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A pneumatic oscillating Chinese wolfberry harvester was designed to improve the efficiency of manual harvesting and minimize fruit damage by mechanical harvesting. The shedding model of Chinese wolfberry under pneumatic forces was established based on kinetic analysis, and the flow field characteristics were investigated using computational fluid dynamics (CFD). The position and shape of the fan outlet were determined by comparing the effects of a linear reduction outlet and a Laval reduction outlet on the outlet airflow rate. The size of the oscillating mechanism was optimized with nonlinear constraints to achieve uniform oscillation of the airflow. A three-factor, three-level orthogonal test was conducted on the NingQi 7 wolfberry variety. The flow rate at the outlet, the oscillation frequency, and the outlet distance were the test factors, and the net harvesting rate of ripe fruits, the harvesting rate of green fruits, and the damage rate of ripe fruits were the test indices. The results showed that the net harvesting rate of ripe fruits was 85.21% at an outlet distance of 10 cm, an outlet flow rate of 70 m·s−1, and an oscillation frequency of 2 Hz. This study provides references for the design of pneumatic harvesters for Chinese wolfberry.
Yun Chen; Jian Zhao; Guangrui Hu; Jun Chen. Design and Testing of a Pneumatic Oscillating Chinese Wolfberry Harvester. Horticulturae 2021, 7, 214 .
AMA StyleYun Chen, Jian Zhao, Guangrui Hu, Jun Chen. Design and Testing of a Pneumatic Oscillating Chinese Wolfberry Harvester. Horticulturae. 2021; 7 (8):214.
Chicago/Turabian StyleYun Chen; Jian Zhao; Guangrui Hu; Jun Chen. 2021. "Design and Testing of a Pneumatic Oscillating Chinese Wolfberry Harvester." Horticulturae 7, no. 8: 214.
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.
In this study, we established an effective finite element model for branch-stem-fruit systems to: (i) simulate responses under different loads; and (ii) intuitively predict the breaking process of branch-stem joints. The constitutive parameters of fruit branches and apple stalks were measured based on the orthotropic transverse constitutive model. Moreover, the maximum traction force, maximum traction displacement and specific fracture energy of the abscission zone were estimated based on the cohesive zone model (CZM). The experimental and simulation results of the branch-stem sample tensile process and horizontal pull test demonstrated the more effortless ability of the tangential load to detach the fruit. Moreover, compared with the horizontal pull tests and simulation results, the maximum relative deviation was less than 10%, revealing that the branch-stem-fruit finite element model can accurately reflect the process of fruit detachment. This research provides a reliable finite element model of the branch-stem-fruit system for future studies on apple harvesting through tree shaking or robotic apple harvesters.
Lingxin Bu; Chengkun Chen; Guangrui Hu; Jianguo Zhou; Adilet Sugirbay; Jun Chen. Investigating the dynamic behavior of an apple branch-stem-fruit model using experimental and simulation analysis. Computers and Electronics in Agriculture 2021, 186, 106224 .
AMA StyleLingxin Bu, Chengkun Chen, Guangrui Hu, Jianguo Zhou, Adilet Sugirbay, Jun Chen. Investigating the dynamic behavior of an apple branch-stem-fruit model using experimental and simulation analysis. Computers and Electronics in Agriculture. 2021; 186 ():106224.
Chicago/Turabian StyleLingxin Bu; Chengkun Chen; Guangrui Hu; Jianguo Zhou; Adilet Sugirbay; Jun Chen. 2021. "Investigating the dynamic behavior of an apple branch-stem-fruit model using experimental and simulation analysis." Computers and Electronics in Agriculture 186, no. : 106224.
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.
The accurate quantitative maturity detection of fresh Lycium barbarum L. (L. barbarum) fruit is the key to determine whether fruit are suitable for harvesting or not and can also be helpful to improve the quality of post-harvest processing. To achieve this goal, abnormal samples were eliminated by the Mahalanobis Distance (MD), and nine components (i.e., R, G, B, H, S, V, L, a, and b) of the ripe fruit, half-ripe fruit, and unripe fruit were extracted, firstly. Then, significant component combinations of the three fruits beneficial to the extraction of their areas were determined. Through binary processing, morphology processing, and other image processing methods, a quantitative maturity detection model of fruit was established based on the support vector machine (SVM) model. On this basis, field experiments were conducted to verify and compare the relationship between the prediction results of the model and the picking forces of fruit. Field experiments showed that the accuracies of both the training set and prediction set were 100% and the prediction results of the model were consistent with the picking forces of fruit. Findings provided a theoretical basis for the accurate quantitative maturity detection of fresh L. barbarum fruit.
Jian Zhao; Jun Chen. Detecting Maturity in Fresh Lycium barbarum L. Fruit Using Color Information. Horticulturae 2021, 7, 108 .
AMA StyleJian Zhao, Jun Chen. Detecting Maturity in Fresh Lycium barbarum L. Fruit Using Color Information. Horticulturae. 2021; 7 (5):108.
