Monthly Archives: September 2014

aMoSeRo – 3D Cheese!

I have implemented a 3D photo function that is computational not very intensive. It gets triggered by pressing a key when a snapshot is wanted. By that it is possible to add a big Point Cloud around the map as you can see here:

Now writing needs to be finished, code needs to be commented and cleaned up – last two weeks already begun.

aMoSeRo – mapping the reality

Today is the day of the first accurate aMoSeRo map. I tried several slamming algorithms e.g. the hector_mapping package, but data has been to bad. So after reviewing nearly all my code, fixing a lot of unit issues and publishing rates, today the first map has been created, which really is a map of the place I am living!

Using Chrony on CubieTruck

Don’t.

Unless you really know what are you doing.

To synchronize the clock and fix a minimal time shift I was detecting, I followed the idea of the TurtleBot2 to use chrony to fix that Chrony is a little daemon that connects to your linux clock or hwclock and detect shifts. For some reason this lead to total chaos on the amosero.
I suppose chrony hasn’t been build for multicore dynamically speeded processors like the A20, which is why the shifting has been erratic and up to 2 seconds per minute.

sudo apt-get remove chrony

Fixed all timing errors on the [amazon &title=CubieTruck&text=CubieTruck]. Also it’s a bit disturbing how little changes can inflict complex setups.

 

 

Resistance to Odometry is futile

It sure is. But a good odometry in a robotic context is an objective that is hard to achieve.  For a robot like the aMoSeRo only two main velocities are relevant: linear and angular speed. Both do not occur on the same time, but still – correctly determining any of them is essential as most higher algorithms like slamming and planning highly depend on it. For me in a out of time running thesis, this task can be the biggest still kinda opened challenge.

All other system parts like gmapping, robot_pose_ekf, tf_broadcasts, sensor code, drivers, dynamic_reconfigure (insert long list of other important things here) are up and well enough running. Most of the thesis is written, only evaluation (experiments) and conclusion (the big round up in the end) is still missing.

Therefore I am really looking forward to a time after my thesis – full of well deserved sleep and a university degree 🙂

Screenshot24.09.2014