Design and Experiment of Precision Control System for Compaction Pressure Force of Corn No-tillage Planter

Abstract:

In response to the practical issues of compaction pressure poor stability and uneven compaction strength in corn no-till seeder, a precise control system for compaction pressure was developed based on PID control. The system consisted of a compaction pressure detection unit, hydraulic regulation device, controller, terminal, and mechanical actuator. By utilizing measurement data from tension sensor and angle sensor, the relationship model between the compaction pressure and the measurement data of the two sensors was established by Origin software. The system employed the PID control algorithm to calculate control variables and adjust hydraulic cylinder extension and retraction in real-time, thereby achieving precise control of compaction pressure. Step response experiments revealed that the system’s mean adjustment time was 1.13s, with the mean steady-state error of 2.7N and the mean overshoot of 3.23%. Field experiments demonstrated that the relative error of compaction pressure under hydraulic control mode was 3.08% to 5.38%, with root mean square error of 6.63N to 10.09N，when the target compaction pressures were set at 159N and 182N, and the seeder’s operating speed ranged from 5km/h to 9km/h. In contrast, the relative error of compaction pressure under mechanical adjustment was from 5.05% to 11.48%, and the root mean square error was from 11.67N to 22.49N. The performance metrics of the seeder based on hydraulic control significantly outperformed those based on mechanical control, enhancing the stability of compaction pressure and providing technical and equipment to ensure the quality of notill sowing of corn.