检索范围:
排序: 展示方式:
基于5 μm厚向列相液晶的高效圆极化相控阵系统的设计、校准和实验验证 Article
Xin Yu Wu,Fengshuo Wan,Hongyuan Feng,Shichao Jin,Chong Guo,Yu Wei,Dunge Liu,Yuqian Yang,Longzhu Cai,Zhi Hao Jiang,Wei Hong
《工程(英文)》 2024年 第32卷 第1期 页码 70-82 doi: 10.1016/j.eng.2023.08.013
This paper presents a systematic investigation and demonstration of a K-band circularly polarized liquid-crystal-based phased array (LCPA), including the design, over-the-air (OTA) in-array calibration, and experimental validation. The LCPA contains 16 phase-shifting radiating channels, each consisting of a circularly polarized stacked patch antenna and a liquid-crystal-based phase shifter (LCPS) based on a loaded differential line structure. Thanks to its slow-wave properties, the LCPS exhibits a maximum phase-shifting range of more than 360° with a figure of merit of 78.3°·dB−1 based on a liquid crystal layer with a thickness of only 5 μm. Furthermore, an automatic OTA calibration based on a state ergodic method is proposed, which enables the extraction of the phase–voltage curve of every individual LCPA channel. The proposed LCPA is manufactured and characterized with a total profile of only 1.76 mm, experimentally demonstrating a scanned circularly polarized beam from −40° to +40° with a measured peak gain of 12.5 dBic and a scanning loss of less than 2.5 dB. The bandwidth of the LCPA, which satisfies the requirements of port reflection (|S11|) < −15 dB, an axial ratio (AR) < 3 dB, beam squinting < 3°, and a gain variation < 2.2 dB, spans from 25.5 to 26.0 GHz. The total efficiency is about 34%, which represents a new state of the art. The use of the demonstrated low-profile LCPA to support circularly polarized scanning beams, along with the systematic design and calibration methodology, holds potential promise for a variety of millimeter-wave applications.
关键词: Circularly polarized Liquid crystal Liquid-crystal-based phased array (LCPA) Phase shifter Over-the-air (OTA) calibration
多入多出系统的空口测量 Review Articles
李俊1,2,漆一宏3,范峻4
《信息与电子工程前沿(英文)》 2021年 第22卷 第8期 页码 1046-1058 doi: 10.1631/FITEE.2000230
关键词: 空中(OTA)测试;无线性能测试;第五代(5G)及超5代;多入多出(MIMO);多探头法(MPAC);辐射两步法(RTS);混响室加通道模拟器法(RC+CE)
用于毫米波性能空口测试的空间衰落信道重现技术:概念和实验验证
范伟1,Lassi HENTILÄ2,Pekka KYÖSTI2,3
《信息与电子工程前沿(英文)》 2021年 第22卷 第4期 页码 548-559 doi: 10.1631/FITEE.2000484
Nasser L. AZAD,Ahmad MOZAFFARI
《机械工程前沿(英文)》 2015年 第10卷 第4期 页码 405-412 doi: 10.1007/s11465-015-0354-x
The main scope of the current study is to develop a systematic stochastic model to capture the undesired uncertainty and random noises on the key parameters affecting the catalyst temperature over the coldstart operation of automotive engine systems. In the recent years, a number of articles have been published which aim at the modeling and analysis of automotive engines’ behavior during coldstart operations by using regression modeling methods. Regarding highly nonlinear and uncertain nature of the coldstart operation, calibration of the engine system’s variables, for instance the catalyst temperature, is deemed to be an intricate task, and it is unlikely to develop an exact physics-based nonlinear model. This encourages automotive engineers to take advantage of knowledge-based modeling tools and regression approaches. However, there exist rare reports which propose an efficient tool for coping with the uncertainty associated with the collected database. Here, the authors introduce a random noise to experimentally derived data and simulate an uncertain database as a representative of the engine system’s behavior over coldstart operations. Then, by using a Gaussian process regression machine (GPRM), a reliable model is used for the sake of analysis of the engine’s behavior. The simulation results attest the efficacy of GPRM for the considered case study. The research outcomes confirm that it is possible to develop a practical calibration tool which can be reliably used for modeling the catalyst temperature.
