维普中文期刊产品整合服务
67篇 您的检索式:作者名="Yang Qifeng"
    题名 作者 年代 出处 被引量
1Xueshuantong improves cerebral blood perfusion in elderly patients with lacunar infarction显示文摘A total of 64 patients with acute lacunar infarction were enrolled within 24 hours of onset. The patients received conventional therapy (antiplatelet drugs and hypolipidemic drugs) alone or conventional therapy plus 450 mg Xueshuantong once a day. The main ingredient of the Xueshuantong lyophilized powder used for injection was Panax notoginseng saponins. Assessments were made at admission and at discharge using the National Institutes of Health Stroke Scale, the Activity of Daily Living and the Mini-Mental State Examination. Additionally, the relative cerebral blood flow, relative cerebral blood volume and relative mean transit time in the region of interest were calculated within 24 hours after the onset of lacunar infarction, using dynamic susceptibility contrast magnetic resonance perfusion imaging technology. Patients underwent a follow-up MRI scan after 4 weeks of treatment. There was an improvement in the Activity of Daily Living scores and a greater reduction in the scores on the National Institutes of Health Stroke Scale in the treatment group than in the control group. However, the Mini-Mental State Examination scores showed no significant differences after 4 weeks of treatment. Compared with the control group, the relative cerebral blood flow at discharge had increased and showed a greater improvement in the treatment group. Furthermore, there was a reduction in the relative mean transit time at discharge and the value was lower in the treatment group than in the control group. The experimental findings indicate that Xueshuantong treatment improves neurological deficits in elderly patients with lacunar infarction, and the mechanism may be related to increased cerebral perfusion.Qifeng Gui Yunmei Yang Shihong Ying Minming Zhang 2013Neural Regeneration Research2013,8,9:27
2Latest Progress of the Chinese Meteorological Satellite Program and Core Data Processing Technologies显示文摘In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satellites(FY-2H,FY-3D,and FY-4A)and their primary objectives are introduced Second,the core image navigation techniques and accuracies of the FY meteorological satellites are elaborated,including the latest geostationary(FY-2/4)and polar-orbit(FY-3)satellites.Third,the radiometric calibration techniques and accuracies of reflective solar bands,thermal infrared bands,and passive microwave bands for FY meteorological satellites are discussed.It also illustrates the latest progress of real-time calibration with the onboard calibration system and validation with different methods,including the vicarious China radiance calibration site calibration,pseudo invariant calibration site calibration,deep convective clouds calibration,and lunar calibration.Fourth,recent progress of meteorological satellite data assimilation applications and quantitative science produce are summarized at length.The main progress is in meteorological satellite data assimilation by using microwave and hyper-spectral infrared sensors in global and regional numerical weather prediction models.Lastly,the latest progress in radiative transfer,absorption and scattering calculations for satellite remote sensing is summarized,and some important research using a new radiative transfer model are illustrated.Peng ZHANG Qifeng LU Xiuqing HU Songyan GU Lei YANG Min MIN Lin CHEN Na XU Ling Sun Wenguang BAI Gang MA Di XIAN 2019Advances in Atmospheric Sciences2019,36,9:26
3Monocular trajectory intersection method for 3D motion measurement of a point target显示文摘This article proposes a monocular trajectory intersection method,a videometrics measurement with a mature theoretical system to solve the 3D motion parameters of a point target.It determines the target’s motion parameters including its 3D trajectory and velocity by intersecting the parametric trajectory of a motion target and series of sight-rays by which a motion camera observes the target,in contrast with the regular intersection method for 3D measurement by which the sight-rays intersect at one point.The method offers an approach to overcome the technical failure of traditional monocular measurements for the 3D motion of a point target and thus extends the application fields of photogrammetry and computer vision.Wide application is expected in passive observations of motion targets on various mobile beds.YU QiFeng SHANG Yang ZHOU Jian ZHANG XiaoHu LI LiChun 2009Science China(Technological Sciences)2009,52,12:10
