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确定被测齿面的平均齿廓线和平均螺旋线是评定齿轮齿廓误差和螺旋线误差的关键步骤。本文介绍了以累积法为基础的平均齿廓线和平均螺旋线的参数估计方法,并给出了相应的齿轮误差评定模型、评定方法及评定实例。 相似文献
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根据齿轮齿距偏差和齿距累积误差的计算方法和图解原理,利用VB程序实现数据自动处理,求得齿轮齿距偏差和齿距累积误差;结合Flash软件实现动态演示,开发了高效、形象、直观的工作系统,提高数据处理的速度和准确度,实现可视化。 相似文献
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针对移动机器人同步定位与地图构建(SLAM)过程中系统测程法误差累积问题,采用测程法误差模型和车轮速度误差模型的映像关系,结合增广扩展卡尔曼滤波(AEKF)算法结构和实际机器人模型,提出了一种有效提高定位精度的SLAM方法。将机器人速度校正参数附加到卡尔曼滤波算法的向量空间中,以形成增广状态空间,同时预测和更新了SLAM初始状态空间和速度校正参数,笔者在线实时修正机器人的速度和航向角,避免积累航向角误差,从而降低了测程法误差。基于均方根误差和归一化估计方差进行了仿真实验分析,研究结果表明:与EKF-SLAM相比,所提出的方法具有更好的估计性能,使算法保持良好的一致性,大幅度提高了机器人自身定位精度和路标估计准确度。 相似文献
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应用实践与分析表明,近似分度法不仅产生较大的周节累积误差,而且还产生相当大的周节偏差与大于周节累积误差的周节差。后两种误差的产生,大大限制了该法的实际应用,下面分析误差产生的机理并提出生产中应急使用时可采取的一些措施。 相似文献
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《光学精密工程》2020,(1)
针对大场景三维重建中,由位姿估计的累积误差而导致的相机漂移和重建模型质量低的问题,提出了减少累积误差的方法。首先,基于由最新K对深度和彩色图像融合的模型,最小化输入RGB-D图像的几何误差和亮度误差来跟踪相机。然后,若相机位置与当前子网格的中心点距离大于给定阈值时,则将子网格平移体素单元整数倍的距离,基于新建的子网格继续跟踪相机并重建局部场景模型。最后,在子网格间以迭代步长式的方法寻找对应表面点,以对应点间的欧氏距离与亮度误差为约束,优化全局相机轨迹。基于数据集的实验结果表明,相机位姿估计精度比主流方法提升14.1%,全局轨迹优化精度提升8%。对于自采数据,本文设计的系统可减少位姿估计中的累积误差、重建高质量的场景模型。 相似文献
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小型光电编码器细分误差校正方法 总被引:7,自引:0,他引:7
为提高小型光电编码器精度,设计了精码莫尔条纹信号细分误差校正方法.首先建立存在直流分量、幅值误差、波形畸变的精码光电信号的波形方程,然后利用牛顿迭代法将两路精码细分信号校正至标准的正弦和余弦信号,最后建立两路信号间的正交性误差模型,通过最小二乘法求解出正交性误差校正参数.运用本文的细分误差校正法对某16位小型绝对式光电编码器进行误差校正处理,经测试,细分误差峰峰值由校正前的160″减小到校正后的48″.实验结果表明:研究的误差校正方法可以有效地减小细分误差、提高编码器精度,对于研制小型化、高精度光电编码器具有重要意义. 相似文献
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基于连续非线性损伤的航空发动机叶片疲劳研究 总被引:3,自引:1,他引:2
利用传统线性损伤累积模型对航空发动机叶片进行疲劳研究,由于不能准确描述损伤与载荷之间的关系,导致计算结果不能令人满意.而对于一般的非线性损伤模型,由于忽略扭转振动的影响而易导致在计算中引入误差.为此,基于连续损伤理论,在钛合金TC4(Ti-6Al-4V)疲劳试验中获得叶片材料的S-N曲线的基础上,对CHABOCHE提出的非线性损伤累积模型进行修正,提出适用于航空发动机叶片的连续非线性损伤模型,并验证了模型的正确性.通过与试验数据及线性损伤累积模型的结果进行比对,证明所建立的非线性损伤累积模型能够更准确地反映叶片的损伤累积过程,并利用该模型对某航空发动机叶片进行疲劳寿命预测. 相似文献
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用基础的测量方法和数据处理方法对直线度误差进行评定。测量方法采用水平仪的节距法。数据处理方法采用两端点连线法、最小二乘法、最小区域法。每一种方法都分别用计算法和作图法评定直线度误差。采用不同的方法对同一组数据评定直线度误差,其结果不尽相同,并对其精度进行比较,从而得出应用这三种方法评定直线度误差的差别。 相似文献
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阐述了分度头分度测量截面圆的方法及其数据处理的办法,其中作图法为补助,计算法为最终计算圆度误差的方法。 相似文献
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P.-C. Tseng J.-L. Ho 《The International Journal of Advanced Manufacturing Technology》2002,19(11):850-858
This study is addressed at the thermal deformation errors resulting from temperature rise that contribute to 40%–70% of the
precision errors in machining at a turning centre, and proposes an economic, accurate, and quick measurement method. It also
investigates the thermal error differentials between static idle turning and in the actual cutting environment. The temperature
measurement units are intelligent IC temperature sensors with correction circuits. The A/D card extracts and transforms data
and saves data in the computer files, and the displacement sensor measures the displacement deviation online during cutting.
