Shrediquette - a multirotor MAV by W. Thielicke

Eight pages article on my trip to Cameroon: RC-Flight-Control Magazine 2011/2

2011-10-17T16:37:00.000+02:00

RC-Flight-Control is the german magazine dedicated to first-person-view (FPV) radio controlled flight. In the latest issue (02/2011), there is an eight pages long article about my trip to cameroon. I included some background information about the challenges I was facing during the preparation of the journey and also during my stay in cameroon.

One of my aerial photographs also ended up on the cover of the magazine (you can actually see my girl friend and me enjoying the sun on the patio :-D ).

The magazine can be ordered online but it is also offered in many book stores at central railway stations.

IMAV2011 - Team AKAflieg Bremen successful

2011-09-19T11:04:00.000+02:00

Results:
1st place indoor pylon challenge
1st place indoor exploration mission
>= 4th place outdoor mission
Special award: KLPD user trophy (best operational MAV)
2nd place endurance mission

The 12th -15th of september 2011 was IMAV time again... The IMAV2011 is an international conference and flight competition for micro air vehicles. This year it took place in 't Harde (The Netherlands). We (a group of five hobbyists that are also members of the academic flight club Bremen) participated in the outdoor and indoor competitions, and I also had the opportunity to give a talk about some of my PhD work.

Antenna tests

I took my BOLT with me, and Tumba, one of my team members, took his "Zecke" and a fully autonomous "Ninja" to the competitions (his copters are also 100% built from scratch). For the outdoor competition, we had to fly 500m away and identify some things. With our standard video equipment, this seemed to be impossible, so we asked Sebastian Seidel from GlobeFlight for help. He kindly provided two diversity systems (ImmersionRC DUO5800 v2), two 12dBi directional antennas and two monitors. We tested the equipment on the ground (see image) and in the air, and got a perfect image over ~500m distance (remember, we are restricted to use 25mW AV-transmitters here in Germany). A big thank you goes out to Sebastian for his important support!!

Indoor Pylon Challenge

Tuesday was the first day of competitions. There were two indoor competitions: In the first one, the mission was to fly as many "8's" around two pylons in three minutes. Many teams participated with the Parrot AR drone, which seems to be a reliable, extremely stable and robust platform. The drone was extended by some extra code by many teams, so that they were able to fly some rounds around the pylons autonomously. That was pretty impressive. We have also seen some very nice "coax-flying-things" (well, I think there is not really a name for it...), that had an brilliant flight performance. And then, there was a quadrotor that was equipped with a laser scanner. This thing was also flying fully autonomously, and I think it was the fastest autonomous robot in the competition. Very nice work!

Demo flight

We participated with the BOLT and the Zecke, I managed to fly 32 rounds in three minutes. People seemed to be impressed by the flight speed of the BOLT, and they asked me to do an extra demo flight with the FPV image being displayed on a big screen. An autonomous flight will give you 12x more points than a flight that is controlled by FPV, but with the high speed and the small size of the BOLT, we managed to receive the first prize for the indoor pylon challenge.

The impressive MAVion Roll & Fly

Indoor Exploration Challenge
The second competition was called "indoor exploration mission". The task was to enter a building, find and identify two patterns, pick up a target and leave the building. The target has to be dropped in the "drop-zone", and a precision landing has to be done. We always attempted the missions with two independent copter systems (Zecke and BOLT).

In preparation for the IMAV competition, the BOLT was equipped with an extra 180° servo and a small hook, so a target could be picked up and dropped. I managed to enter the building through the chimney, identified both patterns, took up the target and left the building through the door. The target was dropped in the correct zone, but unfortunately, the downwash of my copter blew the target away. It seems that no other team attempted to pick up a target. In the end we also received the first prize for this competition (that was a big surprise for us).

A video of the indoor exploration challenge with Shrediquette BOLT:

Outdoor Mission
The outdoor mission was also very interesting. Actually, I wanted to compete with a flying wing, because I can fly very far away with such an aircraft, still having a very good video link. I modified my copter code, so that the aircraft can be controlled in "acro-mode" (that means that I am controlling the angular velocity of roll and pitch of the airplane). Some tests have shown that this really works well, in very windy and turbulent situations, the aircraft is still very easy to fly.

Flapping wing from Egypt, arch & balloon

But after the indoor competition, many people asked me to fly the BOLT also outdoors. The problem is, that I only have one video transmitter and one FPV camera, that means that I always need to change cam + av transmitter from one aircraft to the other. And that takes quite some time. I know that the BOLT flies very well in windy and turbulent conditions, so I decided to attempt some mission elements with the copter. The flying wing was left in the hotel room.
My team decided that I should take-off first, fly through the arch and do the precision landing. After that I took off again and tried to hit a huge balloon. Well, it was clear that my copter is not going to win this fight (see the official video) - I hit the balloon, lost a propeller and smashed into the ground. Two points! ;-D.

Team AKAflieg Bremen

Indoor team

Tumba then took off with his autonomous "Ninja". Although there was quite some wind (and also worth mentioning: Tumba doesn't have a compass on board...), his copter did a perfect flight in ~450m distance. Tumba became a bit nervous, because it was impossible to see the copter anymore... But fortunately, we had a perfect video link, so we could locate a vehicle and count the number of persons leaving that vehicle.
We couldn't get one of the prizes for the outdoor competition, but we were really happy with the results. The "Deutsches Zentrum für Luft- und Raumfahrt (DLR)" won this competition (they came with about 15 people and several AscTec Pelican and Falcon 8 copters). They really did an amazing job and had a very good strategy. ENAC paparazzi reached the second place. They had very nice aircraft which performed really well and these people really know what they are doing. The third place was reached by the KLPD / NLR / Royal Netherlands Army team, they also master the controls of their aircraft.

