Design and Experiment of Electric Control System for Self-Propelled Chinese Herbal Medicine Materials Transplanter

To address the challenges of low efficiency and poor quality in the transplantation of the roots and stems of Chinese medicinal herbs, an electromechanical control system for Chinese medicinal herb transplantation was studied. The electronic control system employs an STM32 single-chip microcomputer as the main controller, utilizes a Hall sensor to capture the movement speed of the transplanter, employs an encoder to monitor the working speed of the DC drum motor and provide feedback to the system, and drives a belt conveyor for transplanter movement using a DC drum motor. The fuzzy PID algorithm is used to adjust the speed of the DC drum in real time based on the difference between the captured speed and the actual monitored speed, ensuring precise matching between the transplanting operation speed and the transplanter movement speed. The control system was simulated using Matlab/Simulink 2022b software. Compared to the traditional PID control algorithm, the steady-state error was reduced by 36.41%, the steady-state time was shortened by 47.26%, the response time was shorter, there was no overshoot, and the robustness was good. Based on the simulation test, a real machine-verification experiment was conducted. The test results indicated that, when operated at the forward speeds corresponding to the low-speed first gear (Low 1) and low-speed second gear (Low 2), the Codonopsis pilosula seedlings exhibited the following characteristics: the exposed seedling rate was 1.1% and 1.5%, the injured seedling rate was 0.5% and 0.7%, the unplanted rate was 1.6% and 2.2%, and the transplant qualification rate was 96.8% and 95.6%, respectively. Similarly, for Astragalus membranaceus seedlings at these speeds, the corresponding rates were as follows: the exposed seedling rate was 1.3% and 1.9%, the injured seedling rate was 0.4% and 0.5%, the unplanted rate was 0.8% and 1.2%, and the transplant qualification rate was 97.5% and 96.4%, respectively. Both results met the design requirements. This study lays a theoretical and technical foundation for controlling the transplanting speed, improving the transplanting accuracy, and promoting the mechanized development of transplantation in traditional Chinese medicine.