基于2D激光探测的立木胸径几何算法优化  

Optimization of Geometry Algorithm for DBH of Standing Tree on 2D Laser Detection

作　　者：王亚雄[1] 康峰[1] 李文彬[1] 郑永军[2] 

机构地区：[1]北京林业大学工学院,北京100083 [2]中国农业大学工学院,北京100083

出　　处：《农业机械学报》2016年第6期290-296,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：中央高校基本科研业务费专项资金项目(2015ZCQ-GX-01);国家林业局引进国际先进林业科学技术计划(948计划)项目(2013-4-02)

摘　　要：目前林业测绘中使用2D激光扫描仪对树干立木胸径及位置的测定研究占据重要地位。针对3种较为常用的几何类算法(弧长法、切线法和双余弦法),提出在近距离下利用补偿角对其测量值进行补偿的方案,研究了弧长法与切线法补偿角随距离的变化关系,并进行回归分析,所得拟合方程的R^2均大于0.85。运用拟合方程在0~5.5 m范围内对实际树干进行验证,试验选取了5株杨树树干,通过算法补偿,半径与距离测量值的准确性均得到提高,其中弧长补偿算法和切线补偿算法对半径的测量精度分别比未补偿前提高了10.6和10.7个百分点,补偿后的绝对误差均值分别为4.8 mm和3.8 mm;补偿后距离测量值绝对误差均值可分别控制在66.0 mm和15.9 mm以内。试验证明2种补偿后的几何算法均可作为近距离下的林业测绘算法,其中切线补偿算法更优。It takes an important role to measure the DBH and position of standing tree by a 2D laser detection in current forestry surveying and mapping. A compensation scheme in short distances contraposing the two variables was put forward on three common geometry algorithms（ arc length method,tangent method, dual-cosine method）, and a compensation angle was used in the scheme. The functionary relation of compensation angles for arc length method and tangent method with distances was researched specifically,the regression analysis was also carried on,and the fitting equations were obtained（ R^2 0. 85 for each fitting equation）. Verification test for trunks using the fitting equations in the range of 0 ~ 5. 5 m was carried out in which five poplar trunks were selected. The accuracies of measured values of radius and the distance were all improved by algorithms compensation. Thereinto,the measure precisions of radius values from arc length compensation algorithm and tangent compensation algorithm were respectively increased by 10. 6 percent and 10. 7 percent,and the mean absolute errors were 4. 8 mm and 3. 8 mm; the mean absolute errors of measured values of distance were controlled within66. 0 mm and 15. 9 mm respectively after algorithms compensation. Experiments proved that the two compensation geometric algorithms could both be used as forestry surveying and mapping algorithms in short distances,and the tangent compensation algorithm is better.

关 键 词：立木胸径 2D激光扫描仪 几何类算法 拟合方程 

分 类 号：S24[农业科学—农业电气化与自动化]