期刊文献+
共找到21,072篇文章
< 1 2 250 >
每页显示 20 50 100
A tightly coupled rotational SINS/CNS integrated navigation method for aircraft 预览
1
作者 NING Xiaolin YUAN Weiping LIU Yanhong 《系统工程与电子技术:英文版》 SCIE EI CSCD 2019年第4期770-782,共13页
Strapdown inertial navigation system(SINS)/celestial navigation system(CNS)integrated navigation is widely used to achieve long-time and high-precision autonomous navigation for aircraft.In general,SINS/CNS integrated... Strapdown inertial navigation system(SINS)/celestial navigation system(CNS)integrated navigation is widely used to achieve long-time and high-precision autonomous navigation for aircraft.In general,SINS/CNS integrated navigation can be divided into two integrated modes:loosely coupled integrated navigation and tightly coupled integrated navigation.Because the loosely coupled SINS/CNS integrated system is only available in the condition of at least three stars,the latter one is becoming a research hotspot.One major challenge of SINS/CNS integrated navigation is obtaining a high-precision horizon reference.To solve this problem,an innovative tightly coupled rotational SINS/CNS integrated navigation method is proposed.In this method,the rotational SINS error equation in the navigation frame is used as the state model,and the starlight vector and star altitude are used as measurements.Semi-physical simulations are conducted to test the performance of this integrated method.Results show that this tightly coupled rotational SINS/CNS method has the best navigation accuracy compared with SINS,rotational SINS,and traditional tightly coupled SINS/CNS integrated navigation method. 展开更多
关键词 celestial navigation system(CNS) rotation modulation technology rotational strapdown inertial navigation system(SINS) rotational SINS/CNS integrated navigation
在线阅读 下载PDF
Ship hull flexure measurement based on integrated GNSS/LINS
2
作者 Di WU Yu JIA +1 位作者 Li WANG Yueqiang SUN 《中国光电子学前沿:英文版》 EI CSCD 2019年第3期332-340,共9页
For precision carrier-based landing aid, the position of reference point on the top of island shall be precisely transferred to the landing point on the deck, so the position transfer error caused by the hull flexure ... For precision carrier-based landing aid, the position of reference point on the top of island shall be precisely transferred to the landing point on the deck, so the position transfer error caused by the hull flexure is not negligible. As the existing method is not very applicable to measure the hull flexure, a new technique based on integrated Global Navigation Satellite Systems/Laser Gyro Inertial Navigation System (GNSS/LINS) is proposed in this paper. This integrated GNSS/LINS based measure- ment method is designed to monitor the hull flexure and set up an integrated GNSS/LINS measurement model based on raw pseudo-range and pseudo-range rate measurement and carrier phase differential positioning measurement to effectively eliminate the measurement error caused by cycle slip and multi-path effect from GNSS. It is shown by demonstration test and analysis that this technique has the capability to precisely measure the hull flexure, with the accuracy being better than 0.02 m. 展开更多
