基于能量天平法的质量量子计量基准特征矢量对准技术

发布时间：2018-04-24 22:22

本文选题：量子计量基准 + 能量天平　；参考：《哈尔滨工业大学》2017年博士论文

【摘要】：质量量子计量基准研究于2012年被《Nature》杂志评为世界六大难题之一,是目前国际计量研究领域的热点。中国计量科学研究院于2006年提出基于能量天平法的千克溯源方案,该方案通过机械能与电磁能的平衡来实现质量单位的复现。能量天平法原理式中存在四种表征线圈状态的特征矢量,分别为线圈受到的安培力和重力、线圈的运动方向以及线圈位移测量所用激光束的方向。上述特征矢量需对准于同一方向上,否则能量天平法测量结果将包含由特征矢量偏离对准状态引起的对准能量误差。针对对准误差测量补偿的精度决定了千克溯源至普朗克常数的准确性,因此如何精确测量对准误差是当前能量天平方案亟待解决的核心问题。本课题在能量天平方案原理的基础上,通过研究能量天平特征矢量对准误差的物理来源,建立能量天平对准误差的数学模型。基于该数学模型,确定了线圈垂向运动直线度和线圈位移测量光束的垂向偏角是对准误差的两项主要误差分量,并针对上述两项误差分量分别提出对应的测量补偿方法,从而通过对对准误差的精确补偿保证能量天平方案的普朗克常数测量结果的准确性。主要研究内容如下:针对目前能量天平法存在线圈特征矢量对准问题的原理内涵尚不明确的问题,首先研究对准误差的产生机理,发现对准误差主要由线圈水平安培力做功、电磁转矩做功和线圈位移测量光束存在垂向偏角所引起,并确立了上述三者引起的能量误差之和与对准误差的相等关系,从而建立能量天平线圈特征矢量对准误差的数学模型。其次,在天平线圈的悬挂结构中加入柔性铰链,实现了线圈所受水平安培力和电磁转矩在作用效果上的解耦,并结合静止线圈的转矩平衡方程推导水平安培力和电磁转矩的表达式,进而可根据该表达式确定水平安培力和电磁转矩对对准误差的影响权重。最后,基于该对准误差模型对能量天平对准误差分量的量值进行计算,发现线圈垂向运动直线度与线圈位移测量光束的垂向偏角所引起的误差是对准误差的两项亟待测量补偿的主要误差分量。针对能量天平线圈存在垂向运动直线度而引起对准误差的问题,提出了一种基于垂丝基准的垂向运动直线度测量方法。该方法首先以重锤牵引的导电细丝作为垂向运动测量基准,并将该基准与线圈上的水平外圆柱面电容极板合并构成线面式电容传感器,从而可利用该电容传感器对线圈垂向运动直线度进行精确测量。其次分析了外圆柱面极板边缘效应对线面式电容传感器测量结果的影响,并利用有限元仿真对该影响引入的误差进行评估,结果表明该影响引入的测量误差可忽略不计。实验结果证明,该方法对垂向运动直线度的测量标准不确定度从现有方法的2.5μm减小为1.7μm。针对线圈垂向位移测量所用激光束存在垂向偏角从而引起对准误差的问题,提出了一种基于液面法线竖直基准的光束垂向偏角测量方法。该方法首先以硅油液面法线作为光束垂向偏角测量基准,并将液面法线基准与光束平行度检测方法相结合对光束的垂向偏角进行精确测量。其次通过对液面不同区域的表面曲率变化进行测量,获取环绕液面中心40×40mm2区域内的液面法线基准的方向不确定度,由测量结果可知该方向不确定度大小约为3.2μrad。实验结果表明,该测量方法的测量标准不确定度从现有方法的25μrad减小为11μrad。最后,基于能量天平实验装置,本课题分别对特征矢量对准误差数学模型、垂向运动直线度测量方法和光束垂向偏角测量方法进行实验验证。实验结果表明,对准误差数学模型不确定度和本文提出的两种对准测量方法的不确定度所引起的能量天平法测量结果的不确定度满足能量天平的精度要求。
[Abstract]:The quality quantum measurement datum is one of the six major problems in the world in 2012 by magazine. It is a hot spot in the field of international metrology. In 2006, China Institute of Metrology Institute proposed a kilogram traceability scheme based on energy balance method in 2006. The scheme realized the reappearance of the mass unit through the balance of mechanical energy and electromagnetic energy. There are four characteristic vectors of the state of the coil in the balance method, which are the ampere force and the gravity of the coil, the direction of the motion of the coil and the direction of the laser beam used in the measurement of the coil displacement. The above feature vectors should be aligned in the same direction, otherwise the measurement results of the energy balance method will include the deviation from the alignment of the eigenvectors. The error of the alignment energy caused by the state. The accuracy of the compensation for the measurement of the alignment error determines the accuracy of the trace to the Planck constant. So how to accurately measure the alignment error is the key problem to be solved urgently. On the basis of the energy balance scheme, this topic studies the energy balance characteristic vector. The mathematical model of the alignment error of the energy balance is established by the physical source of the error. Based on this mathematical model, the vertical deflection of the coil and the vertical deflection angle of the coil displacement measurement beam are two main error components of the alignment error, and the corresponding measurement compensation method is put forward for the above two items of error. The accuracy of the accurate compensation for the alignment error ensures the accuracy of the Planck constant measurement results of the energy balance scheme. The main contents are as follows: in view of the problem that the principle of the current energy balance method is not clear, the mechanism of the alignment error is first studied, and the alignment error is mainly caused by the coil. The horizontal ampere force is done, the electromagnetic torque doing work and the coil displacement measurement beam are caused by the vertical deflection angle, and the equal relation