期刊文献+
共找到913篇文章
< 1 2 46 >
每页显示 20 50 100
Comparison of strapdown inertial navigation algorithm based on rotation vector and dual quaternion 被引量:9
1
作者 Wang Zhenhuan Chen Xijun Zeng Qingshuang 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第2期442-448,共7页
For the navigation algorithm of the strapdown inertial navigation system, by comparing to the equations of the dual quaternion and quaternion, the superiority of the attitude algorithm based on dual quaternion over th... For the navigation algorithm of the strapdown inertial navigation system, by comparing to the equations of the dual quaternion and quaternion, the superiority of the attitude algorithm based on dual quaternion over the ones based on rotation vector in accuracy is analyzed in the case of the rotation of navigation frame. By comparing the update algorithm of the gravitational velocity in dual quaternion solution with the compensation algorithm of the harmful acceleration in traditional velocity solution, the accuracy advantage of the gravitational velocity based on dual quaternion is addressed. In view of the idea of the attitude and velocity algorithm based on dual quaternion, an improved navigation algorithm is proposed, which is as much as the rotation vector algorithm in computational complexity. According to this method, the attitude quaternion does not require compensating as the navigation frame rotates. In order to verify the correctness of the theoretical analysis, simulations are carried out utilizing the software, and the simulation results show that the accuracy of the improved algorithm is approximately equal to the dual quaternion algorithm. 展开更多
关键词 Dual quaternion Inertial navigation system Navigation algorithm QUATERNION rotation vector
原文传递
Application of new void detection algorithm for analysis of feed pressure and rotation pressure of roof bolters 被引量:3
2
作者 Liu Wenpeng Jamal Rostami Eric Keller 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第1期77-81,共5页
Roof and rib instability is an important issue in underground mining. To optimize ground support design,enhance ground stability, and reduce the possibility of roof or rib failure with minimal use of artificial ground... Roof and rib instability is an important issue in underground mining. To optimize ground support design,enhance ground stability, and reduce the possibility of roof or rib failure with minimal use of artificial ground support, it is essential to have an accurate understanding of ground conditions. This includes the location of voids, cracks, and discontinuities, as well as information about the different strata in the immediate roof. This paper briefly introduces ongoing research on void detection by using the roof bolter feed and rotation pressure. The goal of this project is to improve the sensitivity of detection programs to locate smaller joints and reduce the number of false alarms. This paper presents a brief review of the testing procedures, data analysis, logic, and algorithms used for void detection. In addition, this paper discusses the results of preliminary laboratory tests and statistical analysis of the data from these two drilling parameters used for void detection. 展开更多
关键词 Roof bolter Void detection Feed pressure rotation pressure CUSUM algorithm Ground support optimization
在线阅读 下载PDF
Spectral matching based remote sensing identification of two main crop rotation patterns in a large irrigation district
3
作者 DUAN Yuanyuan CHEN Xiuhua +3 位作者 LIU Jun YE Mao LU Wenjing LIU Hongjie 《中国水利水电科学研究院学报(中英文)》 北大核心 2024年第6期640-650,共11页
The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorith... The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorithm and Mean-Shift algorithm were employed to automatically determine threshold values for mapping two main rotated crop patterns at the pixel scale.A time series analysis was conducted to extract the spatial distribution of rice-wheat and wheat-maize rotations in the Chuanhang irrigation district from 2016 to 2020.The results demonstrate that both threshold segmentation algorithms are reliable in extracting the spatial distribution of the crops,with an overall accuracy exceeding 80%.Additionally,both Kappa coefficients surpass 0.7,indicating better performance by OTSU method.Over the period from 2016 to 2020,the area occupied by rice-wheat rotation cropping ranged from 12500 to 14400 hm 2;whereas wheat-maize rotation cropping exhibited smaller and more variable areas ranging from 19730 to 34070 hm 2.These findings highlight how remote sensing-based approaches can provide reliable support for rapidly and accurately identifying the spatial distribution of main crop rotation patterns within a large irrigation district. 展开更多
