| Transplanting can make the crops growing early, increasing the yield each area, and withstand the adverse weather effectively, such as strong wind, rain damage, and low temperature in the seedling stage. The transplanting was influenced and limited by the equipment developmental level and adaptability, the main work of transplanting are rely on manual transplanting and semiautomatic transplanter, and it cannot be completed timely and effectively in a large area of transplanting, the semiautomatic transplanting picking seedling by manual, even though there are some improvement of working mode and labor intensity, feeding seedlings by manual is low speed, and needs more support personnel, the benefit of mechanization is not obvious. Auto-transplanter can be a very good solution to solve current problems of high labor intensity, low efficiency. It was widely considered to be the future direction of development by the domestic and foreign counterparts, so research on transplanter automatic feeding system will promote the automatic transplanter technology development in china.(1) Analysis the current development situation about domestic and foreign auto transplant, and introduce research contents. The research background and significance of the seedling transplanting automatic feeding system were introduced, the development status of the automatic picking seedling device and automatic transplanting mode were summarized including domestic and foreign, the key mechanism and principles of the greenhouse transplanting and the field transplanting were analyzed, and the problem of the automatic picking and feeding was raised that this technology must be development in our country. After comparing the several typical automatic picking styles of domestic and foreign, and combining the exists semiautomatic transplanter styles and existing problems which were used commonly in our country, the research target was determined of developing the automatic picking and feeding seedling system, and the implementation of the specific content were subdivided.(2) Characteristics measurement about pepper seedlings. The development of seedling technology was analyzed, the plug seedling form, features and application were introduced, the common used plug sizes were summarized, and the advantages of the plug seedling raising were generalized. By measuring the morphology characteristics of pepper seedlings, it resulted the suitable heights of plug seedling in the transplanting time is 150-200mm, the diameters of stalks is 1.56-2.06mm, varying height and stem are similar, the leaf in the middle is the longest, the lower part was short slightly, and the top leaf is shortest. The mechanical characteristic test showed the seedlings substrate were lost obviously more when the seedlings dropped from high position, and the second time is more than the first time; the loss rate of the plug seedling with high water content ratio was higher than the plug seedling with low water content ratio. The drop test shows the seedling substrate will be deformation obviously when the plug seedling dropped height than 400mm, and the stem will be bended because of the impact; the substrate appearance changes were not obvious when the heights were 200mm and 300mm, and the stem were not bending.(3) Automatic feeding system design steps and basic requirements. The typical automatic feeding device and the transplanter were analyzed, the layout and basic requirements of the automatic picking and feeding system were proposed which were suitable for the nacelle punch transplanter, the working theory on designing the automatic picking and feeding system was put forward, mechanical picking seedling is desirability and automatic feeding system units can be decomposed design, the design technique route was definite, and the overall design of the transplanter automatic feeding system is divided into 3 modules, which were the plug seedling stepping and shifting device, the seedling picking manipulator, and the seedling feeding device, the basic design requirements were proposed.(4) Tray step shift device design and test. The existing plug shifting devices were compared, the advantages and disadvantages were analyzed and compared, the basic scheme of interval picking seedling was determined, and the shifting rule of the plug-in the style of the letter "n" was planned; the plug stepping and shifting device being fit for 128 holes was designed, the detail of the plug latitude direction shifting, the plug longitudinal direction shifting, and the plug holding device were designed, the structure of the device was determined that the latitude direction shifting being driven by the double bar cylinder TN25×40 and the longitudinal direction shifting being driven by the adjustable cylinder SDAJ32×60-40, and the cylinder driving force meet the requirements by calculation. The test scheme was designed, the functional inspection and movement accuracy test were carried out for the plug stepping and shifting device, and taking the operation air pressure, plug posture, and plug load as influencing factors, the test indices were the deviation of the plug latitude direction shifting at left and right sides, and the movement distance of each step in longitudinal direction, the orthogonal experiment was used to arrange the tests for the plug stepping and shifting device, the experimental data were analyzed by variance method, and the result is the operation air pressure having obvious influence to the plug stepping and shifting device, and the plug posture and load having no obvious influence to the movement accuracy.(5) The design and test of turnover-displacement-style seedlings manipulator. The existing take seedling methods were compared and analyzed, the mode of picking seedling was determined to use plunge type, the design scheme of the single picking unit in automatic picking and feeding system was laid down, and picking seedling be approved by simple seedling picking unit test, with the help of computer electronic testing machine, the plunge required force was measured less than 2N when flexible slide needle into substrate. Based on the principle of the seedling picking unit, the combined seedling picking manipulator was designed which is picking multi plug seedlings at the same time, after calculation the required force for driven the manipulator, the cylinder which was fit for driving manipulator was selected out. and it was checked the cylinder driving force meeting the requirements of pricking seedling. Taking the seedling picking manipulator as core, the turnover-displacement-style seedlings manipulator was designed, the sequence of movement of the turnover-displacement-style seedlings manipulator was determined, the mechanism freedom was calculated, and the relationship was given between the angle of manipulator should be kept and the arm length, arm swing angle. The manipulator route was verified by using the software of ADMAS to simulate the movement of the manipulator and swing arm. Let the operation air pressure, exhaust control, and orientation bar as test factors, the accuracy of manipulator position are measured and analyzed using orthogonal test method, and the result is the orientation bar having obvious influence to the movement accuracy.(6) The design and test of flexible chain transportation feeding mechanism. The active and passive valve opening modes were compared, the passive valve was determined for the flexible chain transport feeding device, the pose of seedlings dropping into tube were observed by high-speed camera, single and 45 degree valve as the seedling tube valve opening form was decided. The flexible chain transport feeding device was designed, and the special chain and swing motor were selected out, the interrupt driving was realized through the swing motor and the ratchet-pawl, it was checked the driving force of the swing motor meeting the driving requirements. The flexible chain transport feeding device was tested when the air pressures at 0.4Mpa,0.45Mpa,0.5Mpa,0.55Mpa, and 0.6Mpa, and the causes of error were analyzed, flexible chain transport feeding device vibration acceleration were measured by LMS multifunction data collection system and acceleration sensor, and vibrating seedling in tube in a cycle was shown.(7) The drive control and performance test on automatic feeding system for seedlings transplanting. The whole seedling automatic feed system was designed, the basic properties of automatic feed system requirements were determined, and driving scheme for automatic feeding system was designed, pneumatic drive system was decided; the total air consumption of automatic take feeding system was calculated which is 60.56L/min; the models for the control were selected out, such as PLC hardware, sensor, and magnet switch, the control procedure and flow of the system was planned, the sequence of automatic picking and feeding system control time was compiled, all movements and functions of the automatic picking and feeding system were realized. According the test, the system reached the design objective of 70 pieces/min, the substrate loss rate of picking seedling was less than 10%, the general seedling picking reliability of the automatic picking and feeding system reached 98.92% in laboratory test. |
PDF Full Text Request