4Stepwise-Nanocavity-Assisted Transmissive Color Filter Array Microprints显示文摘Visible-light color flters using patterned nanostructures have attracted much interest due to their various advantages such as compactness,enhanced stability,and environmental friendliness compared with traditional pigment or dye-based optical flters.While most existing studies are based on planar nanostructures with lateral variation in size,shape,and arrangement,the vertical dimension of structures is a long-ignored degree of freedom for the structural colors.Herein,we demonstrate a synthetic platform for transmissive color flter array by coordinated manipulations between height-varying nanocavities and their lateral flling fractions.Te thickness variation of those nanocavities has been fully deployed as an alternative degree of freedom,yielding vivid colors with wide gamut and excellent saturation.Experimental results show that the color-rendering capability of the pixelated nanocavities can be still retained as pixels are miniaturized to 500 nm.Crosstalk between closely spaced pixels of a Bayer color flter arrangement was calculated,showing minimal crosstalk for 1μm2 square subpixels.Our work provides an approach to designing and fabricating ultracompact color flter arrays for various potential applications including stained-glass microprints,microspectrometers,and high-resolution image sensing systems.Yasi Wang Mengjie Zheng Qifeng Ruan Yanming Zhou Yiqin Chen Peng Dai Zhengmei Yang Zihao Lin Yuxiang Long Ying Li Na Liu Cheng-Wei Qiu Joel K.W.Yang Huigao Duan 2018Research2018,,1:8
5Vision navigation for aircrafts based on 3D reconstruction from real-time image sequences显示文摘In this paper,we propose a novel vision navigation method based on three-dimensional(3D)reconstruction from real-time image sequences.It adapts 3D reconstruction and terrain matching to establish the correspondence between image points and3D space points and the terrain reference(by using a digital elevation map(DEM)).An adaptive weighted orthogonal iterative pose estimation method is employed to calculate the position and attitude angle of the aircraft.Synthesized and real experiments show that the proposed method is capable of providing accurate navigation parameters for a long-endurance flight without using a global positioning system or an inertial navigation system(INS).Moreover,it can be combined with an INS to achieve an improved navigation result.ZHU ZunShang SU Ang LIU HaiBo SHANG Yang YU QiFeng 2015Science China(Technological Sciences)2015,58,7:8
6Research on 3D Target Pose Tracking and Modeling显示文摘This paper tackles pose tracking and model refinement, one of the fundamental work for 3D photogrammetry. The researches belong to the videometrics, an interdisciplinewhich combines computer vision, digital image processing, photogrammetry and optical measurement. Related works are summarized briefly in this paper. This paper studies the problem of pose tracking for target with 3D model. For the target with accurate 3D model, line model based pose tracking methods are proposed for target which is rich in line features. Experimental results indicate that the proposed methods track the target pose accurately. Normal distance iterative reweighted least squares and distance image iterative least squares methods are proposed to process more general targets. This paper adopts bundle adjustment to tackle pose tracking in image sequence for target with inaccurate 3D line model. The proposed method optimizes the model line parameters and the pose parameters simultaneously. The model line orientation, position and mean angle error, mean position error of the pose are 0.3°,3.5 mm and 0.12°,20.1 mm in simulation experiments of satellite pose tracking. Line features are used to track target pose with unknown 3D model through image sequence. The model line parameters and pose parameters are optimized under the framework of SFM. In simulation experiments, the reconstructed line orientation, position error and mean angle error, mean position error of pose are 0.4°,7.5 mm and 0.16°,23.5 mm.Yang SHANG Xiaoliang SUN Yueqiang ZHANG You LI Qifeng YU 2019Journal of Geodesy and Geoinformation Science2019,2,2:7
7Model predictions for behaviors of sand-nonplastic-fines mixtures using equivalent-skeleton void-ratio state index显示文摘It is a challenge to suggest a constitutive model for describing the stress-strain behavior of sand-fines mixtures due to that these granular mixtures exhibited very complex behaviors at different densities, pressures and fines contents. In this study, an elastoplastic constitutive model within the framework of the bounding surface plasticity and critical state theories was proposed for sand-nonplastic-fines mixtures by using the concept of the equivalent-skeleton void ratio and equivalent-skeleton void-ratio state index. The proposed model with a set of material constants calibrated from a few tests could be used to model the fines-dependent and state-dependent behaviors of the sand-nonplastic-fines mixture including the strain- softening and volumetric-expansion behaviors in the drained triaxial compression tests, and also the effects of fines content on the critical state lines in both the deviatoric stress versus mean effective stress and the void ratio versus mean effective stress planes.XIAO Yang SUN YiFei LIU HanLong XIANG Jia MA QiFeng LONG LeiHang 2017Science China(Technological Sciences)2017,60,6:7