关键词 Chuanhang irrigation district rotate crop pattern spectral matching OTSU algorithm Mean-Shift algorithm
在线阅读 下载PDF
A robust color image watermarking algorithm against rotation attacks 被引量:1
4
作者 韩绍程 杨金锋 +1 位作者 王蕊 贾桂敏 《Optoelectronics Letters》 EI 2018年第1期61-66,共6页
A robust digital watermarking algorithm is proposed based on quaternion wavelet transform(QWT) and discrete cosine transform(DCT) for copyright protection of color images. The luminance component Y of a host color ima... A robust digital watermarking algorithm is proposed based on quaternion wavelet transform(QWT) and discrete cosine transform(DCT) for copyright protection of color images. The luminance component Y of a host color image in YIQ space is decomposed by QWT, and then the coefficients of four low-frequency subbands are transformed by DCT. An original binary watermark scrambled by Arnold map and iterated sine chaotic system is embedded into the mid-frequency DCT coefficients of the subbands. In order to improve the performance of the proposed algorithm against rotation attacks, a rotation detection scheme is implemented before watermark extracting. The experimental results demonstrate that the proposed watermarking scheme shows strong robustness not only against common image processing attacks but also against arbitrary rotation attacks. 展开更多
关键词 QWT DCT A robust color image watermarking algorithm against rotation attacks YIQ
原文传递
A Hybrid Conjugate Gradient Algorithm for Solving Relative Orientation of Big Rotation Angle Stereo Pair 被引量:4
5
作者 Jiatian LI Congcong WANG +5 位作者 Chenglin JIA Yiru NIU Yu WANG Wenjing ZHANG Huajing WU Jian LI 《Journal of Geodesy and Geoinformation Science》 2020年第2期62-70,共9页
The fast convergence without initial value dependence is the key to solving large angle relative orientation.Therefore,a hybrid conjugate gradient algorithm is proposed in this paper.The concrete process is:①stochast... The fast convergence without initial value dependence is the key to solving large angle relative orientation.Therefore,a hybrid conjugate gradient algorithm is proposed in this paper.The concrete process is:①stochastic hill climbing(SHC)algorithm is used to make a random disturbance to the given initial value of the relative orientation element,and the new value to guarantee the optimization direction is generated.②In local optimization,a super-linear convergent conjugate gradient method is used to replace the steepest descent method in relative orientation to improve its convergence rate.③The global convergence condition is that the calculation error is less than the prescribed limit error.The comparison experiment shows that the method proposed in this paper is independent of the initial value,and has higher accuracy and fewer iterations. 展开更多
关键词 relative orientation big rotation angle global convergence stochastic hill climbing conjugate gradient algorithm
在线阅读 下载PDF
Improved Disk Scheduling Algorithms Based on Rotational Position
6
作者 胡鸣 《Journal of Shanghai University(English Edition)》 CAS 2005年第5期411-414,共4页
As increase of disk access speed has far lagged the speed of processors and main memory, disk-scheduling performance, although less significant for personal users with dedicated storage, is crucial for internet-based ... As increase of disk access speed has far lagged the speed of processors and main memory, disk-scheduling performance, although less significant for personal users with dedicated storage, is crucial for internet-based intensive data processing. For modern disks, increase of disk rotation rate makes overhead of disk access to data transfer heavier. Therefore, it seems more important to improve both parallel processing capability of disk I/O and disk-scheduling performance at the same time. For disk-scheduling algorithms based on both disk arm and rotational positions, their time-resolving powers are more precise in comparison with those for disk-scheduling algorithms based only on disk arm position. Algorithms of this sort are studied in this paper. Several improved algorithms based on rotational position are proposed, and simulation results of their performances demonstrate. 展开更多
关键词 disk scheduling algorithms disk arm position rotational position.