关键词 SATELLITE NAVIGATION INERTIAL NAVIGATION flexure MEASUREMENT LASER GYRO
Ionospheric time delay corrections based on the extended single layer model over low latitude region
3
作者 Sahithi Karanam D.Venkata Ratnam J.R.K.Kumar Dabbakuti 《大地测量与地球动力学:英文版》 2019年第3期235-240,共6页
Ionospheric delay error is considered to be one of the most prominent factors impacting the Global Navigation Satellite Systems(GNSS) positioning and navigation accuracies. Due to dispersive nature and anisotropic of ... Ionospheric delay error is considered to be one of the most prominent factors impacting the Global Navigation Satellite Systems(GNSS) positioning and navigation accuracies. Due to dispersive nature and anisotropic of the ionosphere above certain regions, the positioning accuracy is seriously affected when using a precision-limited model. In this paper, an attempt has been taken to estimate ionosphere-delays based on Planar Fit(PF) and Spherical Harmonic Function(SHF) models by applying the commonly used single layer Model(SLM) and an extended single layer model(ESLM) which has been explored sparsely over the region. The results show that ESLM of PF and SHF techniques performed better in estimating ionospheric delay compared to the existing SLM model. Although the performance of the ESLM approach is almost comparable to the SLM results during the quiet ionospheric conditions, the ESLM-PF and ESLMSHF models led to respective improvements of 4.66% and 7.14% over the classically used SLM model under the disturbed ionospheric conditions. In view of the uneven variability of equatorial/low latitude ionosphere above the Indian subcontinental region, the suitability of ESLM-PF and ESLM-SHF models has been emphasized and suggested for assessing its completeness and reliableness across other parts of the globe. The output of this work may be useful for high precession GNSS positioning through mitigating the ionospheric delays under quiet as well as varied ionospheric conditions across the low/equatorial latitude regions. 展开更多
关键词 Global Navigation Satellite Systems(GNSS) Planar fit(PF) Spherical HARMONIC Function(SHF) EXTENDED SINGLE layer model(ESLM)
Up-to-date intraoperative computer assisted solutions for liver surgery 预览
4
作者 Apollon Zygomalas Ioannis Kehagias 《世界胃肠外科杂志:英文版(电子版)》 2019年第1期1-10,共10页
