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Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Moisture content is one of the important indicators in grain harvesting, trading, storage and processing. High moisture content will lead to a series of problems of grain such as mildew, deterioration, shortened storage time, lower transaction price and higher processing cost. With the development of precision agriculture, accurate detection of grain moisture content can also accurately assess the growing situation of crops, and then provide guidance for the next season’s crop planting. Compared with the drying method, the capacitance method and the electric resistance method, the microwave method is easy to realize the non-destructive measurement of the grain moisture content, which is an important direction of moisture content detection. In the field of on-line detection of moisture content of rice and wheat in combine harvesters, foreign related research started earlier, and enterprises have commercialized, but this technology is still in the research stage in China. Aiming at the problem that the rice-wheat combine harvester is difficult to accurately measure the moisture content of wheat and rice during harvesting operation, this paper studied a non-destructive on-line detection method of grain moisture content based on microwave reflection method, established the grain moisture content measurement model, designed a non-destructive on-line detection device for grain moisture content used on rice-wheat combine harvesters. The device used a 450 MHz microwave measurement module to measure the moisture content of rice and wheat non-destructively. The voltage conversion circuit was designed to convert microwave parameters into voltage signals, and the average filtering algorithm was used for signal filtering to reduce the impact of interference factors. Finally, the moisture content detection model of rice and wheat, which was established by the calibration experiment, was used to calculate the moisture content. The calculation result was displayed on the display in real time via CAN bus communication. Due to the insufficient installation space in rice-wheat combine harvester, the structure of the detecting device was designed and optimized, and the circuit portion and the sampling mechanism were integrated in a compact structure. Based on the above theoretical research, technology development and structural design, this paper carried out laboratory static experiments and field harvesting experiments. The laboratory static experiment used rice and wheat to illustrate the establishment process of the grain moisture content detection model: 30 groups of rice and 30 groups of wheat samples were prepared, moisture contents and voltages calibration experiment was completed, the rice and wheat moisture content detection models was established and the experimental results were analyzed. The field harvesting experiment was verified the practicability and reliability of the grain moisture content detecting device with rice as the test object. The experiment results show that the performance standard deviations of the laboratory static experiment and the field harvest experiment are 0.458 3 and 1.078 0, respectively, and the relative error are around 2.5% and 5%, respectively. Moisture content measuring range of the detection device for rice and wheat is 14%-34%, which meets the project requirements. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Grain loss rate is one of the most important performance index of corn head in mechanized harvesting. Seed harvesting is the main development direction of mechanized corn harvesting. The characters of seed harvesting corn variaty increased the urgency to reduce grain loss on corn head. The paper was proposed to solve the problem of grain loss on corn head. Theoretical analysis was conducted to the snapping process. Corn ear was subjected to pull force by the snapping rolls and the pull force transferred by corn stalk. Corn kernels were divided into 2 types due to their force condition. A kernel at the bottom end of corn ear was subjected to reaction forces by stripper plates, corn cob and the adjacent kernels and shear force by the pedicel. Kernels out of contact with the stripper plates were subjected to reaction forces by the adjacent kernels, pull force and shear force by corn cob. As the impact force was related to the impact time according to the theorem of impulse, the paper analyzed collision model between corn ear and stripper plates in the snapping process. A mathematical model was obtained about the impact time and intrinsic parameters of the system. The impact time was dependent on system mass, stiffness coefficient and damping coefficient, which lays on the mechanical structure and materials of collision objects. So, the impact force would decrease as the impact time could be prolonged by reducing the stiffness coefficient and raising the damping coefficient. The quantity of shed kernels could be reduced consequently. The paper proposed a corn head with wheel type rigid-flexible coupling snapping device to reduce loss. The corn head consisted of the frame, gear-box, snapping rolls, gathering chain, wheel type rigid-flexible coupling snapping device, and chain wheels. The wheel type rigid-flexible coupling snapping device consisted of snapping