Comparison and Analysis of Multi-body Parafoil Models With Varying Degrees of Freedom

摘要

Guided parafoils are comprised of two primary bodies, a payload and parafoil. While the parafoil generates the majority of aerodynamic loads, the sensor systems used for guidance are located away from the parafoil near the payload. In this paper, miniature wireless sensors are embedded in the canopy and payload during flight and used to measure the parafoil-payload relative motion. Experimental data is compared to models ranging from six to nine degrees-of-freedom. Each model can be justified by different connection configurations; however, in each case the ideal configurations are only approximately satisfied. As a primary example, a six degree-of-freedom model assumes the payload and canopy are rigidly connected while actual systems will have relative payload-canopy motion. In practical applications, it is desirable to model the system with the minimum degrees-of-freedom while capturing all significant dynamics. This paper compares the model configurations with experimental data and shows which models are most appropriate under varying conditions.