8World’s first spaceflight on-orbit demonstration of a flexible solar array system based on shape memory polymer composites显示文摘With a 10%reversible compressive strain in more than 10 deformation cycles,the shape memory polymer composites(SMPCs)could be used for deployable structure and releasing mechanism.In this paper,without traditional electro-explosive devices or motors/controllers,the deployable SMPC flexible solar array system(SMPC-FSAS)is studied,developed,ground-based tested,and finally on-orbit validated.The epoxy-based SMPC is used for the rolling-out variable-stiffness beams as a structural frame as well as an actuator for the flexible blanket solar array.The releasing mechanism is primarily made of the cyanate-based SMPC,which has a high locking stiffness to withstand 50 g gravitational acceleration and a large unlocking displacement of 10 mm.The systematical mechanical and thermal qualification tests of the SMPC-FSAS flight hardware were performed,including sinusoidal sweeping vibration,shocking,acceleration,thermal equilibrium,thermal vacuum cycling,and thermal cycling test.The locking function of the SMPC releasing mechanisms was in normal when launching aboard the SJ20 Geostationary Satellite on 27 Dec.,2019.The SMPC-FSAS flight hardware successfully unlocked and deployed on 5 Jan.,2020 on geostationary orbit.The triggering signal of limit switches returned to ground at the 139 s upon heating,which indicated the successful unlocking function of SMPC releasing mechanisms.A pair of epoxy-based SMPC rolled variable-stiffness tubes,which clapped the flexible blanket solar array,slowly deployed and finally approached an approximate 100%shape recovery ratio within 60 s upon heating.The study and on-orbit successful validation of the SMPC-FSAS flight hardware could accelerate the related study and associated productions to be used for the next-generation releasing mechanisms as well as space deployable structures,such as new releasing mechanisms with low-shocking,testability and reusability,and ultra-large space deployable solar arrays.LAN Xin LIU LiWu ZHANG FengHua LIU ZhengXian WANG LinLin LI QiFeng PENG Fan HAO SiDa DAI WenXu WAN Xue TANG Yong WANG Mian HAO YanYan YANG Yang YANG Cheng LIU YanJu LENG JinSong 2020Science China(Technological Sciences)2020,63,8:7
9An area-based position and attitude estimation for unmanned aerial vehicle navigation显示文摘The paper aims to challenge non-GPS navigation problems by using visual sensors and geo-referenced images. An area-based method is proposed to estimate full navigation parameters(FNPs), including attitude, altitude and horizontal position, for unmanned aerial vehicle(UAV) navigation. Our method is composed of three main modules: geometric transfer function, local normalized sobel energy image(LNSEI) based objective function and simplex-simulated annealing(SSA) based optimization algorithm. The adoption of relatively rich scene information and LNSEI, makes it possible to yield a solution robustly even in the presence of very noisy cases, such as multi-modal and/or multi-temporal images that differ in the type of visual sensor, season, illumination, weather, and so on, and also to handle the sparsely textured regions where features are barely detected or matched. Simulation experiments using many synthetic images clearly support noise resistance and estimation accuracy, and experimental results using 2367 real images show the maximum estimation error of 5.16(meter) for horizontal position, 9.72(meter) for altitude and 0.82(degree) for attitude.LIU XiaoChun WANG Hou FU Dan YU QiFeng GUO PengYu LEI ZhiHui SHANG Yang 2015Science China(Technological Sciences)2015,58,5:7
10Recent Advances in Space-Deployable Structures in China显示文摘Deployable space structure technology is an approach used in building spacecraft,especially when realizing deployment and folding functions.Once in orbit,the structures are released from the fairing,deployed,and positioned.With the development of communication,remote-sensing,and navigation satellites,space-deployable structures have become cutting-edge research topics in space science and technology.This paper summarizes the current research status and development trend of spacedeployable structures in China,including large space mesh antennas,space solar arrays,and deployable structures and mechanisms for deep-space exploration.Critical technologies of space-deployable structures are addressed from the perspectives of deployable mechanisms,cable-membrane form-finding,dynamic analysis,reliable environmental adaptability analysis,and validation.Finally,future technology developments and trends are elucidated in the fields of mesh antennas,solar arrays,deployable mechanisms,and on-orbit adjustment,assembly,and construction.Xiaofei Ma Tuanjie Li Jingya Ma Zhiyi Wang Chuang Shi Shikun Zheng Qifeng Cui Xiao Li Fan Liu Hongwei Guo Liwu Liu Zuowei Wang Yang Li 2022Engineering2022,,10:6