wheel axle, spring seat axle, supporting axle, buffer spring, and snapping wheel frame. Force analysis was conducted on the snapping wheel. According to the force conditions and dimension boundary condition, the structure diameters of snapping wheel, snapping wheel frame, and buffer spring were confirmed. In order to obtain the optimal parameters with the minimum loss rate of wheel type rigid-flexible coupling snapping device, the optimization experiments were conducted of the factors at 3 different levels. In the optimization experiments, the snapping wheel radius was designed at 10, 15 and 20 mm respectively, the flexible body thickness was at 2, 4 and 6 mm respectively, the snapping rolls rotating speed at 700, 800 and 900 r/min respectively. The Response Surface Analysis method was used to design the experiments. The software Design-Expert 8.0.6.1 was used to analyze the data. Regression equation was induced according to the experiment and analysis above. The optimal combination of wheel type coupling snapping device was as follows: The snapping rolls rotating speed was 700 r/min, the snapping wheel radius was 15 mm, the flexible body thickness was 4 mm. Verification contrast test was conducted between corn head with wheel type rigid-flexible coupling snapping device and the one with snapping rolls and stripper plates on corns at different moisture contents. As the kernels moisture contents were 21.8%, 16.7% and 13.4%, the grain loss rate decreased 53.4%, 48.6% and 47.0% respectively. This study provides not only theoretical basis but also design reference for the improvement of corn harvester design. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recently, as scientific research has been further explored, the health care functions of the Lycium barbarum (L. barbarum) in anti-oxidation, anti-aging, anti-fatigue, protecting liver, improving body immunity, eye protection and other aspects have been further confirmed. Its unique and nutrient-rich health function is recognized gradually in western countries, and the market demand of the L. barbarum is expanding each year. The L. barbarum blooms and bears fruit continuously during the growing season which begins in mid-May. Depending on the picking time around the year, the L. barbarum fruit can be divided into spring, summer and autumn fruit. In order to make dried L. barbarum keep good commodity characters, the L. barbarum is harvested at 80 percent maturity. The full bearing period of L. barbarum is from May to September every year, which is the picking peak of L. barbarum. It must be picked once about every 7 days. For centuries, the mechanized harvesting of L. barbarum has been a tough problem. Its harvesting has been artificial, which brings about low picking efficiency and high harvesting costs. With the continuous expansion of L. barbarum acreage, fruit picker has been increasingly scarce, which will be followed by rising picking costs. It's no doubt that the picking has become the bottleneck restricting the development of L. barbarum industry. Aiming at realizing the harvesting mechanization of L. barbarum and establishing the theoretical guidance and design basis for the L. barbarum picking machine, the vibration picking mechanism of L. barbarum plant's fruiting branches in picking was studied, the parameter optimization and simulation analysis was done to determine exciting force vector and rotational speed of driving wheel, and an experiment was conducted to prove the obtained rotational speed of driving wheel in this paper. First, we analyzed the working principle of the picking machine to get the vibration picking mechanism. The fruiting branches' model was simplified and the L. barbarum plant's fruiting branches' physical model and mathematical model were got, which were solved by equation solutions. We then obtained the forced vibration response of the fruiting branch and the forced vibration picking inertia force exerted on ripe and unripe fruits and flowers on each node. Second, 10 L. barbarum trees were selected as the test samples. We measured the binding force and mechanical parameters of the L. barbarum and fruiting branches, such as the number of ripe and unripe fruits and flowers, diameter, length, elastic modulus, damping ratio of fruiting branches, and node number. Based on the principle of successful picking which is the ripe can be picked and the other parts wouldn't be picked, the parameters were optimized, and the inertia force changes of the fruits and flowers with rotational speed were simulated with the MATLAB software. Simulation results showed the reasonable rotational speed was 2 868.84-2 871.21 r/min. Finally, rotational speeds of 7 levels which came from the interval and beyond the interval were selected in the experiment. Using a self-developed experimental L. barbarum picking machine, the test was conducted at planting base of L. barbarum of Ningxia Academy of Agriculture and Forestry Sciences, and the fruit distribution before and after picking was compared. Experiment result showed that reasonable rotational speed was 2 870 r/min, which is within the reasonable simulation interval of rotational speed. Under this rotational speed, picking efficiency of ripe L. barbarum was 815 grains per minute, the picking rate of ripe fruit was 86.70%, the picking rate of unripe fruit was 7.36%, and the picking rate of flower was 7.43%. The damage rate of fruit was 8.62%. The efficiency ratio of machine to worker was 5.43. Due to the actual picking environment, this result differs from simulation conclusion that the ripe is picked totally and none of the unripe and flowers is picked. The results can provide a reference for the development of L. barbarum vibration picking machines. [ABSTRACT FROM AUTHOR]

