Personal air cleaning by a user-tracking robot equipped with a nanofiber air cleaner in a large work space

In large work spaces, such as logistics warehouses, implementing whole-space air cleaning to protect the workers’ health can be costly. To tackle this issue, the present study developed a user-tracking robot equipped with a nanofiber air cleaner to achieve personal air cleaning for a moving worker in a large work space. First, nanofiber air filters with low pressure drop were fabricated using the electrospinning technique. An air cleaner with a deflector for directing the airflow towards the user’s breathing zone and the nanofiber air filters was assembled and then integrated into a user-tracking robot. Experiments were conducted to measure the clean air delivery rate (CADR) of the nanofiber air cleaner, evaluate the accuracy of the user-tracking algorithm, and determine the optimal deflector setup and user-to-robot distance. Field tests were conducted to evaluate the personal air cleaning performance of the proposed method by comparison with a stationary nanofiber air cleaner. The results show that the user-tracking algorithm of the user-tracking robot was accurate, with an average absolute error in the user-to-robot distance of 4 cm. The user-tracking robot with nanofiber air cleaner outperformed the stationary nanofiber air cleaner by reducing the concentration of 0.3–0.4 μm particles in the breathing zone of the user by 16.4 %. Furthermore, compared with commercial panel-type high-efficiency particulate air (HEPA) filters, the use of nanofiber air filters can extend the battery service life, consequently facilitating the practical application of the moving robot.