Our teams MAVs

Best operational MAVs
At the end of the competitions, we additionally received a special price from the dutch police for the best operational MAV system. This is a great honor in my opinion. That was really cool, the trophy is huge and all our copters fit into the cup. Very handy...

Best operational MAV system trophy

There are two errors hidden in this image... Who finds them?

I really would like to thank the organizers of the IMAV2011, it was really fun, I had a lot of exciting and inspiring discussions, and we have seen many great and innovative MAV platforms. See you maybe next year in Braunschweig at the IMAV2012!

Official IMAV2011 video:

Feinkost - music video shoot with Shrediquette MM6

2011-09-07T11:45:00.002+02:00

About two weeks ago, Julian from the german band "Feinkost" wrote an email to me: Together with his band mates, they were giving some concerts in Cameroon. The tenant of the "Seemannsheim" in Douala (I know him from previous trips to Cameroon too) seems to like my Cameroon video very much, so he showed it to the band while they were staying there. They were also enthusiastic about the video and because they were planning to make a video for the new song "Wenn du wiederkommst", Julian decided to ask me for some aerial footage for the new video.

Because these sort of "jobs" always seem to be fun, I agreed, and together with Thomas Leidig (camera operator, director) we shot the video at two locations in and around Hamburg. The weather conditions were a bit challenging, the first day at the tidelands had a lot of wind (although hardly turbulent) and some rain. On the second day we were shooting in the city of Hamburg with some storm and a lot of turbulences between the city blocks.

But in the end we had at least some aerial footage that looked pretty good. The final music video is available at Musicload.de, and soon also on iTunes etc.:

Feinkost - "Wenn du wiederkommst" at Musicload.de
By following this link, you can also see a short preview of the video.

Feinkost - "Wenn du wiederkommst" at iTunes.com

The video shoot was great fun, the guys from Feinkost are really nice and they make some fine music!

Feinkost - "Wenn du wiederkommst" band & video staff

Some stills of the video (by courtesy of Feinkostmusic)

Third place on the short film festival "Vilsflimmern"...!

2011-08-16T21:46:00.001+02:00

On the 29th of july I went to the Vilsflimmern short film festival in southern germany. The people were really friendly and very nice (although sometimes hard to understand, they speak a very special german language version down there... ;-D). Ten short films out of around 40 submitted ones were selected and shown in the evening on a large screen.

Although the weather was really really bad (cold + rain), quite a number of people came to see the shorts.

Nr. 6 was finally my film, it was a strange feeling to see it on such a large screen with many people... Unfortunately, the sound system seemed to suffer from the rain, about one minute of my movie was played without sound... Also a strange feeling ;-D

Then the people from the Kulturverein Amberg announced the winners, and I was really suprised to hear my name! I got the third place for my movie, great!!

There is also a small clip from the television with some details about the festival:

http://www.oberpfalz.tv/nachrichten/vilsflimmern.html
(the guy in green is me @42s remaining)

Both the second and the first place are also very nice movies:

2nd:
"Der Massl-Effekt" from Christopher Schlierf
http://vimeo.com/20965651

1st:
"Das Haus" from David Buob
http://www.dashaus-animation.de/dashaus-trailer.mp4

This is my contribution:

"Etwas über Kamerun"

Shortfilm Festival - "Etwas über Kamerun"

2011-07-24T21:12:00.002+02:00

The FPV movie on Cameroon that I made some months ago will be shown on a short film festival. The festival is called "Vilsflimmern" and it will take place on the 29th of July. It is an open-air event in south-east germany. At that time I am on way way to france on holidays, but most likely, I'll spent some extra kilometers to visit this festival:
http://www.tenano.de/

By the way: The Landkamp Festival was great fun! This is really a very nice Copter-meeting, I am already looking forward to the next year's meeting! I also visited the FPV-community.de meeting, and that was also great. Really nice to meet some people in "real life".

LandKamp!

2011-05-27T21:30:00.000+02:00

Only one week to go for this years LandKamp! Anyone that is interested in copters should really visit this nice meeting. Last year it was a lot of fun with many friendly and interesting people.

This is what I'll take with me this year (actually all copters I have :-D):

This year’s “Landkamp 2.11” takes place from the 2nd of June to 5th of June 2011 at the sports ground which is located next to the soccerclub in Ostheim/Rhön. “Landkamp” is a privately organised event. There will be many “Kopter” fans from all over Germany. “Landkamp” is one of the longest multi-kopter conventions in Germany due to four days of camping, crafting, flying, challenges and lot of nice talks with like-minded people.

Website: http://www.landkamp.de

Watch this video for some impressions of last year:

BOLT is born

2011-05-11T02:55:00.000+02:00

The latest project, a tiny Y6 hexrotor, is airborne...! I am really happy with the results, the copter is great fun to fly. Here is a video of it (it seems to be really hard to film it in flight...):

Shrediquette BOLT from W. Thielicke on Vimeo

I will use it mainly for FPV. The little thing becomes pretty fast for its size, it is very precise and fits through the smallest holes... It does even fly pretty ok when one propeller is missing.

