weak maneuvering, large time-lag and large disturbance, which is difficult to establish accurate mathematical model.... The control system designing of unmanned wave glider(UWG) is challenging since the control system is weak maneuvering, large time-lag and large disturbance, which is difficult to establish accurate mathematical model. The control system for the "Ocean Rambler" UWG is studied in this work. A heading control method based on S-surface controller is designed. For the "rudder zero drift" problem in trials, an improved S-surface control method based on rudder angle compensation is proposed, which can compensate the adverse effects from environmental forces and installation error. The tank test and sea trial results prove that the proposed control method has favorable control performance, and the feasibility and reliability of the designed control system are also verified. 展开更多
关键词 unmanned wave glider heading control S-surface control control system
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Command Filtered Finite/Fixed-time Heading Tracking Control of Surface Vehicles 被引量:2
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作者 Zhenyu Gao Ge Guo 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第10期1667-1676,共10页
This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive cont... This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive control laws are developed by which the vehicle can track the desired heading within settling time with all signals of the closed-loop system are uniformly bounded.The effectiveness and performance of the schemes are demonstrated by simulations and comparison studies. 展开更多
关键词 Command filter finite-time control fixed-time control heading tracking control surface vehicles
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Modeling and Control of Head of the Underwater Snake-like Robot Swimming 被引量:2
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作者 Ke Yang Xu-Yang Wang +1 位作者 Tong Ge Chao Wu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第1期77-83,共7页
In order to solve oscillation of head of the underwater snake-like robot,the Central Pattern Generator( CPG)-based control scheme with head-controller was presented. The Kane dynamic model was constructed to be proces... In order to solve oscillation of head of the underwater snake-like robot,the Central Pattern Generator( CPG)-based control scheme with head-controller was presented. The Kane dynamic model was constructed to be processed with a commercial package MotionGenesis Kane 5. 3,to which the proposed control scheme was applied. The relation between CPG parameters and orientation offset of head was investigated. The target orientation of head-controller was calculated through a convenient method. The advantage of this control scheme is that the head of the underwater snake-like robot remains in the forward direction during swimming. To prove the feasibility of the proposed methodology,two basic motion patterns,swimming along the straight line and swimming along the curved path,had been implemented in our simulation platform. The results showed that the simulation platform can imitate the swimming of the underwater snake-like robot and the head of the underwater snake-like robot remains in a fixed orientation directed towards the target. The oscillation of head's orientation is inhibited effectively. 展开更多