在线阅读 下载PDF
Behavior of quantum search algorithm with small phase rotations
7
作者 李欣 Cheng Chuntian +1 位作者 Li Panchi Xu Shaohua 《High Technology Letters》 EI CAS 2011年第1期91-96,共6页
When the Grover' s original algorithm is applied to search an unordered database, the success probability decreases rapidly with the increase of marked items. Aiming at this problem, a general quantum search algorith... When the Grover' s original algorithm is applied to search an unordered database, the success probability decreases rapidly with the increase of marked items. Aiming at this problem, a general quantum search algorithm with small phase rotations is proposed. Several quantum search algorithms can be derived from this algorithm according to different phase rotations. When the size of phase rotations are fixed at 0. 01π, the success probability of at least 99. 99% can be obtained in 0(√N/M) iterations. 展开更多
关键词 quantum computing quantum searching Grover' s algorithm phase matching small phase rotations
在线阅读 下载PDF
The Development of Highly Loaded Turbine Rotating Blades by Using 3D Optimization Design Method of Turbomachinery Blades Based on Artificial Neural Network & Genetic Algorithm 被引量:3
8
作者 周凡贞 冯国泰 蒋洪德 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2003年第4期198-202,共5页
In order to improve turbine internal efficiency and lower manufacturing cost, a new highly loaded rotating blade has been developed. The 3D optimization design method based on artificial neural network and genetic alg... In order to improve turbine internal efficiency and lower manufacturing cost, a new highly loaded rotating blade has been developed. The 3D optimization design method based on artificial neural network and genetic algorithm is adopted to construct the blade shape. The blade is stacked by the center of gravity in radial direction with five sections. For each blade section, independent suction and pressure sides are constructed from the camber line using Bezier curves. Three-dimensional flow analysis is carried out to verify the performance of the new blade. It is found that the new blade has improved the blade performance by 0.5%. Consequently, it is verified that the new blade is effective to improve the turbine internal efficiency and to lower the turbine weight and manufacturing cost by reducing the blade number by about 15%. 展开更多
关键词 optimization design highly loaded rotating blades artificial neural network genetic algorithm
在线阅读 下载PDF
EARTHQUAKE RESPONSE OF SEMI RIGID FRAME WITH ROTATIONAL DAMPER
9
作者 何琦 喻群 刘志强 《Transactions of Tianjin University》 EI CAS 1999年第2期30-35,共6页
The seismic behavior of frames with semi rigid connections and rotational dampers is examined.The ground acceleration due to earthquake is regarded as a stochastic process,and a pseudo excitation algorithm in frequen... The seismic behavior of frames with semi rigid connections and rotational dampers is examined.The ground acceleration due to earthquake is regarded as a stochastic process,and a pseudo excitation algorithm in frequency domain is implemented in a computer program to handle non orthogonal damping properties of the system.The computer program which incorporates detailed connection models and rotational damping models is used to investigate the effect of the connection of the semi rigid frame.It is shown from analytical studies that semi rigid frames with rotational dampers improve the seismic response of the building and may provide an effective and reliable earthquake resistant design solution. 展开更多
