基于激光雷达的果树智能修剪系统设计与试验

Design and Experiment of Intelligent Pruning System for Fruit Trees Based on LiDAR

摘要:

针对传统果树修剪存在人员劳动强度大、修剪效率低及修剪质量难以保证等问题，本文设计了果树智能修剪机械臂，并利用固态激光雷达与可编程逻辑控制器开发了基于激光雷达的果树智能修剪系统，实现果树自动修剪。为了验证修剪臂的控制精度，分别对修剪机的摆动机械臂、举升机械臂、修剪切割总成进行独立精度试验与修剪目标位置精度试验，独立精度试验结果表明摆动机械臂、举升机械臂、修剪切割总成控制精度平均误差分别为2.32%、3.75%、2.50%，修剪目标位置精度试验结果表明目标位置Xb、Zb平均误差分别为2.98%、1.85%，修剪总成作业倾角α平均误差为4.35%，满足果树修剪精度要求。在新疆阿克苏果树种植基地开展了果树修剪试验，结果表明，搭载固态激光雷达的果树修剪机能够实时获取果树的三维空间信息，修剪机可以根据激光雷达探测到的果树树冠信息制定修剪策略，香梨园与苹果园修剪优良率分别为93.3%与86.6%。该系统能有效提高果树修剪效率，降低修剪人员劳动强度。

关键词:果树修剪机;激光雷达;自动修剪;修剪策略

Abstract:

The traditional fruit tree pruning process has problems such as high labor intensity, low pruning efficiency, and difficulty in ensuring pruning quality. An intelligent pruning robot arm for fruit trees was designed, and an intelligent pruning system for fruit trees was developed based on solid-state LiDAR and programmable logic controller, achieving automatic pruning of fruit trees. In order to verify the control accuracy of the pruning arm, independent accuracy tests and pruning target position accuracy tests were conducted on the swinging mechanical arm, lifting mechanical arm, and pruning cutting assembly of the pruning machine. The independent accuracy test results showed that the average control accuracy errors of the swinging mechanical arm, lifting mechanical arm, and pruning cutting assembly were 2.32%, 3.75%, and 2.50%, respectively. The pruning target position accuracy test results showed that the average length errors of the target positions Xb and Zb were 2.98% and 1.85%, respectively. The operating inclination angle of the pruning assembly was also determined, the average error was 4.35%, which met the accuracy requirements for fruit tree pruning. A fruit tree pruning experiment was conducted at the Aksu fruit tree planting base in Xinjiang. The results showed that the fruit tree pruning machine equipped with solid-state LiDAR can obtain real-time three-dimensional spatial information of the fruit tree. The pruning machine can formulate pruning strategies based on the information of the fruit tree crown detected by LiDAR. The excellent pruning rates of pear orchards and apple orchards were 93.3% and 86.6%, respectively. This system can effectively improve the efficiency of fruit tree pruning and reduce the labor intensity of pruning personnel.

Key words:fruit tree pruning machine;LiDAR;automatic pruning;pruning strategy