关键词 underwater snake-like robot CPG-based control scheme head-controller MotionGenesis Kane 5.3
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Introduction of Several Methods to Control Fusarium Head Blight (FHB)
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作者 张荣 张敏 《中国农学通报》 CSCD 2008年第10期419-426,共8页
Fusarium head blight (FHB) is a worldwide destructive disease of wheat in the warm, semi-humid or humid regions, especially serious in China. The disease not only causes significant losses in yield and reduces grain q... Fusarium head blight (FHB) is a worldwide destructive disease of wheat in the warm, semi-humid or humid regions, especially serious in China. The disease not only causes significant losses in yield and reduces grain quanlity, but also induces toxin to contaminated seeds, which is harmful to the healthy of human and livestocks, So it is important to control it. There are several methods to control Fusarium head blight (FHB). Such as using Crop rotation, Soil cultivation and Fertiliser, biological control, Fungicides control, transgenes, resistance to control Fusarium head blight (FHB). All of these methods gain some effect, but also exist their deficiency. Sometimes crop rotation had no significant effect on DON contamination of wheat grain, subsequent reductions in DON contamination were inconsistent when using Soil cultivation and Fertiliser, Unfortunately, under field conditions, the biological control achieved has been shown to be variable and in some tests has failed to give any control, The use of fungicides, however, have not been consistently effective in controlling FHB and in reducing DON formation, transgene-silencing at different generations is a problem to use transgenes, Information on location of QTL for FHB resistance should improve dramatically in the near future on resistance to control Fusarium head blight (FHB). Therefore, it is pressing to improve control methods, especially to DON. 展开更多
关键词 赤霉病 预防措施 植物 小麦
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A bull-heading water control technique of thermo-sensitive temporary plugging agent 被引量:4
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作者 LIU Pingde WEI Falin +3 位作者 ZHANG Song ZHU Xiuyu WANG Longfei XIONG Chunming 《Petroleum Exploration and Development》 2018年第3期536-543,共8页
