ROS Basics – ROS in a low cost robotic context

UGVs like they are found in industry, education or Do it yourself (DIY) communities are currently not affordable for average technique enthusiasts, teachers in schools or sometimes even universities. The concept of low cost robots tries to solve that issue.

What is low cost in a robotic context?

The traditional interpretation of low cost is minimizing the expenses while keeping most important features. In borders of mostly expensive robotics this term needs to follow the same differentiation as between cheap , which means coming with a significantly reduced price and quality, and keen , considered as maintaining a certain amount of quality at a reduced total cost. For example, the 50 000 USD UBR1 is a low cost version 250 000 USD up to 400 000 USD PR2  of Willow Garage , but still is far away from the term cheap in a common way . Another example and at the same time another robot Melonee Wise worked on is the TurtleBot , which was constructed with the attempt to be the lowest cost version of a ROS robot at time of creation.1

How to achieve low cost?

There is no general solution to this problem. But an approach to solve the issue in the robotic context is to replace expensive single purpose solutions produced by companies in low quantities with mass produced products that get customized to suit the application.
A demonstration of this positive misuse are the first versions of the TurtleBot . Instead of constructing the robot with expensive 3D Laser Scanners they replaced it by a Microsoft Kinect originating from the gaming industry. Furthermore, it used a iRobot Roomba and later a iRobot Create as a low cost mobile base as constructing a custom movable footprint would
have been way more expensive. Also, the mass produced product came at a lower cost and unharmed warranty. An important side-effect of these replaceable parts is the independence of unique cost intensive and sometimes, due to customs regulations, not easily accessible parts. By that, the power to choose a cheap replacement at any time reduces overall expenses and
total risk.

As a consequence, an low cost UGV should be easy to build and reproduce, affordable for education and able to run ROS with some kind of 3D measuring device. It further should consist of easily achievable or replaceable parts.
In conclusion, these properties lead to a modular design concept with communication inter- faces between the inexpensive components. Also a certain degree of flexibility is required to maintain extensibility and independence of expensive parts.