Chicago/Turabian StyleJian Zhao; Jun Chen. 2021. "Detecting Maturity in Fresh Lycium barbarum L. Fruit Using Color Information." Horticulturae 7, no. 5: 108.
The application of fertilizer to the soil for the subsequent extraction by plants is a method to increase crop production. Fertilizer spreaders with an outer groove wheel (OGWFSs) have a large volume, and current metering devices are suitable for precision farming systems. However, the study of OGWFSs has shown that fertilizer metering is impaired due to sudden releases of fertilizer batches. Research has shown the performance advantage of using a pin-roller metering device whose pins are configured in the form of a truncated pyramid. This configuration not only provides highly uniform fertilizer discharge but is also advantageous for use with wet fertilizers and prevents clogging. In this study, an orifice was added between the pins to increase the working volume of the metering device and the amount of fertilizer discharge. The uniform distribution of the fertilizer particles and the amount of fertilizer discharge depends on the pin parameters. Therefore, the objective of this study was to determine the pin-roller parameters to increase the uniformity of the distribution and the amount of discharged fertilizer for variable-rate fertilizer applications. The pin-roller configurations that were investigated included the α angle, height of the roller pin, β angle, and radius between two pins for six right and left entry lines. As a preliminary test, 25 pin-roller configurations were designed and evaluated for fertilizer distribution at three rotation speeds of the metering device. The uniformity of the fertilizer distribution was evaluated in a laboratory test, and the coefficient of variation was used as an evaluation index. A compound fertilizer, N-P2O5-K2O, was used in the experiment. The results indicated that different pin-roller characteristics of the metering device had significant effects on the uniformity of the distribution and discharge capacity of the fertilizer. Based on the results of the preliminary test, a new pin-roller design was developed. The performance of this pin-roller was evaluated and compared to that of the OGWFS. The coefficient of variation and the amount of discharged fertilizer was evaluated at three different rotational speeds. The discharge capacity of the new pin-roller was not as high as that of the OGWFS at all rotation speeds of the metering device, but the coefficient of variation was higher for the pin-roller than the OGWFS at lower speeds. However, there was no significant difference in the coefficient of variation between the metering devices at higher speeds.
A.M. Sugirbay; J. Zhao; S.O. Nukeshev; J. Chen. Determination of pin-roller parameters and evaluation of the uniformity of granular fertilizer application metering devices in precision farming. Computers and Electronics in Agriculture 2020, 179, 105835 .
AMA StyleA.M. Sugirbay, J. Zhao, S.O. Nukeshev, J. Chen. Determination of pin-roller parameters and evaluation of the uniformity of granular fertilizer application metering devices in precision farming. Computers and Electronics in Agriculture. 2020; 179 ():105835.
Chicago/Turabian StyleA.M. Sugirbay; J. Zhao; S.O. Nukeshev; J. Chen. 2020. "Determination of pin-roller parameters and evaluation of the uniformity of granular fertilizer application metering devices in precision farming." Computers and Electronics in Agriculture 179, no. : 105835.
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.
Robotic apple harvesting requires the motion planning of a series of movements to perform the efficient picking of fruit without bruises. The investigation of the underlying characteristics of fruit detachment picking patterns is an important basis for robotic harvesters. In this study, four basic picking patterns including horizontal pull, vertical tension, bending and twisting were performed in order to analyze the effects of picking patterns on fruit detachment. The tension parameter, which includes the horizontal pull and vertical tension, was found to be the dominant factor during the detachment process, with the vertical pull possibly leading to the pull-out of the stem. Apples with long stems were observed to require a large displacement and angle to break the branch-stem joint, which subsequently increased the risk of picking failure. Moreover, the detachment caused by the tangential force required a smaller detachment force. A dynamic simulation was performed to identify the optimal picking model, whereby detachment force and detachment time were used as the optimization parameters. The response surface methodology was used to determine the effects of the horizontal and vertical velocity on the detachment force and detachment time. Optimized results indicated the horizontal pull with a bending and twisting motion as the potential optimum combination. These results provide a theoretical basis for future studies on robotic apple harvesting.
Lingxin Bu; Guangrui Hu; Chengkun Chen; Adilet Sugirbay; Jun Chen. Experimental and simulation analysis of optimum picking patterns for robotic apple harvesting. Scientia Horticulturae 2019, 261, 108937 .
AMA StyleLingxin Bu, Guangrui Hu, Chengkun Chen, Adilet Sugirbay, Jun Chen. Experimental and simulation analysis of optimum picking patterns for robotic apple harvesting. Scientia Horticulturae. 2019; 261 ():108937.
Chicago/Turabian StyleLingxin Bu; Guangrui Hu; Chengkun Chen; Adilet Sugirbay; Jun Chen. 2019. "Experimental and simulation analysis of optimum picking patterns for robotic apple harvesting." Scientia Horticulturae 261, no. : 108937.