Aimed at the disadvantages of secondary damage to oil layers caused by the conventional bull-heading water control technique, a thermo-sensitive temporary plugging agent for water control was synthesized by water solu... Aimed at the disadvantages of secondary damage to oil layers caused by the conventional bull-heading water control technique, a thermo-sensitive temporary plugging agent for water control was synthesized by water solution polymerization and applied in the field with a new secondary temporary plugging technique. The optimization and performance evaluation of thermo-sensitive temporary plugging agent were carried out through laboratory experiments. The optimized formula is as follows:(6%-8%) acrylamide +(0.08%-0.12%) ammonium persulfate +(1.5%-2.0%) sepiolite +(0.5%-0.8%) polyethylene glycol diacrylate. The thermo-sensitive temporary plugging agent is suitable for formation temperatures of 70-90 ?C, it has high temporary plugging strength(5-40 k Pa), controllable degradation time(1-15 d), the apparent viscosity after degradation of less than 100 m Pa?S and the permeability recovery value of simulated cores of more than 95%. Based on the research results, secondary temporary plugging technique was used in a horizontal well in the Jidong Oilfield. After treatment, the well saw a drop of water cut to 27%, and now it has a water cut of 67%, its daily increased oil production was 4.8 t, and the cumulative oil increment was 750 t, demonstrating that the technique worked well in controlling water production and increasing oil production. 展开更多
关键词 bull-heading water control TECHNIQUE THERMO-SENSITIVE TEMPORARY plugging agent secondary TEMPORARY plugging TECHNIQUE thermal degradation property RESERVOIR protection
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Numerical Simulation of Turret Moored Ship Performance in Variable Ice Drift Based on Heading Control
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作者 周利 《舰船科学技术》 北大核心 2016年第S1期75-84,共10页
The frequent change in ice drift direction poses a significant challenge for turret moored ship in ice. Variability in ice drift is mainly caused by the winds and currents. To solve this problem, a new method with num... The frequent change in ice drift direction poses a significant challenge for turret moored ship in ice. Variability in ice drift is mainly caused by the winds and currents. To solve this problem, a new method with numerical simulation based on heading control is applied to reduce the risk of operation of The Arctic Tandem Offloading Terminal(ATOT),which includes an offloading icebreaker(OIB) moored to a submerged turret and a shuttle tanker moored at the stern of the OIB in this paper. An icebreaking tanker, MT Uikku, was modeled in a simulation program. Then the level ice load on the tanker was calculated with different ice thicknesses and drift speeds, after which a heading controller assisted with mooring system is used to simulate the horizontal motion of the tanker under the ice action. 展开更多
关键词 Numerical simulation Mooring system heading control Ice drift Ice loads
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Cutting Characteristics of Force Controllable Milling Head
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作者 Shirakashi Takahiro Shibuya Wataru 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期108-,共1页