Some details on this copter (more pictures on the BOLT page):

BOLT: Compact Y6 FPV hexrotor / hexacopter

Max. dimension 21 cm
Motor shaft distance 10.6 cm
Roxxy 1815/25
Airace propellers
"CCD-Killer" CMOS FPV camera
mGUIDE controller
Turnigy Plush 6A ESCs + I²C->PWM micro converters
3S 1000 mAh battery

Shrediquette MM6 in Japanese TV

2011-03-01T09:18:00.000+01:00

Some days ago, a director from NHK (Japan Broadcasting Corporation) contacted me because he saw my cameroon video in the internet. NHK has a program called "Tokudane Toukou Doga", where interesting internet videos from all over the world are shown with some comments from the film-makers. They wanted to introduce my video and also asked for a small interview via Skype. As this promised to be quite some fun, I agreed of course :-D

The NHK show can be found here:
http://nhk.jp/doga/?375190 My hexacopter part is from 01:35 - 04:00

Shrediquette MM6 in german television

2011-01-20T20:48:00.003+01:00

Hi,
my hexacopter was recently in german television (rb TV). Sven from www.heli-bremen.de made the connection between the TV crew an me. It was fun to do something like that with my copter, but the weather was really awful... Rain, a lot of wind and very low temperature.

TV clips:
Click here for a short clip:
http://www.youtube.com/watch?v=s26Ziv0iXMk

And here for a longer clip:
http://www.radiobremen.de/mediathek/index.html?id=041531

A nice place to fly: Hexacopter in Cameroon / Africa

2011-01-18T12:06:00.002+01:00

Usually I visit my parents on christmas and new year. They live in Cameroon since three years and built a small house in the middle of nowhere. This year they again invited me to come and I had the opportunity to take my hexacopter with me. All flights were done via video-goggles / FPV (except for a single scene that you see in the movie). In total I broke 3 propellers. Two when I was falling down the roof of the car and one when I hit a bamboo tree (which seems to be made of very hard material...;-D). I broke the antenna of my RC transmitter, and lost the antenna of the video link. Fortunately, I was equipped with enough spare parts. Flying in Cameroon was great fun, but flying at the beach seems to be dangerous, as there are immediately some large birds of prey arriving, which were probably not in the best mood. Flying through the palm tree plantation was most fun, but there were a lot of mosquitoes attacking me.
Here is the video:

A nice place to fly: Hexacopter in Cameroon / Africa from W. Thielicke on Vimeo.

Cameroon video in progress...

2011-01-14T12:03:00.002+01:00

I had the opportunity to record 2hrs of FPV video during my holidays in Cameroon. It was great fun, and I am currently making a small movie out of it that will be posted soon. Here are a few stills already:

Everything was filmed with the GoPro HD and video-goggles (FPV) with my MM6 hexacopter:

It's cold outside...

2010-12-20T10:19:00.000+01:00

... so the best thing to do is to escape to Cameroon! And that is what I'll do :-D .

Whats next...?
Hopefully I don't crash my copter in Cameroon on the first day (like I did last year...). I will try to make some nice aerial shots and to create a movie.
Currently, I am working on a very small Y6 Hexacopter that will have 4-5 IR sensors installed. These sensors will be used to stabilize the position of the copter in relation to walls that are close to it. If that works out, this copter will be my small contribution to the IMAV2011 competition next summer.

Shrediquette goes multicopter!

2010-12-03T18:59:00.001+01:00

Several requests "urged" me to release new versions of my firmware. I made a quadrocopter (quadrotor), a hexacopter (hexrotor) and a Y6 version of the Shrediquette firmware, called MM4 respectively MM6. Quadrocopter & hexacopter versions were tested and they seem to work pretty good (see e.g. here). My MM6 flies really good (I am using the same motors/ props/ ESCs as in the DLXm), I built it to make some nice movies when I am in Cameroon on christmas.

Next, I am planning to build a Y6 hexacopter that is even smaller than my DLXm tricopter. The firmware for a Y6 Copter is already included in the zip archive, although I couldn't test it yet. For this tiny copter, I have to design a new PCB with a very small footprint (27 x 37mm). This PCB will be some sort of "minimal circuit", that means it doesn't include components for a servo nor LEDs nor connectors. It is just as small as I could make it:

The new firmware versions are included in the existing zip archive (Source code (.hex and .bas)).

First successful GPS position hold tests!

2010-09-29T02:00:00.018+02:00

I added a GPS module, a compass and a pressure sensor to my tricopter to enable automatic position hold. GPS is implemented using a PD control loop, compass is P only, and height is PID. And... it works! Still not optimal, but in principle it is already ok. There are some things that have to be optimized of course, e.g. a one-axis compass will probably not work for waypoint navigation and position hold when there is wind. And my code is still far from being optimal. At the moment, I have to make my copter hover at the position + height that I want. Then, I flip a switch (connected to channel 6) - current position, heading and height is stored and used as setpoint for position hold. I think I will have to switch to a 3-axes compass in combination with an additional 3-axes accelerometer. That will enable tilt compensation for the compass, as well as improving the D-term for height stabilization.
The tests that you see in the video where done with no wind at all. The tricopter stayed mostly within a circle of around 3m diameter. So that is close to GPS precision. Funny to watch the tricopter for 30 minutes without doing anything...

Additional components used for this setup (maybe I'll try different ones):
GPS: LEA-4H
Pressure sensor: BMP085
Compass: HMC6352

And here for the DLXm (parameters don't fit yet, but pressure sensor is also very close to the propellers...):

Shrediquette with IMU 6DOF Razor - Ultra-Thin IMU

2010-08-19T15:00:00.004+02:00

Sven - a friend of mine - built his Shrediquette using the cheap IMU 6DOF Razor - Ultra-Thin IMU. Some modifications have to be done, because the gyros and accelerometers on this IMU work with 3.3V instead of 5V:

You will also need to modify the source code, because the arduino needs an external 3.3V reference for the ADC. Modify this line to change from AVCC to AREF:

'===ADC SETTINGS===
Config Adc = Single , Prescaler = Auto , Reference = Aref 'reference is changed from AVCC to external reference AREF

The source code for an external reference: Tricopter_m328p_11_external_reference.zip

Here is a video of Sven's Shrediquette. I also had the opportunity to test it in flight, and it flies really good.

