Design of a Bird-inspired Flapping Wing Robot Based on Spatial Four-bar Mechanism

Bird-inspired flapping wing robots are capable of flying into the sky through flapping their wings mimicking the movements of a bird's flight. These kind of flying robots have promising application prospects in surveillance, detection, recreation, rescue, etc. Therefore, this field is developing rapidly and attracts researchers' attention. However, flapping wing mechanism still has problems of complex structure. Moreover, vibration and the friction between two moving parts appear to a large extent when the wings flap at a relatively high speed, which affects the working efficiency of the flapping wing robot. Dealing with the phenomenon stated above, we analyzed and designed a spatial four-bar mechanism for the flying robot with flapping wing. This mechanism has compact structure and ensures symmetrical force. Placing the gears sideways can reduce the influence of airflow on the rotation of the gears and the vibration transmitted to the fuselage can be reduced as well. Based on this spatial four-bar mechanism, a bird-inspired flapping wing robot is designed and fabricated. It weighs only 57.5g. Flying tests are conducted finally to demonstrate the effectiveness and advantage of the designed spatial four-bar mechanism.