Due to long stubble remained in farmland after harvesting as well as hardened and impervious soil in southern farmland of China, the tillage and land preparation parts of multifunctional rape-planting machine tend to wind grass and obstruct with mud, which impairs the working performance of ridging equipment and reduces the percentage of rapeseed seedling germination. In order to solve these problems, a rapeseed planting method is proposed, which combines the straw mulching cultivation with the direct seeding. The method is used to collect and cut the rice stubbles, and then the chopped rice stubbles are evenly covered on the inter-row spaces without involving the tillage apparatus. A multifunctional rape-planting device is mounted to a rice combine-harvester by replacing screening device, using the original harvester header to collect the rice stubbles and replacing the threshing cylinder to chop and scatter the rice stubbles. In this paper, an air-assisted chopping mechanism was designed, in which the moving knives and the transplanting blades were coaxially installed. The performance of the air-assisted chopping mechanism was evaluated by simulating the chopping operation of "stalk-standing" and "crop residue" in farmland through a bench test driven by an electric motor. A quadratic orthogonal rotating experiment was designed by Design-Expert software. Based on the variance analysis and regression fitting, a multiple regression equation was obtained, showing the effects of the rotating speed of feeding press rolls, the rotating speed of rotation shaft of moving knives and the gaps between moving knife and stationary knife on the qualified rate of chopped stalk length and the power attenuation. It was shown that the rotating speed of rotation shaft of moving knives had the most influential effect, followed by the gaps between moving knife and stationary knife, and the rotating speed of feeding press rolls had the least effect on the qualified rate of chopped stalk length and the power attenuation. The response surface method was applied to optimize the operation conditions. The optimum factors for "stalk-standing" and "crop residue" chopping operation were as follows: The rotating speeds of feeding press rolls were 399.2 and 401.64 r/min, the rotating speeds of rotation shaft of moving knives were 968.12 and 977.23 r/min, and the gaps between moving knife and stationary knife were 0.52 and 0.49 mm, respectively. Under the optimal condition, the corresponding qualified rates of chopped stalk length for "stalk-standing" and "crop residue" were 95.89% and 97.09%, as well as the power attenuations were 3.04 and 2.6 kW, respectively. The differences between the experimental and the software analytical value of the qualified rate of chopped stalk length for "stalk-standing" and "crop residue" were both 0.11% and those of power attenuation were 0.05 and 0.08 kW, respectively, which indicated that the software analytical value was in great agreement with the experiment value. Based on the theoretical analysis, the higher qualified rate of chopped stalk length could be achieved under the faster rotating speed of rotation shaft of moving knives and the smaller gaps between moving knife and stationary knife. Taking into consideration the existing form of rice straw in farmland, the rotating speed of feeding press roll was designed to be 401.64 r/min, the rotating speed of rotation shaft of moving knife 977.23 r/min, and the gap between moving knife and stationary knife 0.49 mm. It can provide technical support for the design of rapeseed planter with the combination of straw-mulching cultivation and direct seeding. [ABSTRACT FROM AUTHOR]

Sweet potato is a crop which is drought-resistant, tolerant of poor soil, and owns increasingly enormous potential. It is an important foodstuff, a raw material for starch industry, a kind of health food to prevent cancer and a new raw material for energy as well. The sweet potato planting area in China per year on average is usually 3 667 000 hectares, accounting for 45% of the world's planting area. As sweet potato vines are very long and broomy, the vines must be cleaned up before sweet potatoes are harvested, otherwise are unable to be harvested. Vine crushing and returning machine is usually the dominant form adopted to clean sweet potato vines internationally, but the problems existed in this type of machine were obvious such as low smashing proportion and more stubble residue on the top ridge. New problems have been brought by long stubble such as blocking, larger load and worse smooth working property. Aiming at these problems, the machinery and agronomy should be combined, in order to prove mechanical properties of sweet potato vine and stalk during harvest and working quality of sweet potato vine crushing and returning testing machine. In this paper, the types of fresh purple sweet potato Ningzi 1 and Ningzi 2 in Nanjing, Jiangsu Province were regarded as the