Authors

Abstract

An active-action seeding depth automatic control system was designed , with the purpose of effectively ensure the consistency and stability of the seeding depth when the seeder is operated in the field. Strain-gauge pressure sensor was used in the system, which can detect the force on the tip of the furrow opener in the soil in real time, proceed to the next step judge the change of the seeding depth in the soil according to the change of the pressure signal. In order to achieve consistency and stability of seeding depth, the control signal formation circuit will send a control signal when the pressure on the tip of furrow opener exceeds the appropriate pressure range, and the motor will be controlled to rotate clockwise or counterclockwise to drive the rack and pinion movement to realize the vertical lift of the furrow opener, so that the force on the tip of furrow opener in the soil remains within the appropriate range. The test results indicate that the seeding depth adjustment device based on the tip of furrow opener force measurement has stable and reliable control performance for controlling the seeding depth with an average seeding depth qualification rate of 94.56% and an average seeding depth variation coefficient of only 9.29%, which greatly ensures the consistency and stability of the seeding depth under the condition that the seeding depth is 30-70mm and the working speed is 3-7km/h.

Abstract in Chinese

为使播种机在田间作业时能有效保证播种深度的一致性和稳定性，设计了一种主动作用式播种深度自动控制系统。该系统采用应变式压力传感器实时探测开沟器铲尖在土壤中的受力情况，进而根据压力信号的变化判断开沟器在土壤中开沟深度的变化情况。为了实现播种深度的一致性与稳定性，控制信号形成电路会在铲尖受到的压力超出合适压力范围时发出控制信号，通过控制电机顺时针或逆时针旋转带动齿轮齿条运动进而实现开沟器的垂直升降，使开沟器铲尖在土壤中的受力保持在合适的范围内。试验结果表明，在开沟深度为30-70mm,工作速度为3-7km/h情况下，基于铲尖测力的播深调节装置对控制播种深度具有稳定可靠的控制性能，平均播深合格率高达94.56%，平均播深变异系数仅为9.29%，极大保证了播深的一致性与稳定性。