The only drawback is the IMU's sensitivity to vibration, so you really have to make sure that vibrations are generally low. This is how Sven tried to dampen the IMU:

If you have questions regarding this mod, please contact Sven (email is in the pictures above).

Firmware improvements

2010-08-17T16:45:00.000+02:00

Changes:

Gyro offset measurement changed. Right after the startup, the copter tries to measure the gyro offset. If the copter is moved during this period, it won't continue with the start-up. Instead, it will flash the LED in the middle until the copter is placed on the ground. Only then it will initialize.
Servo control improved: The servo pulse generation is now synchronized to reading out the receiver. Additionally, it is not possible anymore that an interrupt makes the servo jitter (thx to Lutz Meyer). All servos should work much better now.

FPV videos, firmware tweak, user builds

2010-08-12T15:19:00.000+02:00

Some days ago, I added two FPV videos to the video-section:

There are also some more details on the FPV setup that I use in the FPV section. Additionally, there is a new section showing some Shrediquette user builds. Please keep on sending me details about your own build.
Soon (next days) I will release a firmware update, that seems to reduce servo jitter, especially when using fast digital servos. Lutz Meyer tweaked some lines of the source code (thanks! :-D ). Lastly, for all people from northern germany, I would like to point your attention to a quadrocopter meeting that will take place on Aug. 21. in Bremen.

50,000 visits on shrediquette.blogspot.com

2010-07-30T16:00:00.000+02:00

Time for some statistics...:

Although the word "Shrediquette" seems to cause some confusion, still some people found their way to this blog. Here is a bunch of google search word logs:

Thanks to all the visitors, I made a quick video for all of you (don't try this at home...):

Success at the International Micro Air Vehicle Conference and Flight Competition (IMAV2010)!!!

2010-07-09T23:45:00.003+02:00

This year, a friend of mine and I both decided to go to the IMAV 2010 with our "flight devices" (Tumba with his autonomous Lerche 400 & 500 planes, and me with my Shrediquette DLXm + my brand new FPV goggles).

Participants came from many countries to attend the conference and to compete in the four competitions. I participated in two of them: indoor flight dynamics and outdoor flight dynamics (as the GPS add-on for my tricopter isn't yet finished).

The competitions were great fun, I especially enjoyed the outdoor competition where I used a FPV camera for the second time (I had a total of 16 minutes of experience with FPV). It is so cool to fly around in 3D space! I will definitively spent "some" time using these cool video goggles! This is my setup for outdoor flight dynamics:

The Shrediquette DLXm was the smallest MAV in the contest (this yielded some extra points). The results make me especially happy :-D :

1st place outdoor flight dynamics (rotary wings)
1st place indoor flight dynamics (rotary wings)
1st place outdoor flight dynamics (global)
1st place indoor flight dynamics (global)

(image from multirotor.de)

The competition was pretty "efficient", as I only burnt 800mAh in total, and luckily didn't crash anything. Tumba achieved the 2nd place in Outdoor Flight Dynamics - Fixed Wing, the 3rd place in Indoor Flight Dynamics - Rotary Wing, and the 3rd place in Outdoor Autonomy - Fixed Wing. Congratulations to him!

Here are the official results of the IMAV2010:

I would like to attend the IMAV2011 next year if my PhD allows it, but I will have to find a sponsor, as this will by far exceed my hobby budget. Feel free... ;-D

I might add some video footage of the IMAV2010, until then, have a look at this video here to see the Shrediquette DLXm in FPV (sorry for the quality, my framegrabber isn't really good & it skips frames, and all settings are still far from being optimal):

Article on Shrediquette

2010-06-23T10:07:00.002+02:00

Paul Escalier from TomsGuide.com just finished his article on my tricopter. It has become a nice story I think :-)

Make Your Own Gadget: From Idea To Reality

Table of contents

A Time to Make Something Awesome
A Little Bit of Background
The Birth of an Idea
Taking the Plunge: Buying Some Parts
Building the First Prototype
Overhaul: Taking the Prototype to a New Level
A Few Polishing Touches and a Mini Conversion
Future Developments and More Information

Have a look at the article here:
http://www.tomsguide.com/us/tricopter-diy-gadget,review-1552.html

First steps to autonomous outdoor flight...

2010-06-13T23:09:00.001+02:00

Some of you might already suspect that I am trying to make my tricopter fly autonomously not only indoors, but also outdoors. I got some parts as a present from watterott.com (GPS & pressure sensor) and I bought an aditional compass sensor. First of all, I had a look at the GPS. It is a 10Hz, 65 channel SUP500F receiver (SUP500F). Results were a bit disappointing:

I am standing still during logging (~1 minute), with a free view to the sky and no clouds. Next, I tested the pressure sensor (Bosch BMP-085). I was just using some very simple low-pass filters, and results were pretty ok already:

The sensor was moved several times from 0 to 2.5 meters. The compass (HMC6352) also works pretty ok. It delivers very precise heading information, even when the motors are running. But, when the sensor is tilted, there is an error in heading (due to the principle of measuring). There are much more expensive sensors available that can correct for tilt, but that is not really a problem I think: In position hold, the tilt angle will always be pretty low. When doing waypoint navigation, the heading can be read from GPS, hence heading data can be calculated from complementary filtering of gyro/ GPS/ compass if necessary. Here is a extremely boring video of my DLX with pressure sensor and compass active. From second 20 till the end of the video, I am not touching throttle or yaw anymore:

Pressure and compass test on Shrediquette DLX from B. Thielicke on Vimeo.