关键词 semi rigid frames semi rigid connections rotational dampling earthquake respond pseudo excitation algorithm
在线阅读 下载PDF
A recognition method of vibration parameter image based on improved immune negative selection algorithm for rotating machinery 被引量:4
10
作者 窦唯 刘占生 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第1期5-10,共6页
To overcome the limitations of traditional monitoring methods, based on vibration parameter image of rotating machinery, this paper presents an abnormality online monitoring method suitable for rotating machinery usin... To overcome the limitations of traditional monitoring methods, based on vibration parameter image of rotating machinery, this paper presents an abnormality online monitoring method suitable for rotating machinery using the negative selection mechanism of biology immune system. This method uses techniques of biology clone and learning mechanism to improve the negative selection algorithm to generate detectors possessing different monitoring radius, covers the abnormality space effectively, and avoids such problems as the low efficiency of generating detectors, etc. The result of an example applying the presented monitoring method shows that this method can solve the difficulty of obtaining fault samples preferably and extract the turbine state character effectively, it also can detect abnormality by causing various fault of the turbine and obtain the degree of abnormality accurately. The exact monitoring precision of abnormality indicates that this method is feasible and has better on-line quality, accuracy and robustness. 展开更多
关键词 artificial immune system negative selection algorithm abnormality monitor image recognition rotating machinery
在线阅读 下载PDF
Modified Omega-K algorithm for processing helicopter-borne frequency modulated continuous waveform rotating synthetic aperture radar data 被引量:2
11
作者 Dong Li Guisheng Liao +1 位作者 Yong Liao Lisheng Yang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第3期476-485,共10页
With appropriate geometry configuration, helicopter- borne rotating synthetic aperture radar (ROSAR) can break through the limitations of monostatic synthetic aperture radar (SAR) on forward-looking imaging. With ... With appropriate geometry configuration, helicopter- borne rotating synthetic aperture radar (ROSAR) can break through the limitations of monostatic synthetic aperture radar (SAR) on forward-looking imaging. With this capability, ROSAR has extensive potential applications, such as self-navigation and self-landing. Moreover, it has many advantages if combined with the frequency modulated continuous wave (FMCW) technology. A novel geometric configuration and an imaging algorithm for helicopter-borne FMCW-ROSAR are proposed. Firstly, by per- forming the equivalent phase center principle, the separated trans- mitting and receiving antenna system is equalized to the case of system configuration with antenna for both transmitting and receiving signals. Based on this, the accurate two-dimensional spectrum is obtained and the Doppler frequency shift effect in- duced by the continuous motion of the platform during the long pulse duration is compensated. Next, the impacts of the velocity approximation error on the imaging algorithm are analyzed in de- tail, and the system parameters selection and resolution analysis are presented. The well-focused SAR image is then obtained by using the improved Omega-K algorithm incorporating the accurate compensation method for the velocity approximation error. FJnally, correctness of the analysis and effectiveness of the proposed al- gorithm are demonstrated through simulation results. 展开更多
