Midterm colloquium Joost de Jong

25 april 2018 14:00 t/m 14:30 - Locatie: instructiezaal m, 3me - Door: DCSC

"Model-based real-time flight control for a VTOL aircraft with independently tilting rotors"

VTOL aircraft are a type of aircraft that combines the flight envelopes of helicopters and regular jets, integrating hovering capability with long-range flight. The hybrid design of for example a tiltrotor eliminates the need for lengthy runways, because the aircraft can take off and land on any unprepared flat surface with the required minimal dimensions.

Thrust curve and rotor tilting however introduce nonlinear changes to the system. Previously, stabilization in these types of systems has been obtained by mixing separate controllers or by scheduling over pre-configured PID controller gains for locally linearized systems. It is envisioned that over the long term, aircraft control will switch to model-based, optimization type methods, that possess explicit knowledge of the system dynamics, input constraints and provide more fault tolerance. 

The presentation focuses on the application of real-time model predictive control (MPC) of a tiltrotor on a Linux PC running Robot Operating System (ROS), in combination with a functional hardware test setup with stepper motors and Electronic Speed Controllers (ESC's). This is a so-called Hardware-in-the-Loop (HIL) system, where the physical quantities such as rotor speed and tilt angle are measured and fed back to the PC.

The proposed control scheme is adaptive MPC, with the addition that a previous state prediction is used to vary the prediction model over time. Box constraints on the input signal are introduced to handle thrust saturation and possible actuator failures.

Dr.ir. T. Keviczky