Reliability measure model for electromechanical products under multiple types of uncertainties

Reliability measure is a fundamental problem in reliability engineering due to the electromechanical products should be with high performance speed and position control with the flexibility to adapt to the rapidly changing needs. The coexistence of random uncertainty, fuzzy uncertainty and incomplete trust uncertainty is common. However, a reliability measure model for this scenario has not been fully studied. Hence, the fuzzy reliability measure (FRM) model is proposed, which enables the reliability of any combination of random and fuzzy variables to be solved. In order to further consider the incomplete trust uncertainty in the reliability measure process, the improved fuzzy reliability measure (IFRM) model is presented based on the FRM model. The hyper entropy of the cloud model is used to consider the incomplete trust uncertainty, providing improved processing. Besides, the concept of credibility is introduced to indicate the degree of trust in the reliability measure results. The reliability-credibility curve is viewed as the reliability measure result of the IFRM model. The reliability and credibility of the electromechanical products under multiple types of uncertainties can be obtained. Besides, the reliability-credibility curve showed the probability of reliability being greater than a certain value and read one certain credibility and its corresponding reliability interval. The calculated results were compared with those obtained from the other methods, which demonstrated the accuracy and wider applicability of the IFRM model. The IFRM model establishes the relationship between reliability and credibility and used as a theoretical basis for either reliability studies or the development and improvement of the reliability of electromechanical products.