Sensing, Actuation, and Control of the SmartX Prototype Morphing Wing in the Wind Tunnel

Abstract

This paper presents a study on trailing edge deflection estimation for the SmartX camber morphing wing demonstrator. This demonstrator integrates the technologies of smart sensing, smart actuation and smart controls using a six module distributed morphing concept. The morphing sequence is brought about by two actuators present at both ends of each of the morphing modules. The deflection estimation is carried out by interrogating optical fibers that are bonded on to the wing’s inner surface. A novel application is demonstrated using this method that utilizes the least amount of sensors for load monitoring purposes. The fiber optic sensor data is used to measure the deflections of the modules in the wind tunnel using a multi-modal fiber optic sensing approach and is compared to the deflections estimated by the actuators. Each module is probed by single-mode optical fibers that contain just four grating sensors and consider both bending and torsional deformations. The fiber optic method in this work combines the principles of hybrid interferometry and FBG spectral sensing. The analysis involves an initial calibration procedure outside the wind tunnel followed by experimental testing in the wind tunnel. This method is shown to experimentally achieve an accuracy of 2.8 mm deflection with an error of 9%. The error sources, including actuator dynamics, random errors, and nonlinear mechanical backlash, are identified and discussed.

Overview of the SmartX Wing Technology Integrator

“…Additional studies using this sensing approach have shown that the total number of fibres required can essentially be reduced to seven for the SmartX wing without compromising on the accuracy; i.e., one each for the six morphing modules [27] (chordwise) and one for the wing [28] (spanwise). In short, a single morphing surface requires just one fibre containing four FBG sensors [29]. Furthermore, once properly calibrated, this fibre-optic methodology is capable of identifying the position and magnitude of an external load acting on the morphing surfaces [30].…”

Assessment of the Measurement Performance of the Multimodal Fibre Optic Shape Sensing Configuration for a Morphing Wing Section

“…In this paper, we investigate the deformed shape estimation using optical fibre technology with a quasi-distributed Fibre Bragg Grating (FBG) sensor layout. This work is an extension of the successful demonstration of the potential of this method on a 1-dimensional case involving a cantilever beam [ 21 ], a 2-dimensional load monitoring study on a cantilever plate [ 22 ] and in a composite wing prototype [ 23 ]. A morphing wing-section model (with similar shape to the SmartX prototype) is used for the experimental study.…”