tested subject, the electronic universal testing machine, electric drying oven with forced convection, and sweet potato vine crushing and returning testing machine etc. were applied, and the change of moisture percentage and shear strength of sweet potato stalk during harvest were studied. The results showed that at the beginning of experience harvest period, when the percentage of moisture were 81.5% and 78.1%, the shear force were 90.1 and 94.8 N, respectively, during 18 testing days the moisture percentage of sweet potato stalk reduced by 14.8% and 13.97%, respectively, but the shear force of stalk increased by 36.3 and 37.5 N respectively, which showed that the moisture percentage of sweet potato stalk was lower and the shear force was larger as the growth time of plants went on. The internal relations between mechanical crushing quality and percentage of moisture, shear strength were revealed: during the testing period of 18 days, the qualified rates of vine's crushing length for sweet potato type Ningzi 1 and Ningzi 2 dropped by 6.3% and 6.7% respectively, stubble length on top ridge increased by 3.6 and 4.4 cm respectively, which showed that with the increasing of the growth period and the rising of stalk's shear force, the working quality of sweet potato vine crushing and returning machine declined. The quadratic function regression equations on the change between shearing force and moisture percentage of the two types of fresh purple sweet potatoes' stalk were obtained with Matlab when the percentage of moisture was 86.92%-70.08%, and the fitting coefficient of determination R² both reached above 0.99. From the point of increasing the quality of mechanical smashing and mechanical work, it was put forward that the most suitable time of mechanical crushing for the two kinds of purple sweet potatoes during harvest was about 6-8 days, which was a relatively short time. The results offer the direct basis for parameter design of new sweet potato vine crushing and returning testing machine such as machine speed, cutter linear velocity, and also provide the important reference for the selection of suitable harvest period and cultivation agronomic research that fits for machinery operations. [ABSTRACT FROM AUTHOR]

The stem tip of vegetable sweet potato is an excellent nutritious and healthy food, which is widely used in many countries. It’s estimated that the total value of Chinese vegetable sweet potato’s market is about tens of billions of yuan, which means it has a promising future. Due to the difficulties of the long harvest period, high harvest requirement, and low mechanized level, the high cost and low efficiency in harvest is prominent. As such, it decreases the motivation of the farmers deeply. Also, the market still has a strong need for the stem tip harvester urgently. In order to fill the blanket in the mechanized harvest on stem tips of vegetable sweet potatoes in China, and to solve the current problems, in this research, we designed a stem tip harvester for vegetable sweet potatoes in combination with agronomy, which was composed of the reeling, cutting, conveying and collecting devices. It could finish cutting, conveying and collecting the stem tips for vegetable sweet potatoes every single row in one operation. In this paper, we introduced the harvester’s working theory based on analyzing the whole machine’s mechanical structure. To improve the integrity rate of stem tip, to lower the missing rate in cutting, to lower the stubble height and to improve the harvester’s working quality, we did a test on the harvester’s working parameters, using Box-Benhnken's central combination test method based on the single factor test. Three-level quadratic regression orthogonal experimental design was done through the forward speed, the reel speed and the reciprocating cutter line speed. The model of response surface was established to research and analysis the machine’s working quality due to different factors. Finally, the optimization of machine operation parameters was realized. The results showed that the prominent order in the stem tips’integrity rates was the reel speed > the reciprocating cutter line speed > the forward speed. The prominent order in the stem tips’missing rate was the forward speed > the reciprocating cutter line speed > the reel speed. The prominent order in the stem tip’s stubble height was the reel speed > the forward speed > the reciprocating cutter line speed. In 2019, the test was done in three times to verify the model’s correction in Baiba test base, Nanjing Research Institute for Agricultural Mechanization. The field test results showed the optimal working parameters were the forward speed 0.38 m/s, the reel speed 26 r/min, and the reciprocating cutter line speed 0.60 m/s. The integrity rate of stem tips was 97.10%, the missing rate was 12.11%, and the stubble height was 62.09 mm. The error was in the range of 5% compared to the theoretical optimization. Compared with the single manual picking efficiency of 0.001 hm²/h, the operating efficiency of this machine can reach 0.1 hm²/h, The operation effect of the machine was obviously improved compared with that of manual operation, better to meet the requirements of the vegetable sweet potatoes’stem tips machinery harvesting. The test research supplies a strong support and theoretical basis to the mechanical development of the harvester for vegetable sweet potatoes’stem tips. