I. Introduction
With the progression of time, the traditional manual production method is being displaced by the human-machine collaboration production method [1], or even a “machine replacing human’’ mode. This indicates that the production process will involve less human involvement. “Machine replacing human’’ has become popular, and collaborative robots can significantly increase productivity to satisfy the high precision, customization, and adaptability requirements of production. This has resulted in a reshaping of production methods and industry patterns, with the use of collaborative robots becoming more prevalent across a variety of industries and the demand for collaborative robots in industry increasing. Likewise, safety monitoring of collaborative robots has become increasingly crucial. On the one hand, it aids in the prevention of potential safety hazards, and on the other, it effectively reduces losses caused by collaborative robot failures. Consequently, safety monitoring of collaborative robotics is currently a popular research topic.