between the energy error and the alignment error caused by the above three is established, thus the mathematical model of the alignment error of the energy balance coil is established. Secondly, the flexibility of the balance coil is added to the suspension structure. The hinges have realized the decoupling of the water safety and electromagnetic torque in the coil, and the expression of the horizontal ampere force and electromagnetic torque is derived from the torque balance equation of the static coil, and then the influence weight of the horizontal ampere force and electromagnetic torque on the alignment error can be determined according to the expression. Finally, the alignment error is based on the error. The model calculates the amount of the error component of the energy balance, and finds that the error caused by the vertical motion straightness of the coil and the vertical deflection angle of the coil displacement is the two main error component of the alignment error, which needs to be measured. The problem of the alignment error caused by the vertical motion straightness of the energy balance coil is caused by the vertical motion. A vertical motion straightness measurement method based on the vertical wire base is proposed. The method first takes the conductive wire drawn by a heavy hammer as the vertical motion measurement datum, and combines the reference with the horizontal cylindrical capacitor pole on the coil to form a line surface capacitance sensor, and the vertical motion of the coil can be used by the capacitance sensor. The accuracy of the straightness is measured. Secondly, the influence of the edge effect of the cylindrical cylindrical plate on the measurement results of the line surface capacitance sensor is analyzed, and the error introduced by the finite element simulation is evaluated. The results show that the measurement error introduced by the influence is negligible. The experimental results show that the method has the vertical motion straightness. The measurement standard uncertainty is reduced to 1.7 m from the existing method to 1.7 mu m. The vertical deflection angle of the laser beam in the vertical displacement measurement of the coil is caused by the vertical deflection of the laser beam. A vertical deflection angle measurement method based on the vertical datum of the liquid surface is proposed. The method first uses the liquid surface of the silicon oil surface as the vertical deflection of the beam. The angle measurement datum is used to measure the vertical deflection angle of the beam by combining the liquid surface normal datum and the beam parallelism detection method. Secondly, by measuring the surface curvature changes in different areas of the liquid surface, the uncertainty of the direction of the liquid surface of the liquid surface in the center of the 40 x 40mm2 around the center of the liquid surface is obtained, and the results can be seen from the measurement results. The experimental results of the direction uncertainty about 3.2 mu rad. show that the measurement standard uncertainty of the measurement method is reduced to 11 mu rad. from 25 rad of the existing method. Based on the energy balance experimental device, this subject is respectively on the mathematical model of the alignment error of the characteristic vector, the vertical motion straightness measurement method and the beam vertical deflection angle measurement square respectively. The experimental results show that the uncertainty of the mathematical model of the alignment error and the uncertainty of the two kinds of alignment methods proposed in this paper can satisfy the precision requirements of the energy balance.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TH715

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