If you have ever worked in an academic environment you might know that there are students and then there are STUDENTS :-). I mean these kind of students who are really interested into the project and incorporate their own ideas, one of the rare varieties…..  A year ago one of this rare varieties volunteered for one of my projects…. yeah

The goal was to build a BLCD Motor Test-Stand to measure how electric current and buoyancy are changing on several different motor propeller combinations. The motor/props tests are mainly focused for usage with Quadrocopter like vehicles. Furthermore Amir (Godfather of Quadrocopters)
came up with the idea to measure the Tau63 for the PT1 transmission behavior.

The software part is entirely written in G (LabVIEW).  For data acquisition we used the NI PCI-6024E interfaced via DAQmx.

With DAQmx you can set up your measurement hardware very easily (see next snippet).

Measured signals are:

Sampling rate = 10kHz

• BLC- Ctrl. Phase 1
• BLC- Ctrl. Phase 2
• BLC- Ctrl. Phase 3
• motor speed with optical sensor
• power input
• command acknowledge from  BLDC-Controller
• voltage supply

For the measure of the buoyancy force we use a weighing machine 🙂 (see gallery)

To measure the motor/prop. speed we used two different measuring methods.

1. Laser module  and a photodiode:

As you could see in the circuit diagram it is very high sophisticated 🙂

2. Via  Back EMF (back electromotive force)

Back EMF is the voltage that pushes against the current which induces it. This voltage can be used to measure the motor speed.

Some Results for the electric current versus buoyancy measurements:

auftrieb-zu-leistung-hacker-a20-22l

Image 1 of 6

Some Results for the Tau63 measurements:

sprungantwort-50g-hacker-a20-22l

Image 1 of 12

Last but not least, Ladies and Gentleman let me introduce you the Test-Stand itself 🙂

Yesterday a student from another study course asked me if I can help him to get Nagios with NDO support and NagVis up and running.  The main focus of his study course are Network Technologies but for some reason nobody could help him, hmm lol. So I did the job :-), once more. Nagios is the swiss army knife  among the IT infrastructure monitoring systems. It follows the OpenSource Way of life, which promises a big community, a lot of contents concerning problems which could arise , in one word –  getting the system up an running should not be a big deal. I thought…..

Linux seems to be a dark horse @Net….who would have thought it? So….first we started with a short overview about Linux distros, and the essential stuff you should know about. Original he came up with SUSE, so first we did a s\SUSE\Ubuntu. The Lucid release should suit his needs. The students plan was to compile everything from scratch, humpf, after introducing him into synaptics and the build- in-search-function we decided to give the precompiled stuff a try.

It turns out that all needed packages are in universe. Some clicks later we had installed Nagios, MySQL and the Mysql-NDO Module.

After configuring the nagios.cfg and the database accountings/schema we got the core up and running.

The next step would be to get ndo2db up.  Nd02DB acts as a persistence layer for storing Nagios events and configuration data in the database. The DB is the interface between Nagios and Nagvis. To get your data to the DB you have to run ndo2db in daemon mode and provide the ndomod.o for loading.

The Nagios How To speaks about ..

broker_module=/usr/local/nagios/ndo/ndomod.o config_file=/usr/local/nagios/etc/ndomod.cfg

For at least ubuntu you have to change it to….

broker_module= /usr/lib/ndoutils/ndomod-mysql-3x.o config_file=/etc/nagios/ndomod.cfg

Don’t forget to alter the ndomod.cfg.

Check that:

output_typ=unixsocket

We run into the problem that first we could not start the nd02db daemon. The problem was a combination between access rights to the *.o module and an sytax error in the ndomod.cfg file.

After resolving it we were able to start the ng2db daemon and after that Nagios with the ndomod-mysql-3x. 🙂

Next step was to bring NagVis online. Since NagVis GUI is written in PHP you have to make sure you have all essential PHP stuff installed. Check you configuration

/etc/nagvis/nagvis.ini.php) for the DB schema name/credentials.

If you encounter problems to reach NagVis via HTTP: Make sure you have included the /etc/nagvis/apache.conf in your apache conf.d folder.

NagVis uses basic authentication, so first you have to login to Nagios and then you could try to call ../nagios/nagvis.

Have fun.

More than a year ago I joined the NG.UAVP (Next Generation Universal Aerial Video Platform) Project.  Amir and his NG-Gang are the brains of this cool Open-Source project. After fiddling around for about a year i decided to bring up some contents/themes to my field of study.

The idea here is to show our students how theory and practice can be combined and this is shown through the QuadroCopter example.  Since the major components of such a system would cover most of the key course elements I thought my fellow workers would take some of the ideas/themes into their courses. LOL, but the response was zero. No matter,  I already was changing to my new field of study (MedIT). Of course QuadroCopters doesn’t fit as perfect as they did to my former study field. But here I get more support. So I decided to start a workshop for students and some fellow workers with the aim to build a QuadroCopter from “scratch”. To make the whole stuff not to difficult we took the NG.UAVP project as base.

So here we are, some impression of our first workshop, students@work

Markus one of the students who are attending the workshop did a short fast motion video 🙂

[local /files/2010/05/Fim1Quadro.flv]

The Video has about 8Mb, so it could take some time to load.