应用植保机械进行变量喷雾作业是提高化学农药利用率、减少农药危害的有效途径之一。实时、动态、精确地获取靶标的几何特征参数是实现变量喷雾的基础。本研究以主干形梨树为靶标，提出一种融合2D-LiDAR、RTK-DGPS与IMU传感器的靶标精准探测系统，通过杆臂效应补偿算法、横向偏差补偿算法、等比例插值与曲线拟合算法分别消除由地面不平、行驶轨迹偏离与行驶速度不均匀引起的空间位置误差，获取靶标精准的三维激光点云数据集。同时，为解决靶标体积参数在计算过程中因树冠不规则的外轮廓和内部孔隙产生较大误差的问题，提出计算靶标的叶面积密度参数，为施药量的计算提供新的参考信息。叶面积密度参数由施药子区域内的点云密度参数结合叶片形态校正系数进行计算，叶片形态校正系数通过不同生长周期、不同光照条件、冠层不同位置条件下的叶面积指数分布模型与叶片倾角分布模型进行计算。本项目的实施能够为新型植保机械的研发提供基础。

Using variable-rate spraying technology on the plant protecting machine is an important approach to enhance the effective utilization and reduce excessive application of chemical pesticides. The foundation of variable-rate spraying is obtaining the geometric parameters of the target accurately, real-timely and dynamically. This project proposes a detecting system in order to obtain the precise 3-Dimension laser scanning data sets of the target by fusing LiDAR (Light Detection and Ranging), RTK-DGPS (Real time kinematics Differential GPS) and IMU (Inertial Measurement Unit) for pear tree with trunk shape. Three spatial errors caused by the uneven terrain ,the biased trajectory and the uneven speed will be eliminated by using the lever-arm effect compensation algorithm, lateral deviation compensation algorithm, interpolation and curve-fitting algorithms respectively. Meanwhile, this project proposed to utilize leaf area density instead of the volume for calculating the spray rate, which can eliminate the larger error caused by the irregular canopy shape and lots of gaps in the canopy of the target. Leaf area density is calculated by combining the point cloud density and a correction factor of leaf morphology in each spray area with a same volume. The correction factor of leaf morphology is calculated by leaf area index distribution model and leaf angle distribution model under the conditions of different plant growth cycle, different Photo-synthetically Active Radiation and different location in the canopy. The research on this project can provide theoretical and technical methods for the innovative plant protecting machine development.