共查询到20条相似文献,搜索用时 78 毫秒
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为达到微小芯片粘贴系统高精度的性能要求,以二极管粘片机为例在系统分析微小芯片粘贴系统运动控制的各误差因素的基础上,提出了误差校正的方法.特别针对微小芯片粘贴系统的高精度要求,采用了全闭环控制、视觉定位等先进技术.校正方法在具体工作中校正效果良好,对精度提高作用很大. 相似文献
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分析了低轨单星测频定位体制中的定位误差校正问题,由于卫星移动过程受到干扰影响,产生星历误差.为解决上述问题,根据参考站的误差校正算法,推导了引入参考站前后的定位误差协方差矩阵,最后对不同条件下参考站对定位误差的校正作用进行试验.从数学上揭示了参考站对系统定位误差的校正作用,通过引入参考站,实现定位误差的校正.仿真结果表明,在参考站位置附近的区域定位精度明显提高,同时仿真分析了在定位盲区引入参考站时的定位误差分布.研究结果可为实际系统参考站优化定位校正提供理论依据. 相似文献
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文章研究了在视觉增强环境下的校正问题。建立了在视觉增强环境中校正的模型,研究了算法并提出了解决边缘校正问题的方法。利用边缘检测的方法替代了人工干预的方法,避免了在校正过程中人的参与,减少了人为因素导致的误差,实现了自动校正(SelfCalibration)。 相似文献
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高精度长光栅动态光刻机定位误差校正 总被引:1,自引:0,他引:1
本文介绍了一种采用微机对高精度长光栅动态光刻机定位误差进行实时校正的方法,提出了空间域脉冲增减法误差校正原理,设计了误差校正电路和校正软件。该方法可从空间域同时校正定位信号误差和温度误差,校正精度较高。实验结果表明该方法是可行的,该方法的提出为研制高精度长光栅提供了一条新的途径。 相似文献
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本文针对视觉定位控制问题,讨论了机器视觉和受控装置的非线性影响,分析了视觉反馈控制系统中各环节的信息变换关系,用分块线性化方法分析了视觉图像的校正原理和线性回归算法对视觉控制校正的可行性,介绍了实施校正所采取的关键技术及实验方法。 相似文献
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在脑功能磁共振实验中,运动校正是数据预处理的关键环节。运动校正的结果对后续的脑区定位、功能连接等分析有着重要的影响。但因数据量较大,常规分析软件对实验数据进行运动校正时做了一些简化处理,校正误差较大。为减少这种误差,提出了一种基于局部空间数据的运动校正方法,首先从数据获取的角度构造功能像各切片的局部空间数据,然后利用修正的Gauss-Newton最优化方法估计各切片相对于参考图像做刚体变换后的空间位置,最后利用Delaunay三角剖分方法重构功能像以实现精确校正。仿真实验及实际的视觉实验数据分析结果表明,该方法具有较高的校正精度,是一种有效的功能磁共振数据运动校正方法。 相似文献
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一种基于斜率的摄像机畸变校正方法 总被引:8,自引:0,他引:8
普通 CCD摄像机在成像时都存在畸变成像误差 ,在机器人视觉检测及自动装配中 ,有效地进行误差校正对准确确定物体的位置具有重要的意义 .本文采用带有一阶径向畸变的小孔摄像机模型 ,提出一种基于线段斜率的方法 ,对摄像机镜头的径向畸变进行校正 ,不必标定太多的摄像机的外参数 ,方法简洁 ,适合于视觉系统中对摄像机畸变的实时校正 ,或对摄像机捕获的图像进行几何校正 .实验表明 ,具有很强的鲁棒性和较高的校正精度 相似文献
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闭环连续系统仿真若干问题的分析研究 总被引:1,自引:0,他引:1
分析研究了对闭环系统的纯滞后环节如何处理的问题,找到开环系统和闭环系统的理论输出值计算方法,并比较3种Pade近似和全极点近似的精度。将此算法应用到闭环系统中,进一步比较4种近似,以求得闭环系统中误差最小的近似方法。同时提出在计算过程中对纯滞后处理的改进方法,使得误差大大减小,精度提高了一个数量级。研究结果表明,在开环系统和闭环系统,全极点近似由于没有引入零点,使得误差最小;改进方法使误差精度提高了一个数量级。 相似文献
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In robotic machining process, the kinematic errors of serial structure and compliance errors caused by external cutter-workpiece interactions can result in considerable deviation of the desired trajectory. Therefore, this paper proposes an efficient calibration methodology by establishing a unified error model about kinematic errors and compliance errors based on Lie theory, which simultaneously calibrates the kinematic parameters and joint compliances of a serial machining robot. In this methodology, the propagation law of kinematic errors is investigated by analysis of the kinematic error model, and the corresponding equivalent kinematic error model is thus obtained, in which the joint offset errors are regarded as one source of twist (joint twist and reference configuration twist) errors. On this basis, with the segmentation and modelling of the joint compliance errors caused by the link self-weight and cutting payloads, the unified error model is developed by linear superposition of configuration errors of the robotic end-cutter, calculated from the kinematic errors and compliance errors respectively. Meanwhile, to improve the accuracy of parameters calibration, the observability index is adopted to optimize the calibration configurations so as to eliminate the twist error constraints. The calibrated kinematic parameters and joint compliances are obtained eventually, and used to compensate the kinematic and compliance errors of the serial machining robot. Finally, to validate the effectiveness of the proposed unified error model, simulation analysis is performed using a 6-DOF serial machining robot, namely KUKA KR500. The comparisons among calibrated parameters show that the unified error model is more computationally efficient with optimal calibration configurations, rendering it suitable for the calibration of kinematic parameters and joint compliances in actual machining applications. 相似文献
