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The most common harvesting method of Lycium barbarum L. (L. barbarum) is manual harvesting, resulting in low efficiency and high cost. Meanwhile, the efficiency of vibration harvesting, which is considered an efficient mechanical harvesting method, can be significantly improved if the optimized resonance frequency of the shrub can be obtained. To vibration harvest fruit efficiently, a 3D model of the shrub was established based on measurements of the shape parameters, and material mechanics models of the branches were established based on physical tests. The modal analysis of the shrub based on finite element method (FEM) simulation was performed to obtain the range of resonance frequency, and the modal experiment of the shrub using acceleration sensors and an impact hammer was conducted to obtain the accurate resonance frequency. Based on the results of the modal analysis and experiment, the optimized resonance frequency was determined to be 2 Hz. The field experiment showed that the fruit fell off when the branches were vibrated at this frequency. The results provide the design basis for the efficient vibration harvesting of L. barbarum.
Jian Zhao; Satoru Tsuchikawa; Te Ma; Guangrui Hu; Yun Chen; Zhiwei Wang; Qingyu Chen; Zening Gao; Jun Chen. Modal Analysis and Experiment of a Lycium barbarum L. Shrub for Efficient Vibration Harvesting of Fruit. Agriculture 2021, 11, 519 .
AMA StyleJian Zhao, Satoru Tsuchikawa, Te Ma, Guangrui Hu, Yun Chen, Zhiwei Wang, Qingyu Chen, Zening Gao, Jun Chen. Modal Analysis and Experiment of a Lycium barbarum L. Shrub for Efficient Vibration Harvesting of Fruit. Agriculture. 2021; 11 (6):519.
Chicago/Turabian StyleJian Zhao; Satoru Tsuchikawa; Te Ma; Guangrui Hu; Yun Chen; Zhiwei Wang; Qingyu Chen; Zening Gao; Jun Chen. 2021. "Modal Analysis and Experiment of a Lycium barbarum L. Shrub for Efficient Vibration Harvesting of Fruit." Agriculture 11, no. 6: 519.
When harvesting Lycium barbarum L., excess amounts of detachments of the half-ripe fruit, unripe fruit, flowers, and leaves significantly affect the yield and adversely affect the subsequent processing, such as drying and grading. Finite element method (FEM) simulations and experiments of detachments were performed to harvest more ripe fruit and less half-ripe fruit, unripe fruit, flowers, and leaves. Three-dimensional (3D) models of the ripe fruit, half-ripe fruit, unripe fruit, flowers, leaves, fruit calyxes (flower calyx), fruit stems (flower stem), and branches were constructed using a 3D scanner, and material mechanics models of the above parts were established based on physical tests with universal testing machines. Detachment simulations and experiments of the ripe fruit, half-ripe fruit, unripe fruit, flowers, and leaves were performed to determine the detachment mechanisms and sequences. The detachment forces of each set of two parts were obtained. The field experiments showed that the detachment force between the fruit and calyx of ripe fruit was the lowest value of these forces, and only the ripe fruit was the first to detach from the calyx when harvesting. The results provided data support on the mechanics properties of wood and the optimization basis for the harvesting method of L. barbarum.
Jian Zhao; Te Ma; Tetsuya Inagaki; Qingyu Chen; Zening Gao; Lijuan Sun; Haoxuan Cai; Chao Chen; Chuanlin Li; Shixia Zhang; Satoru Tsuchikawa; Jun Chen. Finite Element Method Simulations and Experiments of Detachments of Lycium barbarum L. Forests 2021, 12, 699 .
AMA StyleJian Zhao, Te Ma, Tetsuya Inagaki, Qingyu Chen, Zening Gao, Lijuan Sun, Haoxuan Cai, Chao Chen, Chuanlin Li, Shixia Zhang, Satoru Tsuchikawa, Jun Chen. Finite Element Method Simulations and Experiments of Detachments of Lycium barbarum L. Forests. 2021; 12 (6):699.
Chicago/Turabian StyleJian Zhao; Te Ma; Tetsuya Inagaki; Qingyu Chen; Zening Gao; Lijuan Sun; Haoxuan Cai; Chao Chen; Chuanlin Li; Shixia Zhang; Satoru Tsuchikawa; Jun Chen. 2021. "Finite Element Method Simulations and Experiments of Detachments of Lycium barbarum L." Forests 12, no. 6: 699.
With the increase of labor cost and the development of agricultural mechanization, standardized orchards suitable for autonomous operations of agricultural machinery will be a future development trend of the fruit-planting industry. For field-planting processes of standardized orchards, autonomous navigation of orchard vehicles in complex environments is the foundation of mechanized and intelligent field operations. In order to realize autonomous driving and path-tracking of vehicles in complex standardized orchards that involve much noise and interference between rows of fruit trees, an automatic navigation system was designed for orchard vehicles, based on 2D lasers. First, considering the agronomic requirements for orchard planting such as plant spacing, row spacing and trunk diameter, different filtering thresholds were established to eliminate discrete points of 2D laser point cloud data effectively. Euclidean clustering algorithm and the important geometric theorems of three points collinearity was used to extract the central feature points of the trunk, as the same time, navigation path was fitted based on the least square method. Secondly, an automatic navigation control algorithm was designed, and the fuzzy control was used to realize the dynamic adjustment of the apparent distance of the pure pursuit model. Finally, the reliability of the proposed approach was verified by simulation using MATLAB/Simulink, and field tests were carried out based on electric agricultural vehicle. Experimental results show that the method proposed in this study can effectively improve the precision of automatic navigation in complex orchard environment and realize the autonomous operation of orchard vehicles.
Shuo Zhang; Chengyang Guo; Zening Gao; Adilet Sugirbay; Jun Chen; Yu Chen. Research on 2D Laser Automatic Navigation Control for Standardized Orchard. Applied Sciences 2020, 10, 2763 .
AMA StyleShuo Zhang, Chengyang Guo, Zening Gao, Adilet Sugirbay, Jun Chen, Yu Chen. Research on 2D Laser Automatic Navigation Control for Standardized Orchard. Applied Sciences. 2020; 10 (8):2763.
Chicago/Turabian StyleShuo Zhang; Chengyang Guo; Zening Gao; Adilet Sugirbay; Jun Chen; Yu Chen. 2020. "Research on 2D Laser Automatic Navigation Control for Standardized Orchard." Applied Sciences 10, no. 8: 2763.