In this paper, a reliability-based robust design approach was proposed on the basis of axiomatic theory, aiming at actualizing a reliability-based robust design framework for mechanism motion. First, reliability constraint functions of the motion output error of mechanisms were established by using cumulative distribution method after an accuracy analysis of mechanism motion. Second, the number of effective design parameters was equated to the number of functional requirements by classifying design parameters using sensitivity analysis or constructing additional objective functions based on axiomatic theory, and then the independence axiom was satisfied by establishing objective functions according to regularity and the semangularity. Third, a reliability-based robust design model of mechanisms was established based on the axiomatic theory according to the above objective functions and constraint functions. Taking a planar four bar linkage as an example, a reliability-based robust design was achieved with the optimization and symbol toolbox in MATLAB. Meanwhile, correctness and effectiveness of the proposed method was verified under the condition that the first and second moments of basic random parameters were available. Finally, the method proposed in this paper was applied to the reliability-based robust design of an initiative lock mechanism in space docking latch system.

In order to improve the reliability analysis accuracy of the aircraft high-lift, an approach based on the Copula function theory and Bayesian updating is proposed. Considering the influence of the random variables' correlation in the process of updating, choosing the reasonable prior joint distribution and likelihood function is crucial. Under the condition of the incomplete probability information, the analytic expressions of the prior joint distribution and likelihood function of the correlated random variables are derived through the Copula function. Then, the posterior joint distribution is obtained by Bayesian updating. The reliability of the lifting device is calculated based on the posterior distribution. The case analysis shows that the reliability results based on the proposed approach are more accurate and more coincident with the factual situation than the reliability analysis results based on the independence assumption of random variables.

Prognosis and Health Management (PHM) has exerted a profound impact on the integrated maintenance and support system. By monitoring the fault evolution of the parts or components, the potential fault could be predicted, and the corresponding maintenance and support decisions could be deducted. PHM has transferred the traditional maintenance mode to the Condition-based Maintenance (CBM). In order to validate the availability and the effectiveness of the integrated maintenance and support system, the computer simulation method is widely used. The maintenance drive serves as the starting point of a new cycle of maintenance and support activity in the object-oriented simulation model. Traditional simulations based on the system failure rate or mean time between failures (MTBF) would not ensure an accurate result when PHM functions. This paper makes a discussion on that problem. The concept of fault evolution index (FE I) is put forth in the paper,and several intermittent FEI evolution models are given for simulation reference. In addition, the paper gives a detailed process of modeling and simulating the maintenance drive.

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