TITLE: Hard real-time Control and Coordination of Robot Tasks using Lua

AUTHOR: Markus Klotzbuecher and Herman Bruyninckx

ABSTRACT: Control and Coordination in industrial robot applications operating under hard real-time constraints is traditionally implemented in languages such as C/C++ or Ada. We present an approach to use Lua, a lightweight and single threaded extension language that has been integrated in the Orocos RTT framework. Using Lua has several advantages: increasing robustness by automatic memory management and preventing pointer related programming errors, supporting inexperienced users by offering a simpler syntax and permitting dynamic changes to running systems. However, to achieve deterministic temporal behavior, the main challenge is dealing with allocation and recuperation of memory. We describe a practical approach to real-time memory management for the use case of Coordination. We carry out several experiments to validate this approach qualitatively and quantitatively and provide robotics engineers the insights and tools to assess the impact of using Lua in their applications.

Download paper as pdf file