| Corn no-tillage seeding&fertilizing is the key technical process on protective planting with seed-saving,fertilizer-saving,sprout-welling and effective advantages.Due to the complication of no-tillage planting field,the working performance of seeding and fertilizing are highly requested.The research on monitoring system applied to the corn no-tillage planter's reseeding and hole fertilizing can reduce the cost can be reduced and the quality of seeding and feitilizing can be ensured.Meanwhile the productivity can be improved.The result of this research can provide the reference on relevant studies on improving the performance of corn no-tillage seeding and fertilizing as well as the level of agricultural mechanization based on intelligent technology.The research combines with the National Natural Science Foundation of China “Study on working mechanism and parameter optimization of mechanical no tillage seeding and cutting device”(Grant No.51275318)and Special Fund for Agro-scientific Research in the Public Interst(Grant No.201503116-09),the problems of miss-seeding and fertilizing wasting of the corn no-tillage planter.Based on the analysis and research of precision seeding and fertilizing technology at domestic and overseas on corn no-tillage planter to sloved the problem,the method of mechanical design principle,automatic control principle,discrete element simulation analysis,simulink simulation analysis and orthogonal test are applied on the research of corn no-tillage planter's reseeding and hole fertilizing monitoring system.Meanwhile,the corn no-tillage planting's miss-seeding compensation system and the precise hole fertilizing system has been designed to achieve the agricultural technical requirements of corn no-tillage planter's precise seeding and hole fertilizing.The main research achievement and conclusions are as follows:(1)A portable seeding and fertilizing performance monitoring system test bed has been developed.The performance indicators of the qualification rate,seed-missing rate,seed-repeating rate,coefficient of variation and fertilizing amount can be realtimely monitor.The monitoring system accuracy test shows that accuracy of seeding quantity detection average is 98.59%,coefficient of variation is 0.51%.The relative error of miss-seeding and double-seeding detection average respectively is 8.33% and 11.63%.The accuracy of fertilizing amount detection is 98.47%.Two tests of quadratic orthogonal regression on the rotation speed of planting plate and seed space and speed demonstrates that the performance of the seed-metering device monitoring system.The performance of the system was verified by field experiment,the absolute error of qualification number is 3,the relative error is 0.50%,the absolute error of seed-missing number is 5,the relative error is 11.90%,the absolute error of seed-repeating number is 2,the relative error is 12.50%,(2)By analyzing the performance of the miss-seeding self-compensation,the miss-seeding signal can be tested in advance by leaky testing sensor.Under the specific seed spacing and seeding speed,it can be combined to achieve the function of compensation.By analyzing the performance of the miss-seeding assistance compensation,the reseed metering device and the main seed metering device can be designed reasonably and combined with advanced controlling algorithm to improve the dynamic response performance to achieve the compensation function.The miss-seeding assistance compensation device has been designed to test the single-grain miss-seeding and the continuous double-grain replanting performance.The reseeding maximum and minimum relative error is 7.69% and 2.05% respectively at single-grain miss-seeding,double-grain miss-seeding is better with the seeding speed of 3 to 5 km/h and seeding distance of 25 to 30 cm.The performance of double-grain miss-seeding is greatly affected by seeding speed and seed spacing,and the performance decreases with the increase of seeding speed and the decrease of seed spacing.(3)A mathematical model of the reseed device driver has been established to implement the simulation analysis on the dynamic response performance of the compensation system device.Through the reseeding control algorithm,after determining the mounting position of the reseeding device and the main seeding device,precise reseeding can be achieved by controlling the speed and response time of the compensator.The tests of quadratic orthogonal regression on the height of seed-metering device to ground,the seed spacing and the seeding machine moving speed show that the performance of the reseeding device at machine moving speed of 7 km/h is the best with the height of seed-metering device to ground of 11.98 cm,the seed distance of 22.28 cm,the reseeding success rate was 93.51%.The field test results shows that the machine moving speed of 7 km/h,the rate of missed seeding decreased from 11.82% to 3.24%,which effectively improved seeding quality.(4)A hole fertilization device has been designed to satisfy the technology demand on precise hole fertilization agriculture which has applied a discrete element method software to simulate the hole fertilization controlling device.The result demonstrated that the hole fertilizer device has good cavitation performance at the seeding speed is 3~7 km/h,and the working performance of the hole fertilization system was weaken as the speed of the planter increased.(5)A hole fertilization device has been designed to satisfy the position control and fertilizer amount control of hole fertilization.Based on the orthogonal rotation design test of quadratic regression and the response surface methodology,the speed of the seeding machine,the opening and closing angle of the duckbill valve and the installment height of the hole fertilization device were taken as test factors,the precision of hole distance and the precision of the fertilization amount were taken as test indicators to implement the orthogonal test.The results show that the precision of hole distance and the fertilization amount was 84.76%and 87.20%,When the speed is 3~7 km/h and the opening and closing angle of the duckbill valve is 33.37,and the installment height t is 17.30 cm,which can satisfy the precision and amount controlling demands on the hole fertilization of corn. |
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