共查询到20条相似文献,搜索用时 62 毫秒
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水平式望远镜经纬轴垂直度误差的一种光学检测方法 总被引:1,自引:1,他引:0
水平式望远镜经轴与纬轴的不垂直度直接影响到望远镜的指向误差,准确检测出望远镜两回转轴系的垂直度误差并加以修正是非常必要的。本文以某400 mm水平式望远镜为例,针对水平式望远镜经纬两轴的特点提出了一种经纬轴垂直度误差的光学检测方法。通过检测数据计算获得该水平式望远镜的经纬两轴垂直度误差为46″,分析出检测误差为11″,借助检测数据对实际测量数据进行修正后,达到了提高望远镜指向精度的目的。 相似文献
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水平式光电望远镜目标定位误差的预测 总被引:1,自引:2,他引:1
为了确定水平式光电望远镜的各主要误差对观测精度的影响,提高望远镜的指向精度,对它的目标定位误差进行了分析。针对水平式望远镜的结构特点,通过分析从被测目标到望远镜相面产生目标定位误差的光、机、电等各种误差因素,建立了水平式望远镜目标定位测量方程。应用蒙特卡罗法进行误差仿真,预测出水平式望远镜的目标定位误差,并对各误差的敏感性进行了分析。选取敏感性高的误差项建立误差补偿模型,对实拍星体误差进行补偿实验,结果表明:补偿后经轴转角误差标准差从66.4″降低到3.3″,下降了95%;纬轴转角误差标准差从49.4″降低到5.6″,下降了89%。所用方法和模型能够对主要误差进行分析和预测,可为水平式光电望远镜的总体设计提供参考。 相似文献
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水平式经纬仪静态指向修正模型的比较与改进 总被引:2,自引:2,他引:0
为了对跟踪高轨目标无跟踪盲区的水平式经纬仪的指向进行修正,对经纬仪指向修正模型进行了理论分析和实验研究。介绍了球谐函数、支架、水平式3种指向修正模型,并对水平式模型做了修改。利用实测恒星数据进行matlab回归对比分析,最后采用内符合和外符合两种方法对3种模型的回归精度进行符合对比,得出了适合水平式经纬仪指向修正的模型。应用该水平式修正模型对某型水平式经纬仪的实际指向进行了修正,实验结果表明,其经轴L修正精度为0.4672″,纬轴B修正精度为0.4227″。对3种模型回归精度的对比分析显示,用支架和水平式模型修正水平式光电经纬仪指向精度时,效果均远优于球谐函数模型,支架模型略优于水平式模型,从而得出球谐函数模型不适合修正水平式经纬仪指向的结论。 相似文献
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为了提高机动车载跟瞄发射系统的瞄准精度,提出在其发射光路中引入快速反射镜来修正发射激光的方向。研究了快速反射镜激光指向修正量和粗红外跟踪脱靶量以及反射镜空间实时绝对角度的关系,结合激光发射光路和红外跟踪光路的结构特点,提出了将船摇坐标变换理论应用到快速反射镜激光指向修正量的解算中。建立了快速反射镜激光指向修正量与粗红外跟踪、快速反射镜空间位置的关系,并通过MATLAB编写了M函数,建立了SIMLINK仿真模型。基于仿真模型得出了激光指向修正量与快速反射镜转角的关系数据以及在快速反射镜工作范围(±6′)内的简化公式。试验结果表明:该解算算法正确,解算精度较高,最大静态解算误差为2.9″;载车在三级公路上以20km/h的速度跑车时,激光指向的控制精度为方位角11.65″、俯仰角15.38″,均满足项目指标要求。 相似文献
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为了减小几何误差对数控机床加工精度的影响,提出了一种基于多体系统理论和激光步进对角线矢量测量法的数控机床几何误差识别新方法。首先建立了基于多体系统理论的数控机床几何误差建模方法。然后介绍了激光步进对角线矢量测量方法。最后对直接传统法和激光矢量对角测量法进行了对比实验,并对数控机床进行了误差补偿实验。结果表明,采用多体系统理论和激光步进对角线法相结合的新方法对几何误差进行识别是可行的,补偿后的机床精度提高了63%。 相似文献
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为了减小和消除平台框架的加工、装配误差,传感器误差等对双摆框架导引头指向精度的影响,提出了应用模型线性化方法和分步最小二乘估计的指向误差标定方法。根据双摆框导引头的运动学特性,同时考虑影响指向精度的各误差项,建立了系统运动学方程。然后,重新构造运动学方程,建立了由表示控制输入指向的矢量到实际指向矢量的线性化模型。最后,根据分步求解的思路,采用最小二乘法获得了由表示控制输入指向的矢量到实测指向矢量的映射矩阵,实现了指向误差的标定。实验结果显示:标定后偏航角与俯仰角误差均值分别由原来的92.63″和75.94″减小至2.86″和2.85″,标准差也分别由原来的95.01″和77.44″减小至11.11″和11.15″。结果表明:该标定算法在视轴工作空间中具有较高的精度和良好的稳定性,且方便易行,可广泛应用于各类光电设备的指向误差标定。 相似文献
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点激光测头激光束方向标定 总被引:5,自引:0,他引:5
为了使点激光测头能在任意方向上实现测量功能,提出一种逆向工程中标定激光束方向的方法,设计了一种标定面方向可调的标定块配合标定。标定过程中,让激光测头在标定面上分别沿X、Y、Z3个轴方向做等间距运动,根据进给步长与激光束长度变化量之间的关系确定激光束的方向。以三坐标测量机为平台,给出了以任意方向安置点激光测头时,测量值从传感器坐标系到基准坐标系的转换过程,并对标定算法及整个标定过程进行了详细描述。最后,通过与接触式测量进行对比实验,验证标定后点激光测头的测量效果。实验结果表明,用该方法标定的点激光测头在3σ范围内沿任意方向的测量误差为(0.0452±0.0168)mm,满足逆向工程的测量要求。 相似文献
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激光切割技术因其独特的优势,在现代制造领域占有越来越重要的地位。本文主要采用空气动力学原理对喷嘴内部进行了气流特性分析,提出了拉法尔喷嘴的设计方法,对于今后激光切割机中激光喷嘴设计具有一定指导作用。 相似文献
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Precision laser adjustment using CW diode laser 总被引:1,自引:0,他引:1
Precision adjustment has many applications in various fields, particularly in laser generation systems and precision engineering. In this paper, a laser forming method for the precise adjustment of a rod with a diameter of several millimeters is investigated. Experiments on precision laser adjustment are carried out using a fiber-coupled passively cooled CW diode laser. The effect of important parameters is investigated in detail. Parametric studies are carried out to determine suitable processing windows at which a small and stable laser-adjusting angle is obtained. A coupled thermomechanical model established using the finite element method is validated and applied to predict the deformation of the rod and better understand the mechanism of precision laser adjustment. A simple closed-form expression for the precision laser-adjusting angle is proposed. An application on precision laser adjustment is presented. 相似文献
