REAL-TIME SCHEDULING LIMITATIONS TO ROBOT MOTION PLANNING: EXPERIMENTAL RESULTS

摘要

Most autonomous mobile robots have a complex software arquitecture, consisting of multiple tasks managed by a shared-time operating system. It is evident that the lack of real-time support from the operating system may have negative effects on the robot motion performance, because of temporal deviations among intended and really executed tasks. Even though, the potential importance of such effects is not clearly discussed in the mobile robots literature. This paper presents an experimental evaluation of the consequences of such incorrect task scheduling schemes. Experiments have been carried out in two commercial mobile platforms, a Nomad-200 with DOS OS, and a B-21 with Linux OS. They illustrate two points at issue: a) non real-time scheduling may reduce robot motion accuracy significantly, and b) a correct timing is mandatory in order to maintain convergence and security properties of continuous sensor-based motion planning algorithms.