Design And Experimental Research Of Control System Of Hand-held Vegetable Plug Seedling Automatic Transplanter

At present,the technology of vegetable plug cultivation has been widely promoted due to its high survival rate and short growth cycle.At present,transplanting of plug seedlings mainly relies on manual transplanting,and the cost of artificial transplanting is high,low efficiency and labor intensity.Large,and difficult to ensure quality,at present,China's transplanting machine is mainly semi-automatic transplanting machine,because it still needs artificial feeding,the degree of automation is not high,and still requires a large amount of labor during operation.In addition,because China's vegetable cultivation is mostly greenhouse The transplanting operation is carried out in small areas,and the hand-held transplanting machine has the characteristics of small size,light and easy operation,and is especially suitable for transplanting vegetables in the facility.Therefore,the mechanized and highly automated hand-held vegetable seedlings are fully automatic.The transplanter is of great significance.?1?According to the introduction of the overall structure of the hand-held vegetable plug seedling automatic transplanting machine,the composition and working principle of the tray conveying device,the seedling device and the seedling device of the main control part are expounded.According to its overall working principle,the steps of its workflow are introduced,and the power system of the tray conveying device,the seedling device and the seedling device are selected.?2?According to the torque requirements and precision requirements required for the tray conveying,the stepping motor,the stepping motor driver and the plug-in position sensor are selected;the tray conveying feed includes the initial fast-input in-position and the tray intermittent The two parts of the slow feed are provided,and the parameters are analyzed and calculated.A control method is proposed for the tray transport,and the manual mode is introduced to realize the initial positioning accuracy of the tray;for the precision control of the intermittent seed supply,The photoelectric rotary encoder is introduced as feedback,and the PID control algorithm is used to realize the precise control of the stepping motor.Using the Z-N method to adjust the PID parameters,the optimal parameters are:K_P=37;K_I=18;K_D=0.4.Through the PID module in Xinjie PLC programming software,in the manual PID mode,the parameter sampling time?ms?,proportional gainK_P,integration time_ITand differential time_DTcalculation value are brought into the precise control of the stepping motor rotation angular displacement.?3?Analyze the"plug-in"type seedling movement,according to its work flow,analyze and determine the position of the seedlings,and obtain the damage to the carcass in order to prevent the seedlings under the seedlings from being inserted into the seedlings.The up/down sensor B should be triggered when the needle is inserted into the body 4 mm.Analyze the effect of seedling height on early seedlings,in the range of planting frequency of 40-60 plants/row/min,from the upper edge of the seedling seedlings to the free fall of the upper edge of the rotating seedling cup,the rotating seedlings The line displacement range of the cup is 13-20mm;the implementation method of adaptive planting control of planting frequency is analyzed,that is,when the seedling position is 13.5mm with respect to the center of the rotating seedling cup,the micro-motion The switch triggers as the timing at which the seedling is judged.?4?Using the LW26-20 three-speed three-section series-parallel transfer switch,a series charging and parallel discharging circuit is designed,so that the battery is in the charging mode when the batteries are connected in series,and the battery is in the discharging mode when the batteries are connected in parallel.Based on the V-ELEQ electrical simulation software,the motion components of the seedling device were simulated and controlled.Through the control loop and the main circuit,the operation timing of these cylinders was controlled,the actual motion sequence was simulated,and the reliability of the circuit design was verified.According to the selection of each module and the I/O port allocation,the schematic diagram of the control scheme and the schematic diagram of the control circuit are designed,and the hardware construction is completed.Through the introduction of the control flow chart in the automatic mode of the transplanter and the control flow chart in the manual mode,the software programming design is completed based on the Xinjie XD series PLC editing tool software.?5?Analyzed the influencing factors of the batch feeding accuracy of the tray,and carried out the orthogonal test₉L?3⁴?according to the three factors and three levels.The 72-hole and 128-hole tray cucumber seedlings grown for 28 days were selected as test objects,and the seedlings were tested.In order to verify the reliability of the control system and the coordination of each part,sand transplanting experiments and greenhouses were carried out.Field transplant experiment.At the planting frequency of 60 plants/min/row,the comprehensive planting success rate of 72-well plate and 128-pot plate reached 97.5%.