Finally, I had the opportunity to test a uBlox LEA4 GPS receiver from a friend of mine. On the first picture, I was standing still for ~1 minute, on the second picture I was walking around in several "8's". This GPS receiver seems to be pretty awesome, that's why I instantly ordered one. I am pretty confident that position-hold will work out with this sensor.

GPS, pressure sensor & compass are connected to an extra microcontroller which does all the processing. It sends a small byte array (4 bytes containing throttle, yaw, roll & pitch correction data) to the TriGUIDE via UART. The correction data is forwarded directly to the motors. Like this, modifications on the TriGUIDE firmware are minimal, and processing speed doesn't suffer.

New firmware v1.1 and GUI released

2010-05-21T22:43:00.002+02:00

Today I finished the last test under veeery windy conditions, and everything went fine. The files at the right hand side (GUI and firmware) are updated.

Please note that the new firmware will only work with the new GUI and vice versa! You will also not be able to use your old settings files. Double-check the direction of your servo, something has changed here too.

The firmware should allow to increase control loop parameters, especially Acro-P and Hover-D. That should make your tricopter more stable. A new default-settings file is included, as well as my settings for the DLX and the DLXm. You can flash the firmware using my GUI. The file Tricopter_m328p_11.hex has to be placed into the GUI folder.

Dedicated pages for micro and standard version

2010-05-09T16:45:00.001+02:00

The Shrediquette DLX standard size tricopter and the Shrediquette DLXm micro version, both got a small webpage with new detailed pictures and specifications:

Micro version:

--> Shrediquette DLXm <--

Standard version:

--> Shrediquette DLX <--

If you still miss some details/ pictures, let me know.
I also modified the FAQ section, please have a look at it too.

The mini is airborne!

2010-04-20T01:46:00.004+02:00

The Shrediquette DLXm micro-tricopter flies better than I ever expected. New control loops make it very stable in fast flights, during aerobatics, when there is wind or when it is flying in it's own downwash/ the ground effect.

Watch the DLMx presentation in HD:
Shrediquette DLXm - Self Stabilizing & Aerobatic Micro-Tricopter. The Movie.

Thanks to Stefan for milling the frame (in carbon fiber, hehe) and to Eric for borrowing the ESCs!

Specs Shrediquette DLXm
Motor shaft distance: 132 mm
Max. dimension: 259 mm
Weight: 230 g
Props: 5x3 3-blade GWS
Motors: Roxxy 2216-25

ESCs: Turnigy Plush 6A with I²C->PWM converters
Battery: 3S, 800 mAh
Max thrust per motor: 237 g
Thrust to weight ratio: 3.1:1
Total current during hover: 4 A
Endurance: 11 mins

The control loop now processes angular acceleration in acro and hover mode: I finally managed to calculate "up to date" angular acceleration with only little noise. As a result, the gain of the gyroscopes could be increased by 100% which results in a much better stabilization. The new firmware still has to be tested with a standard size Shrediquette, but I am very optimistic.

-> Update: Some test have already been done,I am not yet satisfied with the results of the new firmware on the standard size copter, but I keep on testing...

Shrediquette DLXm

2010-04-02T22:35:00.001+02:00

Here are some pictures of my Shrediquette DLXm. Unfortunately I am still waiting for the ESCs... Slightly annoying.

EDIT:The ESCs arrived (thanks to Eric!) and first flights were very successfully completed. The control loop had to be modified to account for higher demands of this micro tricopter during aerobatics and fast flights. Because larger Shrediquettes will also benefit from this modification, I will soon release a new firmware and a modified GUI. I will now start to collect some video footage and make a new movie.

Something different...

2010-03-23T19:14:00.000+01:00

Ok, I am actually still waiting for my ESC order to arrive (for the Shrediquette DLXm)... I was hoping that the ESCs would arrive during my holidays last week, but they didn't. So I am not able to present you a nice video of the Shrediquette DLXm in flight, shot with my brand new GoPro HD Hero camera. But you might nevertheless be interested in seeing some footage that was shot with my cam during last week's holidays. I am absolutely impressed by the exposure control of the cam and the high resolution/ slow motion feature. This seems to be THE cam for on-board videos...!

Video: http://www.vimeo.com/10375186

TriGUI tutorial

2010-02-25T18:10:00.000+01:00

Here is a movie showing how to use the GUI:
TriGUI_tut.wmv

Shrediquette DLXm

2010-02-19T14:00:00.000+01:00

The design for the new mini Shrediquette seems to be finished by now. Here are some images:

Specs/ design goals
Motor shaft distance: 139mm
Max. dimension: 266mm
Weight: 261g
Props: 5x3 3-blade GWS
Motors: Roxxy 2216-25
Battery: 3S, 800mAh
Thrust per motor (measured): 237g
Thrust to weight ratio: 2.7:1
Current during hover: 4 A
Endurance: 11 mins

Hopefully I'll soon find some time to put it together...!

CFK chassis...

2010-02-10T23:32:00.000+01:00

Probably, you already know the CFK chassis I am using on my personal Shrediquette. The chassis is really light, and I like the look a lot. While the chassis I am using was cut by hand using a jigsaw, now there seems to be a much easier way to get a chassis like this:
Max from California contacted me some days ago, and has the possibilities to make some sets of my chassis from carbon. If you are interested, please feel free to contact Max:
maximus365@@@juno.com

I made a rendering to show the two different sizes that I designed. I am planning to order the mini chassis, because I am currently making a mini-Shrediquette (153mm distance between motors).

