The Five Coordinates Beam Mobile Gantry Machining Center Reliability Evaluation Technology Research

Reliability assessment is one of the critical tasks in the reliability engineering ofhigh-grade CNC machine tools. It serves as the basic technology in the reliabilityengineering, which can help to identify the design weakness, verify the reliabilityindex and generate the maintenance strategy for the machine tool. However, as thehigh-grade CNC machine tool is characterized as a multi-components system withsmall sample size and heterogeneous multi-resource information, the reliabilityassessment of the high-grade CNC machine has become one of the difficult yetimperative works.To build up a comprehensive lifecycle reliability assessment framework for thedomestic high grade CNC machine tool, we combined the thesis dissertation with thecarrying out of the “High grade CNC machine tools and basic manufacturingequipment” major technology project, where a domestic high-speed five axis beamshifting gantry machining center (GMC) is researched. The Bayesian theory is adoptedin the construction of the lifecycle reliability assessment methodology for the GMC. Acoherent lifecycle reliability assessment framework is constructed, which can help thedomestic manufacturers to carry out the reliability work and improve their product’sreliability. Specific researches are focused on the following critical and urgentreliability technologies:1. Building up a framework for lifecycle reliability assessmentFirstly, the lifecycle of the high-grade CNC machine tool is defined and thespecific characteristic of the reliability estimation in each stage is analyzed. Based onthese analyses, the complex system with small sample size and multisourceinformation fusion are identified as the critical difficulties need to be coped with. Then,the lifecycle reliability assessment framework for the high-grade CNC machine centeris constructed and the specific technology needs to be developed for each lifecyclestage is figured out.2. Reliability estimation in the design stage (pre-development stage)Target on the situation that the available reliability information in the design stage is full of subjective information with sparse field data, an information fusiontechnology dealing with multisource prior information is developed based on theBayesian method.3. Reliability estimation in the development stage (pre-development stage)Dealing with the reliability estimation in this stage which characterized asmultisource heterogeneous information fusion, we adopt the hierarchical Bayesianmethod and the prior information fusion technology into the reliability estimation inthis stage. A hierarchical Bayesian method based multisource and heterogeneousinformation fusion method is construct for the reliability assessment of the GMC inthis stage.4. Reliability estimation in the in-service stage (post-development stage)Specified on the data evolving and dynamic parameter characteristic of thereliability assessment in this stage, the regression model with covariate is incorporatedinto Weibull models. A dynamic parameter Weibull model is developed and thecorresponding Bayesian estimation method is investigated. A dynamic parametermodel based Bayesian reliability estimation method is developed for this stage.