Shrediquette - the award-winning multirotors by William Thielicke

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 d...

The 2014 International Micro Air Vehicle Conference and Competition ( IMAV 2014 ) will take place on August 12-15 in Delft, The Netherlands. I am very happy that I can join this event again this year (after my longer 'baby-break' last year). Just as in the previous IMAV competitions, I'll team up with Tumba. He will use several autonomous and FPV-controlled "Alpha" quadrotors and I will take some FPV BOLTs and GEMiNis with me. This year, the competition is especially fun, because the organization committee from TU Delft decided to combine the indoor and outdoor competitions in a single event. Tasks include to create a photomap of a village, detect obstacles, street numbers and open windows, and to finally enter some houses and explore the rooms. This might be pretty challenging, depending on the wind conditions and the video link quality. You can have a look at the competition rules here. I am very much looking forward to the event, and I expect to see...

Maybe you've already heard of the HEXO+ follow-me copter. The kickstarter campaign recently ended and it was really successful. Check it out here: 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: The idea was to make something pretty aerodynamic. The booms are flat plates (each is a very stiff and light sandwich of glas fibre / balsa end-grain / glas fibre) that are arranged parallel to the airflow of the propellers (8"). They hence have very low aerodynamic drag, similar to the body of the copter which is tilted 30° with respect to the propeller plane. Unfortunately, my time for supporting the development of the HEXO+ project will be very limited in the future. But as I really like these kind of projects, I'll try to stay involved somehow.

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 mo...

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 probl...