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能量天平精密无固有力低漏磁电磁阻尼器的设计与应用 被引量:1
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作者 王大伟 许金鑫 +5 位作者 刘永猛 白洋 曾涛 李正坤 张钟华 谭久彬 《机械工程学报》 EI CAS CSCD 北大核心 2022年第4期269-276,共8页
针对能量天平试验中力矢量加载引起悬挂系统持续摆动给测量引入系统误差的问题,提出一种同时兼顾悬挂线圈和砝码托盘的精密被动电磁阻尼器。该电磁阻尼器基于磁场的涡流效应,由金属阻尼片和永磁体组成。为了避免置于磁场中的弱磁性阻尼... 针对能量天平试验中力矢量加载引起悬挂系统持续摆动给测量引入系统误差的问题,提出一种同时兼顾悬挂线圈和砝码托盘的精密被动电磁阻尼器。该电磁阻尼器基于磁场的涡流效应,由金属阻尼片和永磁体组成。为了避免置于磁场中的弱磁性阻尼片给天平称重引入附加力,阻尼片由抗磁性材质和顺磁性材质按一定比例采用“铜-铝-铜”三层复合结构组合而成,复合型阻尼片在磁场中静止时受力被抵消。此外,为了避免阻尼器泄漏的强磁场磁化精密金属砝码,电磁阻尼器外设计组合式磁屏蔽罩:内部单层电工纯铁屏蔽罩和外部双层坡莫合金屏蔽罩。设计的阻尼器及其屏蔽罩进行有限元仿真分析、试验验证,结果表明,复合阻尼片静止时,固有力约为0.92μg;电磁阻尼器在称重砝码位置的外泄磁场约为5.04μT,小于地磁场量级;阻尼器将原有悬挂系统摆动时间缩短约88.3%;设计的阻尼器总体满足能量天平试验要求。 展开更多
关键词 质量量子基准 能量天平 电磁阻尼器 低漏磁 无固有力
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Evaluation of measurement uncertainty based on grey system theory for small samples from an unknown distribution 被引量:18
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作者 HAN LianFu TANG WenYan +2 位作者 liu yongmeng WANG Jun FU ChangFeng 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第6期1517-1524,共8页
To evaluate measurement uncertainty for small sample size and measurement data from an unknown distribution, we propose a grey evaluation method of measurement uncertainty based on the grey relation coefficient. The u... To evaluate measurement uncertainty for small sample size and measurement data from an unknown distribution, we propose a grey evaluation method of measurement uncertainty based on the grey relation coefficient. The uncertainty of measurement is analyzed using grey system theory, and the defects of the grey evaluation model of measurement uncertainty (GEMU) are studied. We then establish an improved grey evaluation model of measurement uncertainty (IGEMU). Simulations show that the precision of IGEMU is greater than that of GEMU, and that sample size has only a small effect on the precision of IGEVU. In particular, IGEMU is applied to evaluating measurement uncertainty for small sample size and measurement data from an unknown distribution. The measurement uncertainty of total profile deviation, which is measured by the CNC gear measuring center, can be evaluated by a combination of IGEMU and the Monte Carlo method. 展开更多
关键词 grey system theory grey relational coefficient measurement uncertainty tooth profile gear measuring center
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