Abstract: Birds in nature exhibit excellent long-distance flight capabilities through formation flight, which could reduce energy consumption and improve flight efficiency. Inspired by the biological habits of birds, this paper proposes an autonomous formation flight control method for Large-sized Flapping-Wing Flying Robots (LFWFRs), which can enhance their search range and flight efficiency. First, the kinematics model for LFWFRs is established. Then, an autonomous flight controller based on this model is designed, which has multiple flight control modes, including attitude stabilization, course keeping, hovering, and so on. Second, a formation flight control method is proposed based on the leader–follower strategy and periodic characteristics of flapping-wing flight. The up and down fluctuation of the fuselage of each LFWFR during wing flapping is considered in the control algorithm to keep the relative distance, which overcomes the trajectory divergence caused by sensor delay and fuselage fluctuation. Third, typical formation flight modes are realized, including straight formation, circular formation, and switching formation. Finally, the outdoor formation flight experiment is carried out, and the proposed autonomous formation flight control method is verified in real environment.

Key words: Bionic , · Large-sized fapping-wing fying robot , · HIT-Phoenix , · Periodic fight characteristics , · Formation fight , · Leader follower strategy