Design And Experiment Of Target Detection-based Device For Directional Transplanting Of Panax Notoginseng Seedlings

In China,Panax notoginseng is considered the second most valuable Chinese herbal medicine after ginseng,and it is also a highly distinctive economic crop in Yunnan Province.As of 2021,the planting area of Panax notoginseng in Yunnan Province was approximately 700,000 acres.During the planting process,seedling transplanting plays a crucial role.However,manual transplanting operations suffer from issues such as high labor intensity,low quality,and productivity.To address these shortcomings and meet the agronomic requirements of directional transplanting,a target-detection-based directional transplanting device for Panax notoginseng seedlings was developed in this study.The device primarily utilizes a pneumatic adsorption device and combines it with a target detection algorithm and a directional actuator to achieve directional transplanting.The details of the study are presented below.(1)To clarify the working principle of the directional transplanting device,the classical target detection algorithm is introduced,Panax notoginseng seedling image data is collected,and the features to be detected are labeled.A dataset in VOC format is built,and the algorithm is trained with different target detection algorithms.Through500 iterations of training,it is observed that the average accuracy of each algorithm is as follows: 92.97% for Faster R-CNN,73.69% for SSD,92.90% for YOLOv5＿s,and96.37% for YOLOv5＿x.The average detection frame rates of each algorithm were 2.33 Hz for Faster R-CNN,38.22 Hz for SSD,27.13 Hz for YOLOv5＿s,and 17.45 Hz for YOLOv5＿x.The selection for the pose detection process of Panax ginseng seedlings for directional transplanting took into consideration the accuracy,frame rate,and algorithm size,resulting in the YOLOv5＿s algorithm being chosen.(2)A target detection-based Panax notoginseng seedling orientation transplanting device is proposed according to the agronomic demands of transplanting Panax notoginseng seedlings.The working principle of the device is introduced,and the structural parameters of the air-absorbing main part are determined by theoretical analysis and empirical formulae to ensure the adsorption stability of seedlings on the air-absorbing plate.The ideal attitude of the seedlings after completing the attitude orientation is specified,and the orientation actuator is designed based on the demand of attitude change.The mechanism of seedling attitude orientation is obtained,and the attitude orientation process is divided into combined actions to facilitate the application of the mechanism control module.(3)The target detection algorithm and the directional transplanting device are connected using the serial port.The seedling pose detected by the algorithm is converted into planar coordinates and transmitted to the microcontroller.In the microcontroller,the coordinate system is converted to derive the posture of the seedling in the plane right-angle coordinate system centered on the air suction hole.The directional actuator is controlled to make corresponding actions according to the different suction postures.The output content of the detection algorithm undergoes the DMA direct register method to reject multiple duplicate seedling coordinates and keep the one with the most occurrences.The directional actuator is controlled using the FreeRTOS multi-thread method to complete different actions of each component with high independence and not easily interfered with.(4)The force and kinematic analysis of the four processes of seedling adsorption,seedling loading,orientation,and seedling throwing are carried out,combined with the mechanism of directional transplanting.The conditions required for stable seedling adsorption are determined,and the force models of seedling stable state,rotational orientation state,and seedling throwing state are established.The investigation was conducted on the process of rotational orientation and post-orientation adsorption of seedlings under the action of multiple factors based on classical mechanics.The mechanism of seedling orientation was clarified,and the model of seedling motion in the throwing stage was established.The expression of horizontal distance for seedling throwing was derived.(5)The test factors that have a significant impact on the test index,including the speed of the suction plate with the index of orientation qualification rate and the index of seedling shedding rate,the speed of the Servo,and the angle between the camera and the actuator,were selected based on the results of the previous experiments.A single-factor experiment was performed.The optimal operational performance parameters of the directional grafting device were investigated using the Box-Behnken test in order to further explore the effect of the number of factors and crossover conditions on its performance.According to the test results,when the speed of the air suction plate is 5.73 r/min,the speed of the Servo is 0.86 r/s,and the angle between the camera and the actuator is 35°,the theoretical orientation qualification index is90.86% and the seedling shedding index is 6.86%.Experimental verification was carried out under this parameter combination.The average directional qualification index of the directional transplanting device was 89.87%,and the average seedling shedding index was 6.57%.