Computer assisted surgical planning allowed for a better selection of patients,evaluation of operative strategy,appropriate volumetric measurements,identification of anatomical risks,definition of tumour resection mar... Computer assisted surgical planning allowed for a better selection of patients,evaluation of operative strategy,appropriate volumetric measurements,identification of anatomical risks,definition of tumour resection margins and choice of surgical approach in liver oncologic resections and living donor liver transplantations.Although preoperative computer surgical analysis has been widely used in daily clinical practice,intraoperative computer assisted solutions for risk analysis and navigation in liver surgery are not widely available or still under clinical evaluation.Computer science technology can efficiently assist modern surgeons during complex liver operations,mainly by providing image guidance with individualized 2D images and 3D models of the various anatomical and pathological structures of interest.Intraoperative computer assisted liver surgery is particularly useful in complex parenchyma-sparing hepatectomies,for intraoperative risk analysis and for the effective treatment of colorectal metastases after neoadjuvant therapy or when they are multiple.In laparoscopic liver surgery,intraoperative computer aid is definitively more important as,apart from a restricted field of view,there is also loss of the fine haptic feedback.Intraoperative computer assisted developments face challenges that prevent their application in daily clinical practice.There is a vast variety of studies regarding intraoperative computer assisted liver surgery but there are no clear objective measurements in order to compare them and select the most effective solutions.An overview of up-to-date intraoperative computer assisted solutions for liver surgery will be discussed. 展开更多
关键词 Computer assisted SURGERY Liver INTRAOPERATIVE 3D models Navigation Image guidance AUGMENTED REALITY Hepatic SURGERY HEPATECTOMY
在线阅读 免费下载
一种零值测试基带信号源设计 预览
5
作者 徐茜 宫海波 《计算机测量与控制》 2019年第4期263-266,270共5页
北斗是我国自主研发并独立运行的全球卫星导航系统,为了解决北斗导航系统的基带信号调试处理难题,提出了一种零值测试基带信号源设计方案;针对导航系统信号通道多、信号传输速率高且时钟信号精度要求高的特点,单板上集成高性能FPGA和DS... 北斗是我国自主研发并独立运行的全球卫星导航系统,为了解决北斗导航系统的基带信号调试处理难题,提出了一种零值测试基带信号源设计方案;针对导航系统信号通道多、信号传输速率高且时钟信号精度要求高的特点,单板上集成高性能FPGA和DSP处理器,系统采用模块化设计,采用直接数字射频信号发射技术及高速时钟系统设计,信号源可模拟并输出多制式多路调制基带信号,可完成4通道射频信号采集以及4通道直接射频信号的产生,可灵活配置工作参数及设备工作状态的实时监测;该信号源在北斗导航系统的研发过程中获得成功应用,实验结果表明,该信号源兼备收发两大信号处理链路功能,系统具有通用性强、配置灵活、稳定性好等特点,解决了导航系统领域基带信号调试处理难题。 展开更多
关键词 导航 处理器 零值测试 基带 信号源
在线阅读 下载PDF
星敏感器技术舰船导航应用建模与实验验证
6
作者 唐君 徐轩彬 《国外电子测量技术》 2019年第7期126-130,共5页
为开展星敏感器面向舰船导航应用的实践性研究,基于星敏感器技术和天体照相学理论的深入分析,建立了一套完整的捷联式舰船天文自动导航模型,并研制了实验验证设备。首先,根据舰载星敏感器的工作流程,分析了星体矢量在各空间坐标系中的... 为开展星敏感器面向舰船导航应用的实践性研究,基于星敏感器技术和天体照相学理论的深入分析,建立了一套完整的捷联式舰船天文自动导航模型,并研制了实验验证设备。首先,根据舰载星敏感器的工作流程,分析了星体矢量在各空间坐标系中的变换过程,并说明了建模的关键问题;然后,基于天体照相学理论,介绍了根据星体成像坐标在像空间坐标系中获取星体矢量坐标的方法;最后,通过对建模相关坐标系理论及各坐标系间空间变换关系的深入研究,确定了像空间坐标系—设备坐标系—舰船坐标系—地平坐标系—赤道坐标系的系列转换矩阵,建立了导航模型。实验结果表明,导航模型建立准确,易于解算,基于该模型的航向测量误差优于2″,定位误差优于100m,满足高精度舰船自主导航需要。 展开更多
