Model of Linear Quadratic Regulator (LQR) Control Method in Hovering State of Quadrotor

Abstract

Quadrotor is an unmanned aircraft which has vertical take-off and landing (VTOL) capability. However quadrotor requieres a good control system to itself during flight. So, the aim of this research is to design and implement a control system on quadrotor using LQR method to obtain the best feedback gain K value in hover state. LQR is a method that calculates the optimal feedback gain K. The feedback gain K can determined by tuning of Q and R. The feedback gain is used to control the system in control signal form. The control signal values are converted into PWM to control brushless motor speed to maintain quadrotor's position. The test results show, Q and R values of the same roll and pitch were Q = 0.08 and R = 1, where the average angle of roll of 0.25 degrees and the average angle of pitch of 0.15 degrees. While the value of Q and R yaw angles were Q = 0.01 and R = 1, the yaw angle maintains in the range of an angle of 0 degrees to 2 degrees. As for the rise time, roll angle was able to handle distractions for 0.09 seconds, 0.15 seconds during the pitch angle and 0.12 seconds during the yaw angle.