Gust Alleviation and Wind Tunnel Test by Using Combined Feedforward Control and Feedback Control

Abstract

Gust alleviation is of great significance for improving aircraft ride quality and reducing gust load. Using aircraft response (feedback control) and gust disturbance information (feedforward control) to improve the gust alleviation effect is worthy of attention. In this paper, a combined control system (CCS) composed of feedforward control system (FFCS) and feedback control system (FBCS) is designed and analyzed. At the same time, the gust alleviation effect of the CCS, the single FFCS and the single FBCS are analyzed and compared by means of numerical simulation and wind tunnel test, respectively. Taking a flexible wing as the research object, the gust alleviation effects of three control systems under different forms of gust excitation (1-cos discrete gust, sine gust and Dryden turbulence) are analyzed by numerical simulation. In the wind tunnel test, the sine gust generated by a gust generator was used, and the gust alleviation test was carried out under different wind speeds and gust frequencies. The simulation and experimental results show that the CCS has better gust alleviation performance for various gust excitations. When comparing FFCS and FBCS, the FFCS has better robustness and control effect than the FBCS. When comparing FFCS and CCS, the better the alleviation effect of FFCS, the more difficult it is to achieve significant effect improvement by using CCS, which is obtained by adding FBCS on the FFCS.

Keywords

• gust alleviation
• wind tunnel test
• feedforward control
• feedback control
• gust detection
• aeroelasticity