Browsing by Author "Sousa, J. M. C."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Fault Diagnosis of Maritime Equipment Using an Intelligent Fuzzy FrameworkPublication . Mendonça, L. F.; Sousa, J. M. C.; Vieira, S. M.The task of automatically and intelligently diagnosing faults in marine equipment is of great significance due to the numerous duties that shipboard professionals must handle. Incorporating automated and intelligent systems on ships allows for more efficient equipment monitoring and better decision-making. This approach has attracted considerable interest in both academia and industry because of its potential for economic savings and improved safety. Several fault diagnosis methods are documented in the literature, often involving mathematical and control theory models. However, due to the inherent complexity of some processes, not all characteristics are precisely known, making mathematical modeling highly challenging. As a result, fault diagnosis often depends on data or heuristic information. Fuzzy logic theory is particularly well suited for processing this type of information. Therefore, this paper employs fuzzy models to diagnose faults in a marine pneumatic servo-actuated valve. The fuzzy models used in fault diagnosis are obtained from the data. These fuzzy models are identified for the normal operation of the marine pneumatic servo-actuated valve, and for each fault, predicting the system’s outputs from the inputs and outputs of the process. The proposed fault diagnosis framework analyzes the discrepancy signals between the outputs of the fuzzy models and the actual process outputs. These discrepancies, known as residuals, help in detecting and isolating equipment faults. The fault isolation process uses an intelligent decision-making approach to determine the specific fault in the system. This method is applied to diagnose abrupt faults in a marine pneumatic servo-actuated valve. The approach presented was used to detect and diagnose three very important faults in the operation of a marine pneumatic servo-actuated valve. The three faults were correctly detected and isolated, and no errors were detected in this detection and isolation process.
- Intelligent Fault Diagnosis of Marine EquipmentsPublication . Mendonça, L. F.; Vieira, S. M.; Sousa, J. M. C.The automatic and intelligent diagnosis of faults in marine equipment is a task that is considered to be of great importance considering the numerous tasks that are associated with professionals working on ships. The possibility of including automatic and intelligent processes on a ship makes it possible to monitor equipment more effectively and make more informed decisions. This approach has received a lot of attention in the academic and industrial fields as it can offer considerable economic and safety advantages. Some fault diagnosis approaches can be found in the literature, where mathematical and control theory models are taken into account. However, in complex processes not all their characteristics are always known exactly, so mathematical modelling of processes is an extremely difficult task. Fault diagnosis can therefore be based mainly on data or heuristic information. The inherent characteristics of fuzzy logic theory make it suitable for processing this type of information, which is why it will be used to model processes and diagnose faults in a marine equipment valve. The fault diagnosis architecture proposed in this paper is based on analysing the discrepancy signals obtained between the outputs of the fuzzy models and the process data under study. These discrepancies, the residuals, are indicative of equipment fault. The proposed fault diagnosis architecture uses an intelligent decision-making approach to indicate the occurrence of faults. In this paper, this architecture will be used to diagnose abrupt faults in a marine equipment valve.