时序分析在排种轴转速检测数据处理中的应用

The application of timing analysis in processing of test data of rotational speed of seeding shaft

利用CCD摄像机获取气吹式精密排种器排种轴视觉检测样本,通过图像处理获得转速序列,在分析转速序列特点的基础上,采用时序分析方法研究排种轴转速。利用转速序列数据计算各种转速下的自协方差函数、自相关函数和偏自相关函数,选用AR模型进行转速序列的分析。将实测数据代入AR模型求得模型参数,应用模型进行转速序列数据拟合(以45 r/min为例),获得模型拟合值、残差序列。残差序列和模型拟合优度分析结果表明,模型预测的残差最大值为19.920 6,并且有83.83%的残差在允许值±6.912 312 r/min范围内;模型拟合度为74.631 2%,标准方差为0.050 136,模型系数t检验结果为16.805 28,显著性水平0.000通过t检验。

Visual inspection samples of seeding shaft of air blowing precision seeder were got by CCD camera, rotational speed serials were obtained by image processing, whose characteristic was analyzed based on which rotational speed of seeding shaft was investigated through timing analysis. Based on the speed serial data, the auto-covariance function, autocorrelation function and partial autocorrelation function were calculated, and the AR model was selected for analysis of speed serial. The fitted and residual serials were obtained using the actual serials and the AR model（under 45 r/min for example）. Through fitting analysis of the residuals and the model, the calculated maximum of residuals is 19.920 6, and 83.83% of the residuals were within ± 6.912 312 r/min, which is the allowed value range; the fit of the model was 74.631 2% with standard deviation of 0.050 136. The model＇s coefficients were 16.805 28 at the significance level of 0.000 by t-test.