DESIGN OF VISUAL NAVIGATION SYSTEM FOR AGRICULTURAL ROBOTS BASED ON PID-FUZZY CONTROL AND MONOCULAR VISION

This study proposes a monocular vision navigation control system based on PID-fuzzy control, which travels along the edge of the path. It collects path image information through monocular vision, identifies the path edge through image processing to determine the preview point, and uses a combination of PID and fuzzy control to design a controller to track the preview point for path navigation. Firstly, coordinate calibration and conversion were performed on the monocular camera, achieving coordinate conversion from the image coordinate system to the world coordinate system. The accuracy of the calibration results was verified through experiments. According to the navigation strategy of driving along the edge of the path, the world coordinate equation of the path edge is obtained through image processing technology, and the preview point tracked by the navigation system is determined. The navigation parameters are determined based on the position of the preview point. The PID fuzzy controller system designed in this study can switch different control methods based on the position of the preview point. Finally, an experimental verification was conducted on the monocular visual navigation system of the control system. The verification results showed that the average error of the navigation control system in tracking the path when driving in a straight line was 0.039 m, the average error when turning left was 0.079 m, and the average error when turning right was 0.121 m. The error range can meet the basic requirements of agricultural robot farmland operations. Research has shown that the navigation strategy based on PID-fuzzy joint controller to track the preview point along the path edge has a good effect on the visual navigation control system of agricultural robots. This study provides important reference value for the research and development of monocular visual navigation systems of agricultural robots.