Design And Experiment Of Cooperative Adaptive Seedling Feeding System For Electric Transplanters In Cavity Tray Seedling Facilities

Vegetables are the second largest crop in China after food.Although the semi-automatic transplanting machines currently used in vegetable production have improved operational efficiency and quality compared with manual transplanting,they still require manual assistance,and even save labor on some occasions,especially in high-intensity seedling feeding operations,because of long periods of high mental stress,misplanting,omission of seedlings in cavity trays and lower transplanting quality also limit the improvement of transplanting speed.Domestic has not yet suitable for the application of vegetable transplanting operation machine in the facility.There is no vegetable transplanting machine suitable for the operation in the facility in China.Therefore,in order to meet the urgent needs of the survival of modern vegetables in China and adapt to the domestic situation,it is necessary to develop a semi-automatic transplanter that can reduce the leakage rate and is economical under the premise of ensuring the stability of transplanting quality.The adaptive feeding control system is designed to reduce the lack of seedlings during transplanting,reduce the leakage of seedlings,improve the quality of transplanting,and provide the development direction for fine agriculture.In order to reduce the size of the transplanter,the traditional gearbox is eliminated and different motors are used to drive the planters and travel motors respectively,and then the spacing of the plants is adjusted by the synergistic control of the two motors in an electromechanical way.The main contents of the research are as follows.(1)This paper proposes a new seedling feeding mechanism and equipped with adaptive seedling feeding control system,and uses the combination of electromechanics to achieve adjustable plant spacing to achieve the synergistic control of the whole machine;and conducts transplanter bench test and transplanting test to solve the problems of low seedling feeding efficiency and high leakage rate of transplanter.(2)A seedling identification system with photoelectric sensor as the detection element is proposed,and a feeding compensation strategy is proposed for the problem of missing seedlings;multiple photoelectric sensors are used to identify the stems and leaves of seedlings to determine whether there are seedlings in the feeding cups,and according to the number of consecutive seedling cups without seedlings detected,feeding compensation is made to ensure that seedlings fall into the planters every time the seedling feeding mechanism feeds seedlings;in order to make the feeding mechanism feed seedlings accurately every time,the feeder’s spacing is adjusted to ensure that the seedlings fall into the planters.In order to make the feeding mechanism feed seedlings accurately every time,the closed-loop control of the power components of the feeding mechanism is carried out,and the PID control algorithm is used for the theoretical analysis and the simulation model is established.(3)The adaptive seedling feeding control system and the whole machine cooperative control system are designed and the construction of the control system is completed;the adaptive control system uses PLC as the controller to complete the work,including potted seedling identification,continuous no seedling cup judgment,closed-loop control of the stepper motor;the whole machine cooperative control system includes the measurement of walking speed,analog voltage control planting controller to realize motor speed regulation,etc.(4)The adaptive seedling feeding control system and the whole machine cooperative control system were tested with cucumber seedlings as the test object,which were verified by different planting frequencies and other conditions during the test.The test results of the adaptive seedling feeding control system showed that the success rate of seedling identification reached more than 95.9% for different planting frequencies selected within the normal working planting frequency of the transplanter,compared with the success rate of seedling identification after the test pretreatment.The rate of missed planting was reduced by about 15% compared with that of cavity tray seedlings after pretreatment.The whole machine synergistic control test shows that the planting spacing is stable and the spacing variation coefficient is within a reasonable range by using the combined electromechanical control of two motors,which facilitates the adjustment of different plant spacing.