关键词 星敏感器 转换矩阵 坐标系 星体矢量 导航
移动机器人多信标SLAM技术 预览
7
作者 高沛林 高赟 《西安科技大学学报》 CAS 北大核心 2019年第5期905-911,共7页
针对大型煤矿中的露天移动机器人自主行走问题,应用基于卡尔曼滤波的SLAM算法,研究了移动机器在不携带惯性导航设备,也无先验地图的情况下,通过自身携带的传感器与环境特征量进行应答式通信,建立环境地图,并利用该地图计算自身位置,从... 针对大型煤矿中的露天移动机器人自主行走问题,应用基于卡尔曼滤波的SLAM算法,研究了移动机器在不携带惯性导航设备,也无先验地图的情况下,通过自身携带的传感器与环境特征量进行应答式通信,建立环境地图,并利用该地图计算自身位置,从而实现自主导航与定位。仿真结果显示,SLAM算法的定位误差保持在±1 m以内,速度误差保持在±0.2 m/s以内,对环境特征量的定位误差随着机器人的移动逐渐减小,最终保持在±2 m以内。同时,通过对不同距离量测噪声与速度量测噪声的情况也进行了分析。仿真结果显示,当保持距离量测噪声不变,增大速度量测噪声时,或保持速度量测噪声不变,增大距离量测噪声时,SLAM算法的定位精度均会下降。研究表明,基于卡尔曼滤波的SLAM算法很好地控制了移动机器人在未知环境中的定位误差,保证了机器人的定位精度。 展开更多
关键词 露天移动机器人 同时制图与定位 导航定位 随机信标
在线阅读 下载PDF
Adaptive network fuzzy inference system based navigation controller for mobile robotAdaptive network fuzzy inference system based navigation controller for mobile robot
8
作者 Panati SUBBASH Kil To CHONG 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第2期141-151,共11页
Autonomous navigation of a mobile robot in an unknown environment with highly cluttered obstacles is a fundamental issue in mobile robotics research. We propose an adaptive network fuzzy inference system(ANFIS) based ... Autonomous navigation of a mobile robot in an unknown environment with highly cluttered obstacles is a fundamental issue in mobile robotics research. We propose an adaptive network fuzzy inference system(ANFIS) based navigation controller for a differential drive mobile robot in an unknown environment with cluttered obstacles. Ultrasonic sensors are used to capture the environmental information around the mobile robot. A training data set required to train the ANFIS controller has been obtained by designing a fuzzy logic based navigation controller. Additive white Gaussian noise has been added to the sensor readings and fed to the trained ANFIS controller during mobile robot navigation, to account for the effect of environmental noise on sensor readings. The robustness of the proposed navigation controller has been evaluated by navigating the mobile robot in three different environments. The performance of the proposed controller has been verified by comparing the travelled path length/efficiency and bending energy obtained by the proposed method with reference mobile robot navigation controllers, such as neural network, fuzzy logic, and ANFIS. Simulation results presented in this paper show that the proposed controller has better performance compared with reference controllers and can successfully navigate in different environments without any collision with obstacles. 展开更多
关键词 Adaptive network fuzzy INFERENCE system ADDITIVE white GAUSSIAN noise AUTONOMOUS navigation Mobile robot
地球空间环境的野外科学观测研究
9
作者 宁百齐 李国主 +1 位作者 胡连欢 赵秀宽 《中国科学院院刊》 CSSCI CSCD 北大核心 2019年第6期726-733,共8页