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Shingo Kashima 《Scanning》1995,17(2):66-69
We have developed a legitimate fluorescence con-focal scanning microscope (CLSM) using a near ultraviolet (UV) laser. This system has almost no chromatic aberration from the near UV region to the visible region (350–600 nm), and the objectives are designed as water-immersion type. Therefore this system provides the high-quality fluorescence image excited by the near UV laser, and high-quality image of deep points in a sample. 相似文献
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利用半导体激光束实现激光隧道放样研究 总被引:1,自引:0,他引:1
提出了一种利用半导体激光器实现隧道激光扫描放样的方法 ,该方法满足了放样仪器需轻巧、便于携带的要求。其中用单透镜准直法对有大发散角的半导体激光光束成功地实现了准直 ,既简单又经济实用 ;用平移物镜法实现了激光点的扫描。理论分析和实验结果都证明这一放样方法是可行的 相似文献
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T. Ussing L. V. Petersen C. B. Nielsen B. Helbo L. Højslet 《The International Journal of Advanced Manufacturing Technology》2007,33(1-2):198-205
The use of laser welding for joining micro parts has experienced a substantial increase in popularity during recent years.
Specifically translucent microfluidic devices are assembled using laser welding; however, a major issue is the laser beam
size of commercially available laser-welding equipment and thus the resulting welding seam size, which may be orders of magnitude
larger than microfluidic channels and structures. We have successfully achieved extremely small welding seams using focussed
low-power laser diodes. Commercial laser welding stations for polymer assembly will typically operate in the power-region
15–50 Watts. The focussed laser beam will have a size of typically 500 μm × 500 μm and may, depending on optical configuration,
be up to several mm2. The resulting welding-seam will thus be in the area of 300–600 μm depending on beam energy distribution; additionally the
melt will spread to unheated areas due to capillary forces. As microfluidic channels are in 20–100 μm regions, even a very
limited amount of stray melt may completely fill a part of a channel and thus render it useless. We have used commercially
available “single-die” laser-diodes of optical power 200–500 mW. The beam has been focussed and directed using simple optical
installations, resulting in a beam-size in the area of 50 μm × 5 μm full width half maximum (FWHM) We have achieved firm welding
seams of width <10 μm, with a welding speed of 15 mm/s and with virtually no noticeable spread of melt. 相似文献
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Felipe Vásquez Jorge Andres Ramos-Grez Magdalena Walczak 《The International Journal of Advanced Manufacturing Technology》2012,59(9-12):1037-1045
This work reports a theoretical and numerical study of the parameters related to the process of laser powder deposition through a lateral nozzle. For this purpose, a 3D quasi-stationary finite element model was developed analytically and implemented numerically. The proposed model estimates the shape of the melt pool depending on the process parameters including scanning speed, powder mass flow, laser power, and physical properties. Also, phase transformations and physical properties (density, thermal conductivity, and specific heat) vary as function of temperature. In addition, thermo-capillary forces and their effect on fluid flow inside the melt pool are considered. The obtained set of equations coupled through the temperature variable was solved using COMSOL Multiphysics. The results are presented and compared with previously obtained experimental data, in which chromium powder was deposited, allowing validation of the model. Finally, variations at the melt pool geometry in terms of the operational parameters are analyzed. This model aims at estimation of melt pool geometry during laser powder deposition in time reasonably short to allow for predictable process control. 相似文献