共查询到20条相似文献,搜索用时 72 毫秒
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针对位移加载的结构试验这一实际问题 ,我们研究了系统的工作原理、分析了系统控制性能 ,根据自动控制技术和计算机控制技术设计了控制方法 ,结合现代测试技术研制开发了一套性能优良的位移加载计算机控制系统 相似文献
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一种用于可靠性自动化分析的故障系统描述模型 总被引:3,自引:0,他引:3
为了对系统的可靠性进行自动化分析, 本文在两个方面发展了进行故障系统描述的故障传递表模型: (1)对故障传递表的格式进行了较大改进; (2)提出了能流故障类, 以它为故障传递表描述的补充。采用这种改进的模型可方便地对系统进行多模态及复杂的故障关联描述。将模型应用于航空发动机液压机械控制系统的描述, 并自动建造故障树, 取得了较好的效果。 相似文献
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A digital frequency-lock generator has been developed which produces an output pulse train automatically locked to the pulse repetition rate, or frequency, of an input pulse train. This device, which exhibits a wide capture range and has no static output frequency drift, offers several advantages over a phase-lock loop in frequency-locking applications. 相似文献
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STADAR is a Servo Tester with Automatic Data Acquisition and Reduction developed for the Apollo program. This paper describes the operational capability of STADAR and discusses certain aspects of the design. STADAR evaluates system performance by supplying an input stimuli and two data acquisition and analysis channels. Stimuli (0.02-30 c/s 0-10 V peak) are automatically programmed to a frequency accuracy of ±0.01 percent and an amplitude accuracy of ± 0.1 percent. Data acquisition accuracy is 0.1 percent or 50 microvolts. System design utilizes programmable data filters to improve system S/N ratio. Active filter mechanization methods and results are presented as well as techniques for instantaneous precise generation of stimuli which are automatically programmed. 相似文献
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《中国航空学报》2021,34(5):585-600
This article concentrates on ground vision guided autonomous landing of a fixed-wing Unmanned Aerial Vehicle (UAV) within Global Navigation Satellite System (GNSS) denied environments. Cascaded deep learning models are developed and employed into image detection and its accuracy promoting for UAV autolanding, respectively. Firstly, we design a target bounding box detection network BboxLocate-Net to extract its image coordinate of the flying object. Secondly, the detected coordinate is fused into spatial localization with an extended Kalman filter estimator. Thirdly, a point regression network PointRefine-Net is developed for promoting detection accuracy once the flying vehicle’s motion continuity is checked unacceptable. The proposed approach definitely accomplishes the closed-loop mutual inspection of spatial positioning and image detection, and automatically improves the inaccurate coordinates within a certain range. Experimental results demonstrate and verify that our method outperforms the previous works in terms of accuracy, robustness and real-time criterions. Specifically, the newly developed BboxLocate-Net attaches over 500 fps, almost five times the published state-of-the-art in this field, with comparable localization accuracy. 相似文献
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基于参数化设计和模拟方法,采用VB开发了放射状散热器参数化设计模拟软件,可自动生成高质量的六面体网格和进行数值计算.利用该软件快速对风扇散热器组件的结构参数进行性能分析和讨论,加深了对风扇散热器组件各主要参数在散热器整体性能中影响程度的认识.采用并行计算流体力学方法,基于组合优化策略以熵产最小为目标函数对多参数结构风扇散热器组件进行优化,曲线型散热器优化结果比初步设计方案的性能提高了7%. 相似文献
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针对定常低速预处理在双时间步长内收敛性差、旋翼干扰流场数值模拟中非定常低速预处理自动退化为无预处理的问题,在非定常低速预处理方法的基础上,采用量级分析方法研究了对流项和黏性项量级,通过组合定常和非定常预处理特征值矩阵,建立了一种新型Blend低速预处理方法。通过圆柱非定常扰流、前飞直升机旋翼/机身干扰非定常流场和直升机/舰船干扰非定常流场的数值模拟,对各低速预处理方法的收敛性和预测精度进行了细致研究。结果表明,本文方法解决了在旋翼干扰流场数值模拟时非定常低速预处理自动退化为无预处理的问题,相比定常低速预处理大幅提高了收敛效率。 相似文献
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Using the adaptive model following control (AMFC) technique, a control system is developed to obtain high performance of an industrial manipulator that has wide variations in its payload and spatial configuration. The main advantage of this technique over other methods is simplicity in computation, which provides the capability of real-time control calculation with today's microprocessors. Moreover, it guarantees automatically the stability of the overall system without requiring any additional stability analysis. In order to demonstrate the capability of this technique, we have conducted a computer simulation for the Unimation PUMA 600 series manipulator. The simulation results agree well with the expected high performance of the control system: (1) computational requirements are much less than other existing ones, and (2) it provides the capability of adapting to large variations in payload and spatial configuration. Also presented is a comparison of the amount of its required computation with that of other methods. 相似文献
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《中国航空学报》2021,34(12):214-226
In the aviation industry, cable bracket is one of the most common parts. The traditional assembly state inspection method of cable bracket is to manually compare by viewing 3D models. The purpose of this paper is to address the problem of inefficiency of traditional inspection method. In order to solve the problem that machine learning algorithm requires large dataset and manually labeling of dataset is a laborious and time-consuming task, a simulation platform is developed to automatically generate synthetic realistic brackets images with pixel-level annotations based on 3D digital mock-up. In order to obtain accurate shapes of brackets from 2D image, a brackets recognizer based on Mask R-CNN is trained. In addition, a semi-automatic cable bracket inspection method is proposed. With this method, the inspector can easily obtain the inspection result only by taking a picture with a portable device, such as augmented reality (AR) glasses. The inspection task will be automatically executed via bracket recognition and matching. The experimental result shows that the proposed method for automatically labeling dataset is valid and the proposed cable bracket inspection method can effectively inspect cable bracket in the aircraft. Finally, a prototype system based on client-server framework has been developed for validation purpose. 相似文献
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在转子故障信号的小波降噪研究中,降噪效果常常依赖小波分解层数、故障转子转速和信号的采样频率,难于自动完成.针对该问题,提出了一种转子故障信号的自适应小波降噪新方法,该方法先对原始数据进行重采样,然后将重采样信号用小波变换分解到规定的层数,最后运用Donoho软阈值法实现降噪.该方法无需人为选取小波分解层数,降噪过程自动完成.大量的仿真和实验算例验证了方法的正确有效性. 相似文献
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本文介绍的是为有源雷达回波增强器研制的阿基米德平面螺旋和等角平面螺旋天线,并给出方向性图,电压驻波比和圆极化等电参数从S波段到X波段的测试结果。 在研制过程中用SKG语言(配DJ-052微机和绘图仪)进行编程并自动画出各种天线的精确形状,它捂言简练,工效很高。 相似文献
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