| With the development of super rice planting technology,the area of super rice planting is continuously expanding,and people have put forward higher requirements on the planting equipment of super rice.At present,production line of rice seeding for nursing seedlings at home can meet 3~5 seeds per hole for conventional rice,and it cannot meet the precision seeding of 1~2 seeds per hole for super rice.To further promote the mechanization of super rice nursing seedling,improve the precision and efficiency of super rice nursing seeding,and reduce production costs,it is urgent to develop the assembly line equipment suitable for super rice nursing seedling.Through the research of rice seedling equipment at home and abroad,vacuum-vibration tray seeding device has the advantages of high seeding precision,which causes a less serious seeds injury.So it is one of the main seeding methods of super rice seeding.In this thesis,designing a device that combines an vacuum-vibration tray seeding device and a seedling assembly line to realize the precision seeding pipeline of the super rice and improve the precision and efficiency of super rice nursing seeding.The main research works of this thesis are as follows:(1)Structural design of three-stage assembly line of vacuum-vibration tray.After analyzing the working process of the vacuum-vibration tray seeding device and the agronomic requirements of rice nursing seedling,the vacuum-vibration tray seeding assembly line is designed in the software of UG.The structure of the assembly line is three-stage.The first conveyor belt is equipped with mechanism for laying soil,sweeping soil and pressing holes.A seeding positioning mechanism is installed on the second conveyor belt,which is integrated with a precision seed metering device to form a seeding mechanism.The third conveyor belt is equipped with mechanism for covering another layer of soil,sweeping topsoil and sprinkler Then,connect the three sections of conveyor belt into a whole through the connecting plate.Through theoretical analysis,20 Pressure points are placed around the cavitation roller which can ensure the accuracy of the pressure points of the seedling tray.The mechanical structure is optimally designed many times,and then the prototype machine is manufactured.(2)The hardware design of the control system of the assembly line for vacuum-vibration tray precision seeding.To study the working process and control requirements of the seeding assembly line,and design the hardware of the control system of the vacuum-vibration tray seeding device.The hardware part mainly includes the main control unit,sensor module,drive module,execution module and human-computer interaction module.Detecting the rotating speed of working parts by Hall sensor.The photoelectric sensor detects the position of the seedling raising tray,and then feeds back the information to the PLC,then the PLC sends instructions to the corresponding drive equipment,and then drives the working mechanism to run.Controlling and monitoring the assembly line through industrial touch screen.And anti-interference design is applied.(3)The software design of the assembly line for vacuum-vibration tray precision seeding.According to the control requirements of the system,the automatic control program design of the vacuum-vibration tray precision seeding is carried out,which mainly includes PLC program design and human-computer interaction interface design.PLC program includes three-stage conveyor control program,positioning motor and pressure cavity motor step control program and Hall sensor speed measurement program design,PLC and transducer communication program and vibration motor frequency conversion control program design.Human-computer interaction interface includes the main interface,manual control interface,automatic control interface,historical information interface and system help interface.(4)Simulation debugging and operation performance test of the assembly line for vacuum-vibration tray precision seeding.Using GX Simulator and GT Simulator to carry out the joint simulation of the control system to verify the feasibility of the control system.Test items include seed suction rate test of seed sucking disc,precision test of pressure hole positioning,coordinated operation test of precision seed metering device and three-stage assembly line,working performance test of seeding assembly line.The tests show that the precision seed metering device has good compatibility with the three-stage assembly line,the positioning accuracy of the pressure cavity is good,and the working stability of the pipeline is good.Under the working efficiency of 460 discs/h,Sowing pass rate can reach 95.42%,the multicast rate is 2.1%,the hole rate is 2.48%.This design has basically achieved the expected results,and has achieved a new breakthrough in the technology of super rice planting precision seeding assembly line. |
PDF Full Text Request