地球空间包括地球中高层大气、电离层和磁层,其环境变化深刻影响着人类生活,如空间灾害性事件的发生,可能危害地面电网安全,造成星地无线电通讯中断。在科技部、国家自然科学基金委和中国科学院等部门支持下,北京空间环境国家野外科学... 地球空间包括地球中高层大气、电离层和磁层,其环境变化深刻影响着人类生活,如空间灾害性事件的发生,可能危害地面电网安全,造成星地无线电通讯中断。在科技部、国家自然科学基金委和中国科学院等部门支持下,北京空间环境国家野外科学观测研究站通过研制和发展一批具有国际先进水平的观测仪器,建立了电离层、中高层大气和地磁等多学科综合观测台链,并开发成功新的探测模式和诊断技术,实现对我国上空多种空间环境参量的科学观测,揭示其区域特征和空间精细结构与变化,推动数据服务于原创科学研究和空间天气预报保障任务。基于观测数据,通过发展理论模式,采用数据分析与数值模拟相结合等研究方法,系统研究了大气层-电离层耦合、磁层-电离层耦合和太阳辐射的光电离光化学3类最为重要的驱动过程对电离层变化性的影响和控制作用。 展开更多
关键词 地球空间环境 探测模式 电离层 导航 通讯
船用显控一体化终端设计 预览
10
作者 严纬华 黄杰 《通信与广播电视》 2019年第1期7-17,共11页
本文在阐述一种船用显控一体化终端设计要素基础上,介绍了系统与终端的组成,各部分的功能与工作原理,重点描述了终端的主要技术特点及其电路设计原理。
关键词 工控机 一体化终端 AIS 导航 定位 信息化
在线阅读 下载PDF
专利导航产业发展的模式探索与实践--以武汉东湖高新区为例 预览
11
作者 王丹 陈仁松 《中国发明与专利》 2019年第5期38-42,48共6页
专利导航是一种以专利数据为主要信息主体,综合运用信息分析和市场分析,进而揭示产业格局、明确产业定位、预测技术方向、防范产业风险的新方法。自国家知识产权局开展国家专利导航试点工程以来,对于专利导航体系如何构建、如何在产业... 专利导航是一种以专利数据为主要信息主体,综合运用信息分析和市场分析,进而揭示产业格局、明确产业定位、预测技术方向、防范产业风险的新方法。自国家知识产权局开展国家专利导航试点工程以来,对于专利导航体系如何构建、如何在产业发展中发挥积极作用就一直是研究的热点。本文结合武汉东湖高新区的专利导航实践,从政策、资金、企业培育、微导航、专利布局与运营、招商招才等方面出发,探究专利导航产业发展的基本模式。 展开更多
关键词 专利 导航 运营 东湖
在线阅读 下载PDF
基于自适应有限冲激响应-卡尔曼滤波算法的GPS/INS导航 预览
12
作者 靳标 李建行 +2 位作者 朱德宽 郭交 苏宝峰 《农业工程学报》 EI CAS CSCD 北大核心 2019年第3期75-81,共7页
导航定位系统一般采用卡尔曼滤波算法提高定位精度。传统卡尔曼滤波算法的性能很大程度上依赖观测噪声的先验统计信息,不精确的统计特性将会降低定位精度。针对此问题,该文提出一种基于FIR(finite impulse response)预测模型的卡尔曼滤... 导航定位系统一般采用卡尔曼滤波算法提高定位精度。传统卡尔曼滤波算法的性能很大程度上依赖观测噪声的先验统计信息,不精确的统计特性将会降低定位精度。针对此问题,该文提出一种基于FIR(finite impulse response)预测模型的卡尔曼滤波算法。将FIR预测模型与卡尔曼滤波结合,FIR预测模型的系数可以通过求解一个凸二次规划问题得到。该凸二次规划以目标的多项式运动规律为约束条件,以最小白噪声增益为目标函数,具有闭式解。仿真试验和实测结果均表明,在相同的参数设置条件下,基于FIR预测模型的卡尔曼滤波算法比传统的卡尔曼滤波算法具有更高的估计精度,仿真结果表明定位精度提高29.54%,实测结果表明X方向定位精度提高21.71%,Y方向定位精度提高22.62%。该算法可应用于GPS接收信号的降噪处理,提高目标状态的定位精度。 展开更多
关键词 导航 模型 FIR预测模型 自适应卡尔曼滤波 全球定位系统
在线阅读 下载PDF
高校地图系统的规划设计与实现 预览
13
作者 黎志生 陈瑛 《电子设计工程》 2019年第16期122-127,共6页
针对目前高校校区增加,校园面积扩大,校园路网和地下管网越来越复杂,导致校园规划、交通导航、资产管理和工程建设困难的现状,采用了通过构建校园地图系统,将2.5D三维仿真技术、WebGIS技术、虚拟现实技术、数字技术、信息技术、网络技... 针对目前高校校区增加,校园面积扩大,校园路网和地下管网越来越复杂,导致校园规划、交通导航、资产管理和工程建设困难的现状,采用了通过构建校园地图系统,将2.5D三维仿真技术、WebGIS技术、虚拟现实技术、数字技术、信息技术、网络技术等技术与校园管理、规划、建设等多个方面进行结合,采用多层数据管理的方法,结合华南理工大学校园地图系统的项目实施和研究,对校园规划、交通导航、资产管理和工程建设有着重要的作用,同时为校园资源一体化管理打下扎实的空间信息承载基础。 展开更多
关键词 导航 高校信息化 校园精细管理 地图系统
在线阅读 下载PDF
Application of computer-assisted navigation in treating congenital maxillomandibular syngnathia: A case report 预览
14
作者 Li-Qin Lin Shan-Shan Bai Min Wei 《世界临床病例杂志》 2019年第5期650-655,共6页
BACKGROUND Congenital maxillomandibular syngnathia is an extremely rare disorder characterized by craniofacial malformations and inability to open the mouth adequately, which leads to problems with feeding, swallowing... BACKGROUND Congenital maxillomandibular syngnathia is an extremely rare disorder characterized by craniofacial malformations and inability to open the mouth adequately, which leads to problems with feeding, swallowing, and breathing as well as temporomandibular joint ankylosis. The main goal of the surgery is to release the