关键词 helicopter-borne rotating synthetic aperture radar(ROSAR) frequency modulated continuous wave (FMCW) improved Omega-K algorithm two-dimensional spectrum.
在线阅读 下载PDF
Image Reconstruction from Fan-Beam Projections without Back-Projection Weight in a 2-D Dynamic CT: Compensation of Time-Dependent Rotational, Uniform Scaling and Translational Deformations 被引量:1
12
作者 A. V. Narasimhadhan Aman Sharma Dipen Mistry 《Open Journal of Medical Imaging》 2013年第4期136-143,共8页
In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent... In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent backprojection weight which compensates for the time-dependent translational, uniform scaling and rotational deformations occurring in the object of interest during the data acquisition process. We shall also compare the computational cost of the proposed reconstruction algorithm with the existing one which has position-dependent weight. To accomplish the objective listed above, we first formulate admissibility conditions on deformations that is required to exactly reconstruct the object from acquired sequential deformed projections and then derive the reconstruction algorithm to compensate the above listed deformations satisfying the admissibility conditions. For this, 2-D time-dependent deformation model is incorporated in the fan-beam FBP reconstruction algorithm with no backprojection weight, assuming the motion parameters being known. Finally the proposed reconstruction algorithm is evaluated with the motion corrupted projection data simulated on the computer. 展开更多
关键词 Fan-Beam Reconstruction algorithm Hilbert Filter Virtual Acquisition Geometry Equiangular Detector Geometry rotationAL UNIFORM SCALING and Translational Deformation Position Dependent BACK-PROJECTION Weight
在线阅读 下载PDF
A Method of Disc Inclination Correction Based on the Inversion Model of Rotation Law
13
作者 Yanan Zhang Lin Ouyang +1 位作者 Qinqin Li Haichen Ju 《Journal on Big Data》 2020年第3期125-133,共9页
Under the traditional dynamic model,the conventional method for solving the rotation angle of a rigid body is to use the fixed-axis rotation law of the rigid body,but the known rotation shaft position must be used as ... Under the traditional dynamic model,the conventional method for solving the rotation angle of a rigid body is to use the fixed-axis rotation law of the rigid body,but the known rotation shaft position must be used as a prerequisite.In practical work,for the rotation of a rigid body under multiple forces,solving the shaft is often a difficult problem.In this paper,we consider the rigid body of the disc is subjected to the force of uneven magnitude from multiple angles,the position of the rotating shaft is obtained by iterative inversion through the rigid body rotation law and the dichotomy method.After the position of the shaft is determined,we