The
aim of this study is designing an optimal controller with linear quadratic
regulator (LQR) method for a small unmanned
air vehicle (UAV). To better evaluate the effect of disturbances on the
obtained measurements a Kalman filter is also used in the system. For this
purpose a small UAV that is normally used as a radio controlled plane is
chosen. The linearized equations for a wings level flight condition and the
state space matrices are obtained. An optimal controller using LQR method to
control the altitude level is then designed. The effect of the disturbances on
the measurements are taken into account and the effectiveness of the Kalman
filter in obtaining the correct measurements and achieving the desired control
level are shown using the controller designed for the system. The small UAV is
commanded to the desired altitude using the LQR
controller through the control inputs elevator deflection and thrust rate. The
LQR effectiveness matrices are chosen to find the gains necessary
to build an effective altitude controller. Firstly the controller is tested
under the situation where disturbances are absent. Then a Kalman filter is
designed and the system under disturbances
is tested with the designed controller and the filter. The results reveal the
effectiveness of the Kalman filter and the LQR controller.
References
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