| dc.description.abstract | This thesis describes the development and flight testing of a compact, re-configurable, rotary-wing micro air vehicle concept capable of sustained hover and could potentially be launched from a 40mm grenade launcher when scaled down. By launching these energy-constrained platforms to a target area, the mission range could be significantly improved. The vehicle design features coaxial rotors with foldable blades, and a thrust-vectoring mechanism for pitch and roll control. Yaw control was accomplished with a specialized counter-rotating motor system composed of two independently controlled motors. Passive unfolding of the coaxial rotor blades in flight utilizing centrifugal force was demonstrated. A cascaded feedback control strategy was implemented on a 1.7 gram custom-designed autopilot. Systematic wind tunnel tests were conducted with the vehicle on a single degree-of-freedom stand, which proved the ability of the controller to reject wind gusts up to 6 m/s and stabilize the vehicle during the powered axial descent phase. Free flight testing verified that the vehicle could hover and fly forward in winds up to 5 m/s. In-flight drop tests were conducted by throttling down the vehicle from a high altitude to attain high decent speeds followed by recovery using the rotor thrust to aggressively brake the descent and achieve a stable hover. Finally, the 366 gram vehicle was launched vertically from a pneumatic cannon followed by a stable projectile phase utilizing the fins, passive rotor unfolding, and final transition to a stable hover from arbitrarily large attitude angles demonstrating the robustness of the controller. | en |
