Design And Experiment Of Automatic Precision Seeder For Protected Vegetables

The rapid development of my country’s facility vegetable industry has put forwa rd new requirements for its supporting planting equipment.However,traditional supp orting vegetable seeding equipment cannot meet the current development trend of int elligent,refined,green,and high-efficiency agriculture.The traditional facility vegetab le planter is a hand-held type,and the planting pitch is adjusted by gears,which is troublesome and has low precision.Moreover,the ground wheel driving mode is ado pted,and the qualified rate of plant spacing is often reduced due to the ground whe el slipping.In addition,the seeding depth and suppression pressure cannot be adjuste d intelligently in real time according to the actual soil environment,which reduces t he quality of precise seeding operations.Moreover,due to the small particle size of vegetable seeds,it is easy to cause missed seeding in the actual seeding process,an d real-time monitoring of the seeding process is required during the seeding process.In response to the above problems,this project carried out the design and experime nt of the intelligent precision planter for facility vegetables.According to the plantin g agronomy of common vegetables,the working parameters of the planter were for mulated,the key components of the whole machine and the precision seeding contro 1 system were explained in detail,and the test was verified.The performance of the whole machine can be further improved and optimized to finally realize the precise planting operationof vegetables in the facility environment.First of all,this subject investigated the specific requirements of common facility vegetable planting agronomy and precision seeding indicators.Secondly,the overall design plan of the intelligent precision planter for facility vegetables is formulated based on agronomy.In terms of mechanical structure design,this paper adds a parallel four-bar profiling mechanism based on the basis of the traction type vegetable seeder,and adds the downforce of the sowing depth,the pressure control mechanism,and the seed metering monitoring device based on the parallel four-bar profiling mechanism.The seed metering driving device enables the seed metering motor to independently drive the seed metering device,and the speed measuring wheel is modified.In terms of control system,the overall design plan of the control system is introduced,and the software and hardware are designed.Finally,the laboratory test and field test of the facility vegetable intelligent precision seeder were carried out,including the rotation accuracy verification of the seed metering device and the seeding performance verification test.The test results show that in laboratory experiments,the actual rotation speed of the seed-metering motor differs very little from the theoretical rotation speed,the measured coefficient of variation is less than 9%,the rotation speed control accuracy is high,and the stability is good;the actual plant spacing values are all within the error range of the plant spacing.All plant spacing coefficients of variation are≤7%,far less than the specified ≤40%,which meets the requirements of precision seeding;within the operating speed of 0.5km/h～3km/h,the average coefficients of variation are 9.5%,11.2%,13.7%,14.1%,15.2%,15.8%,the coefficient of variation of plant spacing are all within the specified index range;in the seeding performance test,the qualified rate of plant spacing is greater than 92%under different operating speeds and plant spacing conditions,and the missed seeding index is ≤4.01,The replay index is ≤3.67,which meets the specified standards.In the field experiment,the measured average sowing depth values all fluctuate within±0.5cm,which is in line with the allowable range of sowing depth.The qualified rate of seeding depth can reach up to 93.8%;in the actual seeding operations in the field,the qualified rate of plant spacing can reach 94.1%and the minimum is 88.9%.The plant spacing control accuracy is high and the stability is good.The rebroadcast and missed broadcast index are both less than 5%,which meets the requirements of precise seeding.