Blog:Gluonpilot

One of the things I claimed possible with the gluonpilot is flying both my funjet AND a quadrocopter with it.

Well it is possible! Even using some very cheap components.

Despite the use of SI-units (and thus floating points) in every line of code, an update rate of 333Hz is no problem. Except for a few lines in control.c, and the use of simple_quaternion.c instead of ahrs_kalman_2x3.c, the code is exactly the same as the one I use for flying my funjet.

Here you can see the first flight:

Autopilots are so much fun!

After finishing the circle navigation code I decided to test it by letting my funjet climb until the critical point where you can barely see it's orientation (but still can!). Then I turned the motor off to let it descent.

The result is a very cool KML file:

After successfully stabilizing funjets (and other planes), it's time to tackle the quadrocopters!

The code was slightly changed to make the filter and control loops run at 200Hz, the ESC's are updated at 400Hz. Gyroscope values are sent directly to the ESC's for fast response times (D-term). Filtered angles are used for the absolute attitude (P-term, slower response).

Hopefully the weather will be better next weekend so we can do some real tests!

This is on the future roadmap ;-)

A blocked servo (NEVER use cheap servos) caused a fatal crash (from 50m height straight down). My good old funjet is no more...

Here comes the Funjet Ultra! I took this opportunity to build a nice airframe for the gluonpilot module! Everything is under the so-called "turtledeck". This turtledeck is a major contributor to the structural strenght of the funjet. I added some carbon reinforcements to make sure it all remained stiff and strong:

The open hatch allows easy access to the module

The gate is closed with the carbon bar, which is also used for structural strenght

Looking nice and sleek!

Ready to fly!

For most people, accessing the SVN code repository is a bigger hassle than I expected. As a result, I'm planning to make releases of both the firmware and the Gluonpilot configuration tool. The files can be found in the download section. Version 0.2 is the latest release and supports everything (datalogging, configuration, stabilization) except navigation (which is currently undergoing tests). Stay tuned!

Flight 22: rock solid funjet stabilization, even at take-off. Yellow=manual, Red=stabilized.

Time for an update! I'm proud to announce that stabilization works very well! It has no problem with my Funjet at a roll angle of 40 degrees. Pitch is also very stable. Altitude hold makes things even more fun :-) Stabilized take-off worked without any issues (see attached .kml).

I will report soon on the used algorithms. The flexible design of the gluonpilot firmware made things easy:

1. Data logging at 50Hz
2. Matlab simulation on that data
3. In hardware simulation on the raw sensor data logged in flash

Pre-release code can as always be found on the SVN.

Download KML file of flight 22

After a long period with snow, rain and wind, the weather is finally clearing up. Time for the first flights!

This weekend, I made 8 short flights with my funjet to test the basic funtionality:

• Manual Control
• Datalogging
• Stabilization (Stabilized control: RC-transmitter sticks control the pitch and roll angle instead of the elevon deflection)

Stabilization needs more tests but apart from that, everything was rock solid!

Download datalog Download Google Earth KML

The weather is ready, I'm ready, and the gluonpilot datalogging functionality is ready for the first flights!

Right now, 17 variables are saved on the on-board flash chip at 4Hz (this is enough for about 2.5 hours of logging!). The firmware can easily by adapted to log other variables or at other speeds. The client application (gluon config) doesn't need to be changed, as it is fully transparant. The module sends the columns, and the config tool interprets them!

A quick demo after a walk around the house:

The software is slowly getting ready for the first flight tests! Last updates include:

• PWM or PPM RC-receiver input changeable by the configuration tool (See Getting started)
• GPS setup procedure now works stable for locosys and EB-85 modules
• Stabillized control with configurable PID loops

Right now I'm working on the datalogging to Flash to make sure the data can be analysed after the first flight tests.

Once the flight tests are successful, configuration files and howto's will be created for 3 different airframes:

• Easystar (with ailerons) - standard aileron plane
• Funjet - Delta plane/Flying wing
• Quadrocopter- Using cheap hobbycity components

People owning a gluonpilot module: don't forget to use the latest source code from the SVN server!

Any questions are welcome on the forum, now with over 120 posts!

Easystar

Funjet - Old track record

Quadrocopter

The friendly folks at DIY Drones were so nice to interview me about the gluonpilot. You can listen to it all here.

Now, some people already received their gluonpilot module! The first alpha-software can be found in the SVN repository on google code. This includes both the autopilot firmware and the groundstation utilities. When there is a stable version, it will be packaged into a .zip file and put in the download section.

All questions are welcome on the forum. Documentation is/will be available on the wiki, and I hope for your feedback and cooperation :-)

After a very long waiting period, the first batch of gluonpilots finally arrived:

A very big thanks to everybody who ordered a gluonpilot! I hope to mail them all next week after a weekend of testing.

The first version of the gluonpilot IMU is finished! I decided to use quaternions because it's just so darn easy! As you can see from the video, there are no "dark spots" (aka gimbal lock) in it's attitude. I'm just moving it randomly in every direction. Yaw is drifting a tiny little bit, because there's no magnetometer to compensate. Still not bad I'd say! Must be good enough to keep a funjet, easystar or quadrocopter in the air :-) As you see, I added a graph window to the configuration tool. Very easy for debugging and finetuning! The OpenGl-window that shows the attutide is also included in the configuration tool, but that's only eye candy to be used in promotion videos ;-) Code for the firmware + C# configuration tool will follow soon!

Santa (in disguise as a fedex mailman) brought me a nice present: the production prototype of the first official gluonpilot!

What's new:

• Low pass filter on 5V
• Low pass filter on 3V3
• Extra PWM input (now 5 in total: ideal for quadrocopter!)

Bottom comparison: see the 2 low pass filters

Top comparison: see the extra PWM input!

I decided to start with the most annoying work: writing a protocol and a windows application to configure the gluonpilot module. This is the current state:

This configuration tool is supposed to work with the RTOS pilot version. In a few days I will post more info on the wiki, and put the code for both the firmware and windows application on google code (read: I need to do some code cleanup first :-) ).

One of the gluon "project milestones" in my mind was the development of a bootloader. This would make the purchase of a programmer (ICD2 or similar) no longer necessary.

Guess what?! Our friend Mikael developed an excellent GPL bootloader with a beautiful front-end. I decided to install this bootloader on all gluonpilot modules! A programmer will no longer be needed!

To all people who already bought the ICD2 for their gluon module: I'm sorry I didn't find out about this sooner! To all people who didn't get one yet: what are you waiting for?! :-)

The components for the first gluonpilot batch are arriving! If you would like to get your hands on one, hurry because there are only a few left!!

I added a new article on temperature compensation to the wiki. Read it here! It will be added to the next release of the gluonpilot libraries, so stay tuned.

All components for the first batch of gluonpilot modules are ordered. Hopefully the assembler can do his work next week, so the modules will be available the week after that.

Hi, Welcome to the gluonpilot weblog!