| At present,most seeders have used the ground wheel to drive seed metering devices to sow in China.The ground wheel slips when the soil surface is covered with straw or high soil humidity,resulting in uneven sowing and inaccurate sowing amount.Moreover,the traditional seeder needs to adjust the seed spacing through the transmission ratio of the transmission mechanism by the farmer,which can not realize stepless regulation.Then,the sowing process is in a relatively closed environment,which can not directly see the sowing state only by eyes and can not find the phenomenon of sowing abnormalities in time.In addition,the manual measurement of sowing depth has low efficiency and low accuracy.Aiming at a series of problems existing in domestic seeders,this dissertation designs an intelligent control system for air-suction no-tillage corn seeders based on previous studies,which combine singlechip microcomputer technology,motor control technology,and sensor technology.The intelligent control system takes single-chip microcomputer as the main control chip,which can realize the speed closed-loop control of seed metering motor,sowing state monitoring,seeding depth measurement,and human-computer interaction.This dissertation mainly carries out the following research work:（1）Structural optimization of seeder: We refit 2BYQD-4A1 electric controlled corn no-tillage seeder and focus on improving the seed metering driving mode based on retaining the functions of ditching and soil covering.DC motor is used as seed metering driving mode instead of the ground wheel to avoid ground wheel slip and realize stepless adjustment of seed metering shaft speed.In addition,a seed metering monitoring module and sowing depth measurement module are installed on each sowing monomer.（2）Design of the speed control module of seed metering motor: The speed control module of the seed metering motor establishes the corresponding mathematical model according to the relationship between sowing speed,target seed spacing,and driving motor speed.The speed control module combines the Kalman filter fusion genetic PID control algorithm to realize the speed closed-loop control of the seed metering driving motor,which improves the sowing uniformity.（3）Design of the seeding status monitoring module: The seeding status monitoring module adopts the infrared photoelectric sensor to monitor the seed metering state.The traditional infrared photoelectric sensor monitoring module was optimized according to the principle of convex lens imaging.In the process of sowing,the man-machine interface can display the sowing amount in real-time.The audible and visual alarm module was triggered when sowing faults such as over seeding,miss sowing,or seed blocking,and reminded operators to take prompt measures to reduce agricultural losses.（4）Design of the seeding depth measurement module: The seeding depth measurement module collects the sowing depth values directly and indirectly through two-way ultrasonic sensors.The two-way ultrasonic values were filtered and fused through the Kalman filter data fusion algorithm to obtain a more accurate sowing depth value.The relevant field experiments were designed to verify the sowing performance,monitoring performance,and sowing depth measurement performance of the intelligent control system of the air-suction no-tillage corn seeder.Through the analysis of the test results,the following conclusions are obtained: the rotating speed of the seed metering motor can well match the traveling speed of the tractor,and the sowing uniformity is good;The seeding monitoring system has high monitoring accuracy,and the acoustooptic alarm system has high sensitivity;The accuracy of sowing depth measurement system can meet the requirements of sowing industry.Figure [55] Table [11] Reference [103]... |
