De Eurotrochilus Mechanicus: Een robot kolibrie aangedreven door een resonant flappermechanisme

The use of drones, or unmanned aerial vehicles (UAVs), is increasing every day. Although they were originally developed mainly for military purposes, commercial and personal applications start to emerge as they become smaller and more affordable. Micro air vehicles (MAVs) are UAVs with limited size and weight; often designed for indoor use. Most of them use propellers as they can take off vertically and operate at low speeds or even hover. At small scales, MAVs propelled by flapping wings are a promising alternative as they could be able to mimic the exceptional flight capabilities of hummingbirds and insects. The objective of this PhD. is to develop a robotic hummingbird; A tail-less flapping wing MAV that flies by flapping its wings and looks just like a hummingbird. To drive the wing motion a resonant flapping mechanism has been developed. To minimize the power consumption of this flapping mechanism, spring elements are added and the mechanism is tuned such that its damped resonance frequency is close to the desired flapping frequency. The resonant flapping mechanism is able to generate asymmetric wing motions necessary for flight stabilization and steering. Because the robotic hummingbird is not passively stable a custom made on-board flight controller is designed and implemented that actively stabilizes flight. The flight controller consists of a wireless transceiver, motor drivers, motion sensors, encoders and a micro controller that contains the control algorithm. The robotic hummingbird presented in this text is able to perform stable flight. The longest flight recorded so far lasted for 55 seconds. In the framework of this research PIV (Particle Image Velocimetry) measurements are performed to study the flow and the aerodynamic phenomena around artificial hummingbird-like flapping wings. Also a parameter study is done to study the average thrust generated by a flapping wing and the power consumption of the flapping mechanism that drives the wing motion for a broad range of flapping frequencies, stroke amplitudes, angle of attacks and wing sizes.status: publishe