Category: ROS

Hungarians On Mars Competition 2013

There is a competition in my country which is called Hungarians On Mars, official site. It is held once in a year, and it’s about robotics challenges. As always, we attended.

palyarajz2013small
Game field overview

This years challenge was to make a two wheeled robot and capture points by dropping magnet onto them while other three challengers try to do the same thing.

(more…)

Beaglebone + thermal sensor with ROS

Robots self testing

As we build more complex robots we need more feedback from them to know what state they are in. In my case I want to know some temperature information about my rover. These things are the motors, the outside environment, and the battery temperature. For this purpose, I want to create an Arduino thermal sensor. Later it will be only an Atmel chip with the sensors but for prototyping and developing the Arduino is the best solution.
The central computer on the Rovers will be Beaglebone. So after I create the thermal sensor, I need to make the communication between these devices. If that is done, the only thing is left to make the ROS package. I have chosen ROS because in the near future I want to make more sensors and ROS is ideal for information distributing.

(more…)

ROS on BeagleBone with Debian

If it comes to complex robotics software I’m always looking for ROS. I wanted to be able to use it on my BeagleBone but Ubuntu was not satisfying so I though of keeping Angstrom since it is the ‘official’ distribution of the board but I had trouble with installing ROS onto it. The final solution was to install Debian Squeeze on the BeagleBone so ROS can go on the top of this. The importance of Debian is that it supports all hardware interfacing features Angstrom does (PWM, GPIO, Analog). First I tried Fuerte but there were some problems and I don’t really need any fancy stuff yet so I went back to Electric. (more…)

Sonar sensor on the BeagleBone part 1, direct approach

When building a robot one needs to use sensors. I used sonar sensors before for this post:

https://fleshandmachines.wordpress.com/2011/09/16/arduino-double-sonar-with-ros/

The main idea is to get rid of the Arduino on our rover “Scarabeus” and use the sonar sensor directly on the BeagleBone. The problem is that this sensor needs a 5V pulse to trigger ultrasonic output and it also answers with a pulse according to the received incoming signal but all the GPIOs on the BeagleBone operate at 3.3V. There are several possible ways to solve this and I’m presenting two of them here.

  1. Do some electronic hack and apply the sensor directly onto the BeagleBone.
  2. Use a dedicated 5V chip to handle the sensor and communicate via serial port (uart) to the BeagleBone.

This article will describe the first one, the direct approach. (more…)

Image segmentation nodes for ROS

Hello guys!

Check out this part of my (Bence Magyar) MSc thesis work where I created ROS nodes to mask regions in an image based on different attributes.

The nodes can be applied on each other’s output in a pipeline-style way.

They can help to speed up your Computer Vision algorithms by masking the not interesting (defined by you) regions of the images.

http://www.ros.org/wiki/pal_vision_segmentation

Happy segmenting!

Beaglebone and ROS + Webcam + remote ROS master (+OpenCV)

This tutorial assumes that you already have Ubuntu on your Beaglebone. If not, you can get it done this way: https://fleshandmachines.wordpress.com/2012/05/03/beaglebone-on-ubuntu-11-04/

Although Fuerte is out I don’t recommend it yet.
Connect to your BeagleBone using ssh.

A nice guide can be found to install ROS Electric here:
http://www.ros.org/wiki/electric/Installation/Ubuntu/Source

(more…)