Liu, Zhengduo, Zhaoqin Lü, Wenxiu Zheng, Wanzhi Zhang, and Xiangxun Cheng. 2019. “Design of Obstacle Avoidance Controller for Agricultural Tractor Based on ROS”. International Journal of Agricultural and Biological Engineering 12 (6). Beijing, China:58-65. https://www.ijabe.org/index.php/ijabe/article/view/4907.