Research Work

As part of my time spent in Reutlingen I did some reasearch work for Prof. Dr -Ing Gruhler of the Mechatronics Department of the Hochschule Reutlingen. I ended up compiling two reports. The first was a purely research based one and the second included some practical work on a mobile robot. The work on the second report was used in a journal article available here.

Summary of Omni-Directional Drive Choices

This report briefly introduces the concept of an  omni-directional drive. It then proceeds to give overviews of many of the the currently available and in use methods of achieving omni-directional drive. Both units which have received commercial use, and those restricted to hobby robotics have been listed. Because no specific application was in mind, no recommendation towards a specific drive method was made. The appendix includes some further information and links to a design report and video demonstration of most of the drive methods listed in the report.

Drive types mentioned include: Omni-Wheels, Anisotropic Wheels, Omni-Ball, Mecanum Wheel, Swerve Drive, Ball Drive, Vuton Tracks, Omni-Crawler, Hemispherical Gimbaled.

The report can be downloaded here (4.5 MB PDF)

Notes on Robot Odometry

In this report a pre-built omnidirectional robot is  modified to allow for better odometry as well as control. The report investigates several possibilities for odometry, and then making use of available equipment adds a proximity sensor to the robot for accurate tracking. In addition to this the movement control code is replaced with PID controllers for both directions of movement. Slight adjustments are made to the visual interface with the robot and a Wi-Fi connection is re-established.

The full report can be downloaded here (2.1 MB PDF)

Skiing in the Alps (Lech, Austria)

So this weekend I had the opportunity to join a couple guys from Reutlingen to a skiing trip to the Alps. It was originally supposed to be in Ischgl, but a small admin error brought us to Lech in the Arlberg.

We didn’t have a particularly nice drive there or back. The roads were fairly busy and snow was falling almost throughout. Fortunately our Finnish driver handled our Mercedes Vito and the roads well getting us there and back again safely. Although a bit of a push was required up the final hill in Lech to get to our accommodation :)

We stayed at the Pension Juliana, a large building with several spacious apartments, we had two 4 bed apartments. Each has a lounge and kitchen area with separate bathroom and two bedrooms. The building also houses a sauna which enjoyed after our first day of skiing. It’s located 50m from a bus stop which makes getting into town and onto the slopes fairly painless.

I didn’t really know what to expect. I’d never skied on snow before, and had only seen pictures and movies before, but I really had a great time. I was firstly surprised at how many different routes one could take. Lech lies in a valley along with a few other small towns, but on both sides of the valley stretching the length of the towns there are routes everywhere. Ski-lifts of varying design and size to get you to the top, and your choice of blue/red/black routes to get down.

Three of our group were snowboarders and the other three skiiers. I had done neither but decided to choose the alleged easier of the two, skiing. I also opted out of taking any lessons and decided to jump right in to some skiing, the other three skiiers in the group were a great help giving me some tips to get going. Going however wasn’t my problem, slowing down being my biggest problem, especially when losing my balance a bit. A couple falls occurred but my confidence gradually grew.

We hired gear from a rental company in Lech and spent most of Saturday and Sunday going up and down the various slopes around Lech and neighbouring Zeurs. It was a rather expensive trip, but well worth it. I’d love to give snowboarding a go some time, maybe I can find a slope back home some where.

I took my camera with me on the slopes, but had one or two issues. Apparently my Canon 350D and my Sigma 18-200 don’t like the cold weather too much. Under normal temperatures everything works fine. But with cold temperatures, the moment that I zoom in a bit I get an Error 99 and no photo. At 18mm however I can still take photos, so I got one or two at least. I experienced the same thing the previous weekend when I climbed the Achalm in Reutlingen.

A few more photos can be seen here.

Snowy Achalm

So a couple of plans unfortunately fell through the last few weeks. But last weekend we had just had a nice foot of snow in some places and Saturday was a beautiful clear day so I decided to go for a short walk. I started off walking towards one of the hills near to us but halfway there decided to go climb the Achalm.

We climbed it once previously with the international group and I had wanted to climb it in the snow, so this seemed like the opportune moment. I walked all the way from the Hochschule and up to the top, took a few photos along the way before heading back down and grabbing the bus back the rest of the way.

Nothing specifically exciting, just a beautiful view over Eningen. The view over Reutlignen was unfortunately quite smoggy.

A bunch of pics can be seen here.

Wilhelma Zoo – Stuttgart

Photo gallery can be seen here.

With not much happening this weekend, and a beautiful slightly sunny day ahead we decided to spend the afternoon in Stuttgart and take a stroll through the Wilehelma Zoo.

The zoo had quite a nice selection of different animals, including a small aquarium and insectarium. During wintermonths entrance is down to 8 Euro from 12, half of that on student discount meant a very reasonable 4 euro entrance.

The biggest complaint from the group was the lack of Lion. It didn’t bother me much, I was quite happy with the Cheetah, Tiger, Jaguar, Leopard, Polar Bear and other animals :)

he didn’t seem to enjoy the attention much