Development of a Seeding Control Method Based on Seed Height in the Hopper of a Precision Wheat Drill
Jianping Hu, Xingsheng Zhao, Wei Liu, Mengjiao Yao, Zhao Jun
Abstract
Highlights Seed height in the hopper has an important influence on seeding accuracy. Through experiments, the relationship between the seed height and seeding quantity discharged per rotation of the flute roller is obtained. A compensation algorithm for rotational speed is built, which greatly improves the seeding accuracy. Abstract. The aim of this study was to develop a control method for precise seeding that is able to keep the seed discharged quantity per flute roller rotation stable when the seed volume in the hopper is insufficient. The designed experimental equipment consists of an embedded controller, ultrasonic sensor, square hopper, stepper motor, stepper motor driver, flute roller, and pressure sensor. Seed height in the hopper was measured by an ultrasonic sensor, whose installation location was determined by the distribution of seeds in the hopper. Then, the rotational speed of the flute roller was adjusted based on seed height. A pressure sensor was used to monitor the quantity of seeds discharged per flute roller rotation. Moreover, laboratory experiments were conducted to compare the seeding control method based on seed height and the traditional seeding control method. The average seeding accuracy of the seeding control method based on seed height was 4.07% higher than the traditional seeding control method, and the seeding coefficient of variation was 3.56% less than that. The testing results show that the control method that used a compensation algorithm for rotational speed effectively improves the seeding accuracy, especially when the seed volume is insufficient. Keywords: Compensation algorithm, Precise seeding, Seed distribution, Seed height, Ultrasonic sensor.