Improving the impact point accuracy of unpowered flight vehicles under uncertain wind conditions by using parameter-based adaptive control

Abstract

The paper focuses on the problem of pre-programmed trajectory tracking control under uncertain wind conditions for unpowered flight vehicles operating at transonic and subsonic speeds. In the vertical plane, the trajectory is assumed to be affected by the environment at low altitudes, where complex and unpredictable winds often occur, manifesting randomly as gusts, turbulence, or longitudinal winds. The influence of wind can cause significant deviations from the pre-programmed trajectory by hundreds of meters. To cope with these wind effects and improve the impact point deviation, an adaptive control combining Linear Quadratic Regulator (LQR) and Recursive Least Squares (RLS) based on model parameter estimation is implemented. Consequently, the adaptive LQR exhibits a flexible response and achieves high accuracy in tracking the pre-programmed trajectory. Compared with a non-adaptive one, adaptive LQR shortens the impact point deviation from tens of meters to meters.