establish a differential equation model based on the law of rigid body rotation,the rotation angle of the rigid body thus being solved based on this model.Furthermore,an optimization algorithm such as genetic algorithm is used to search for a correction scheme to return the rigid body to equilibrium at any given deflection angle.The model and method are based on computer to explore the law of rotation,the practical application of them play an important role in studying the concentric drum movement and the balance of handling furniture. 展开更多
关键词 Dynamics rigid body rotation law iterative inversion DICHOTOMY genetic algorithm
在线阅读 下载PDF
Gradient Optimizer Algorithm with Hybrid Deep Learning Based Failure Detection and Classification in the Industrial Environment
14
作者 Mohamed Zarouan Ibrahim M.Mehedi +1 位作者 Shaikh Abdul Latif Md.Masud Rana 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1341-1364,共24页
Failure detection is an essential task in industrial systems for preventing costly downtime and ensuring the seamlessoperation of the system. Current industrial processes are getting smarter with the emergence of Indu... Failure detection is an essential task in industrial systems for preventing costly downtime and ensuring the seamlessoperation of the system. Current industrial processes are getting smarter with the emergence of Industry 4.0.Specifically, various modernized industrial processes have been equipped with quite a few sensors to collectprocess-based data to find faults arising or prevailing in processes along with monitoring the status of processes.Fault diagnosis of rotating machines serves a main role in the engineering field and industrial production. Dueto the disadvantages of existing fault, diagnosis approaches, which greatly depend on professional experienceand human knowledge, intellectual fault diagnosis based on deep learning (DL) has attracted the researcher’sinterest. DL reaches the desired fault classification and automatic feature learning. Therefore, this article designs a Gradient Optimizer Algorithm with Hybrid Deep Learning-based Failure Detection and Classification (GOAHDLFDC)in the industrial environment. The presented GOAHDL-FDC technique initially applies continuous wavelettransform (CWT) for preprocessing the actual vibrational signals of the rotating machinery. Next, the residualnetwork (ResNet18) model was exploited for the extraction of features from the vibration signals which are thenfed into theHDLmodel for automated fault detection. Finally, theGOA-based hyperparameter tuning is performedtoadjust the parameter valuesof theHDLmodel accurately.The experimental result analysis of the GOAHDL-FD Calgorithm takes place using a series of simulations and the experimentation outcomes highlight the better resultsof the GOAHDL-FDC technique under different aspects. 展开更多
关键词 Fault detection Industry 4.0 gradient optimizer algorithm deep learning rotating machineries artificial intelligence
在线阅读 下载PDF
直立旋转自平衡演示仪的设计
15
作者 吴庆州 王涛 李雷 《机械设计与制造》 北大核心 2025年第7期195-199,共5页
为了在教学中直观展示倒立摆的实时受力情况及其在不同情况下的控制方法,设计了教学用直立旋转自平衡演示仪。通过分析长方形摆杆在各个不同状态下的受力情况,推导出长方形摆杆和竖直状态的夹角θ以及电机臂和水平状态夹角α之间的关系... 为了在教学中直观展示倒立摆的实时受力情况及其在不同情况下的控制方法,设计了教学用直立旋转自平衡演示仪。通过分析长方形摆杆在各个不同状态下的受力情况,推导出长方形摆杆和竖直状态的夹角θ以及电机臂和水平状态夹角α之间的关系,用霍耳编码器和WDD35d4电位器获取了长方形摆杆的实时运动数据,利用开环控制思路实现摆杆起摆,通过采集传感器数据控制仪器运行状态,从而实现自适应调整。演示仪的平衡控制中采用了模糊自适应算法,利用模糊自适应PID算法解决了稳定性差的控制难题,分别对长方形摆杆从静止到起摆以及稳定后被外力破坏再自平衡进行了模拟仿真,仿真结果与实物作品运行效果一致。该设计实现了倒立摆演示功能的多样化,可实现简谐运动、转动惯量、倒立摆等实验现象的演示,解决了教学演示现象单一的问题。 展开更多
