Authors

Abstract

To ensure the stability of seeding depth for a corn planter unit under different soil moisture conditions, a control system was designed to adjust the seeding depth of the unit based on soil moisture content. Using a PLC controller as the control foundation, the system employs a hydraulic system as its actuator. Soil moisture content is detected by moisture sensors, and the PLC controller processes the analog signals from the sensors. The controller then adjusts the forward and reverse rotation and speed of the motor via a variable frequency drive, thereby controlling the vertical displacement of the depth-limiting wheel to regulate the seeding depth. At the same time, a pressure sensor provides feedback to the PLC controller to control the switching time of the solenoid directional valve, driving the hydraulic cylinder stroke. The profiling mechanism connected to the hydraulic system moves the depth-limiting wheel accordingly, achieving stability in the planter's seeding depth. The control system is further optimized using the Mamdani fuzzy PID algorithm. Experimental results demonstrate that the designed seeding depth control system is stable and reliable, accurately adjusting the seeding depth according to different soil moisture levels. When the unit operates at speeds of 8 ~10 km/h, the stability of the seeding depth reaches 90%, significantly improving the stability of the unit's seeding depth.

Abstract in Chinese

为了使玉米播种机单体在不同含水率土壤播种工作时保持播种深度的稳定性，设计了一种根据土壤含水率控制播种单体播种深度的的控制系统。以PLC控制器为控制基础，系统采用液压系统作为其执行机构，通过水分传感器检测土壤含水率，PLC控制器分析处理传感器检测所获得的模拟信号后，控制器通过控制变频器调节电机正反转和转速，实现对限深轮的上下位移，完成对播种深度的控制。同时压力传感器将信号反馈给PLC控制器控制电磁换向阀的开断时间来驱动液压缸行程，与之相连接的仿形机构带动限深轮一同运动，实现对播种机播深的稳定性调节。利用Mamdani模糊PID算法对控制系统进行优化。实验结果表明，所设计的播种深度控制系统稳定可靠，能根据不同土壤含水率精确控制播种深度，单体作业速度在8～10 km/h时，播深稳定性 达到90%，系统提高了单体的播种深度稳定性。