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the combination of finite element modeling and experiment was used to study the effects of different vibration parameters such as vibration time (A), amplitude (B) of the vibration excitation point on apricot tree vibration and vibration frequency (C), and optimize the performance of forest fruit vibration harvesting prototype. The effects of different vibration parameters on the vibration detection points of apricot trees were analyzed by vibration response test. The response analysis of apricot tree free modal vibration using ANSYS Workbench software showed that apricot trees had typical free modal responses at 15, 26, 30 and 40 orders, the corresponding frequencies were 5.5, 10.5, 15.1, and 29.3 Hz, respectively; and the maximum displacement deformation of fruit trees was 286.5, 261.9, 267.2, and 273.5 mm, respectively. The typical free modal cloud image analysis showed that the typical free modalities of the 15th and 26th orders were higher in the terminal end responsiveness of the apricot branches. The 30th order fruit tree had a high overall response consistency, and the apricot tree had the largest deformation response at the end; at the 40th order of 29.3 Hz, some branches of the fruit trees were severely deformed, and the overall structure of the tree was easily destroyed. The optimal response frequency of apricot tree vibration harvesting ranged from 0 to 20 Hz. The harmonic response analysis showed that in the optimal frequency range, the acceleration of the same position increased with the increase of the excitation amplitude at the same frequency, but the overall variation of the vibration curve was consistent with the trend; When the amplitude of the vibration excitation point of the apricot tree was 5, 10 and 15 mm, at the same frequency, as the excitation amplitude increased, the acceleration at the same position increased, but the overall variation of the vibration curve was consistent with the trend. The three-factor and three-level vibration response tests were conducted to study the effects of vibration time, vibration frequency and excitation point amplitude on the acceleration of three different detection points. The multivariate regression analysis of variance showed that the accelerations P1 and P2 of detection points 1 and 2 were less than 0.000 1, the overall model was highly significant (P<0.01), and the model regression terms B and C were significant. The acceleration P3 of the detection point 3 was 0.000 1, and the overall model was highly significant (P<0.01), except that the acceleration P3 value of the detection point 3 of the model regression terms AB, AC and A2 was not significant (P>0.05), and other regression terms were significant (P<0.05). The factors which affected the acceleration of the detection points 1 and 2 were the same as the amplitude of the excitation point, vibration frequency and vibration time. The order of the magnitude of the acceleration affecting the detection point 3 was the vibration time, the amplitude of the excitation point, and the vibration frequency. Through the response equations of the three detection points, the coefficient of determination R2 of the regression equations from the bottom to the top three detection points were 0.906 7, 0.879 3 and 0.973 3, respectively. Using the Design-Expert 10.0.3 software to optimize the detection point response equation, the optimal vibration recovery parameter combination was that the vibration time was 7.207 s, the vibration frequency was 15 Hz, and the amplitude of the excitation point was 10 mm. The verification test showed that the acceleration from the bottom to the top of each detection point was 10.4, 10.2 and 9.3 g, which was similar to the optimized value. These conclusions can provide design and theoretical basis for the design of mechanical parameters of apricot vibration harvesting. [ABSTRACT FROM AUTHOR]

Fruit and vegetable picking grippers are important technology to achieve rapid and labor-saving harvest. However, most of the existing fruit and vegetable picking grippers still use traditional rigid or underactuated grippers, which often cause fruits and vegetables damage by the heavy mass and lack of high-precision control, and have poor compliance in the operation process. In recent years, inspired by soft creature’s tentacles, soft robotic grippers have appeared and been used in robotics due to the emergence of soft robots. Soft robotic gripper, which is made of flexible material, is a new type of gripper for general purposes with grasping and holding capabilities enabled by a simple control scheme. Under the infinite degrees of freedom, the soft robotic gripper can change its shape and size corresponding to the load in a large range. These advantages overcome the defects of traditional fruit and vegetable picking robots, such as rigidity and poor adaptability. Moreover, soft robotic gripper is easy to manufacture and can be integrated with manual operation without any large-scale safe requirement. This paper gives a research on limitations of the traditional grippers and summarizes the characteristics of ideal picking grippers of fruit and vegetable. In addition, the concept of soft robotic grippers is introduced in detail, and the current development