Comparison of parameter-varying decoupling based control schemes for a quadrotor

This paper presents and compares approaches to the design of flight controllers for quadrotor helicopters based on Linear Parameter-Varying (LPV) decoupling techniques. It is shown that parameter-varying decoupling makes it possible to use SISO LTI control design to address all degrees of motion freedom subject to high-speed maneuvers that require large pitch and roll angles. Specifically a decoupling method based on local linearizations (gain-scheduling decoupling) is compared to a global scheduling-dependent decoupling method inspired by computed-torque control, where the scheduling is based on the tilt angels of the drone. Based on an extensive simulation study, it is demonstrated that such a relatively simple control architecture can achieve significantly better performance than LTI control. Conceptually, the presented techniques can be used for the design of control schemes for aircraft and missiles.