A 3D scanner was used to reverse engineer a model to assess impact bruising of fresh Goji (Lycium barbarum L.) fruit. Based on the results of physical compression tests, an elastic-plastic model was selected as the material mechanics model for the fruit. A finite element method explicit dynamics simulation was performed to predict impact bruising using Abaqus software. Simulation results showed that fruit were not damaged at a drop height of 0.2-0.5 m, an impact angle of 10–30 °, and with an impact material of wood board, foam board, and nylon board. Using response surface methodology, the effects of drop height, impact material, and impact angle on the bruise rate of fruit were determined. The optimized parameters were a drop height of 0.24 m, foam board as the impact material, and an impact angle of 13.11°. Near infrared hyperspectral reflectance imaging was also applied to this problem, and visualization models were established in Matlab. The field experiment showed a bruise rate was 9.8%. These results provide a theoretical basis for future studies of harvesting, transporting, sorting, grading, and packaging machines designed for use with L. barbarum.
Jian Zhao; Adilet Sugirbay; Yu Chen; Shuo Zhang; Fanyi Liu; Lingxin Bu; Zhiwei Wang; Jun Chen. FEM explicit dynamics simulation and NIR hyperspectral reflectance imaging for determination of impact bruises of Lycium barbarum L. Postharvest Biology and Technology 2019, 155, 102 -110.
AMA StyleJian Zhao, Adilet Sugirbay, Yu Chen, Shuo Zhang, Fanyi Liu, Lingxin Bu, Zhiwei Wang, Jun Chen. FEM explicit dynamics simulation and NIR hyperspectral reflectance imaging for determination of impact bruises of Lycium barbarum L. Postharvest Biology and Technology. 2019; 155 ():102-110.
Chicago/Turabian StyleJian Zhao; Adilet Sugirbay; Yu Chen; Shuo Zhang; Fanyi Liu; Lingxin Bu; Zhiwei Wang; Jun Chen. 2019. "FEM explicit dynamics simulation and NIR hyperspectral reflectance imaging for determination of impact bruises of Lycium barbarum L." Postharvest Biology and Technology 155, no. : 102-110.
Dynamic obstacle detection is the key to ensure the agricultural robots could move autonomously in the non-structural environments. In this study, a method of dynamic obstacle detection based on multi-sensor information fusion is presented by selecting a Compass Equipment, an Inertial Measurement Unit and a 2D laser scanner as the system’s external sensors. A method based on Kalman filter to fuse data from a Compass Equipment and an Inertial Measurement is presented to obtain the position of agricultural machinery. 2D laser scanner has the feature of scanning widely and getting the angle and distance of each obstacle directly. On this foundation, the absolute position and motion state of the obstacle is obtained by the transformation of the relative coordinates. After filtering, clustering and segmentation of laser data by using the method of Voxel grid method and Euclidean method, the absolute position of the same obstacle in the adjacent sampling period is analyzed to distinguish the static and dynamic obstacles. The experiment verify the effectiveness of the algorithm and have certain significance for the realization of autonomous mobile robot.
Liu Meichen; Chen Jun; Zhao Xiang; Wang Lu; Tian Yongpeng. Dynamic obstacle detection based on multi-sensor information fusion. IFAC-PapersOnLine 2018, 51, 861 -865.
AMA StyleLiu Meichen, Chen Jun, Zhao Xiang, Wang Lu, Tian Yongpeng. Dynamic obstacle detection based on multi-sensor information fusion. IFAC-PapersOnLine. 2018; 51 (17):861-865.
Chicago/Turabian StyleLiu Meichen; Chen Jun; Zhao Xiang; Wang Lu; Tian Yongpeng. 2018. "Dynamic obstacle detection based on multi-sensor information fusion." IFAC-PapersOnLine 51, no. 17: 861-865.
Chinese wolfberry is one of the important economic crops in Northwest china. Wolfberry harvest is seasonal and labor intensive, and, the existing various types of Chinese wolfberry harvesting equipment cannot meet the operation requirements. Thus the development of low damage and intelligent equipment is important to guarantee the healthy development of the industry. Many kinds of intelligent recovery equipment need accurate location information of branches of Chinese wolfberry. However, the color of the branches is close to the natural background, and the occlusion is serious, resulting in difficulties in identifying the branches. Aiming at solving these problems, a method of identifying branches of wolfberry based on mathematical morphology and convex hull theory is proposed in this paper. Compared with artificial recognition, the success recognition rate is more than 60%.
Chen Yun; Wang Yalei; Zhao Jian; Chen Jun. Recognition of the position of Chinese wolfberry branches under the artificial background. IFAC-PapersOnLine 2018, 51, 321 -325.
AMA StyleChen Yun, Wang Yalei, Zhao Jian, Chen Jun. Recognition of the position of Chinese wolfberry branches under the artificial background. IFAC-PapersOnLine. 2018; 51 (17):321-325.
Chicago/Turabian StyleChen Yun; Wang Yalei; Zhao Jian; Chen Jun. 2018. "Recognition of the position of Chinese wolfberry branches under the artificial background." IFAC-PapersOnLine 51, no. 17: 321-325.