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数控机床空间误差分析及综合误差建模 被引量:2
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作者 杨拴强 吴新江 《福建江夏学院学报》 2019年第3期95-102,共8页
基于等效坐标系运动链系统误差分析方法,利用运动学公式对数控机床空间误差进行分析,建立误差模型。通过两条机床运动链模型,可以建立机床的坐标变换矩阵,构成数控机床的空间误差的数学模型。在机床存在误差的情况下,建立机床基准坐标... 基于等效坐标系运动链系统误差分析方法,利用运动学公式对数控机床空间误差进行分析,建立误差模型。通过两条机床运动链模型,可以建立机床的坐标变换矩阵,构成数控机床的空间误差的数学模型。在机床存在误差的情况下,建立机床基准坐标系下刀位点误差矢量模型和切削点误差的矢量模型,得到刀位点和切削点在基准坐标系中的位置关系。 展开更多
关键词 坐标变换 运动链 误差矢量模型 误差建模
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陀螺效应对精密离心机加速度的影响研究 被引量:1
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作者 成永博 卢永刚 +1 位作者 黎启胜 张映梅 《机械科学与技术》 CSCD 北大核心 2013年第6期801-804,共4页
为了研究精密离心机主轴回转运动模式以提高其加速度精度,以转子刚体动力学为基础分析了精密离心机回转主轴的定点陀螺运动,建立了考虑公转效应的转盘测试点处的精密离心机加速度矢量模型;同时提出了针对精密离心机动态半径测量的内外... 为了研究精密离心机主轴回转运动模式以提高其加速度精度,以转子刚体动力学为基础分析了精密离心机回转主轴的定点陀螺运动,建立了考虑公转效应的转盘测试点处的精密离心机加速度矢量模型;同时提出了针对精密离心机动态半径测量的内外基准测量法的加速度矢量模型及加速度误差矢量模型;根据给定参数计算并分析了考虑公转效应时的加速度绝对误差值在100g时为5.89 m/s2,相对误差为6‰;而通常精密离心机相对精度要求为10-5~10-6,此时主轴定点陀螺运动的公转不可忽略。 展开更多
关键词 定点陀螺运动 精密离心机加速度矢量模型 内外基准测量法 加速度误差矢量模型
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Errors Prediction for Vector-to-Raster Conversion Based on Map Load and Cell Size 被引量:1
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作者 LIAO Shunbao BAI Zhongqiang BAI Yan 《Chinese Geographical Science》 SCIE CSCD 2012年第6期695-704,共10页
Vector-to-raster conversion is a process accompanied with errors.The errors are classified into predicted errors before rasterization and actual errors after that.Accurate prediction of the errors is beneficial to dev... Vector-to-raster conversion is a process accompanied with errors.The errors are classified into predicted errors before rasterization and actual errors after that.Accurate prediction of the errors is beneficial to developing reasonable rasterization technical schemes and to making products of high quality.Analyzing and establishing a quantitative relationship between the error and its affecting factors is the key to error prediction.In this study,land cover data of China at a scale of 1:250 000 were taken as an example for analyzing the relationship between rasterization errors and the density of arc length(DA),the density of polygon(DP) and the size of grid cells(SG).Significant correlations were found between the errors and DA,DP and SG.The correlation coefficient(R2) of a model established based on samples collected in a small region(Beijing) reaches 0.95,and the value of R2 is equal to 0.91 while the model was validated with samples from the whole nation.On the other hand,the R2 of a model established based on nationwide samples reaches 0.96,and R2 is equal to 0.91 while it was validated with the samples in Beijing.These models depict well the relationships between rasterization errors and their affecting factors(DA,DP and SG).The analyzing method established in this study can be applied to effectively predicting rasterization errors in other cases as well. 展开更多
关键词 vector-to-raster conversion rasterization error prediction map load cell size
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