Robohub.org
 

This flying machine uses ducted fans for propulsion and control


by
05 January 2016



share this:

Ducted_Fan_Flying_Robot_Muehlebach_ETHZThe Flying Platform is a new flying machine developed at the Institute for Dynamic Systems and Control at ETH Zurich. Its purpose is to study the use of electric ducted fans as control and propulsion systems for flying machines in applications where size is limited and high static thrusts are required, for example in aerial vehicles capable of vertical take-off and landing (VTOL), hovercrafts or even actuated wingsuit flight. The video below shows how the thrust vectoring is used to stabilize the vehicle.

 

 

Design process

As a starting point we derived a physical model of the flying machine, which helped us to understand the behavior of the system. For instance, as the electric ducted fans are placed farther away from the center of the vehicle, the lever arm of the thrust vectoring system increases – but so does the inertia of the system. These are conflicting requirements for high maneuverability, where one seeks to maximize the lever arm, but still keep the inertia small. The physical model helped us to find a suitable tradeoff.

In parallel, the electric ducted fan and the thrust vectoring mechanism were characterized quantitatively by doing measurements on a separate test bench. In this way, the properties of the actuation – e.g. the total thrust, the time constants of the fan, and the thrust vectoring mechanism – could all be determined experimentally.

Figure 1: The test bench for characterizing the electric ducted fan and the thrust vectoring system.

Figure 1: The test bench for characterizing the electric ducted fan and the thrust vectoring system.

The measurements on the test bench were used to update the physical model of the flying machine and to assess its flight performance in simulations.

Figure 2: Electric ducted fan with exit nozzle and control flaps.

Figure 2: Electric ducted fan with exit nozzle and control flaps.

Key Facts

Flying Platform Website

Researchers
Michael Muehlebach
Raffaello D’Andrea

Mechanical and electrical design
Michael Egli
Marc-Andrè Corzillius

Status
Ongoing research project

Hardware design and specifications

The analysis based on the physical model was used to determine the specifications of the hardware design. The three electric ducted fans (Schübeler DS-51-DIA-HST) were aligned on an equilateral triangle of 30cm side length. A carbon fiber honeycomb structure was used to connect the fans, and a 3D printed exit nozzle was mounted on each fan (see Fig. 2) in order to increase the airflow velocity and augment the thrust vectoring capabilities. The exit nozzle also integrated the two servos that actuate the control flaps. The flaps were optimized for a high stall angle using the XFoil software package (see https://en.wikipedia.org/wiki/XFOIL). Three aluminum feet support the structure when the Flying Platform is on the ground. In total it weighs 7.6kg.

Power is delivered by six 2-cell (or alternatively three 4-cell) battery packs that have a capacity of approximately 6.6Ah. The power consumption at hover is roughly 5.3kW at 120A. A PX4 flight computer is used to run the control algorithms. Each fan delivers a maximum thrust of 4.2kg, which results in a payload of approximately 3kg.

 

Research on control algorithms

The Flying Platform is used for benchmarking novel control strategies that account for actuation limits. In particular, the flaps are limited to a range of approximately 18°. Control algorithms explicitly accounting for this limitation can provide larger stability margins and other performance enhancements.

We are currently investigating model predictive control algorithms. The idea is to explicitly exploit the physical model of the system – including input and state constraints – for making model-based predictions. Since these methods are computationally expensive, we seek to trade off the prediction accuracy with computational cost, and quantify the consequences of such approximations.


If you liked this article, you may also be interested in:

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

 



tags: , , , , , ,


Michael Muehlebach is a PhD student at ETH Zurich.
Michael Muehlebach is a PhD student at ETH Zurich.





Related posts :



Livestream of RoboCup2025

  18 Jul 2025
Watch the competition live from Salvador!

Tackling the 3D Simulation League: an interview with Klaus Dorer and Stefan Glaser

and   15 Jul 2025
With RoboCup2025 starting today, we found out more about the 3D simulation league, and the new simulator they have in the works.

An interview with Nicolai Ommer: the RoboCupSoccer Small Size League

and   01 Jul 2025
We caught up with Nicolai to find out more about the Small Size League, how the auto referees work, and how teams use AI.

RoboCupRescue: an interview with Adam Jacoff

and   25 Jun 2025
Find out what's new in the RoboCupRescue League this year.

Robot Talk Episode 126 – Why are we building humanoid robots?

  20 Jun 2025
In this special live recording at Imperial College London, Claire chatted to Ben Russell, Maryam Banitalebi Dehkordi, and Petar Kormushev about humanoid robotics.

Gearing up for RoboCupJunior: Interview with Ana Patrícia Magalhães

and   18 Jun 2025
We hear from the organiser of RoboCupJunior 2025 and find out how the preparations are going for the event.

Robot Talk Episode 125 – Chatting with robots, with Gabriel Skantze

  13 Jun 2025
In the latest episode of the Robot Talk podcast, Claire chatted to Gabriel Skantze from KTH Royal Institute of Technology about having natural face-to-face conversations with robots.

Preparing for kick-off at RoboCup2025: an interview with General Chair Marco Simões

and   12 Jun 2025
We caught up with Marco to find out what exciting events are in store at this year's RoboCup.



 

Robohub is supported by:




Would you like to learn how to tell impactful stories about your robot or AI system?


scicomm
training the next generation of science communicators in robotics & AI


©2025.05 - Association for the Understanding of Artificial Intelligence


 












©2025.05 - Association for the Understanding of Artificial Intelligence