Wilhelm, J. and Close, J., "Roll and Pitch Produced During an Uneven Wing Deployment of a Hybrid Projectile," SAE Int. J. Aerosp. 7(1):16-23, 2014, doi:10.4271/2014-01-2112.
Uneven wing deployment of a Hybrid Projectile (HP), an Unmanned Aerial Vehicle (UAV) that is ballistically launched and then transforms, was investigated to determine the amount of roll and pitch produced during wing deployment. During testing of an HP prototype, it was noticed that sometimes the projectile began to slightly roll after the wings were deployed shortly after apogee. In this study, an analytical investigation was done to determine how the projectile body dynamics would be affected by the wings being deployed improperly. Improper and uneven wing deployment situations were investigated throughout the course of this study. The first analyzed was a single wing delaying to open. The second was if only one wing was to lock into a positive angle of incidence. The roll characteristics when both wings were deployed but only one was locked into an angle of incidence resulted in a steady state roll rate of 4.5 degrees per second. It is imperative to ensure that an HP wing deployment mechanism must be designed to deploy as evenly as possible.