The project started as a "tricopter-only" project, but as I wanted to build smaller vehicles with more payload capacity, I decided to make some quadrotor, hexacopter and Y6 hexacopter firmwares too. My main interest is to build very small MAVs that fly as good as larger ones (or even better) and that can be controlled by wireless video link. I also experimented with autonomous flight in GPS-denied areas (video), and with GPS assisted autonomous hover (video). It would be cool to add more features to this project but I am pretty busy with my PhD research. But maybe one day I could combine my scientific interests with my hobby projects...
Contact: Shrediquette @ g m x . d e --- All content published under CC Attribution-Noncommercial-Share Alike 3.0 Germany
Recently, I finished publishing my PhD thesis. The public defense will take place on the 31. of october 2014. Although my thesis mostly deals with aerodynamics and flapping flight, there is one chapter that could also be of interest to the readers of my multirotor blog:
Chapter 5: Micro Air Vehicles - linking aerodynamics with application
Here is the full thesis.
The link to the pre-order:
This year, the 'International Micro Air Vehicle Conference and Flight Competition' (IMAV2014) took place on the 13th of August in the Netherlands. I am very happy to announce that together with my team (called 'Dipole', consisting of Prof. Klaus-Peter Neitzke, Dr. Hans-Peter Thamm and me = William Thielicke), we won the second prize in the IMAV competition!
Fifteen international teams accepted the challenge and tried to score points in the simulation of a major natural disaster inside a small artificial village. Several tasks had to be solved during a 30 minute time slot: Creating a stitched orthophoto of the whole village; flying through the village and identifying house numbers and survivors inside the houses; observing a given spot; entering a two-storeyed house and flying through the rooms while identifying objects in the rooms (see the detailed rules here). Points were awarded for each of these tasks, and summed for the final score.
Our team used three different multirotors in parallel, including my 'GEMiNi' hexrotor, an 'Alpha' quadrotor by Klaus-Peter Neitzke and the larger 'Geocopter' by Hans-Peter Thamm. This year, the 'Alpha' and the 'GEMiNi' were again the smallest vehicles of the competition. While the 'Geocopter' flew over the village autonomously creating a high-resolution orthophoto, the 'Alpha' and 'GEMiNi' went through the houses of the village to identify some house numbers. This was pretty challenging, because we had to use 5.8 GHz for the video link, and there were a lot of obstacles between the antennas, making the video quality very poor. These copters also entered a large house and flew through many rooms. This was not as easy as I thought, as there was a strong wind that was clearly noticeable also inside the house (because the windows were open). The space in the rooms was very limited, and we didn't know anything about the floor plan and potential obstacles before we entered the building.
The first prize went to the team of the National University of Singapore. They came with eighteen people and ten copters. Most of these copters were equipped with impressive laser range finders and other fancy sensors. This team really deserved the first prize, they did a great job!
Here's the scoring of the first three teams, the scoring of the other teams can be found here.
1st prizeNational University of Singapore (Singapore) points: 683
Onboard automatic image stitching, onboard number recognition(*), onboard autonomous laser-based room navigation, onboard computer vision based precision roof landing, autonomous takeoffs, autonomous landings (*), onboard computer vision based 7-segment digit recognition (*), autonomous flying WiFi-relay.
2nd prizeTeam Dipole (Germany) points: 425
Smallest MAV's of the competition. Very talented FPV flight with many take-off, precision landings, reading house numbers, visiting 18 indoor rooms (several double and not counted), recognizing 16 indoor objects correctly. Geocopter auto-take-off and flight, precision auto landing and partial high resolution ortophoto.
3rd prizeEcole Nationale de l'Aviation Civile (France) points: 189
Autonomous takeoff, Best overall photomission, all blockades visible, full village high resolution map at 6cm/pixel, autonomous computer vision based 7-segment display reading (**), longest correct observation string, autonomous roof landing (*), reading house numbers with many ARdrones in autonomous flight. Several autonomous landings.
(*) Item attempted but either failed, or needed manual flight, or not according to competition rules.
(**) Item attempted in autonomous mission mode, but human intervention was needed and it got scored in autonomous flight mode.
Here are some photos of the event:
Letting the cat out of the bagThe TBS GEMiNi is a small hexrotor that is meant for fpv racing. The frame is based on my Shrediquette GEMiNi that I developed in spring 2013. Team Blacksheep (Trappy, Riscyd and Perna) contacted me a while ago, and we started to modify the design in order to improve it further and to make it more user and crash friendly. After some information had already leaked before the offical release (may it be on purpose or not... ;-D), the new TBS GEMiNi has now been officially announced on fpvlab.com. This means that you can very soon buy the GEMiNi multicopter!
Features of the TBS GEMiNi
- Forward-tilting motors for efficient, high speed flight
- Built-in FPV camera (TBS ChipChip V2)
- Optional HD camera (Mobius Action Cam)
- CORE OSD/power supply with integrated current sensor
- Ready for long range FPV
- Custom 4A ESCs with SimonK firmware
- Custom T-motors
- 4" propellers
- Motor distance: ca. 215 mm = 8.5"
- Taulabs Quanton-based flight control
- Crash-friendly, yet integrated layout
- Top speed: About 90 km/h
- Weight: About 340-370 g
- Price: Less than 600 USD
The package includes the TBS Gemini main frame + plastic parts, a canopy for race and film, the motors / ESCs / props, a flight control, a pre-configured CORE PNP25 (optionally upgrade to CORE PRO), a FPV camera, a TBS BOSS 5.8GHz (optionally upgrade to 2.4GHz), a 3S battery and a fancy carrying case. The GEMiNi can be ordered by end of august, and it will be shipped by late september.