In order to control cutting force and its direction i n milling operation, a new milling head was developed. The head has two milling cutters, which are connected by a pair of gears and rotate in opposite direction re... In order to control cutting force and its direction i n milling operation, a new milling head was developed. The head has two milling cutters, which are connected by a pair of gears and rotate in opposite direction respectively. Both up-cut and down-cut can be carried out simultaneously by t hese milling cutters. The each depth of cut, the ratio of up/down cutting depth , by these cutters can be also selected. The cutting force characteristics were experimentally discussed by changing the ratio. The cutting force and its locus can be also changed by the selection of the ratio of up/down cutting depth. For practical usage of the head the analytical prediction method of the cutting forc e characteristics under selected cutting condition was proposed based on the ene rgy approach method proposed, in which both of cutting force characteristics of a single milling cutter and the combined milling cutter under a selected up/dow n cutting depth ratio were analytically estimated based on the two dimensional c utting data. It was experimentally shown that in NC milling machine the cutting force locus was controlled in pre-determined direction under various tool paths . 展开更多
关键词 Cutting Characteristics of Force controllable Milling head
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On-line current feed and computer aided control tactics for automatic balancing head
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作者 李勇 陆永平 +1 位作者 须根发 夏松波 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2002年第2期205-207,共3页
In the designed automatic balancing head, a non contact induction transformer is used to deliver driving energy to solve the problem of current fed and controlling on line. Computer controlled automatic balancing expe... In the designed automatic balancing head, a non contact induction transformer is used to deliver driving energy to solve the problem of current fed and controlling on line. Computer controlled automatic balancing experiments with phase magnitude control tactics were performed on a flexible rotor system. Results of the experiments prove that the energy feeding method and the control tactics are effective in the automatic balancing head for vibration controlling. 展开更多
关键词 AUTOMATIC balancing balancing head ON-LINE control TACTICS
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Damage Characteristics and Control Measures of Maize Head Smut
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作者 Bai Yanfeng Jiang Long +5 位作者 Ren Haixiang Wang Yanping Wang Xiaomei Zong Chunmei Sun Xiaohuan Qi Yuxin 《Plant Diseases and Pests》 CAS 2014年第5期15-16,24,共3页