关键词: automotive engine calibration coldstart operation Gaussian process regression machine (GPRM) uncertainty and random noises
Shaoxia YANG,Yu SUN,Hongwei YANG,Jiafeng WAN
《环境科学与工程前沿(英文)》 2015年 第9卷 第3期 页码 436-443 doi: 10.1007/s11783-014-0681-x
关键词: catalytic wet air oxidation (CWAO) carbon nanotubes (CNTs) phenol nitrobenzene aniline
Halima Sassi, Gwendoline Lafaye, Hédi Ben Amor, Abdelaziz Gannouni, Mohamed Razak Jeday, Jacques Barbier-Jr
《环境科学与工程前沿(英文)》 2018年 第12卷 第1期 doi: 10.1007/s11783-017-0971-1
关键词: Water Catalytic wet air oxidation Pillared clays Microwave Phenol
周武,林明森,李延民,王振占,黄磊
《中国工程科学》 2013年 第15卷 第7期 页码 75-80
本文研究了海洋二号(HY-2A)扫描微波辐射计冷空定标方法和数据反演算法。针对HY-2A扫描微波辐射计对地观测和定标扫描的设计原理和观测几何,基于微波辐射计的对地观测数据修正进入冷空反射器的地球信号,建立地面观测亮温的冷空反射器权重系数矩阵修正冷空观测信号;基于海面温度、海面风速、水汽含量和云液态含量的微波辐射计辐射传输模型,计算HY-2A扫描微波辐射计不同条件下的各频率极化方式下的理论亮温,建立线性回归模型,拟合不同地球物理参数的反演系数,采用多元线性回归算法反演HY-2A微波扫描辐射计地球物理参数,对比国外成熟微波辐射计数据,得到产品精度。
马耀明
《中国工程科学》 2012年 第14卷 第9期 页码 28-34
青藏高原作为地球的第三极,是“水—冰—气—生”多圈层体现最全,且相互作用最强烈的地区。高原强大的动力和热力作用显著地影响着东亚气候格局、亚洲季风进程和北半球大气环流。全球气候变化不仅影响到青藏高原本身的水圈与冰冻圈过程,改变青藏高原内部的生态系统与环境,影响该地区社会经济发展与人民生存条件,而且通过大气环流与水循环过程直接影响到东亚及周边国家的用水安全和自然灾害防护。正确认识青藏高原复杂地表多圈层相互作用规律的一条有效途径是在各种不同的下垫面上建立多圈层相互作用综合观测站(点)。在中国科学院和国家相关部门的支持下,过去的7年中,中国科学院青藏高原研究所与其他相关单位一道正在整个青藏高原面上逐步建立“青藏高原观测研究平台”以研究该地区复杂地表的多圈层相互作用规律。首先具体介绍中国科学院青藏高原研究所在高原上已经建立的5个综合观测研究站,然后介绍利用各个站点观测资料分析得到的多圈层相互作用(主要是地气相互作用)的研究结果,最后提出了青藏高原多圈层相互作用观测试验研究所面临的难题和可能的解决办法。
《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0698-y
关键词: minimally invasive surgery hand−eye calibration intuitive control surgical robot dual quaternion
Jian-wen XU, Kaoru OTA, Mian-xiong DONG, An-feng LIU, Qiang LI
《信息与电子工程前沿(英文)》 2018年 第19卷 第12期 页码 1546-1557 doi: 10.1631/FITEE.1800519
一种机械臂在线标定装置开发 Research Article
万梓威1,2,周春琳1,3,张昊天4,吴俊1
《信息与电子工程前沿(英文)》 2023年 第24卷 第2期 页码 217-230 doi: 10.1631/FITEE.2200172
提出一种名为MultiCal的新型接触式三维测量装置,可用于机械臂的现场标定和在线精度测量,具有使用方便、成本低(低于5000美元)、性能可靠等优点。该设备可灵活地设置在机械臂的工作环境中进行微米级精度三维测量。在标定过程中,通过一个三维位移测量装置,让机械臂的工具中心点运动至一个固定点,之后再绕该点旋转运动至不同姿态角并测量各关节角度(单点约束测量)。然后采用一个创新设计的夹具,将三维位移测量装置精确地安装在该夹具的不同工位上,并重复上述测量过程,从而实现多点约束测量。夹具上不同工位的相对位置在标定前已被精确测量,并作为标定的先验信息,以提高标定的精度与鲁棒性。理论分析表明,在相同水平的测量误差下,MultiCal的理论标定精度与传统的非接触式三维或六维测量设备(如激光跟踪器)相比降低10%—20%。而在Staubli TX90机械臂上进行的实际标定实验结果表明,MultiCal实际标定精度仅比带激光扫描仪的测量臂低7%—14%,时间效率比六维双目视觉测量系统低21%—30%,标定后的机械臂的最大和平均绝对定位误差分别为0.831 mm和0.339 mm。