ankylosis, establish functioning mandible, and prevent re-fusion. However, surgical procedures for this disease are rarely reported. CASE SUMMARY Here, we report a 7-mo-old girl with bilateral maxillomandibular syngnathia. The patient presented with difficulty in feeding, breathing, sounding, and swallowing and had developmental dysplasia. For treatment, we performed bone isolation by computer-assisted navigation and used silicone to fix the wound surface to prevent refusion of bone. To our knowledge, this is the only syngnathia case in the literature treated using computer-assisted navigation. With the guidance of precise navigation, we were able to minimize operation time by at least one hour, the patient's blood vessels, nerves, and tooth germs were well protected, and excessive bleeding was avoided. After six weeks, the patient showed improvement in mouth opening and no major issues of feeding. CONCLUSION Application of computer-assisted navigation can significantly improve accuracy, effectiveness, and surgical safety in correcting congenital maxillomandibular syngnathia. 展开更多
关键词 CRANIOFACIAL ABNORMALITIES MANDIBULAR diseases MAXILLA COMPUTER-ASSISTED NAVIGATION Case report
在线阅读 免费下载
旋转驱动型自动舵系统研究 预览
15
作者 徐峰 梁炯炯 +1 位作者 黄毫军 陈岱岱 《舰船科学技术》 北大核心 2019年第3期70-74,共5页
国内仍有许多中小船舶采用带全液压转向器的舵机,无法安装采用电磁阀控制的新型自动舵系统。本文设计一种旋转驱动型自动舵系统,用于全液压转向舵机的自动化改造。系统通过舵轮驱动器实现手动-自动操舵转换,在手动模式下,舵轮直接带动... 国内仍有许多中小船舶采用带全液压转向器的舵机,无法安装采用电磁阀控制的新型自动舵系统。本文设计一种旋转驱动型自动舵系统,用于全液压转向舵机的自动化改造。系统通过舵轮驱动器实现手动-自动操舵转换,在手动模式下,舵轮直接带动全液压转向器实现操舵;在自动模式下,由无刷电机带动全液压转向器实现操舵。系统采用CAN总线用于舵角信号和控制信号传输。仿真结果表明,所设计系统性能可靠、控制稳定,可以用于老旧船舶的自动舵改造,有效降低操舵强度,提高航迹精度,减少船舶燃油消耗。 展开更多
关键词 自动舵 航向控制系统 船舶导航 无刷电机
在线阅读 下载PDF
基于CFD的导流墩几何参数对闸站合建枢纽通航水流条件的影响研究 预览
16
作者 徐波 张从从 +2 位作者 李占超 高琛 毕超 《灌溉排水学报》 CSCD 北大核心 2019年第2期115-122,共8页
闸站合建枢纽通航时容易在导流墩附近出现复杂水流现象。【目的】改善导流墩墩头前的斜流、偏流以及面层横向速度和轴向速度大的问题。【方法】基于计算流体力学(CFD)对某闸站合建枢纽节制闸通航水流条件进行数值模拟,研究分析了导流墩... 闸站合建枢纽通航时容易在导流墩附近出现复杂水流现象。【目的】改善导流墩墩头前的斜流、偏流以及面层横向速度和轴向速度大的问题。【方法】基于计算流体力学(CFD)对某闸站合建枢纽节制闸通航水流条件进行数值模拟,研究分析了导流墩长度、开孔与否、开孔宽度、相邻孔口中心间距及开孔高度等参数对闸站合建枢纽通航水流条件的影响。【结果】综合考虑导流墩前横向流速、轴向流速及斜流面积,采用单因素递进分析表明,随着导流墩长度增加,导流墩前流速和斜流面积先减小后增大;当开孔宽度增加到4.5m时,墩头前流速进一步减小,大于4.5m时,墩头前流态恶化;随着开孔中心间距的增加,导流墩前流速呈现先减小后增大的趋势,孔口中心间距为6.25m时,流态较优;当开孔高度增加到3.8m时,墩头前流速和斜流面积进一步减小,大于3.8m时,墩头前流速和斜流面积随之增大。【结论】通航水流条件的优劣受导流墩结构影响显著,导流墩开孔能够减小墩头前水流面层横向和轴向速度及斜流面积,提高通航安全性。导流墩最优开孔方案为:导流墩长度25m、开孔宽度4.5m、相邻孔口中心间距6.25m、开孔高度3.8m,相应墩头前水流横向和轴向速度及斜流面积分别为0.25m/s、0.75m/s、12.56m^2。 展开更多
关键词 闸站合建枢纽 导流墩 几何参数 通航 水流条件
在线阅读 免费下载
机载导航信息化与航图设备设计 预览
17
作者 陈国军 茅坪 张贞 《现代导航》 2019年第2期98-101,共4页
导航系统是飞机的眼睛,为飞行人员和自动驾驶仪提供载机的位置、速度和航向等信息。机载导航设备是引导载机安全起降、航线飞行、完成应急转场、迫降等任务所必须的设备,其显示方式正逐渐从指针、数字、简易符号画面向着包含有二维地图... 导航系统是飞机的眼睛,为飞行人员和自动驾驶仪提供载机的位置、速度和航向等信息。机载导航设备是引导载机安全起降、航线飞行、完成应急转场、迫降等任务所必须的设备,其显示方式正逐渐从指针、数字、简易符号画面向着包含有二维地图和三维地形的综合视景显示方向发展。本文根据飞机导航显示技术的现状及其发展趋势,针对新型机载航图设备,简要分析了航图辅助导航相关的技术、功能特点和应用优势,指明了导航信息集成显示发展的方向。 展开更多
