Design of a H2 Robust Controller for a Small UAV Based on LMI Method

Due to the small rotation inertia and the incomplete symmetry of its mass, a Small Unmanned Aerial Vehicle (SUAV) is vulnerable to the influence of crosswind and engine torque in the process of flight, and traditional control methods are difficult to ensure the UAV's lateral attitude stability and track the scheduled flight path. In this paper, a robust control strategy based on H2 optimal control theory is used to enhance the anti-interference and adaptability to time-varying parameters of UAV lateral control system. Through the analysis of a SUAV lateral multivariable linear model in a key laboratory, a Linear Matrix Inequality (LMI) method is introduced to design the H2 robust controller. The results show that the closed-loop system of the SUAV with the H2 robust controller can effectively reduce the sideslip angle error and reduce the coupling of flight attitude variables in aileron roll control. At the same time, it has a good performance of suppressing the perturbation of various external disturbance systems and internal structure parameters.