FG-HOCBF: Safe Operation Area Extension and Obstacle Avoidance Direction Guidance for Surface Detection in Narrow Environments
Yujie Li, Zhitao Gao, Chen Chen, Fangyu Peng, Yukui Zhang, Rong Yan, Xiaowei Tang, Wenke Zhou
Abstract
High-order control barrier functions (HOCBFs) that can achieve strict safety guarantees are widely used in robot safety control. However, robot obstacle avoidance in narrow environments with curved surfaces, as represented by aircraft blade detection, is still a challenge. Considering the narrow space between adjacent blades, the traditional spherical barrier boundary is not suitable for flat curved surface blades, which cannot obtain sufficient operational space. Furthermore, the lengths of obstacle avoidance paths in different directions vary greatly under the overall distortion characteristics of the blades, and HOCBF lacks explicit direction guidance. To navigate these challenges, we firstly propose an accurate surface envelope method with short solution time through rotated and scaled super-ellipsoids to obtain a large operational space. Building upon this, we propose a novel force-guided high-order control barrier function (FG-HOCBF) method to guide robot to closely adhere to the surface along the desired direction and complete detection of specific areas, which consists of two components: surface normal approach judgment and guiding force generation in desired direction. Finally, simulations and experiments validate the performance of the proposed method.