ArticleGust Alleviation by Active–Passive Combined Control of the Flight Platform and Antenna Array for a Flying Wing SensorCraft

Abstract

SensorCraft is an intelligence, surveillance, and reconnaissance (ISR) system that integrates unmanned flight platforms and airborne antenna arrays. Under gust loads, the high–aspect–ratio, light–wing structure of SensorCraft has considerable bending and torsion deformation, affecting the flight performance of unmanned flight platforms and leading to the loss of antenna arrays’ electromagnetic performance. Taking SensorCraft as the background, a wing conformal antenna array was designed, an aircraft model with a passive wingtip device was established, a control law was developed by the LQG/LTR method, and a gust alleviation active–passive combined control method of a “LQG/LTR active controller + passive wingtip device” was proposed. By constructing an unsteady aerodynamic reduced–order model (ROM) based on the Volterra series and a conformal array pattern fast method based on the modal form, the effectiveness of the gust alleviation active–passive combined control method on the aircraft platform and antenna array was analyzed. The results show that structural deformation of the wing conformal antenna leads to changes in the main lobe gain, beam direction, and sidelobe level. The active–passive gust alleviation method has obvious advantages. Compared with the LQG/LTR active gust alleviation method, the peak value of wingtip displacement is reduced by 15.6%, and the peak value of the gain loss is reduced by 0.72 dB, which is conducive to better performance of the airborne conformal antenna array.