Autonomous hover flight for a quad rotor helicopter: Linear Quadratic Controller, Piecewise Affine -Hybrid systems controller

摘要

This master thesis concerns two control approaches for the quad rotor helicopter. A Linear Quadratic controller with the aim of autonomous flight, and a PAHS controller on a theoretical level. A new hardware platform to the quad rotor is developed, equipped with sensors and computing power. Software is developed in order to interface to the sensors and render an environment in which an estimator and controller can be implemented. The platform is through an acceptance test verified to fulfill the requirements. A revision of a previously derived non-linear model for the quad rotor is carried out, with the aim of deriving a model based LQ state feedback controller. The controller is tested by simulation on the model and proves to stabilize the quad rotor. The controller is however not implemented. A method designated the Combinatoric Controllability Method is derived in the framework of PAHS, in order to generate a control law on convex polytopes applicable to a simplified quad rotor system. The method is applied to a 3-cube and succeeds in generating a control law, that through simulation eventually proves to fulfill the control objective. The results however, indicate that one specific trajectory plot, briefly exits a non-admissible facet of the 3-cube, for then again to enter and converge towards the expected facet.