Remote calibration system for frequency based on in-place benchmark
Xiaobin HONG, Guixiong LIU, Zhuokui WU, Xipeng DU,
《机械工程前沿(英文)》 2010年 第5卷 第3期 页码 316-321 doi: 10.1007/s11465-010-0021-1
关键词: remote calibration in-place benchmark frequency comparison global position system (GPS)
《机械工程前沿(英文)》 2022年 第17卷 第1期 页码 3-3 doi: 10.1007/s11465-021-0659-x
关键词: ultrasound image guidance prostate percutaneous intervention parallel robot kinematics identification particle swarm optimization informative value
Edge detection of steel plates at high temperature using image measurement
Qiong Zhou, Qi An
《机械工程前沿(英文)》 2009年 第4卷 第1期 页码 77-82 doi: 10.1007/s11465-009-0013-1
关键词: thermal expansion image measurement edge detection image calibration
Design and calibration of a new high-definition three-dimensional laparoscopic system
Jia TANG,Li-qiang WANG,Bo YUAN,Hong JIANG,Qi-ming ZHU
《信息与电子工程前沿(英文)》 2015年 第16卷 第1期 页码 79-84 doi: 10.1631/FITEE.1400149
关键词: Dual optical channels Three dimensional Camera calibration Pinhole model Depth measurement Laparoscopic system
标题 作者 时间 类型 操作
基于5 μm厚向列相液晶的高效圆极化相控阵系统的设计、校准和实验验证
Xin Yu Wu,Fengshuo Wan,Hongyuan Feng,Shichao Jin,Chong Guo,Yu Wei,Dunge Liu,Yuqian Yang,Longzhu Cai,Zhi Hao Jiang,Wei Hong
期刊论文
Calibration of catalyst temperature in automotive engines over coldstart operation in the presence of
Nasser L. AZAD,Ahmad MOZAFFARI
期刊论文
Catalytic wet air oxidation of phenol, nitrobenzene and aniline over the multi-walled carbon nanotubes
Shaoxia YANG,Yu SUN,Hongwei YANG,Jiafeng WAN
期刊论文
Wastewater treatment by catalytic wet air oxidation process over Al-Fe pillared clays synthesized using
Halima Sassi, Gwendoline Lafaye, Hédi Ben Amor, Abdelaziz Gannouni, Mohamed Razak Jeday, Jacques Barbier-Jr
期刊论文
Development of a novel hand−eye calibration for intuitive control of minimally invasive surgical robot
期刊论文
Remote calibration system for frequency based on in-place benchmark
Xiaobin HONG, Guixiong LIU, Zhuokui WU, Xipeng DU,
期刊论文
Ultrasound-guided prostate percutaneous intervention robot system and calibration by informative particle
期刊论文