基于光学编码成像的新型角位移传感器

A novel angular displacement sensor based on optical coding imaging

传统光学角位移测量方法存在光路复杂、抗干扰能力弱等问题。为此,提出一种基于光学编码成像的新型角位移测量方法。首先,该方法借鉴格雷码转换成二进制的原理,在直径为50 mm的圆周面上均匀分布两圈红色、绿色、蓝色(Red、Green、Blue,RGB)色块,通过检测外圈目标点周围的颜色信息将其转换为与绝对位置对应的二进制数;然后,为降低噪声,利用高斯滤波与中值滤波对图像进行预处理,并使用霍夫圆算法定位跟踪目标点以获得其始末位置,从而计算出粗角度;最后,利用视频最后一帧目标点所处位置与最终位置之间的角度对粗角度进行补偿,实现角度测量。通过搭建实验平台与制作实物传感器,在光圈整周360°测量范围内,对实验装置进行精度测量与稳定性实验,实验结果表明,分辨力达到16位,测量均方差为0.23°。提出的新型角位移测量方法为角位移测量领域提供了新的思路。

In the traditional optical angular displacement measurement method,there are some problems such as complex optical path and weak anti-interference ability.Therefore,a novel angular displacement measurement method based on optical coding imaging is proposed.Firstly,the method uses the principle of converting gray code into binary for reference,evenly distributes two circles of RGB(Red,Green,Blue)blocks on the circular surface with a diameter of 50 mm,and converts the color information around the outer circle target point into binary number corresponding to the absolute position by detecting the color information.Then,in order to reduce the noise,Gaussian filtering and median filtering are used to preprocess the image,and the Hough circle algorithm is used to locate and track the target point to obtain its starting and ending positions,so as to calculate the coarse angle.Finally,the coarse angle is compensated by the angle between the position of the target point in the last frame of the video and the final position to achieve angle measurement.By building the experimental platform and making the sensor,the accuracy measurement and stability experiment of the experimental device are carried out in the 360°measurement range.The resolution is 16 bits,the measured mean square deviation is 0.23°.The new angular displacement measurement method proposed brings new ideas for the field of angular displacement measurement.