Maize head smut is a worldwide disease, widely occurred in most maize fields. The disease had occurred in large area in the late 1970s, and became a limiting factor restricting the improvement of maize yield and total... Maize head smut is a worldwide disease, widely occurred in most maize fields. The disease had occurred in large area in the late 1970s, and became a limiting factor restricting the improvement of maize yield and total yield in China. After efforts of several generations of agricultural scientific workers, the symp- toms, pathogen, infection pathway, infection conditions, infection regularity and resistance genetic law of maize head smut have been studied. This paper introduces the incidence symptoms, pathogen sources, infection pathway, infection conditions, and physiological races of maize head smut, and put forwards the corresponding prevention measures, such as crop rotation, selection of resistant varieties, seed dressing, soil treatment with fungicides, promoting seedling emergence and strengthening field management. 展开更多
关键词 Maize head smut Damage characteristics control measures
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预设性能下的输出受限船舶航向切换容错控制 被引量:1
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作者 宁君 张军 李伟 《计算机仿真》 2024年第1期385-389,451,共6页
针对船舶输出受限、执行器故障不确定性和受到未知海洋扰动的船舶航向控制问题,提出一种基于切换策略的自适应容错控制方案。利用对数障碍李雅普诺夫约束航向误差并将状态输出约束在有限范围内。结合预设性能理论和反步法,针对具有不确... 针对船舶输出受限、执行器故障不确定性和受到未知海洋扰动的船舶航向控制问题,提出一种基于切换策略的自适应容错控制方案。利用对数障碍李雅普诺夫约束航向误差并将状态输出约束在有限范围内。结合预设性能理论和反步法,针对具有不确定参数和执行器故障的船舶控制系统,将健康执行器作为备用。通过设计一套监控函数来监督航向误差的动态范围,实现了在执行器故障且故障模式未知的情况下,船舶航向控制器从故障执行器切换到健康执行器,同时满足跟踪误差的收敛性及控制系统稳定性。仿真验证了所提出算法的有效性。 展开更多
关键词 预设性能 航向控制 输出受限 容错控制
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我国小麦赤霉病流行与化学防控现状及控病降毒关键技术理论创新与应用 被引量:2
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作者 段亚冰 周明国 《现代农药》 CAS 2024年第2期13-21,共9页
概述了我国小麦赤霉病发生危害现状,深入剖析了该病流行危害的原因,回顾了近年来我国小麦赤霉病化学防控历程,综述了化学防控及其抗药性发生的现状,并总结了小麦赤霉病菌抗药性检测技术的发展过程。此外,对小麦赤霉病控病降毒关键技术... 概述了我国小麦赤霉病发生危害现状,深入剖析了该病流行危害的原因,回顾了近年来我国小麦赤霉病化学防控历程,综述了化学防控及其抗药性发生的现状,并总结了小麦赤霉病菌抗药性检测技术的发展过程。此外,对小麦赤霉病控病降毒关键技术理论创新与应用成果进行了分析和总结,展望了小麦赤霉病精准防控的科学用药技术方案,并对其可行性和有效性进行了阐释。旨在为小麦赤霉病的精准选药、科学用药提供重要的参考数据,保障我国的粮食生产安全和食品安全,进而推动我国农业实现可持续、高质量发展。 展开更多
关键词 小麦赤霉病 化学防控 抗药性 DON毒素 抗病降毒
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Occurrence of Rice Dry Straight Head Disease and Its Control
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作者 黄自安 刘小林 +2 位作者 倪春耕 胡宏云 王振荣 《Plant Diseases and Pests》 CAS 2010年第2期1-4,9,共5页
[Objective] Cause of disease and control measures of rice dry straight head disease in Chuzhou area was discussed. [Method] Field investigation and comprehensive analysis of the literature were conducted to study the ... [Objective] Cause of disease and control measures of rice dry straight head disease in Chuzhou area was discussed. [Method] Field investigation and comprehensive analysis of the literature were conducted to study the reason of dry straight head disease in Chuzhou area, some common control measures were summarized. [Result] The characteristic of main symptoms included incidence of single plant, incidence of cluster, inclusive incidence between clusters. Sporadic normal rice grains existed in diseased spikes under the incidence of grains. The main pathogenic factors of dry straight head disease were concentration of arsenic or lack of elements, belonging to physiological disease, while the effect of other pathogenic factors could not be excluded. Heavy