Sizes of the chassis':
Mini: 10cm diameter
Standard: 14,5cm diameter

Oguz's Shrediquette

2010-01-31T21:47:00.001+01:00

Here is another Shrediquette, built by Oğuz. He experimented with a fixed motor and some control surfaces to enable yaw control.

Although the propellers are too heavy to allow an efficient stabilization, his tricopter seems to fly pretty good:

Tricopter test flight from Oguz on Vimeo.

Edit: Here is another outdoor video of Oguz:

Tricopter Stability from Oguz on Vimeo.

Finished I²C to PWM converter and TriGUIDE mini

2010-01-29T00:17:00.005+01:00

The last nights were a bit shorter for me, since the PCBs I ordered at bilex-lp.com arrived. They look really good and seem to be of high quality (I ordered a different "solder resist" colour, well, I like bright colors, but anyway... ).
So I had the opportunity to do my very first SMD solderings. This really seems to be comfortable... I will completely switch to SMD I think.
The I²C to PWM converters work! Here are the features:

Weight under 1 g
Works with (most likely many) standard ESCs (currently tested: HK SS 18-20A, ...)
I²C address selectable via solder jumpers (4 standard mikrokopter addresses dec 82, 84, 86, 88)
Refresh rate selectable via solder jumpers (417 Hz, 292 Hz, 155 Hz, 49 Hz)
Pulse width (I²C 0-255): 990µS - 2010µS
Pulse width at startup (3 s): 920µS
Motor off when no I²C connection longer than 256ms
Motor off when microcontroller crashes (veeeery unlikely)
Powered by the BEC of the ESC, or by an external 5V source (prepared as well)
Very easy to connect: plug the servo cable of your ESC to the converter, connect the converter to your TriGUIDE via a two-wired I²C cable
Does also support standard servos

I could test the converters today together with three unmodified Hobbyking SuperSimple 18-20A ESCs (@Dave: thank you very much!!) in flight. These ESCs work with 417Hz (probably like many other ESCs). I couldn't notice any difference in stability or noise or anything compared to my modified I²C-ESCs ("Quax" firmware) or compared to the "Holger-Regler" with my tricopter. Different refresh rates were also tried. 292Hz doesn't feel different to 417Hz; 155Hz is a bit more nervous when flying in the ground effect and doesn't "lock" that well when releasing the sticks after a fast manoeuvre. 50Hz isn't possible without changing the settings of the tricopter. The gain of the gyros has to be decreased about 50%. After adjustment, flying around is possible without problems. But the reactions are generally less precise.

Eagle schematics & layout, source code are available here:
I²C->PWM converter files (updated with jumper description)
Edit:
I could successfully test the following ESCs on the ground with 417Hz:
Turnigy Plush - 60A, Turnigy Plush - 40A, Turnigy Plush - 25A, Turnigy Plush - 10A, Turnigy Plush - 6A

Second news: My SMD version of the TriGUIDE is finished. I could also test it and it works (phew...!). I added the Eagle files to the existing Eagle zip archive. The software doesn't have to be modified. Weight is 13g.

Updated manual & tricopter firmware

2010-01-23T02:22:00.002+01:00

Interestingly, the first thing that people try when they flashed the firmware to the Arduino, is to connect to my GUI. But the GUI would only work if receiver and sensors were connected to the board. This seemed to cause some confusion.

Tonight, I updated the firmware and the manual. Now, the connection to my GUI should even work if the receiver & transmitter isn't set up correctly. I also introduced a "special LED flashing code" that will show you if the tricopter is ready for a GUI connection (see the manual for details). It is different from the regular "in flight flashing code".

As this will probably not be the last time that I am modifying the source code, I put a text file into the zip that contains the firmware. This textfile ("_changes.txt") will track all modifications.

Most likely, I will not announce every change in the source code. Just have a look at the top right corner: Everytime I changed anything, the timestamp will be updated.

Receiver tool released etc.

2010-01-20T20:47:00.000+01:00

I released a simple tool that allows you to check if the serial connection of TriGUIDE works, and if your receiver can be read out correctly. This tool (actually it is a firmware for the arduino) is included in the source code zip-archive (you'll still find it at the top right corner of this blog). I also put some short instructions on how to use it in the archive.

The PCBs for my I²C->PWM converter should arrive within one week. I will of course instantly test them in flight as soon as I put them together. I will post any news on this very soon. Here is a picture of the latest layout:

I also made a smaller version of the TriGUIDE controller PCB. It will arrive together with the converter PCB's. The new TriGUIDE mini will not have a MAX232 on board any more. The ISP-connector has also been removed (transferring the firmware will be done via the serial connection). The LEDs are not driven with external transistors any more, they are connected directly to the controller. Current is limited to 10-15 mA.

Eric's Shrediquette

2010-01-12T17:31:00.002+01:00

Eric from France made a video that nicely shows the stability of Shrediquette when set up properly.
In the end he also shows a nice low-altitude 180° flip and he demonstrates that multicopters with fixed pitch can't hover in inverted flight... ;-D

tricopter test de stabilité from erictrex on Vimeo.

I2C -> PWM converters

2010-01-09T12:40:00.000+01:00

I2C to PWM converters will make it possible to use standard ESCs with my tricopter design (and other multicopters) without modifying anything. Each converter has it's own I2C address and will deliver one PWM signal for one ESC. The refresh rate will be selectable via solder jumpers (50 to 400 Hz). The final PCB for the converters will have a size of about 20x20mm (0.8x0.8'').
After some setbacks while trying to build a converter with a tiny45, I finally decided to take an ATmega8 (TQFP) instead. This controller features a 16bit timer and I know how to talk to it via I2C...

