Output controller for quadcopters based on mathematical model decomposition

Abstract

In the paper an output control approach for a class of nonlinear MIMO systems is presented. A multicopter with four symmetrical rotors, i.e. a quadcopter, is chosen to illustrate effectiveness of the proposed adaptive control approach based on the high-gain principle so-called “consecutive compensator”. Output controller is designed by decomposition of the mathematical model on two parts. The first one is a static MIMO transformation (more precisely, in the considering case a system of linear equations which relates lift forces generated by the actuators and virtual control inputs). The second one is a few SISO channels. Such trick allows to design a control law in two steps. At the first step we design virtual controls for each SISO channel. Here we apply the mentioned systematic approach “consecutive compensator”. And then after the inverse MIMO transformation we get a set of real lift forces.