为了从目标拍摄源上提高直线电机动子位置检测的精度和抗干扰性, 构造了一种非周期正弦条纹图像, 并引入一种基于梯度法的图像亚像素测量方法, 实现对动子位置的高精度测量。首先, 改变正弦条纹的条纹周期, 得到一系列非周期正弦条纹, 并生成非周期正弦条纹图像; 其次, 采用图像的Pnatt熵优选出具有强鲁棒性的非周期正弦条纹图像; 最后采用基于Barron算子的梯度法计算相邻目标图像的亚像素位移, 结合标定系统物像标定系数, 获得直线电机动子的实际位移。仿真和实验结果表明, 对比于非周期栅栏图像, 本文构造的非周期正弦条纹图像具有较强的鲁棒性, 且测量精度达到0.02 pixel。

To improve the accuracy and anti-interference of the position detection of a linear motor mover from a target shooting source, an aperiodic sinusoidal stripe image was constructed and a sub-pixel measurement method based on the gradient method was introduced to achieve high-precision measurement of the mover position. First, by changing the stripe cycle of the sinusoidal stripe, an aperiodic sinusoidal stripe image was generated. Second, an aperiodic sinusoidal stripe image with strong robustness was selected by using the Pnatt entropy of the image. Finally, the subpixel displacement of the adjacent target image was calculated using the gradient method based on the Barron operator, and the actual displacement of the linear motor mover was obtained by combining the calibration coefficients of the calibration system. Simulation and experimental results show that when compared to the aperiodic fence image, the aperiodic sinusoidal stripe image has strong robustness and a measurement accuracy of 0.02 pixels.