关键词 直立旋转 自平衡 自适应 PID 演示仪 倒立摆 模糊算法 STM32
在线阅读 下载PDF
基于遗传算法BP神经网络的猫粮糊化特性研究
16
作者 张琦 许耀辉 +6 位作者 陈阳 韩栋梁 张润哲 严骅彬 Lela Susilawati 魏文广 奚小波 《中国饲料》 北大核心 2025年第9期87-92,共6页
为了解猫粮的糊化特性,本试验采用快速黏度分析仪(RVA)对不同RVA转子转速(160、200、240、280、320、360、400、440、480 r/min),不同保持温度(75、80、85、90、95℃),不同质量猫粮和蒸馏水比值(1/21、2/21、3/21、4/21、5/21、6/21、7/... 为了解猫粮的糊化特性,本试验采用快速黏度分析仪(RVA)对不同RVA转子转速(160、200、240、280、320、360、400、440、480 r/min),不同保持温度(75、80、85、90、95℃),不同质量猫粮和蒸馏水比值(1/21、2/21、3/21、4/21、5/21、6/21、7/21)进行研究。结果表明:随着转子转速的增加,峰值黏度、谷值黏度、终值黏度显著降低,衰减值变小,热糊稳定性增强。随着保持温度的增加,峰值黏度增加,谷值黏度和终值黏度先上升后下降,淀粉糊稳定性变差,原料更容易糊化。随着猫粮质量的增加,糊化温度降低,峰值黏度、谷值黏度、终值黏度增大,淀粉糊稳定性降低,凝胶性增强。另外,以本试验数据为基础,提出一种基于遗传算法的神经网络预测峰值黏度的模型。 展开更多
关键词 转速 温度 淀粉 糊化特性 神经网络 遗传算法 快速黏度分析仪(RVA)
在线阅读 下载PDF
基于GWO-LMS-RSSD的旋转机械耦合故障分离及特征强化方法
17
作者 许文 施卫华 +3 位作者 李红钢 华如南 刘厚林 董亮 《机电工程》 北大核心 2025年第4期677-685,共9页
针对旋转机械耦合故障中较弱故障易被较强故障淹没及噪声干扰严重的问题,提出了基于灰狼优化算法(GWO)的自适应滤波最小均方(LMS)算法,结合共振稀疏分解(RSSD)的耦合故障特征分离及强化方法。首先,采用自适应滤波LMS算法对耦合故障信号... 针对旋转机械耦合故障中较弱故障易被较强故障淹没及噪声干扰严重的问题,提出了基于灰狼优化算法(GWO)的自适应滤波最小均方(LMS)算法,结合共振稀疏分解(RSSD)的耦合故障特征分离及强化方法。首先,采用自适应滤波LMS算法对耦合故障信号进行了滤波处理,使故障特征得到了初步强化;然后,根据耦合故障的不同共振属性,利用RSSD算法将故障耦合分解为高共振分量和低共振分量,完成了耦合故障分离;特别地,针对LMS算法中参数依赖人工经验、自适应差等问题,研究了基于灰狼优化算法(GWO)的参数自适应优化方法,设计了以信噪比和均方误差构成的优化目标;最后,对稀疏分解得到的信号进行了包络解调,完成了耦合故障分离及特征强化,同时,利用模拟信号和实验信号对该方法进行了验证分析。研究结果表明:GWO-LMS-RSSD算法能用于有效降低噪声干扰,分离旋转机械耦合故障及强化故障特征。该研究成果可为强噪声干扰下耦合故障的特征分离及强化提供一种新的思路。 展开更多
关键词 耦合故障诊断 旋转机械 共振稀疏分解 自适应滤波最小均方算法 灰狼优化算法 信噪比 均方误差
在线阅读 下载PDF
基于阶域线性峭度的变转速驱动轮损伤频带定位分析
18
作者 张宏 李巨才 +2 位作者 王景宇 田利晨 张晨 《振动与冲击》 北大核心 2025年第7期232-238,共7页
掘进履带行驶系统作业于煤矿巷道恶劣地形和复杂环境中,其关键承载部件驱动轮长期承受不均匀载荷,导致轮齿损伤甚至断裂,影响掘进装备的正常生产作业和行驶平稳性。为了及时检测驱动轮轮齿损伤状态,避免故障扩大和降低维修成本,在阶次... 掘进履带行驶系统作业于煤矿巷道恶劣地形和复杂环境中,其关键承载部件驱动轮长期承受不均匀载荷,导致轮齿损伤甚至断裂,影响掘进装备的正常生产作业和行驶平稳性。为了及时检测驱动轮轮齿损伤状态,避免故障扩大和降低维修成本,在阶次跟踪算法、包络谱分析、线性峭度算法和滤波算法的基础上,提出了一种适用于变转速机械的阶域线性峭度算法。通过对只含基频、包含基频和谐频的合成仿真信号进行包络谱分析及特征分布统计,表明线性峭度相较于峭度更具优势。通过使用变转速和多噪声振动信号进行驱动轮齿损伤状态识别,并与快速谱峭度、阶域线性峭度等算法进行对比分析,表明阶域线性峭度算法具有适用性和鲁棒性。该方法可有效提高故障检测的准确性和效率,为履带行驶系统的安全健康运行提供了有力保障。 展开更多
关键词 履带行驶系统 轮齿损伤 线性峭度算法 变转速 频带定位
在线阅读 下载PDF
基于PCA的短跑运动员起跑蹬腿动作特征提取方法
19
作者 沈营 章明辉 《河南财政金融学院学报(自然科学版)》 2025年第2期69-74,共6页
以提高短跑运动员起跑速度为目标,提出基于PCA的短跑运动员起跑蹬腿动作特征提取方法,降低特征提取的误差。选取含有CMOS传感器组件摄像头的机器视觉系统,采集短跑运动员的起跑蹬腿动作图像;利用LBP算法构建动作识别模型,通过对比图像... 以提高短跑运动员起跑速度为目标,提出基于PCA的短跑运动员起跑蹬腿动作特征提取方法,降低特征提取的误差。选取含有CMOS传感器组件摄像头的机器视觉系统,采集短跑运动员的起跑蹬腿动作图像;利用LBP算法构建动作识别模型,通过对比图像各像素灰度值与邻域像素灰度,获取图像灰度区间内的纹理信息,经直方图转换后,形成LBP动作样本特征矩阵;通过PCA算法K-L变换降低特征矩阵维数,通过“平均脸”法获取动作图像的“平均动作”,实现动作的特征提取。实验结果表明,该方法可有效提取起跑运动员起跑蹬腿动作特征,识别最大误差率不超过3.5%。 展开更多
关键词 短跑运动员 起跑蹬腿 动作特征 特征提取 PCA算法 旋转不变性 特征矩阵
在线阅读 下载PDF
基于NIC与Givens旋转的DS-CDMA信号伪码估计
20
作者 张天骐 吴仙越 +1 位作者 李春运 唐娟 《系统工程与电子技术》 北大核心 2025年第7期2399-2405,共7页
针对直接扩频序列码分多址(direct sequence code division multiple access,DS-CDMA)信号伪码估计问题,在已知DS-CDMA信号参数的条件下,提出一种基于新信息准则(novel information criterion,NIC)与Givens旋转的多伪码盲估计方法。该... 针对直接扩频序列码分多址(direct sequence code division multiple access,DS-CDMA)信号伪码估计问题,在已知DS-CDMA信号参数的条件下,提出一种基于新信息准则(novel information criterion,NIC)与Givens旋转的多伪码盲估计方法。该方法通过对观测数据按照一倍的伪码周期进行不重叠分段构造数据矩阵。利用NIC获得数据矩阵主子空间,并利用Givens旋转提取信号主成分,再通过梅西算法恢复多用户生成多项式,从而实现多用户伪码盲估计。仿真实验表明,该算法较特征值分解算法抗噪性能提高了3 dB,且在信号数据量较少时也能实现较优估计。 展开更多
关键词 直接扩频序列码分多址 伪码估计 主子空间分析 Givens旋转 梅西算法
在线阅读 下载PDF
上一页 1 2 46 下一页 到第
使用帮助 返回顶部