Authors

Abstract

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.

Abstract in English

本研究提出了一种沿路径边缘行驶，基于PID-模糊控制的单目视觉导航控制系统，它通过单目视觉采集路径图像信息，图像处理识别路径边缘确定预瞄点，利用PID和模糊控制相结合的方式设计控制器跟踪预瞄点实现路径导航。首先对单目摄像机进行坐标标定与转换，实现了从图像坐标系到世界坐标系的坐标转换，并通过试验验证了标定结果的准确性。根据沿路径边缘行驶的导航策略，通过图像处理技术得到路径边缘的世界坐标方程，确定导航系统追踪的预瞄点，根据预瞄点的位置确定导航参数。本研究设计的PID-模糊控制器系统，能够根据预瞄点的位置不同切换不同的控制方式。最终对该控制系统的单目视觉导航系统进行了试验验证，验证结果表明该导航控制系统在直线行驶时跟踪路径的平均误差是0.039 m，左转弯时的平均误差为0.079 m，右转弯平均误差0.121 m，误差范围能够满足农业机器人农田作业的基本要求。研究表明，基于PID-模糊联合控制器控制沿路径边缘追踪预瞄点行驶的导航策略对农田机器人视觉导航控制系统效果良好，本研究对农田机器人单目视觉导航系统的研究与开发提供了重要的参考价值。