Feasibility‐guaranteed safety‐critical control with high‐order control barrier function method

• Published in: International journal of robust and nonlinear control 2024-03, Vol.34 (5), p.3425-3441
• Main Authors: Zhang, Sihua, Zhai, Di‐Hua, Xiong, Yuhan, Xia, Yuanqing
• Format: Article
• Language: English
• Subjects: control barrier function; Feasibility; feasibility constraint; Obstacle avoidance; quadratic program; Quadratic programming; Safety; safety‐critical control
• ISSN: 1049-8923; 1099-1239
• DOI: 10.1002/rnc.7141

The optimization of control systems under the presence of safety constraints and input constraints frequently involves the decomposition into a sequence of quadratic programs (QPs) facilitated by the utilization of high‐order control barrier function (HOCBF). When the safety constraint conflicts with the input constraint, however, it leads to infeasibility within the QPs. In this article, a feasibility‐guaranteed QP is proposed to tackle the challenge posed by the conflict between HOCBF constraint and input constraint. Firstly, the classical QP is added with a feasibility constraint which is derived from input constraint and HOCBF constraint, where the parameter of feasibility constraint is updated via a new QP obtained by control sharing property. Then, Type‐2 HOCBF is investigated for the system with multiple HOCBF constraints, which effectively confines the system within a single HOCBF at the current time step. Finally, the efficacy of this approach is demonstrated through the application of obstacle avoidance in a 3‐DOF robot system.