application of organic fertilizer and crop rotation should be conducted, white soil field should be paid more attention about the changes of disease condition with more wet and dry roasting over fields. Application time of micro fertilizer should be chosen properly, while tillering final stage and pollen formation stage must be adjusted to avoid high temperature, irrigation management should also be improved. [Conclusion] The study could provide reference for preventing rice dry straight head disease. 展开更多
关键词 Rice dry straight head disease Research SYMPTOM Cause of disease Arsenic concentration Prevention and control measure
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丙硫菌唑与丙环唑混剂对小麦赤霉病菌的联合毒力及田间防效 被引量:1
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作者 陈宏州 王兵兵 +5 位作者 王陈斌 张新建 杨红福 徐超 张建华 朱凤 《中国农学通报》 2024年第2期114-120,共7页
为研发防治小麦赤霉病的新药剂,采用菌丝生长速率法分别检测了丙硫菌唑、丙环唑及其7种配比混剂对赤霉病菌的室内毒力,并进行了优选配比制剂对赤霉病、籽粒DON毒素、白粉病和叶锈病的田间药效试验。结果表明,丙硫菌唑与丙环唑配比为1:1... 为研发防治小麦赤霉病的新药剂,采用菌丝生长速率法分别检测了丙硫菌唑、丙环唑及其7种配比混剂对赤霉病菌的室内毒力,并进行了优选配比制剂对赤霉病、籽粒DON毒素、白粉病和叶锈病的田间药效试验。结果表明,丙硫菌唑与丙环唑配比为1:1时增效系数为2.4375,增效最显著。田间药效试验中,40%丙硫菌唑·丙环唑可分散油悬浮剂(OD)600 g/hm^(2)对赤霉病病指防效和籽粒DON防效分别为93.46%和91.26%,2次药后21 d对白粉病和叶锈病病指防效分别为93.50%和93.19%,均高于常规药剂戊唑醇和多菌灵,并且对小麦生长安全。40%丙硫菌唑·丙环唑OD对赤霉病和籽粒DON毒素防效优良,同时对白粉病和叶锈病兼治效果优良,具有较好的开发潜力。 展开更多
关键词 小麦赤霉病 脱氧雪腐镰刀菌烯醇 丙硫菌唑 丙环唑 联合毒力 防治效果
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基于自注意力PPO算法的智能配电网多设备协同无功优化控制策略
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作者 张黎元 宋兴旺 +3 位作者 李冰洁 梁睿 刘长德 彭奕洲 《智慧电力》 北大核心 2024年第10期40-48,共9页
针对智能配电网无功可调控资源多样化场景下的快速趋优难题,提出了一种基于多头自注意力近端策略优化算法的多设备协同无功优化控制方法。首先,将无功优化问题建模为马尔可夫决策过程;然后,在深度强化学习框架下使用多头自注意力改进近... 针对智能配电网无功可调控资源多样化场景下的快速趋优难题,提出了一种基于多头自注意力近端策略优化算法的多设备协同无功优化控制方法。首先,将无功优化问题建模为马尔可夫决策过程;然后,在深度强化学习框架下使用多头自注意力改进近端策略优化(PPO)算法对策略网络进行优化训练,算法采用多头自注意力网络获取配电网的实时状态特征,并通过剪切策略梯度法动态控制策略网络的更新幅度;最后,在改进IEEE69节点系统进行仿真验证。结果表明,所提算法的控制性能优于现有先进强化学习算法。 展开更多
关键词 配电网 分布式光伏 电压无功控制 多头自注意力 近端策略优化算法
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面向对象技术的智能插秧机控制系统设计研究 被引量:2
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作者 史丽丽 《农机化研究》 北大核心 2024年第1期151-154,共4页
以插秧机智能控制系统为研究对象,基于面向控制对象技术设计一种无人驾驶插秧机智能控制系统,并在水泥路面和水田两种不同环境中对插秧机进行性能试验测试。试验结果表明:在水泥路面上插秧机行进过程最大横向偏差小于50mm,最大航向偏差... 以插秧机智能控制系统为研究对象,基于面向控制对象技术设计一种无人驾驶插秧机智能控制系统,并在水泥路面和水田两种不同环境中对插秧机进行性能试验测试。试验结果表明:在水泥路面上插秧机行进过程最大横向偏差小于50mm,最大航向偏差小于2°;在水田内插秧机行进过程最大横向偏差小于60mm,最大航向偏差小于3°,表明智能控制系统在使用过程中具有较高的可靠性和稳定性。 展开更多
关键词 智能插秧机 控制系统 面向对象 横向偏差 航向偏差
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变输出无模型自适应无人艇艏向控制方法分析 被引量:1
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作者 廖煜雷 陈聪聪 +2 位作者 杜廷朋 王博 李晔 《中国舰船研究》 CSCD 北大核心 2024年第1期75-83,共9页
[目的]针对无人艇(USV)艏向控制存在模型摄动、外部干扰等不确定性问题,提出一种适用于USV的改进无模型自适应控制(MFAC)方法。[方法]基于USV艏向控制子系统存在非自衡特性,直接使用紧格式MFAC方法讨论USV的艏向控制子系统在不确定影响... [目的]针对无人艇(USV)艏向控制存在模型摄动、外部干扰等不确定性问题,提出一种适用于USV的改进无模型自适应控制(MFAC)方法。[方法]基于USV艏向控制子系统存在非自衡特性,直接使用紧格式MFAC方法讨论USV的艏向控制子系统在不确定影响下的控制问题。在标准控制准则中引入历史输入项,提出一种变输出紧格式MFAC方法,削弱USV艏向控制子系统中存在的积分作用。最后,开展艏向控制仿真实验以及“海豚IB”小型USV的外场试验验证所提方法的有效性。[结果]结果显示,相比标准紧格式MFAC方法和PID方法,变输出紧格式MFAC方法的USV艏向控制更加稳定。[结论]所做研究可为USV提供一种对环境扰动、模型摄动等影响不敏感、具有较好自适应性及鲁棒性的艏向控制算法。 展开更多