11Sandwich structured graphene-wrapped FeS-graphene nanoribbons with improved cycling stability for lithium ion batteries显示文摘三明治组织了包 graphene 的 FeS-graphene nanoribbons (G@FeS-GNRs ) 被开发。在这合成, FeS nanoparticles 在 graphene 和 graphene nanoribbons 之间被夹。当在锂离子电池(解放) 用作阳极时, G@FeS-GNR 合成表明了突出的电气化学的表演。这个合成显示出的高可逆的能力,好率表演,和由于在电子上传导性的 graphene, graphene nanoribbons,和 FeS 之间的协同作用的提高的骑车的稳定性。这里开发的设计概念为为解放与改进电气化学的稳定性构造阳极开创一条新大街。Lei Li Caitian Gao Anton Kovalchuk Zhiwei Peng Gedeng Ruan Yang Yang Huilong Fei Qifeng Zhong Yilun Li James M. Tour 2016Nano Research2016,9,10:5
12A displacement-relay videometric method for surface subsidence surveillance in unstable areas显示文摘When measuring the surface subsidence of unstable areas such as railroad beds and large construction fields, it is not practical to always find stable positions to install measurement instruments. Yet installing those instruments in unstable positions will cause measurement errors or even the complete failure of long-term subsidence surveillance. In this paper, the innovative concept and its method of 'displacement-relay videometrics' are proposed. With the method, a double-headed camera is designed, and two constraints, the 'fixation constraint' and the 'homologous constraint', are established to construct the displacement-relay measurement equations, which can concurrently give the subsidence of the points to be measured and the positions where the cameras are fixed. The method and its measurement system are thus capable of automatically measuring the surface subsidence under the condition that the cameras are mounted on unstable locations over long durations. Therefore, the method has the broad prospect of undertaking automatic, long-term and continuous measurement for surface subsidence in engineering projects such as railroad beds, bridges and the ground beds of tall buildings. The proposed method opens a new area that cameras can be mounted on unstable platform to make high accuracy measurements, which is of great significance for applications.YU QiFeng JIANG GuangWen SHANG Yang XU Yong LIU XiaoLin FU SiHua GUAN BangLei ZHU XianWei 2015Science China(Technological Sciences)2015,58,6:5
13Torsional phenomena in 2008 great Wenchuan earthquake显示文摘It is well known that there are some torsional damages in earthquakes. In Taibai park, Jiangyou city, Sichuan province, most of the stone statues, which were placed upon the banisters of one zigzag bridge, exhibited different torsional phenomena in 2008 Wenchuan earthquake. This paper introduces the torsional phenomena of all the statues on the zigzag bridge firstly. Then one eccentricity model is established and the equivalent rotational accelerations are calculated in order to analyze the causes of the torsional damage. In addition, the torsional components are synthesized by using translation accelerations recorded at Jiangyou station in the Wenchuan earthquake. The results show that the equivalent rotational acceleration is larger than the synthesized rotational components, which suggests that the torsional phenomena of the statues on the zigzag bridge might mainly come from its eccentricity. The comparison between the estimated torsional component at Jiangyou and that presented by Trifunac shows that they are in the same order. The research im-plies that the torsional phenomena in earthquakes are very complicated, and not only caused by torsional motions.Fan Yang Qifeng Luo Wei Che 2010Earthquake Science2010,23,1:4
14Gliquidone versus metformin: differential effects on aorta in streptozotocin induced diabetic rats显示文摘Tan Zhongju Xu Zherong Gui Qifeng Wu Weizhen Yang Yunmei 2014Chinese Medical Journal2014,,7:4
15Highly Selective Biomimetic Flexible Tactile Sensor for Neuroprosthetics显示文摘Biomimetic flexible tactile sensors endow prosthetics with the ability to manipulate objects,similar to human hands.However,it is still a great challenge to selectively respond to static and sliding friction forces,which is crucial tactile information relevant to the perception of weight and slippage during grasps.Here,inspired by the structure of fingerprints and the selective response of Ruffini endings to friction forces,we developed a biomimetic flexible capacitive sensor to selectively detect static and sliding friction forces.The sensor is designed as a novel plane-parallel capacitor,in which silver nanowire-3D polydimethylsiloxane(PDMS)electrodes are placed in a spiral configuration and set