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

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 X_b and Z_b 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.