Experimental Investigation of On-Ground Flightworthiness Determination for Modular Vertical Lift Vehicles

Abstract

Cooperative transportation of payloads by multiple unmanned air vehicles has received increasing interest due to unique operational advantages. These include the portability of the individual vehicles and the scalability of the lifting strategy in the presence of differing payloads. By rigidly attaching a set of unmanned air vehicles to a payload, the control effort required to transport the payload is divided across the vehicles. In the presence of uncertainty about a payload’s mass and inertial characteristics, there is no inherent flightworthiness guarantee for a specific connected unmanned air vehicle configuration. This Paper describes a method for determining on-ground flightworthiness of the unmanned air vehicle-payload system while making minimal assumptions about inertial properties of the payload or the attachment configuration of the unmanned air vehicles. The probabilistic model itself is initialized and updated (built) by the algorithm. Within the model, the vehicles are positioned. Building upon prior theoretical developments, this Paper explores the differing sources of error in the estimates and experimentally validates the algorithm through a series of tests using prototype modular vehicles. Overall, simulation and test results highlight the dominant performance factors and demonstrate the feasibility of the approach for a range of payload geometries.