perpendicular to the substrate.Silver nanowires are uniformly distributed on the surfaces of 3D polydimethylsiloxane microcolumns,and silicon rubber(Ecoflex^(■))acts as the dielectric material.The capacitance of the sensor remains nearly constant under different applied normal forces but increases with the static friction force and decreases when sliding occurs.Furthermore,aiming at the slippage perception of neuroprosthetics,a custom-designed signal encoding circuit was designed to transform the capacitance signal into a bionic pulsed signal modulated by the applied sliding friction force.Test results demonstrate the great potential of the novel biomimetic flexible sensors with directional and dynamic sensitivity of haptic force for smart neuroprosthetics.Yue Li Zhiguang Cao Tie Li Fuqin Sun Yuanyuan Bai Qifeng Lu Shuqi Wang Xianqing Yang Manzhao Hao Ning Lan Ting Zhang 2020Research2020,,1:4
16Relay camera videometrics based conversion method for unstable platform to static reference显示文摘This article proposes a relay camera videometrics based method to convert an unstable measuring platform to a static reference to solve the problems of large error or invalidation caused by measuring platform instability in photogrammetric and videometric measurements.The method installs a relay camera on the unstable platform and captures images of a reference marker fixed on a static reference or vice versa to resolve the 3D movement of the unstable platform relative to the static reference,based on which it corrects the error of the measured results and thus eliminating the influence of the platform movement.It finds new and important applications for videometrics by making high-precision dynamic measurement possible on unstable platforms.Verification experiments and numerical simulations have proven its validity and practicability.YU QiFeng SUN XiangYi JIANG GuangWen LIU XiaoLin ZHANG XiaoHu ZHOU Jian SHANG Yang 2011Science China(Technological Sciences)2011,54,4:4
17Serum semaphorin 4C as a diagnostic biomarker in breast cancer:A multicenter retrospective study显示文摘Background:To date,there is no approved blood-based biomarker for breast cancer detection.Herein,we aimed to assess semaphorin 4C(SEMA4C),a pivotal protein involved in breast cancer progression,as a serum diagnostic biomarker.Methods:We included 6,213 consecutive inpatients from Tongji Hospital,Qilu Hospital,and Hubei Cancer Hospital.Training cohort and two validation cohorts were introduced for diagnostic exploration and validation.A pan-cancer cohort was used to independently explore the diagnostic potential of SEMA4C among solid tumors.Breast cancer patients who underwent mass excision prior to modified radical mastectomy were also analyzed.We hypothesized that increased pretreatment serum SEMA4C levels,measured using optimized in-house enzymelinked immunosorbent assay kits,could detect breast cancer.The endpoints were diagnostic performance,including area under the receiver operating characteristic curve(AUC),sensitivity,and specificity.Post-surgery pathological diagnosis was the reference standard and breast cancer staging followed the TNM classification.There was no restriction on disease stage for eligibilities.Results:We included 2667 inpatients with breast lesions,2378 patients with other solid tumors,and 1168 healthy participants.Specifically,118 patients with breast cancer were diagnosed with stage 0(5.71%),620 with stage I(30.00%),966 with stage II(46.73%),217 with stage III(10.50%),and 8 with stage IV(0.39%).Patients with breast cancer had significantly higher serum SEMA4C levels than benign breast tumor patients and normal controls(P<0.001).Elevated serum SEMA4C levels had AUC of 0.920(95%confidence interval[CI]:0.900–0.941)and 0.932(95%CI:0.911–0.953)for breast cancer detection in the two validation cohorts.The AUCs for detecting early-stage breast cancer(n=366)and ductal carcinoma in situ(n=85)were 0.931(95%CI:0.916–0.946)and 0.879(95%CI:0.832–0.925),respectively.Serum SEMA4C levels significantly decreased after surgery,and the reduction was more striking after modified radical mastectomy,compared with mass excision(P<0.001).The positive rate of enhanced serum SEMA4C levels was 84.77%for breast cancer and below 20.75%for the other 14 solid tumors.Conclusions:Serum SEMA4C demonstrated promising potential as a candidate biomarker for breast cancer diagnosis.However,validation in prospective settings and by other study groups is warranted.Ya Wang Long Qiao Jie Yang Xiong Li Yaqi Duan Jiahao Liu Shaoqi Chen Huayi Li Dan Liu Tian Fang Jingjing Ma Xiaoting Li Fei Ye Junxiang Wan Juncheng Wei Qin Xu Ensong Guo Ping Jin Mingfu Wu Lin Zhang Yun Xia Yaqun Wu Jun Shao Yaojun Feng Qing Zhang Zongyuan Yang Gang Chen Qinghua Zhang Xingrui Li Shixuan Wang Junbo Hu Xiaoyun Wang Mona P.Tan Kazuaki Takabe Beihua Kong Qifeng Yang Ding Ma Qinglei Gao 2021Cancer Communications2021,41,12:3
