棉花采摘机器人红外测距技术研究

Infrared Distance Measurement Used for Cotton Picker Robot

为定位棉株上的棉花，用红外测距实验装置和计算机图像处理技术结合棉花的农学生长特性测量单朵棉花的距离。在0．7～1．6m的距离区间内建立红外测距模型，获取了棉株表面点云的距离图像，测量精度达0．0085m。以0．65为标准差设计高斯滤波器的尺寸，用1一D高斯滤波器平滑棉株图像，用2一D高斯滤波器求取其梯度图像，以0．2m、0．08m为强、弱阈值，基于Canny边缘检测算子构建闭环边缘，结合形态学运算提取棉花区域，去除棉枝。用峰点滤波器削弱棉花图像中的粘连重叠现象，基于分水岭算法提取单朵棉花并求取其距离。结果表明，单朵棉花的图像识别率达91．3％，红外与人工测距结果的相关系数为0．9922，为采机器人运动轨迹的规划提供了参数。

In order to detect cotton position on a plant, an infrared distance measurement device and the computer image processing technology, combined with the growth characteristics of cotton, were used to measure the distance of single cotton. The infrared measurement model was established in the distance of 0.7 m to 1.6 m. The distance image of plant surface point cloud was obtained with the measurement accuracy of 0. 008 5 m. The Gaussian filter size was designed with the standard deviation of 0.65. 1D Gaussian filter was used to smooth the plant image and 2D Gaussian filter was used to obtain the gradient image. With the strong threshold of 0.2 m and the weak threshold of 0.08 m, the closed loop edge was constructed based on Canny edge detection operator. The image of cotton area was extracted by morphological operations, and the cotton sticks background was removed. Peak filter was used to weaken the adhesion and overlap of the cotton image. The cotton distance image was segmented based on watershed algorithm to extract the single cotton image and obtain the distance. The results show that the image recognition rate of single cotton on the plant is 91.3% and the correlation coefficient between the infrared and artificial measurement results is 0. 992 2, which provides parameters for cotton picker robot to plan motor path.