基于网络摄像机的株高远程无损测量系统

Crop Height Non-destructive Remote Measurement Based on IP Camera

作物株高是体现作物长势的重要指标。为此,针对现有基于图像分析测量方法需设置标定物、图像分割困难、精度不高的问题,提出一种基于网络摄像机的株高远程无损测量方法。利用三角测量原理,通过控制网络摄像机云台运动,计算光轴旋转角度,实现了株高的远程无损测量。以玉米为研究对象,在喇叭口期,通过焦距固定和焦距可变两组实验,测试了焦距变化对测量数据的影响。在三叶期、拔节期、大喇叭口期和抽雄期,随机选取10株作物,进行远程无损测量和人工测量,并生成株高数据连续变化曲线。实验结果表明:使用该方法,测量结果不受作物与摄像机距离远近和摄像机焦距变化的影响,鲁棒性强,对于无倾斜或倾斜度较小的作物,测量平均相对误差为3.66%,最大相对误差为6.71%,可满足农业生产的要求。

Crop height is an important indicator of crop growth condition , for the problems of existing image processing methods when calculating the crop height , which are need to set calibration object manually , in addition of the calculation result is not accurate and the operation is difficult , this paper researched and proposed a crop height remote measurement method which based on geometric principles .With triangular measurement , control IP camera PTZ ’ s motion and calculate rotation angle of optical axis .Take maize as the subject , at the bell stage , two experiments were carried out to find out how focus change affects the results .At trefoil stage , jointing stage , booting stage and heading stage , measure automatically and manually 10 randomly selected plants .The results showed the proposed method made the measurement not affected by the distance between crop and camera as well as focus change .It exhibited high robustness：average relative error is 3 .66%, maximum relative error is 6 .71%, and the accuracy satisfies the requirements of agricultural production .