An All Servo-Driven Bird-Like Flapping-Wing Aerial Robot Capable of Autonomous Flight

Almost all flying creatures, from centimeter-scale insects to meter-scale birds, maneuver through flapping-wing propulsion. Development of flapping-wing robots capable of long-term autonomous flight remains an ongoing challenge owing to manufacturing, actuation, and control considerations. In this article, we report the design and the control system of an all servo-driven bird-like flapping-wing aerial robot called USTBird. Different from most common flapping mechanisms combining gear transmission and motor, USTBird is driven by two independently programmable servos, which makes the wingbeat kinematics of USTBird diverse and enables it to do some agile aerobatic maneuvers. The enhanced controllability brought by the servo-driven method allows USTBird to produce both flight force and control force relying solely on the flapping wings, and exert decoupled control torques about all three body axes without a controllable tail. The flapping gait optimization problem is considered for USTBird, and three different kinds of drive signals are compared for larger aerodynamic forces generation. Toward practical applications, an outdoor flight task of autonomous patrol around a building, which can be subdivided into a coordinated takeoff and a low-altitude patrol and reconnaissance, is conducted on the robot with a good performance.