18Pose optimization based on integral of the distance between line segments显示文摘In this paper, new solutions for the problem of pose estimation from correspondences between 3D model lines and 2D image lines are proposed. Traditional line-based pose estimation methods rely on the assumption that the noises(perpendicular to the line) for the two endpoints are statistically independent. However, these two noises are in fact negatively correlated when the image line segment is fitted using the least-squares technique. Therefore, we design a new error function expressed by the average integral of the distance between line segments. Three least-squares techniques that optimize both the rotation and translation simultaneously are proposed in which the new error function is exploited. In addition, Lie group formalism is utilized to describe the pose parameters, and then, the optimization problem can be solved by means of a simple iterative least squares method. To enhance the robustness to outliers existing in the match data, an M-estimation method is developed to convert the pose optimization problem into an iterative reweighted least squares problem. The proposed methods are validated through experiments using both synthetic and real-world data. The experimental results show that the proposed methods yield a clearly higher precision than the traditional methods.ZHANG YueQiang LI Xin LIU HaiBo SHANG Yang YU QiFeng 2016Science China(Technological Sciences)2016,59,1:3
19HGF percutaneous endocardial injection induces cardiomyocyte proliferation and rescues cardiac function in pigs显示文摘Objective:To investigate the effect of cardiomyocyte proliferation induced by human hepatocyte growth factor(HGF)in pigs with chronic myocardial infarction(CMI).Methods:A steerable,deflectable 7F catheter incorporating a 27-guage needle was advanced percutaneously to the left ventricular myocardium of 18 pigs with CMI.Pigs were randomized(1:1:1)to receive adenoviral vector HGF(total dose,1×1010 genome copies),which was administered as five injections into the infarcted myocardium(total,1.0 mL),or saline,or Ad-null(control groups).Injections were guided by Ensite NavX left ventricular electroanatomical mapping.HGF and cyclin proteins were detected by western blot and immunoprecipitation analysis.Histological and immunohistochemical analysis determined proliferating cardiomyocytes.Myocardial perfusion and cardiac function were estimated by Gated-Single Photon Emission Computed Tomography(G-SPECT).Results:Western blot analyses showed that HGF were predominantly expressed in the infarct core and border in the myocardium of the infarcted heart.G-SPECT analysis indicated that the HGF group had better cardiac function and myocardial perfusion four weeks after the injection of Ad-HGF than before the injection of Ad-HGF.After treatment there were more proliferating cardiomyocytes in the HGF group compared to either of the control groups.Furthermore,the HGF group myocardial samples expressed higher levels of p-Akt,cyclin A,cyclin E,cyclin D1,cdk2,cdk4 than those in the control groups.Conclusion:The over-expression of HGF activates pro-survival pathways,induces cardiomyocyte proliferation,and improves the perfusion and function of the porcine CMI heart.Zhengxian Tao Bo Chen Yingming Zhao Hongwu Chen Liansheng Wang Yonghong Yong Kejiang Cao Qifeng Yu Danian Ke` Hua Wang Zuze Wu Zhijian Yang 2010The Journal of Biomedical Research2010,24,3:3
20Precise monocular vision-based pose measurement system for lunar surface sampling manipulator显示文摘Space manipulator has been playing an increasingly important role in space exploration due to its flexibility and versatility. This paper is to design a vision-based pose measurement system for a four-degree-of-freedom(4-DOF) lunar surface sampling manipulator relying on a monitoring camera and several fiducial markers. The system first employs double plateaus histogram equalization for the markers to improve the robustness to varying noise and illumination. The markers are then accurately extracted in sub-pixel based on template matching and curved surface fitting. Finally, given the camera parameters and 3D reference points, the pose of the manipulator end-effector is solved from the 3D-to-2D point correspondences by combining a plane-based pose estimation method with rigid-body transformation. Experiment results show that the system achieves highprecision positioning and orientation performance. The measurement error is within 3 mm in position, and 0.2° in orientation,meeting the requirements for space manipulator operations.WANG Gang SHI ZhongChen SHANG Yang SUN XiaoLiang ZHANG WenLong YU QiFeng 2019Science China(Technological Sciences)2019,62,10:3
返回顶部 每页显示:
共4页 首页 上一页 第1页 下一页 末页 /4 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费