Application of fuzzy logic for safe autonomous subsea IMR operations

Abstract

Numerous technical and knowledge gaps pose challenges towards implementation of autonomous subsea intervention, maintenance, and repair operations. One such gap is related to development of methods for ensuring subsea asset and operational safety during autonomous subsea interventions. This paper describes a novel approach of using fuzzy logic to develop an asset safety decision support basis in resident underwater vehicles. A fuzzy inference system is developed with remotely operated vehicle envelope and sensor condition as input variables. Fuzzy sets and their respective membership functions are defined. On the basis of existing subsea knowledge in subsea operations, fifteen fuzzy rules are derived. The aggregated conclusions vary for different range values of ROV envelopes and conditions of the sensor system. The initial findings from simulation of the fuzzy inference system show that application of fuzzy logic to subsea intervention operations can be valuable for development of asset safety related aspects, such as for consequence analysis, operational safety, and development of safety philosophies.