共查询到19条相似文献,搜索用时 234 毫秒
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用VB图解评定圆度误差,克服手工作图评定圆度误差的繁琐、粗糙性,以及计算法的不可观性。展示评定圆度误差过程,为制造加工、质量鉴定与研究提供精确误差值和可视化平台。 相似文献
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介绍了几种Matlab与VB混合编程的方法,说明比较了各自的优缺点。并选用其中一项混编方法进行计算,结果表明,较好地解决了TCA分析过程中非线性方程组的求解与啮合仿真图形的绘制问题,使螺旋锥齿轮的TCA数学算法和编程过程大大简化。 相似文献
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在圆度误差测量中,圆度误差的数据处理和评定一般都是采用绘制简图及用同心模板逼近的方法完成,但这种方法处理效率及准确度偏低。应用AutoCAD软件的绘图和标注功能对圆度误差进行评定的方法,能够很好的弥补传统方法的不足。 相似文献
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本文从数学推理着手,推导出与国际传统公式不同的最小二乘方圆的参数公式。运用本文推出的新公式来评定圆度误差,既具有传统计算简便迅速的优点,而精确程度远比传统公式高。 相似文献
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一、数学模型形状和位置公差国家标准规定,最小条件是评定形状误差的基本原则。圆度误差按这一原则的判别准则为:而同心圆包容被测实际轮廓,至少应有内、外交替四点接触。此时,两最内点的连线与两最外点的连线相交叉。由“小偏差假设”和“小误差假设”可将圆度评定数学模型进行线性化处理。在分度装置上测量圆度误差为半径变化量测量法,按极坐标,所测各点极径变化量r为极角a的函数:r=f(a)。设满足最小条件的两同心圆的圆心距坐标原点为(-u1,-U2),则各测点相对于此圆心极径变化量为:F(a;u1,u2)=[(r… 相似文献
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针对圆度误差已有评定方法的不足,提出了一种新的精确评定方法.该方法在测点分类的基础上,搜索符合最小包容区域定义的同心圆,大大提高了误差评判效率,并在实例中得到了很好的验证. 相似文献
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曲轴轴颈圆度是评价曲轴合格性和加工精度的一项重要指标。针对曲轴综合测量过程中连杆轴颈沿主轴颈公转运动,导致连杆轴颈的检测数据无法直接用于圆度误差评定的问题,建立基于运动坐标系的圆度误差检测模型,实现了连杆轴颈检测数据转换处理。同时,深入分析用于圆度误差评定的3种最小二乘法的适用条件,结合采样数据的特点实现了连杆轴颈圆度误差的高精度检测。以某型号发动机曲轴为例进行大样本误差检测试验,并与最小区域评定结果进行对比,偏差在1μm以内。数据分析表明了所提出的曲轴连杆轴颈圆度误差检测方法理论上的正确性及工程实践的可行性。 相似文献
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基于遗传算法的圆度公差评定法与采用最小二乘法评定的比较 总被引:4,自引:0,他引:4
根据提出的计算模型,对基于遗传算法的圆度误差评定和传统上采用最小二乘法的评定算法进行了比较分析,根据方法本身的特点和计算结果,分析了二者的不同点以及在工程应用中的适用场合.所构造的模型包括边界控制点和区域随机点,其中边界控制点模拟了由圆度误差最小区域条件所定义的最大内切圆和最小外切圆,而区域随机点模拟了实际情况下测试点的随机性和不确定性.计算结果表明基于遗传算法的圆度评定法精度较高,优于基于最小二乘法的评定算法. 相似文献
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Form error evaluation plays an important role in processing quality evaluation. Conicity error is evaluated as a typical example in this paper based on sequential quadratic programming (SQP) algorithm. The evaluation is carried out in three stages. Signed distance function from the measured points to conical surface is defined and the cone is located roughly by the method of traditional least-squares (LS) firstly; the fitted cone and the measured point coordinates are transformed to simplify the optimal mathematical model of conicity error evaluation secondly; and then optimization problem on conicity error evaluation satisfying the minimum zone criterion is solved by means of SQP algorithm and kinematic geometry, where approximate linear differential movement model of signed distance function is deduced in order to reduce the computational complexity. Experimental results show that the conicity error evaluation algorithm is more accurate, and has good robustness and high efficiency. The obtained conicity error is effective. 相似文献
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LABVIEW与MATLAB的混合编程在测试系统中的应用 总被引:2,自引:1,他引:1
介绍了LABVIEW和MATLAB各自的优势与不足,然后提出LABVIEW与MATLAB的混合编程及其实现方法,通过一个简单的例子实现他们的优势互补。让虚拟测试系统更加的智能化。 相似文献
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《Measurement》2014
Minimum zone circle (MZC) method and least square circle (LSC) method are two most commonly used methods to evaluate roundness, but only the MZC method complies with the standard definition and can obtain the minimum roundness error value. The determination of the center of MZC is a nonlinear optimization problem which is suitable to be solved by particle swarm optimization (PSO) algorithms. In this paper, the standard PSO algorithm was introduced and theory analysis about the impact of value selection of some important parameters, such as inertia weight ω, on the algorithm’s stability and convergence was carried on so as to provide basis for giving these parameters better values. Furthermore, the superiority of making ω decrease linearly with iterations was verified through a computation experiment in terms of stability and accuracy, compared with the other three cases of ω = 1, 0.5, 0. Based on the analysis, the novel PSO algorithm, with ω decreasing linearly from 0.9 to 0.4 and the LSC center as the initial positions of the particles, is implemented to obtain MZC-based roundness errors of sampling points collected from circular section profiles by a coordinate measuring machine (CMM). By comparing the novel PSO–MZC results with the LSC-based results, it is concluded that the former are a little smaller than the latter, which verifies that the novel PSO algorithm is feasible to calculate roundness error and the fact that a LSC-based one is generally larger than a MZC-based result; the values of the two roundness errors are both related to sample size and increase with an increase in the sample size with a decreasing increment. 相似文献