Functionability Analysis of Redundant Mechatronic Systems in Bond Graph Framework

A redundant system can continue to perform its intended function in a faulty condition using its multiple configurations. However, the performance may be degraded due to varying functional performance of each configuration. Thus, redundancy improves the reliability of a system. This article presents a method to analyze the level of functional performance of a redundant system with faults. In this article, a new indicator, called functionability, is proposed for a class of redundant systems, namely engineering mechatronic systems. The developed method is integrated with the bond graph based theory of fault diagnosis, in order to develop a methodology for the functionability analysis of redundant systems. The developed methodology is applied on the steering function of a heavy redundant mobile robot called Robutainer. Due to redundancy, Robutainer shows multiple steering configurations, namely front, rear, and dual. The approach is validated through experiments and real-time cosimulation of Robutainer for trajectory tracking in a port environment and considering different components faults in its multidomain hybrid steering system.