关键词 无人艇 无模型自适应控制 艏向控制 非自衡特性 变输出
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综掘工作面风流调控下风速及瓦斯粉尘浓度融合预测模型研究
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作者 龚晓燕 邹浩 +6 位作者 刘壮壮 陈龙 付浩然 孙育恒 李昊 王新雨 牛虎明 《煤炭科学技术》 EI CAS CSCD 北大核心 2024年第10期136-146,共11页
针对综掘工作面传统的通风总量控制管理模式不能根据实际需求进行风流调控,造成瓦斯及粉尘聚集和污染隐患等问题,对风流调控下的风速及瓦斯粉尘浓度多源数据融合神经网络预测模型进行了研究。采用欧拉-拉格朗日法建立了风流调控下的瓦... 针对综掘工作面传统的通风总量控制管理模式不能根据实际需求进行风流调控,造成瓦斯及粉尘聚集和污染隐患等问题,对风流调控下的风速及瓦斯粉尘浓度多源数据融合神经网络预测模型进行了研究。采用欧拉-拉格朗日法建立了风流调控下的瓦斯及粉尘气固耦合模型并进行了测试验证,模拟分析瓦斯和粉尘颗粒在综掘巷道的分布情况,获取大量不同风流调控方案下的风速及瓦斯粉尘浓度样本数据。采用多层感知器神经网络技术建立预测模型结构,选取对瓦斯及粉尘浓度具有较大影响的风流调控等参数作为输入层,根据风速及瓦斯粉尘的隐患位置确定输出层,对样本数据进行预处理,通过引入差分进化算法搜索最佳隐藏层节点数和学习率,利用TensorFlow框架搭建多源数据融合神经网络预测模型。以陕北某矿综掘工作面为研究对象,对不同风流调控方案进行预测和井下实测验证。结果表明:该模型相对误差最大值为9.7%,具有较高的准确性;选取出风口距端头最短距离5 m和最远距离10 m这2种工况下的最佳调控方案,与调控前相比,风速符合规范要求,端头死角区瓦斯体积分数分别降低34%和35%,回风侧人行处平均粉尘质量浓度分别降低40%和41%,司机处粉尘质量浓度分别降低38%和36%,研究可为风流调控提供参考。 展开更多
关键词 综掘工作面 风流调控 风速 瓦斯及粉尘浓度 多源数据融合 神经网络预测 差分进化算法
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基于S形速度曲线的键合头运动控制系统研究与分析
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作者 高岳 《电子工业专用设备》 2024年第2期52-57,共6页
根据用户工艺需求,针对全自动芯片键合设备的运动控制模块以及键合头子模块开展需求分析,结合典型试验,设计出基于S形速度曲线的键合头运动控制系统,根据S形速度曲线重新规划了键合头的运动轨迹,使其对芯片键合周期缩短的同时也保证了... 根据用户工艺需求,针对全自动芯片键合设备的运动控制模块以及键合头子模块开展需求分析,结合典型试验,设计出基于S形速度曲线的键合头运动控制系统,根据S形速度曲线重新规划了键合头的运动轨迹,使其对芯片键合周期缩短的同时也保证了键合精度。 展开更多
关键词 运动控制模块 键合头 S形速度曲线
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己唑醇及其复配剂对河南省禾谷镰孢菌的抑制活性及对小麦赤霉病的室内防效
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作者 李梦雨 高续恒 +2 位作者 钱乐 姜佳 刘圣明 《农药学学报》 CAS CSCD 北大核心 2024年第3期540-548,共9页
禾谷镰孢菌Fusarium graminearum是河南省小麦赤霉病的优势致病菌。为明确己唑醇对禾谷镰孢菌的抑制活性,测定了己唑醇对禾谷镰孢菌不同发育阶段的毒力,并采用菌丝生长速率法测定了己唑醇对采自河南省6个地区的205株禾谷镰孢菌的抑制活... 禾谷镰孢菌Fusarium graminearum是河南省小麦赤霉病的优势致病菌。为明确己唑醇对禾谷镰孢菌的抑制活性,测定了己唑醇对禾谷镰孢菌不同发育阶段的毒力,并采用菌丝生长速率法测定了己唑醇对采自河南省6个地区的205株禾谷镰孢菌的抑制活性,最后采用胚芽鞘接种法测定了己唑醇对小麦赤霉病的室内防效。结果表明:己唑醇对禾谷镰孢菌不同发育阶段的抑制活性存在较大差异,EC_(50)值(μg/mL)从大到小依次为孢子萌发(22.5750)>分生孢子产量(2.1686)>芽管伸长(0.8922)>菌丝生长(0.3862)。己唑醇对205株禾谷镰孢菌的EC_(50)值在0.0345~0.9439μg/mL之间,平均EC_(50)值为(0.3578±0.1928)μg/mL;敏感性频率分布均呈连续单峰曲线,表明田间不存在对己唑醇敏感性下降的抗性亚群体。己唑醇与多菌灵、咯菌腈、氰烯菌酯、咪鲜胺及氟唑菌酰羟胺复配,表现出不同程度的相加或增效作用,增效系数(SR)范围在0.5042~3.7293之间。其中,己唑醇与氟唑菌酰羟胺按质量比1:5复配时,SR最大,为3.7293,实际EC_(50)值为0.0133μg/mL。室内防效测定结果显示,复配剂的防治效果显著高于单一药剂多菌灵、己唑醇和氟唑菌酰羟胺。己唑醇与氟唑菌酰羟胺按质量比1:5复配后在9μg/mL下,对小麦胚芽鞘的防效为93.93%。生产中可将己唑醇与氟唑菌酰羟胺或咯菌腈进行复配或轮换使用,以延缓田间抗药性的产生。该研究结果可为己唑醇的科学使用以及小麦赤霉病的综合防治提供理论依据与数据支持。 展开更多
关键词 己唑醇 杀菌剂复配 禾谷镰孢菌 抑制活性 小麦赤霉病 防治效果
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混合遗传算法下欠驱动船舶航向保持控制方法
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作者 阳熠恒 王志博 《舰船科学技术》 北大核心 2024年第13期77-81,共5页
欠驱动船舶容易受到风、浪、洋流等外部环境因素的影响,导致航向偏离、船体摇晃,航行安全风险增加,为提高其在各种海况下的稳定性和安全性,提出混合遗传算法下欠驱动船舶航向保持控制方法。构建欠驱动船舶数学模型描述其动态行为,设计... 欠驱动船舶容易受到风、浪、洋流等外部环境因素的影响,导致航向偏离、船体摇晃,航行安全风险增加,为提高其在各种海况下的稳定性和安全性,提出混合遗传算法下欠驱动船舶航向保持控制方法。构建欠驱动船舶数学模型描述其动态行为,设计包含跟踪微分器和分数阶滑膜控制器的航行保持控制器,生成期望航向的平滑过渡过程,为后者提供航向角速度和角加速度信号。以航向误差作为其输入控制量,通过设计的分数阶滑膜面和控制律实现期望航向追踪,采用混合遗传算法优化控制器参数,提高航向跟踪效果。实验结果表明:该方法可实现不同海况下船舶航向保持控制,控制效率高、航向控制超调量小。 展开更多
关键词 混合遗传算法 欠驱动船舶 航向保持控制 期望航向 控制律
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