Passive stability of vehicles without angular momentum including quadrotors and ornithopters

The paper presents a model for adding stabilizers to a flying device without rotational momentum (such as quadrotors or ornithopters) that will create passively stable vehicles in hover. This model enables the design of the size and location of these stabilizers that will vary the stability and performance of the vehicle. The model is verified with nine experimental vehicles that span the stability design space. Passive stability allows the removal of costly inertial sensors and increases the robustness of the vehicle. Analysis of the cost and drag that impacts flight performance is also discussed.