Evaluation of Multibody Parafoil Dynamics Using Distributed Miniature Wireless Sensors

Guided parafoils are comprised of two primary bodies, a payload and parafoil. The payload encompasses the majority of the overall system mass; however, the parafoil generates the majority of aerodynamic loads and is the sole source of control. Despite the canopy being the source of control, the sensor systems used for guidance are located away from the parafoil. Many multi-body models exist in literature and use different degrees-of-freedom to represent parafoil-payload relative motion. However, in all cases, simulations are used to investigate how the relative motion between bodies affects the overall dynamics without experimental validation determining accuracy of the motion predicted. Lack of validation for parafoil-payload relative motion has primarily been due to challenges in accurately measuring parafoil canopy motion which include; its flexibility, light weight, need to be packed in a small volume before deployment, and connection through suspension lines to the payload. In this paper, multiple miniature wireless sensors are embedded in the parafoil canopy and payload during flight and used to measure the parafoil-payload relative motion. Experimental measurements are then compared to a nine degree-of-freedom model and relative payload-parafoil motion is analyzed.