status about soft robotic grippers is described. The manuscript also summarizes the progress and superiority of soft robotic grippers in fruit and vegetable picking as well as strong adaptability to the environment. The characteristics of the soft robotic grippers driven by the common driving mode including pneumatic, cable, shape memory alloy and electroactive polymer mode have been analyzed in the process of fruit and vegetable grasping and picking. Compared with the rigid grippers, in addition to the simple control and mechanism, the soft robotic grippers have high-degree flexibility, adaptability and versatility. Based on the related work, the problems of modeling and control of fruit and vegetable picking devices have been discussed, and possible solutions of soft robotic grippers are also summarized by means of analysis and classification. We can choose the appropriate control methods according to the surface characteristics of picked fruits and vegetables. Finally, we conclude that multi-sensing, variable stiffness, multi-functional composite materials, as well as control strategies of fusion intelligence will be future development directions of fruit and vegetable picking grippers with the progress of micro-sensors and biomaterials. This research will provide theoretical and technical guidance for the development of fruit and vegetable picking grippers. It is expected that more fruit and vegetable picking operations could be carried out by soft robotic grippers, and the application will effectively reduce the damage rate of fruit and vegetable picking. As a new-generation operating device, the soft robotic grippers involve the development of materials, chemistry, machinery and other multidiscipline. Further studies are required to improve its design, controllability, manipulating methods, and so on. [ABSTRACT FROM AUTHOR]

Overlapped apples are common in natural scenes, and they can seriously affect the execution of picking task. Accurate segmentation of overlapped apples is one of the key problems that picking robot must solve. As the existing overlapped apples segmentation methods could not retain the contour of overlapped parts, a new method of segmenting overlapped apples was proposed in this paper. The steps of the algorithm were as follows: Firstly, the image was processed with morphological opening operation using disk-shaped structural element with the radius of 5 pixels so as to ensure the data information consistent in small area and to make the image more smooth. In order to distinguish the target and the background automatically, the image was then transformed from RGB color space into L*a*b color space. Then -means clustering method was used to segment images to extract apple region. Secondly, in order to extract accurate and entire contour of apple region and keep the contour of overlapped part simultaneously, Normalized Cut (Ncut) method was adopted. To ensure the accuracy of Ncut algorithm, the cluster number was chosen as 5. Thirdly, contour segmentation method was used to extract contour of each apple. The procedures of contour segmentation method were as follows: 1) The extracted contours were connected by simply using eroding operation in order to avoid disconnection at intersection of contours of 2 adjacent apples; 2) Refine the connected contour and search three cross point, then break off the contour at three cross point by assigning zero at three cross point, and 3 contours could be got; 3) Add the 2 contours whose bending directions were opposite, and this was the contour of unblocked apple and the other contour was the contour of blocked apple. Lastly, Spline interpolation method was used to reconstruct the contour of blocked apples. In order to verify the validity of this algorithm, 20 images of adjacent apples were used to conduct the experiment, and the result was compared with the comparison method. The comparison method is a method that uses the connection line of 2 concave points to segment overlapped apples, and then utilizes the Hough transform method to reconstruct the contour of apples. The experimental results showed that for unblocked apples in apple images, average segmentation error of the presented method was 3.15%, 7.73% less than that of comparison method (10.88%). Average overlap ratio of the presented method was 96.08% and was increased by 9.71% compared to comparison method (90.85%). In addition, this method could keep the complete contour information of unblocked apples and thus improved segmentation accuracy effectively. For blocked apples, average segmentation error and average overlap ratio were 5.24% and 93.81%, respectively. The segmentation error was decreased by 11.35% and average overlap ratio was increased by 12.74% compared to comparison method, which indicated that the method could reconstruct contour of blocked apples well. In conclusion, the presented algorithm is feasible to segment and reconstruct 2 overlapped apples without blocking by branches and leaves. However, for the images of overlapped apple blocked by branches and leaves, the images of more than 2 overlapped apples, and the images of 2 overlapped apples unblocked by branches and leaves with unclear contour at overlapped part, this method cannot complete the segmentation, and thus further research would be needed. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)