Evaluation of a ReconOS-ROS Combination based on a Video Processing Application

Robots are becoming increasingly autonomous and more capable. Because of a limited portable energy budget by e.g. batteries, and more demanding algorithms, an efficient computation is of interest. Field Programmable Gate Arrays (FPGAs) for example can provide fast and efficient processing and the Robot Operating System (ROS) is a popular middleware used for robotic applications. The novel ReconROS combines version 2 of the Robot Operating System with ReconOS, a framework for integrating reconfigurable hardware. It provides a unified interface between software and hardware. ReconROS is evaluated in this thesis by implementing a Sobel filter as the video processing application, running on a Zynq-7000 series System on Chip. Timing measurements were taken of execution and transfer times and were compared to theoretical values. Designing the hardware implementation is done by C code using High Level Synthesis and with the interface and functionality provided by ReconROS. An important aspect is the publish/subscribe mechanism of ROS. The Operating System interface functions for publishing and subscribing are reasonably fast at below 10 ms for a 1 MB color VGA image. The main memory interface performs well at higher data sizes, crossing 100 MB/s at 20 kB and increasing to a maximum of around 150 MB/s. Furthermore, the hardware implementation introduces consistency to the execution times and performs twice as fast as the software implementation.