Mosquito-inspired active tactile perception for indoor navigation and escape of a rigid-soft coupling blimp robot.

For autonomous navigation in indoor environments, aerial robots mostly take cameras, LiDAR, ultrasonic ranging sensors, and other devices for collision avoidance, rarely using tactile sensors. However, cameras are susceptible to lighting conditions, LiDAR requires high computational resources, and ultrasonic sensors have blind zones when measuring at short distances. In contrast, insects and rodents can perceive their surroundings via tactile sensing even in complete darkness. Inspired by the escape strategy of mosquitoes that navigate along boundaries using tactile sensing in confined spaces, this paper proposes an indoor navigation and escape method based on active tactile perception for a blimp robot. The robot comprises a rigid multi-rotor structure and a soft balloon body, with bio-inspired whisker sensors mounted on the soft body surface to enable safe contact with walls. First, we studied mosquito escape behavior experimentally. Then, we designed the robot's mechanical structure and tactile perception system. Subsequently, an interaction model between the robot and the wall was established, and a flight controller was developed. We classified the typical indoor wall scenarios and proposed a 'Sense-Plan-Act' framework for wall-following navigation and escape. Next, the designed controller and strategy were validated through simulations. Finally, we conducted experiments using a robot prototype to verify the proposed method. Results showed that the robot successfully achieved indoor wall-following navigation during flight and ultimately escaped. The proposed active tactile perception method is straightforward and practical for the indoor navigation and escape tasks of blimp robots.