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An experimental remote-controlled helicopter with suspended load

This paper describes a testbed for studying externally-loaded helicopter dynamics in a controlled, indoor environment. A remote-controlled helicopter is attached to a mechanical framework that limits the helicopter motion to pitch rotation and longitudinal translation. The framework allows a load suspended beneath the helicopter to swing freely. The helicopter position, helicopter pitch angle, and load swing angle are measured in real time. This testbed can be used to investigate the dynamic effects of changes in suspended load weight, suspension cable length, and automatic flight control system architecture. The mechanical and electrical systems are described, along with methods to minimize the forces and torques applied by the helicopter in the constrained degrees of freedom. Two example experiments are discussed.