I put the circuit on a breadboard (with larger electronic components...) and it already works with a servo. I am optimistic that it will also work with ESCs and in flight. I'll try to make the PCB soon...

New brushless motors

2010-01-05T17:21:00.000+01:00

As some of you might know, I am using Scorpion S-2212-26 motors for quite a while now. I am extremely happy with these motors.
Short time ago, SCORPION POWER SYSTEM LTD offered to provide three recently developed motors (prototypes of the SII-2212-960KV) for tests with my tricopter . Of course I didn't say no...!! I had the opportunity to test them recently, and these motors are absolutely great! They seem to be even more efficient and powerful than the S-2212-26 I used before. These motors stay absolutely cold (prop: EPP 10x4.5'') even if I do aerobatics with my copter. I am not a real expert with motors, but if no heat is produced, all the available energy should be converted to mechanical energy/ thrust... And that is also what it feels like :-D . So, I would absolutely recommend to use these motors with my tricopter!
And last but not least, they look pretty nice...

Construction and set-up manual released

2009-12-14T23:40:00.001+01:00

The set-up manual is finished (you'll find it at the top right of this blog). I tried to address all potential questions & difficulties, but I am sure I missed some. The manual will be improved when I get some feedback from you.

Stability tests...

2009-12-05T15:12:00.002+01:00

A quick video: Using different props or adding weight to one of the booms doesn't really change anything.

I also tried to make the tricopter as small as possible. I can't see any differences in flight characteristics nor in flight stability:

GUI released and some other things

2009-12-04T23:54:00.001+01:00

Okay, today there are some more news on the project:
First of all, I can release the GUI. It was tested on Windows Vista and Windows XP. I hope that the GUI is at least partially self-explanatory, but I'll write a tutorial soon.
TriGUI v1.0 features:

COM ports 1-30 selectable
Saving and loading parameter-sets to/ from hard disc
Stick sensitivity (roll & nick, yaw) for acro and hover mode
Exponential agility boost for acro mode
Minimum throttle (idle up)
Free channel assignment (CH. 1-4) for throttle, nick, roll, yaw
Motor deactivation (safety feature)
Inversion of the directions of the gyro's and the ACC's
Modify parameters for the complimentary filter
Hover and acro mode PID parameters
Voltage warning threshold
Display problems with reception
Realtime display of sensors, transmitter and voltage level
Firmware update via RS232 with a single button click

If you're using windows XP, you might have to install the .NET framework 3.5 prior to using the GUI:
http://www.microsoft.com/downloads/details.aspx?familyid=AB99342F-5D1A-413D-8319-81DA479AB0D7&displaylang=en

The newest release will always be available from the link in the right column of this blog. There, you'll also find the latest firmware (.bas and compiled as .hex).

I built a second Shrediquette for Eric, a nice guy from Paris/ France. This gave me the opportunity to check the setup again. I had no problems during construction at all, everything worked very fine. As soon as I did some outdoor test, the tricopter will be shipped to Eric.

I am thinking about making a I²C -> PWM converter, to enable the use of standard ESCs (a number of people requested this possibility). I already designed a PCB, I would like to use an ATtiny45 (one µC for each ESC). The converter is only 17 x 17 mm (0.7 x 0.7 inch). The converter will be powered by the BEC of the ESC. Using two solder jumpers, the user can select PWM refresh rate (like 50Hz, 100Hz, 200Hz, 400Hz or so). Now for the problems...: As you might have noticed, my personal Shrediquette flies very good with I²C ESCs. Therefore, I don't need this converter. I don't have any standard ESCs, so I can't test the converters (my programming skills always require extensive testing to find all the errors I made ;-D). I am not willing to buy three ESCs because I simply don't need them. So, if anyone out there is planning to build a Shrediquette with standard ESCs, it would be very nice if he or she would borrow me the ESCs for testing purposes.

The last news is that I succeeded in doing a double and a triple flip. The double flip is not critical, but the height loss for the triple flip is quite high... I will keep on trying to improve my flying skills...

GUI almost done...

2009-11-16T22:32:00.007+01:00

The GUI for my tricopter is almost finished. Watch a screen capture video here. It's working very fine and it is pretty handy.

What needs to be added is a possibility to flash new firmware to the tricopter. I would like to include avrdude in my GUI, but I still need to do some test with avrdude, Arduino bootloaders & RS232 cables... The GUI will be released when it is finished.
The Arduino pro mini m168 is now filled to 85%. I will change over to an Arduino pro mini m328 so that I'll never run out of space.
It seems as if I am going to build an extra tricopter with the ESC's from mikrokopter.de. That is a good opportunity to test everything again, making sure that building a Shrediquette DLX doesn't cause any problems.

Edit: Today I sucessfully flashed my m168 and my new m328 via RS232 + bootloader + avrdude! I also managed to run avrdude hidden inside my GUI (so you don't have to enter any parameters, everything is done automatically with one single button press!). I will soon write an extensive tutorial on how to build a Shrediquette and how to set all parameters etc....

Last project tweaks

2009-11-09T08:37:00.000+01:00

I realized that programming an Arduino with Bascom & ISP-Programmer might be too complicated for people that to not work with robots and microcontrollers frequently. That is why there will be some changes to the setup soon:
I will write a tutorial on how to transfer my program to the Arduino via avrdude and a simple RS232 serial link (first, I have to find out if it really works...).
The second simplification will be a GUI, where you can set, change and check every parameter of the tricopter. Development of the GUI might maximally take a month or so. I will begin to make it soon. In the end, making your own Shrediquette-tricopter might work like this:

Buy an Arduino pro mini + RS232 cable
Get or make the TriGUIDE pcb
Get the RC components (motors, ESC's, etc)
Build a frame
Flash the Arduino using my precompiled source code + avrdude
Install my GUI (TriGUI might be the name...)
Set the parameters that match your equipment
Fly

Outdoor performance

2009-11-03T23:33:00.002+01:00

Today, I recorded some outdoor scenes. Agility was improved, I think I should try a double-flip....