关键词 导航 航图 显示 影像
在线阅读 下载PDF
Electrification Solution with Supercapacitor Storage of a Bow Thruster for River Tugboat 预览
18
作者 Alexandre De Bernardinis Jeff Moussodji 《能源与动力工程:英文版》 2019年第2期43-58,共16页
Bow thrusters usually are hydraulic and mechanically driven engines,used for the positioning maneuvers of River and sea boats.The peculiarity of these systems operating on short time intervals is their low rate of use... Bow thrusters usually are hydraulic and mechanically driven engines,used for the positioning maneuvers of River and sea boats.The peculiarity of these systems operating on short time intervals is their low rate of use(approximately 2%)but requiring maximal power.The main purpose of the work is to propose an innovative electrical hybridization of the bow thruster for a river tugboat.This electrification solution enables the bow thruster to operate with no-emissions,reduced noise and is a subsystem of green ship.Main challenge is to manage high torque and low speed requirements of the bow thruster system during the positioning maneuvers,by adding a dynamic electrical storage system,based on high capacitance value Supercapacitors,and in association with the electrified propeller motor.The knowledge concerns hybrid electrification,involving new-technology elements,energy storage based on supercapacitors,the high amplitude low speed torque control strategy.With fully reversible electrical motorization,the propeller is able to operate for both direct-reverse ways of rotation.Proposed electrical solution would hence provide large expected benefits in terms of energy efficiency,compactness,weights,costs,and contribute to a more eco-friendly ship.Numerical simulation and first results on laboratory test bench validate the proposed electrification concept. 展开更多
关键词 Energy storage marine navigation PERMANENT MAGNET machines SUPERCAPACITORS TORQUE control
在线阅读 下载PDF
导航与定位中RTK技术研究 预览
19
作者 彭旭飞 佀荣 +1 位作者 李立功 余文明 《测绘与空间地理信息》 2019年第1期116-118,122共4页
RTK(Real-time Kinematic)技术是卫星导航技术的一个分支,利用卫星信号中的载波相位差分可实现实时动态的精密相对定位,在导航与定位中拥有广泛的应用前景。本文介绍了RTK系统基准站、移动站和数据链三大组成部分和载波相位双差观测的... RTK(Real-time Kinematic)技术是卫星导航技术的一个分支,利用卫星信号中的载波相位差分可实现实时动态的精密相对定位,在导航与定位中拥有广泛的应用前景。本文介绍了RTK系统基准站、移动站和数据链三大组成部分和载波相位双差观测的基本原理,利用Lambda算法求解整周模糊度的关键技术,从卫星导航系统、信号传播、RTK系统等方面分析了影响RTK定位精度和可靠性的因素并提出解决措施。最后论述RTK技术在导航与定位领域的应用现状及未来发展趋势。 展开更多
关键词 RTK 载波相位差分 导航 定位
在线阅读 下载PDF
基于模糊预测迭代算法的AGV导航研究 预览
20
作者 葛笑寒 《三门峡职业技术学院学报》 2019年第1期123-127,共5页
为了提高移动机器人移动精度和动作效率,提出了一种模糊迭代算法,并进行了仿真。首先对AGV小车的工作原理进行分析,在分析迭代控制的基础上对AGV小车路径纠偏进行研究,并设计了模糊预测迭代算法的控制器。为了验证方案的可行性,进行了... 为了提高移动机器人移动精度和动作效率,提出了一种模糊迭代算法,并进行了仿真。首先对AGV小车的工作原理进行分析,在分析迭代控制的基础上对AGV小车路径纠偏进行研究,并设计了模糊预测迭代算法的控制器。为了验证方案的可行性,进行了仿真调试,结果表明:采用模糊预测迭代算法的PI控制器比传统的PI控制器具有小的超调,高鲁棒性,误差小,更接近于期望的方波信号。该控制系统具有较高的控制精度,将该控制器引入到移动AGV控制系统中是可行的。 展开更多
关键词 AGV小车 模糊预测 控制器 导航
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