The temperatures and the deviation of thermal drifts so obtained are used to establish the relationship function using multivariable
linear regression and nonlinear exponential regression models, respectively. Finally, this paper compares software compensation
methods for the thermal-drift relationship. As proven by experiments, the software compensation method can limit the thermal
error of a turning centre to within 5 μm. Moreover, the software compensation for the thermal error relationship using a single
variable nonlinear exponent regression model can reduce the error by 40% to 60%. 相似文献
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Flexible roll forming is a promising manufacturing method for the production of variable cross section products. Considering the large plastic strain in this forming process which is much larger than that of uniform deformation phase of uniaxial tensile test, the widely adopted method of simulating the forming processes with non-supplemented material data from uniaxial tensile test will certainly lead to large error. To reduce this error, the material data is supplemented based on three constitutive models. Then a finite element model of a six passes flexible roll forming process is established based on the supplemented material data and the original material data from the uniaxial tensile test. The flexible roll forming experiment of a B pillar reinforcing plate is carried out to verify the proposed method. Final cross section shapes of the experimental and the simulated results are compared. It is shown that the simulation calculated with supplemented material data based on Swift model agrees well with the experimental results, while the simulation based on original material data could not predict the actual deformation accurately. The results indicate that this material supplement method is reliable and indispensible, and the simulation model can well reflect the real metal forming process. Detailed analysis of the distribution and history of plastic strain at different positions are performed. A new material data supplement method is proposed to tackle the problem which is ignored in other roll forming simulations, and thus the forming process simulation accuracy can be greatly improved. 相似文献
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Robot applications in manufacturing of aircraft sheet metal parts require real-time methods for determining the surface normal using a digitized point data set measured by a 3D laser scanner. For this reason, six archived surface normal algorithms are compared. Though using different weights, these methods are all set to determine the surface normal at a given point by averaging the surface normals of the adjacent facets. In this paper, a comparison study is designed with a nearest neighboring method searching for adjacent facets, along with the introduction of a dynamic sampling method to investigate the effect of the resolution of a data set on the accuracy of surface normal determination. Three performance indices are proposed including the total number of final data points, the number of times of up-sampling and the total computing time. Three geometric models are considered including a sphere representing an aircraft cockpit, a cylinder representing a fuselage, and an ellipsoid representing a wing. The laser scanner error is modeled by a log-normal distribution. While all the six methods can generate satisfactory results in error-free case, the simulation results indicate that in error case MWE (mean weighted equally) and MWAAT (mean weighted by areas of adjacent triangles) are not favorable while the other four methods exhibit no obvious difference. 相似文献
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研究了齿轮误差三维评定方法,以消除测量仪器定位误差对齿轮误差评定的影响,提高齿轮测量仪器的测量精度。分析了传统齿轮二维评定方法的弊端,提出将齿轮误差评定从二维评定模式转变为三维评定模式。该评定模式不再要求齿轮各项误差测量点位于特征面内,实现了三维空间内的齿轮误差测量与评定。为提高齿轮三维误差评定算法的效率,通过螺旋降维方法将三维数据降至二维数据,再对二维测量数据进行各项误差的评定。以特大型齿轮激光跟踪在位测量系统作为实验对象,对4级标准齿轮的齿廓误差进行了测量,并与传统的齿轮二维误差评定方法以及德国ZEISS公司InvolutePro软件的评定结果进行了对比。结果表明:传统齿轮二维误差评定方法有较大误差,三维齿廓评定方法与德国ZEISS公司InvolutePro软件评定结果一致,精度达到0.1μm,证明了提出的齿廓误差三维评定方法完全正确,可以消除仪器定位误差对测量结果的影响,提高了测量仪器的测量精度。 相似文献
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介绍了一种利用激光干涉仪修正测控仪器运动轴定位误差的方法,着重从误差数据采集、误差数据处理和误差修正软件的编写3个方面,阐述了误差修正方法的具体设计和实施过程。 相似文献