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Beside the usual projects at LieberLieber, I found the time to work on a spare time project with my friends Martin and Andy. I don’t fly gliders, but like to join them on the weekends. (“Landeplatz Combo”)
The goal of our “Uniglide” project is to improve the benefits GPS_LOG supported by Henryk Birecki can provide for the hang glider pilot. Originally developed for Soaring Plane pilots this great Freeware can also help hang glider pilots, as you can see in the below picture from our proven old solution. We wanted to improve it for hang gliders and sailplanes with out high cost instruments! The main purpose of of GPS_LOG is calculating the most efficient speed to fly. This speed is based on the gliders specific polar (it tells the sink rate depending from Airspeed), the horizontal wind and the vertical wind. For a good wind calculation you need a GPS, an airspeed sensor and a variometer.
Our old Solution was already based on GPS_LOG but with outdated Hardware and an external Garmin GPS. It’s mounted in Front of the Pilot on the Hangglider.
The outdated solution with the mounting bracket
The old solution had no possibility to attach an Airspeed Sensor. So Martin and Andi where pushing me for two years on how to integrate an air speed sensor into their existing solution on Windows Mobile hardware.
Compared to a state of the art embedded hardware for hang gliding , like the Bräuniger Compeo, the Windows Mobile solution has many advantages. GPS_LOG can indicate the reachable area on a moving map, based on wind, height and topography! This is quite useful to remain in “landable area” all over your flight. Just by selecting a waypoint on your touch screen you can see distance, direction and “height needed”. There are waypoint files available to show inexperienced pilots where to find the common thermal lifts and so on. Henryk is quite fast launching version updates with new features!
With the old hardware the only chance would have been to buy a hardware
component from k6-team. These setups are used in Soaring planes.
To go this way would have been quite expensive and complicated. Additionally there is a issue with the size and power consumpation constraints that apply for a hang glider application.
All of us are also into RC – we found an alternative, but were skeptic if it would fulfill the requirements.
UniLog from SM-Modellbau is a clever RC data logger that can work in a “live” mode when connected to a serial port. SM-Modellbau did a good job in supporting us in the process of attaching the our Software via the FTDI USB Interface to the UniLog.
Now we were sure that with a Windows Mobile device featuring an USB-Host we would get around the professional instruments and equipment.
The selection process for the new Windows Mobile hardware replacing the IPAQ was a short one. The only device that was affordable and has an USB-Host is the Pocket Loox n560 from FJS. At 180€ it is really a great deal. We would have preferred a device with an integrated GPRS module – but those are not affordable.
An unilog from sm-modelbau could enhance a Pocket PC with an Integrated GPS with the Sensors required. But which Pocket PC to buy? USB-Host is also inspired by k6-team.de so we choose the loox n560.
Pocket Loox n560 connected to the Unilog via it’s USB-Host
The last open point was to find a Virtual Serial Port driver to be able to combine two or more incoming NMEA streams with Uniglide into one stream that would be read by GPS_LOG. This was solved by buying a SerialPort.Net Pro from Franson,
The main tasks Uniglide manages:
- Collect data from the built in GPS and forward it to the Virtual Serial Port
- Read data from the Unilog and build Custom NMEA sentences to be sent to GPS_LOG
- Do some flight related calculations
Sounds simple – is simple if you do all the plumbing right 😉
Test runs with a hang glider are very time-consuming – so we went for an rc-plane for our initial “integration” testing phase last weekend.
Unilog Airspeed Sensor mounted on the RC Plane for testing purposes
Pocket Loox n560, Unilog and the Airspeed Sensor all fitted into our 280cm electric glider. (the glider is happy not to be abused for UAV tests this time ;))
Preflight Calibration on the Ice of Lake Keutschach – a RC Plane on a Windows Mobile.
The test flight was in done in a pretty small area to have the same wind conditions all over the testing flight. By flying in different directions for roughly 10sec., we collect packages of GPS Speed, GPS Heading and Airspeed. With this data we calculated the wind by hand and compared it with GPSLOG calculation to find out if GPSLOG understands UNILOG.
And yes this Phase 1 proved to be a success! For roughly 500€ we have a very good solution on hand now.
Everybody waiting for the new Season and Dreaming…. … and preparing for the first test on a real glider.
Nevertheless we are thinking about phase 2, phase 3, …
some ideas are:
- a magnetic compass module for even more fast and accurate Wind calculation.
- Teamflight option which makes your friends visible on a moving map during the whole flight. (any windows mobile phones with USB-Host?)
- By implementing an OS4000 compass from Ocean Server we might be able to build an artificial horizon for just 250$ additional… ok maybe we stop here…