Abstract:A set of gust load alleviation control system of a 2-D airfoil is presented. It starts with the design of gust generator, which can generate harmonic flow filed in perpendicular direction. Then, the paper introduces suboptimal controller and H∞ controller. When designing the H∞ controller, damping uncertainty in plunge and pitch direction and modeling error of ultrasonic motor are taken into consideration. The numerical simulation and wind tunnel test show that these two kinds of controllers can both alleviate gust load to airfoil. In addition, the comparison of suboptimal controller and H∞ controller shows that the former is superior to the latter in numerical simulation, while the latter is more effective than the former in wind tunnel test. Besides, the actual results of H∞ controller in wind tunnel test are closer to those of its simulation.