Development And Experiment Of Adaptive Control System For Rapeseed Seed Cleaning Loss

The loss rate and impurity rate of rapeseed are important parameters to measure the harvesting performance of the rapeseed combine harvester,and are the basis for adjusting the working parameters of the harvester during field harvest.At present,the mechanization rate of rapeseed harvesting in my country is only 29.40%.The large loss of rapeseed combined harvesting is an important reason for the low level of mechanization of rapeseed harvesting in my country.Among them,the cleaning loss accounts for about half of the total loss.This paper introduces the current research status of cereal loss monitoring methods and devices at home and abroad and the intelligent adaptive control of the combine harvester,and improves the integrated multi-block rapeseed loss sensor and the cleaning device of the rapeseed combine harvester.A block rapeseed loss sensor was used for monitoring performance calibration test;in view of the problem of poor real-time adjustment methods affecting the operating parameters of cleaning losses,an adaptive control system for cleaning losses was developed.The specific work is as follows:(1)Improvement of integrated multi-block rapeseed grain monitoring sensor and cleaning device of rapeseed combine harvesterAccording to the problems found in the rape field experiment in 2018,the integrated multi-block rapeseed grain monitoring sensor monitoring board,monitoring board installation device,sensor and machine connection device and sensor circuit were improved to improve the adaptability of the rapeseed loss sensor;and The cleaning device of rapeseed combine harvester was improved,lower punching screen,upper bionic screen,tail filter device,fish scale screen adaptive adjustment mechanism were designed,and indoor scale test of fish scale screen opening was conducted.(2)Test calibration and bench test of integrated multi-block rapeseed loss sensorIn order to determine the optimal installation height and the optimal installation angle of the sensor and to check the improved integrated multi-block rapeseed loss sensor for monitoring the performance of different properties of rapeseed,differentinstallation heights and different installations were made for the integrated multi-block rapeseed loss sensor Indoor calibration test of rapeseeds with different angles,monitoring boards with different thicknesses within 0.5mm~1mm,same ratio,different quality of rapeseed extraction mixture,different moisture content,and 10 varieties of rapeseed.In order to check the monitoring accuracy of the sensor under different working parameters of the cleaning device and the cleaning performance of the cleaning device,a bench test was designed.The test showed that the monitoring accuracy of the sensor under different working parameters ranged from 95.07% to96.81%,with an average value of 95.91%;the main factors affecting the rate of rapeseed cleaning loss and impurity content are the fan speed and the opening of the fish screen,and a mathematical model between the rate of cleaning loss and the main working parameters was established.(3)Design of adaptive control system for rapeseed lossAiming at the non-linear and time-varying characteristics of the field operation process of the rapeseed combine harvester cleaning device,a gray predictive fuzzy control theory is proposed to design an adaptive control system for the cleaning loss of the combine harvester using a single-chip microcomputer as the controller.Ensure that the cleaning loss of the combine harvester is near the ideal value,timely control the opening of the fish scale screen,and solve the lag problem in the adaptive control system for cleaning loss.(4)Field testIn order to test the cleaning performance of the rapeseed combine harvester cleaning device,the monitoring performance of an integrated multi-block rapeseed cleaning loss sensor and the control performance of an adaptive control system for rapeseed cleaning loss were designed,and a rape field test was designed.The results show that the improved rapeseed combine harvester has a loss rate of 1.11% and an impurity rate of 1.43%,which is far lower than the national standard;the monitoring accuracy range of the sensor is 89.85%~91.70%,with an average value of 90.68%;When the rapeseed cleaning loss per second is too large or too small,the fish scalescreen opening can be adaptively adjusted to maintain the rapeseed cleaning loss per second near the ideal value,which verifies the effectiveness of the control system.