Enhancing fault tolerance of autonomous mobile robots

Abstract

Experience demonstrates that autonomous mobile robots running in the field in a dynamic environment often breakdown. Generally, mobile robots are not designed to efficiently manage faulty or unforeseen situations. Even if some research studies exist, there is a lack of a global approach that really integrates dependability and particularly fault tolerance into the mobile robot design. This paper presents an approach that aims to integrate fault tolerance principles into the design of a robot real-time control architecture. A failure mode analysis is firstly conducted to identify and characterize the most relevant faults.Then the fault detection and diagnosis mechanisms are explained. Fault detection is based on dedicated software components scanning faulty behaviors.Diagnosis is based on the residual principle and signature analysis to identify faulty software or hardware components and faulty behaviors. Finally, the recovery mechanism, based on the modality principle, proposes to adapt the robot's control loop according to the context and current operational functions of the robot.This approach has been applied and implemented in the control architecture of a Pioneer-P3DX mobile robot.

SMOF: A Safety Monitoring Framework for Autonomous Systems

“…This approach has been used in robotics architecture, at functional level [9] or decisional level [10], [11] for instance. A popular form of fault tolerance dedicated to safety is safety monitoring, through which the functional system is forced to a safe state (recovery) should some hazardous behavior be detected (error detection).…”

A Safety Monitoring Model for a Faulty Mobile Robot

“…Nevertheless, there is mention to the lack of effort of incorporating fault detection and diagnosis, or even to progress in the field of fault tolerance concerning Unmanned Surface Vehicles (USVs) actuators or communication systems [17]. Even in the case of UGVs, both military and rescue, an analysis showed a problem with mobile robots reliability [18]. There is also mention to the lack of studies focusing on the impact that a decision layer on mobile robots has on engineering system's usual safety measures [5].…”

“…There is also a mention of the extension of these methods with the inclusion of mechanisms to estimate the probability that conclusions are correct. 'Databased' are described as models that don't require prior knowledge of the system, but rather large amounts of historical data that allow the creation of a knowledge base [5,18].…”

Fault tolerant autonomous robots using mission performance guided resources allocation

“…In [4], a large state of the art summarizes the different fault tolerant architectures. The fault tolerance principles are enunciated.…”