What about the tilted propellers and the canopies?On the GEMiNi hexrotor, the motors are tilted 10 degrees forward in order to decrease the angle of attack of the copters body in forward flight, which decreases the net aerodynamic drag in fast translational flight. Additionally, the canopies help to reduce the drag coefficient of the copter. I measured the effects in a wind tunnel using a two-axes force balance, and the results show that the drag is reduced by something around 30%. See my detailed wind tunnel measurements here.
The handling of the copter is not affected as long as the IMU is aligned parallel to the propellers (you can also rotate the IMU by software via calibration). It seems likely that tilted propellers might become more popular in the future, similar to my 2010 "design invention", the spider frame.
What are the differences compared to the Shrediquette GEMiNi?On the TBS GEMiNi, we don't use my own flight controller (Shrediquette Xmega MPU60X0), but a Taulabs Quanton based controller. In "heading hold" (= angular velocity control), it feels very much like my flight controller. But the Taulabs also has a "stabilize" mode (= angle control), which makes it more suitable for the broader audience and for beginners. Taulabs additionally has a large number of interesting features that I like a lot.
There are also no LEDs on the canopy. This is because it is team black sheep that produces the copter and not team christmas tree sheep. But LEDs can easily be added to facilitate LOS flight.
For me, the most important difference is the 4S capability. The ESCs I had to use in the Shrediquette GEMiNi were actually designed for 2S and I was using them at 3S. The custom TBS ESCs allow to use 4S (which I do all the time), that makes the TBS GEMiNi pretty fast.
The most important question: How to convince your wife that you need to get the TBS GEMiNi...I started working on the GEMiNi while it was clear that I'd soon become father of twins. So I decided to make something beautiful and dedicate it to my gemini girls. The idea was to sell some canopies and invest the money in diapers. Now, I am extremely happy with the result (the girls are just awesome), and each TBS GEMiNi somewhat actively contributes to bringing them up. I am sure that is something your wife would support :-D
Here are the props I tested:
|The propellers under test: APC Multi Rotor 12x4.4" ; Xoar Electric precision 12x4" ; Maxxprod EPP 12x4.5" ; Aeronaut CAM Carbon light 12x5" ; Graupner E PROP 12x6"|
Here are the measurements:
|Thrust and power at 3S (12 Volts)|
|Thrust and power at 4S (16 Volts)|
|Graupner E PROP 12x6"||21 g|
|APC Multi Rotor 12x4.4"||22 g|
|Aeronaut CAM Carbon light 12x5"||17 g|
|Maxxprod EPP 12x4.5"||9 g|
|Xoar Electric precision 12x4"||16 g|
So, my choice is the Aeronaut CAM carbon light propeller (they exist in quite a number of diameters).
Images taken from TVinfo.de (note to the copyright owners: if you don't want to see your images here, drop me an email!)
Die große Show der Naturwunderam 31.07.2014 um 20:15 Uhr auf ARD Heiß her geht es diesmal in "Die große Show der Naturwunder". Frank Elstner und Ranga Yogeshwar präsentieren ein geniales Löschmittel und einen neuartigen Flugroboter, der die Natur zum Vorbild hat.Zu Gast sind Comedian Guido Cantz, die Schauspielerinnen Stefanie Stappenbeck und Marie Bäumer sowie Fernsehkoch Horst Lichter. Sie stellen sich den Quizfragen, müssen aber auch außerhalb des Studios ran.via TVinfo
I am very much looking forward to the event, and I expect to see a lot of very interesting and great autonomous systems from different teams all over the world!
--> Results in this post here! <-- a="">
HEXO+ on Kickstarter
As you might already guess from the look of this hexrotor, I was involved in designing the airframe and selecting the electrical components for this project. Here are some pictures of early prototypes:
I am giving a short demo flight with the GEMiNi and video goggles. Ranga Yogeshwar also does a short interview with me. The show will be broadcasted on the 31. Juli 2014 at 20.15h in the ARD.
It took around 4 days to produce this show, so my partner, my twin (gemini) girls an me spent a very nice week in a lovely hotel in south Germany. I really enjoyed the time over there, it is so interesting to get insights in such kind of TV productions!
Here's a description of the "multirotor part" in the show.
I can not show pictures of the show itself or give further details, but here's an image with the host Ranga Yogeshwar (as I expected, I was impressed that he is such a clever and friendly person) at the after-show party, and another one of my "personal wardrobe" (this is the proof that I was there ;-D).
|Ranga Yogeshwar and William Thielicke|
|My wardrobe ;-)|
Here are photographs and some more information (in german however...):
|Photo: Karin Lehmann, Peter Blei|
|Photo: Karin Lehmann, Peter Blei|
|Photo: Karin Lehmann, Peter Blei|
Some more photographs by Fotoservice Kötz
Thüringer Allgemeine article
We had a small multirotor-meeting here in Bremen last weekend, and there were also some people that were up for a FPV-competition. So the GEMiNi had its first opportunity to do what is was built for: Race!
A track was quickly built from chairs, tape and some other stuff we found. It was a lot of fun (well I could do FPV-competitions every day because I like it very much to fly "for a reason"), and the GEMiNi finished first.
See the video here: