Unmanned VTOL Propulsion: Scalability of Quadcopter Rotor-Motor Configurations Outside the Small UAS (sUAS) Regime
Abstract
Consumer-based small unmanned aircraft systems (sUAS) or "drone" products with a useful load under 55-lbf use variable-speed rotor-motor configurations to provide aircraft thrust and maneuverability. The success of these quadcopter-type platforms makes them desirable to scale into higher UAS groups. However, the feasibility of these variable-speed configurations is unknown in the commercial/military UAS design space between 100 - 1,000-lbf of useful load. As the size of the rotor-motor configurations increase, so does their inertia. It is unclear what the effects of the increased inertia are on the transient settling time of the rotor-motor system. To that end, a vertical take-off and landing (VTOL) propulsion experimental test stand was constructed at Kent State University to characterize the transient performance of various configurations. Experiments captured over 35 parameters of seven different rotor-motor combinations and yielded approximately 4,800 data points. It was discovered that inertia does indeed have an effect on the transient coast-down settling time of a rotor-motor. However, the inertia is not the only contributor to the settling time. A stochastic model was generated from the experimental data to predict coast-down settling time as a function of significant parameters. Temperature and thermal management proved to be significant items of concern and must be addressed when using electrical motors for large rotary-wing applications. While the results presented are significant, more expansive experiments are required to adequately predict the transient response of much larger systems.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 06, 2019
- Accession Number
- AD1080032
Entities
People
- D. B. Stringer
- Kendy E. Edmonds
Organizations
- Vaughn College of Aeronautics and Technology