Trajectory Tracking of Unmanned Helicopter Using Optimized Integral LQR Controller

Unmanned helicopters (UHs) are a versatile class of aerial vehicles with huge potential in civil and defense settings. In this paper, the linear time invariant mathematical model of unmanned helicopter at hover and small speed conditions is used. The linearized dynamics is regulated using Linear Quadratic Regulator (LQR) controller. This constitutes the inner loop of the control topology. The inner loop holds the attitude angles of the UH, which are fast varying and responsible for its stability. Outer loop holds the position dynamics (for trajectory tracking), which are slower in nature. The trajectory tracking of UH is achieved using a novel Integral LQR controller. The weighing matrices associated with the optimal control problem are tuned using particle swarm optimization. The controller is implemented in simulation and the results obtained are fairly promising in terms of the control effort required and tracking error.