Control System Design for a Morphing Wing Trailing Edge

Shape control of adaptive wings has the potential to enhance wing aerodynamic performance during cruise and high-speed off-design conditions. A possible way to attain this objective is to develop specific technologies for trailing edge morphing, aimed at variating the airfoil camber. In the framework of SARISTU project (EU-FP7), an innovative structural system incorporating a gapless deformable trailing edge has been developed. A related key technology is the capability to emulate and maintain pre-selected target wing shapes within an established margin, enabling optimal aerodynamic performance under current operational pressure loads. In this paper, the design of a control system aimed at preserving the specific geometry envelope under variable conditions, is numerically and experimentally explored. The actuation concept relies on a quick-return mechanism, driven by load-bearing actuators that act on morphing ribs, directly and individually. The adopted unshafted distributed electromechanical system arrangement uses servo-rotary actuators each rated for the torque of a single adaptive rib of the morphing structure. The adopted layout ensures compactness and weight limitations, essential to produce a clean aerodynamic system. A FBG-based distributed sensor system generates the information for appropriate open- and closed loop control actions and, at the same time, monitors possible failures in the actuation mechanism. The research leading to these results has gratefully received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 284562.