Experimental Research On Controlling System Of Rape Variable Seeding

Traditional agricultural production generally exists the phenomenon of low input and output,also the waste of resources.In particular, a large number of blind application of excess fertilizer and sowing the seeds,resulting in soil and groundwater pollution, serious waste of seeds over, affecting the overall quality of agricultural products and crop yield. Therefore, converting the traditional agriculture to precision agriculture, quantitative inputs to variable investment and management can save energy, improve environmental conditions, so as to improve the level of agricultural production and crop quality. Variable seeding is a sowing method based on the amount of different kinds of land using to adjust to different sowing automatically.In this paper, eccentric round hole-wheel seedmeter device developed by Hunan Agricultural University is taken as research object, variable control of rape seeding rate is achieved by increasing the control system and auxiliary equipment. The following aspects are mainly carried out.(1) This test proved that seeding amount changes can be achieved by changing the speed of the shaft of the eccentric round hole-wheel seedmeter device. Bench test research is carried out according to the seeding amount and the speed of the shaft of the eccentric round hole-wheel seedmeter device, the linear equation relation between rotate speed(n), whose span is 30-70r/min, and seeding amount(q=0.2283 n+0.6638) was obtained on the premise of ensuring the characteristics of seedmeter coming up to the standard.The result shows that seeding amount changes can be achieved by changing the speed of the shaft of the eccentric round hole-wheel seedmeter device.(2) Mathematical model among rotate speed of seedmeter (n), the forward speed of equipment(v) and seeding amount of seeder(Q) was established. Field sowing not only related to seed volume and seed characteristics,but also affected the forward speed of traction equipment. For this reason, the mathematical model, Q= (0.2283n+0.6683)/6v, among rotate speed of seedmeter (n), the forward speed of equipment(v) and seeding amount of seeder was established under the condition of the equipment forward speed in the span of 0.8-2.6 km/h.(3) The detection system and sowing seed rate control system was developed. When taking servomotor as actuators and microcomputer as the controller's core, moreover, adopting photoelectric coding to collect the forward speed of the machine and optical fiber sensors to detect unit seeding amount, the man-machine interface operating system can be realize with the combination of LCD 1602 module and 1x4 type keyboard based on the established mathematical model. Then software development was carried out according to the objective that the system required to achieve, in addition, fuzzy algorithm was added into the detection system to improve the detection precise. Finally, rape variable seeding control system and seeding amount test system of eccentric round hole-wheel seedmeter were studied out through the connection of various components and the download of the programe.(4) Trial on rape by variable seeding system has been verified. Conducted two experiments, one group is entering a different sowing rate by manually keyboard, and the other is a virtual one hectare seeding rate curve of the changes with time as the prescribing information field, and then the seeding rate through the serial port input to the MCU function table to achieve automatic variable seeding. That the variable seeding system and the equipment had been proved to meet the requirement of rape variable seeding in this paper, the test error of seeding amount lower than 15%.