Circuit and PCB layout released!

2009-11-02T22:14:00.002+01:00

Today I can release the circuit and the PCB. My little tricopter project seems to be fully documented now, it was a success and lots of fun. And now for something new.... I want to become snowboard pro ;-D.
I will most likely post a video of the outdoor performance of the tricopter soon.

This is the layout:
(thanks to "AVR-Frickler" for tweaking the layout!)

And here comes the circuit:
TriGUIDE_v3.pdf

You can download the Eagle files here:
TriGUIDE_v3.zip

Source code released!

2009-11-01T20:46:00.004+01:00

Almost exactly one year after starting this project, I can finally release the source code of the tricopter. I translated the code to english (mainly variable names etc.) and added a lot of comments and explanations. I hope that you can understand the code, it is actually quite straight forward. Feel free to ask questions and give comments.
Source code:
Tricopter_02_ShrediquetteDLX.txt

PCB layout etc. will follow during the coming days.

A new version of the tricopter is finished

2009-10-27T23:09:00.003+01:00

News...:
A completely new version of the copter recently did it's first flight. I rebuilt chassis, electronics and replaced the battery. I was able to save 35% weight (996g -> 628g). Outdoor flight tests still have to be done. But I am really looking forward to that. Lowering the kinetic energy might significantly increase flight performance.
P.S.: In the meantime I did three outdoor flights: Absolutely great!! I can hardly believe that I built this thing on my own ;-D. Lots of power, very agile and absolutely precise and fun to fly!

Currently, I am working my way through the source code (cleaning up and adding comments), so I can post it here. The electronics circuit + PCB will also be made available.

Matlab source code

2009-09-29T16:09:00.001+02:00

I got a lot of requests for the matlab source code of my tracking algorithm. (If you wonder what I am talking about, watch this video of the tracking process via Matlab: http://vimeo.com/6347100 )
As you will see, it is not that complicated. I did not upload the complete source code, because that doesn't make too much sense. My GUI for example, contains a lot of code and it is most likely irrelevant to most of you. I left out the calculations of the different parameters for my PID control loop too, they will make things appear more complicated than they really are.

Here comes the code:
Matlab Tricopter Tracking

If you have questions, I would suggest that you put them into the comments for this post. Doing so, more people might benefit from it.

Tricopter - The Movie...

2009-09-27T14:02:00.003+02:00

...a new movie showing some of the capabilities of my copter design. This is supposed to be a somewhat less technical movie... Enjoy!

Tricopter - The Movie... from W. Thielicke on Vimeo.

2009-09-02T22:22:00.001+02:00

Next Steps...: I will also post the circuit layout, the source code of the copter and everything else on this webpage soon.

Fully autonomous indoor flight!

2009-09-02T22:21:00.010+02:00

Finally, it's done... My tricopter flies along a three-dimensional path without me doing anything. The waypoints are recorded by some sort of "teach in" (basically taking snapshots of different positions in space, the flightpath is hence calculated as the cubic interpolation between these snapshots).

Using a cell phone to control the copter

2009-09-02T22:21:00.009+02:00

A mobile phone (K800i) controls the tricopter. The phone is linked via bluetooth to the laptop.

2009-09-02T22:20:00.007+02:00

This movie demonstrates how the tricopter hovers autonomously inside a room. There are three LEDs fixed to the copter which are filmed by a webcam from below. A Matlab script then makes the copter hover in place.

2009-09-02T22:20:00.006+02:00

Improved algorithms and a more confident operator...

2009-09-02T22:19:00.006+02:00

Matlab displays the attitude of the copter live and in 3D (and in colour ;-D !!)

2009-09-02T22:19:00.004+02:00

Due to the improvements mentioned above, I was able to do the very first looping...

2009-09-02T22:19:00.002+02:00

Some changes...: I got new motors (Scorpion s2212-26) and new gyro's (ADXRS610). The ESC's were modified for fully digital I2C control. Additionally, I rewrote most of the control loop (finally, I understood what I actually have to control to make stable flights possible). This movie demonstrates two different control modes (control of the angle vs. control of angular velocity).

2009-09-02T22:18:00.009+02:00

... interestingly, decreasing the size of the tricopter did not have any noticeable effect on flight stability.

2009-09-02T22:18:00.004+02:00

Smaller = easier to transport...

2009-09-02T22:18:00.002+02:00

Flying around in the parc... The control loops are still not optimal.

2009-09-02T22:17:00.007+02:00

A flight through my balcony door.

2009-09-02T22:17:00.004+02:00

This is, by the way, how my board looks like from below. Beautiful chaos... but still functional. I am planning to make a PCB soon...

2009-09-02T22:17:00.002+02:00

... and this is how it looks like in flight. Still not 100% stable, but I seemed to be on the right track.

2009-09-02T22:16:00.007+02:00

... electronics installed...

2009-09-02T22:16:00.005+02:00

... the new frame...

2009-09-02T22:16:00.001+02:00

A 3D model of prototype 2...

2009-09-02T22:15:00.002+02:00

Some scenes of the first prototype.

2009-09-02T22:14:00.002+02:00

First release of my "tricopter debug tool". It displays all the parameters that are relevant for a (potentially) successful flight...

2009-09-02T22:13:00.003+02:00

Birth of the tricopter (03.11.2008)...: The second flight of the first prototype... Not very stable yet. But at least it seemed to work after all!