Energy-Based Modelling and Control for Helicopter Autorotation: A port-Hamiltonian approach

Energy-Based Modelling and Control for Helicopter Autorotation: A port-Hamiltonian approach

Mavrocordatos, Nicolas (TU Delft Mechanical, Maritime and Materials Engineering)

Giordano, Giulia (mentor)
Pavel, Marilena (mentor)

Delft University of Technology

Mechanical Engineering | Systems and Control

2020-04-06

Automation is playing an increasingly important role in today’s society and is revolutionising nearly all industries. In this thesis, the helicopter industry is considered. Helicopters are complex systems capable of Vertical Take-Off and Landing (VTOL). Many companies and organisations are now looking to automate VTOL vehicles in order to break through the urban air mobility market. In order to transport individuals, strict safety regulations have to be adhered to. The goal of this thesis is therefore to address the event of engine failure of a helicopter. In the case of engine failure, a helicopter enters a manoeuvre, called autorotation, in order to safely land. To tackle this problem, a port-Hamiltonian (PH) approach is taken. Within the PH framework, energy transfers between system nodes are defined. By controlling the flow of energy between these nodes, control of the vehicle is possible. This is done by shaping the energy of the system through the use of Passivity-Based Control (PBC). Prior work on the topic of helicopter control using PBC has only been carried out on pointmass models. In order to understand why that is the case, this thesis attempts to derive the PH formulation directly from the Newtonian flight mechanics. It was found that doing so is not possible due to the presence of non-passive terms. These originate from the Blade Element Theory (BET), which is necessary to calculate the thrust and torque of the main rotor. A novel analytical tuning method has also been developed in order to minimise the rise-time and oscillations of the time-response for a PBC. This tuning method has been implemented on a 3-Degrees-of-Freedom (DoF) point-mass model. However, the degree of underactuation of the 6-DoF model has proven to be a limitation for this tuning method. Instead, the 6-DoF was tuned manually. The two models were verified against flight data of the Bo105 helicopter in powered flight. Finally, the first step of the autorotation manoeuvre has been performed. Further work is required to complete the manoeuvre.

Autorotation
port-Hamiltonian
Passivity-Based Control
helicopter

http://resolver.tudelft.nl/uuid:3200fd5d-bb24-4288-9f68-9cc590a47634

Student theses

master thesis

© 2020 Nicolas Mavrocordatos