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Comparing error estimation measures for polynomial and kriging approximation of noise-free functions 总被引:1,自引:0,他引:1
Tushar Goel Raphael T. Hafkta Wei Shyy 《Structural and Multidisciplinary Optimization》2009,38(5):429-442
Error estimation measures are useful for assessing uncertainty in surrogate predictions. We use a suite of test problems to
appraise several error estimation measures for polynomial response surfaces and kriging. In addition, we study the performance
of cross-validation error measures that can be used with any surrogate. We use 1,000 experimental designs to obtain the variability
of error estimates with respect to the experimental designs for each problem. We find that the (actual) errors for polynomial
response surfaces are less sensitive to the choice of experimental designs than the kriging errors. This is attributed to
the variability in the maximum likelihood estimates of the kriging parameters. We find that no single error measure outperforms
other measures on all the problems. Computationally expensive integrated local error measures (standard error for polynomials
and mean square error for kriging) estimate the actual root mean square error very well. The distribution-free cross-validation
error characterized the actual errors reasonably well. While the estimated root mean square error for polynomial response
surface is a good estimate of the actual errors, the process variance for kriging is not. We explore a few methods of simultaneously
using multiple error measures and demonstrate that the geometric means of several combinations of error measures improve the
assessment of the actual errors over individual error measures. 相似文献
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地形辅助导航系统中的数字地图误差模型辨识* 总被引:1,自引:0,他引:1
地形辅助导航系统在引入量测时便引入了与数字地图有关的误差,含数字地图制作误差及地形随机线性化误差两类。本文在建立系统误差模型的基础上研究了两类误差产生的机理、影响误差的因素、样本获取的手段及误差模型辨识等问题,并采用扩维系统仿真的方法研究了误差的平稳特性、白度、模型参数等特性及其对系统精度的影响,获得了对数字地图误差模型的基本估计。 相似文献
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《Mathematics and computers in simulation》2004,67(3):217-233
In this paper the splitting error arising in the Danish Eulerian Model is investigated. Sufficient conditions under which the local splitting error vanishes are formulated for the continuous case. The numerical solution of the model problem introduces several other error sources, which makes the task of determining the effect of the splitting error more complicated. Therefore, we need numerical examples which will allow us to separate the splitting errors from the other errors in order to evaluate both the magnitude of these errors and the relationships between splitting errors and other errors for different values of the discretization parameters. Several such examples have been constructed and analysed. The appropriate conclusions were drawned. The experiences obtained from these experiments can be a starting step towards a total error analysis of the numerical solution of split systems of partial differential equations. 相似文献