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[Cubex] First corner balancing of Cubli based hardware

You shouldn't judge a book by a cover they say, and likewise you shouldn't judge a project by what just meets the eye. During our current master thesis work I had the chance to get better acquainted with some of the works of among others Leonhard Euler and Joseph-Louis  Lagrange. These people spent thousands of hours on things that have been  beneficial to even the whole human race. Few people know this though.Why? Because the works consist of truckloads of books full of equations, and it is not as easy to see the use of this as for instance painting a wall or something that is easily recognized and valued. 



This stands in contrast to Cubli. It makes use of abstract science in a way that is perceivable more easily. Although it is a great deal of fun to use the results of among others Euler and Lagrange for various things  it is useful to also demonstrate the concrete use and validity of it for ourselves and others. Therefore we choose to do our master thesis around a Cubli base…
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[RR] Automated rescue boat

We have a project course at our  master program System, Control and Mechatronics, were we could apply to one of around 30 projects available. I was really happy that I got my first choice, which is a project carried out as a joint effort between SSRS (Swedish Sea Rescue Society) and Chalmers. The goal is to develop  autonomous or/and semi-autonomous vehicles that can help out in rescue missions. The current vehicle, a large water scooter named Rescue Runner, is able to follow a larger leader boat.




However, the people involved want some better tracking capabilities and stability of the control system. We are currently a team of three persons hoping to achieve this. Stay tuned, more information will be posted when we finish. Or well, not if we sink though. Then I'll try to cover it up, and hope for dedicated readers to spam me with comments ;)

Here you can read some in Swedish about the project:
http://www.chalmers.se/sv/nyheter/Sidor/Autonomous-Rescue-Runner.aspx

Mars rover project

This summer I worked at a project for RUAG Space in Sweden where we constructed a robot arm from scratch more or less. First we were in a recruitment competition for a week where we proposed a draft solution and won. We were all master students from Chalmers University of Gothenburg. Then RUAG decided they wanted the arm, and launched it as a summer job. We built it from scratch in around 16 workdays. Everything from hardware design, to software development to laser-cutting of metal parts and all in between those was done.

 We got to show it at a major event in Sweden called Almedalsveckan where our foreign minister Margot Wallström and first Swedish astronaut Christer Fuglesang took a good look at it. Here is a video describing it all:





I took care of modeling, simulation, some of the electronics construction and most of the low-level programming in this project. Previous experience came in handy and I think we managed to avoid many time consuming traps. 
Funny thing, it's one of t…

Guide: Get more distortion from an HCM65R amp

I got my hands on an HCM65R guitar amplifier. It's an okay amp I guess, if anything it's loud enough to rise a mob against you even if you live off in a rural area. But, something that's been bothering me and many fellow reviewers it is that it lacks distortion. For me it's usually enough for blues but some palm muted metal, like Into the void with Black Sabbath, comes out a bit soft.


As both of the volumeknobs were broken I took the amplifier apart and started thinking about a way how to get this loudly purring kitty to growl like a beast. When taking it apart I saw that the PCB is really old school with large components placed with a lot of space between them. So, hack friendly! I found out what to change and how, tried and it worked. Check the video below to hear how different it got.

Demonstration I play some random stuff with and without the modification and I think that the difference in tone is very clear.


How to do it This is for you who knows how to solder and…

Visiting Itaipu

Itaipu dam has the second largest rated capacity of all hydropower plants in the world, next after Three Gorges Dam in China. However, as the Paraná river has a more even flow throughout the year, the Itaipu dam in the end is the hydropower plant in the world that supplies the most energy.
A normal year, this plant alone supplies more than 150% of the nuclear plants in Sweden together.

The dam was built and is operated within a binational co-operation between Paraguay and Brazil, that then divide the energy in between them, The ground where it stands has a somewhat international status.

Traveling in Brazil, I off course had to see this dam with my own eyes. Let's see some pictures I took. 
I photographed this overview picture of the dam for a start. 
The dam seen from the side. It doesn't look to vast here, but it's 7235 meters long in total. The turbines outlets are underneath the water surface and cannot be seen here.
 This is the outlet of cooling water from the generato…

What "extremely hot" means in Sweden

Last summer in Sweden 2014 we had like five days straight with temperatures around 28 celsius (82 fahrenheit) during the day. Such temperature is considered more or less extreme and during such circumstances things go bad for some of us frozen swedes. Yeah, you read correctly, that is extreme for many of us. You're laughing right? Come here when it's -5 celsius instead and see who has the last laugh ;) Alright, I'm exaggerating a little. bit Most people like temperatures as such. But I believe I found an exception here.


Most housings in Sweden don't feature a cooling system, which is reasonable. I mean, it would be sort of the same thing as opening a sand shop in the desert of Sahara. However, sometimes maybe there is a need for sand even in Sahara. Some fellow engineering student (I guess), suffering in his rented student housing in Gothenburg, found a remedy to his hardships. Down at the yard there was a storage room for solid waste were disposed fridges ocassionally…

Improvement of Skype

Being abroad I'm using Skype regularly. During calls with some people, the call starts just fine but is drenched in low frequent noise after a while.

From some instrumental recordings I've done using my laptops internal mic, I knew that it has quiet a lot of background noise. What if that noise is transferred to the other persons speaker, amplified, fed back into my speaker, fed back into my mic again and added to the background noise it produces already, back to the other persons speaker and back again creating an unstable positive feed-back loop?



The theory was easily proved in practice. By using head phones, the feedback loop was broken and the high levels of noise disappeared.

The software engineers at Skype could probably have good use of the noble teachings of Nyquist to get rid of this. I bet though that a simple noise gate could do the trick. There is one such avaliable online as a plugin but Skype hasn't incorporated that in to their software yet as standard.