Autonomous Flight of a Samara MAV

Conventionally Micro/Nano scaled hovering flight presents a myriad of challenges and unique design opportunities. The culmination of microelectronics and state of the art measuring devices has enabled the creation of a Micro-air-vehicle (MAV1) resembling one of nature's most efficient fliers, the seed of the Maple tree. The planform design of the VTOL mechanical samara is based on previous work2, which characterized autorotation efficiency, and is employed as the main lifting surface of the vehicle. The collective pitch is controlled by a servo actuator, and the rotation rate is maintained by a propeller oriented parallel to the plane of rotation and is offset from the center of mass. Vertical speed and height are controlled by variation of collective pitch at constant propeller rpm, or variation of propeller rpm at a constant collective pitch. Precise attitude data is collected by a VICON3 motion capture system. The commanded altitude of the Samara is maintained by feeding back the error in position to a control loop which contains the system and actuator dynamics. Identifying the relationship between vertical velocity and collective pitch for a given thrust is one of the main goals of these experiments. Two vehicles are presented and compared in this study. The first vehicle, Samara-I has a maximum dimension of 27cm, and weights 75 grams. The second vehicle, Samara-II has a maximum dimension of 18cm, and weighs 38 grams. The vehicles can be launch from the ground, or by hand and have been flown outdoors in winds up to 10 mph. Advantages over traditional micro-scaled VTOL configurations include passive stability, efficient autorotation, low body drag, mechanical simplicity, low cost, high payload capacity, and substantial damage tolerance.