The Research And Application Of Elevator Serials Product Quality Design And Dynamic Quality Characteristics Prediction And Analysis

The level of quality control in the period of product development determines the final quality of product. The technology for product quality design oriented to quality characteristics is the main technology in quality control field. Though the research on static quality characteristics has made a great progress, the dynamic quality characteristics were ignored, and the result of processing the fuzzy data is still not so objective. As a result, a new technology of quality design oriented to dynamic fuzzy quality characteristics is proposed in this dissertation.The dissertation is organized as follows:In the first chapter, the dissertation presents the basic theory of product quality design, and summarizes the key technology and research result related to product quality design. The technology of product design oriented to quality characteristics is summarized, and the problem of ignoring the dynamic quality characteristics is indicated. At last, the thought of oriented to dynamic fuzzy quality characteristics is proposed, and the background of research and train of thought is introduced.In the second chapter, the dissertation presents that acquiring and analyzing the customer requirements is the basic of the extracting of quality characteristics. To deal with fuzzy, subjective, uncertain customer requirements, based on Variable Precision Rough Set, a method to deal and analyze customer requirements is proposed. Applying attribute reduction in rough set theory, the redundancy information is removed. Based onβ-classification accuracy method of variable precision rough set, the method determined the weight of customer requirement. Finally, a case study of super-high-speed elevator is provided to prove the feasibility and effectiveness of the proposed method.In the third chapter, to deal with fuzzy, subjective, uncertain relationship between the customer requirements and quality characteristics, a method to extract the fuzzy quality characteristics is proposed. Firstly, a decision-making system is constructed, and based on method of multi-attribute decision-making analysis in variable precision rough set, the relationship matrix is determined. Secondly, the quality characteristics were extracted from the customer requirements based the relationship matrix. Finally, a case study of super-high-speed elevator is provided to prove the feasibility and effectiveness of the proposed method. In the fourth chapter, aiming at the dynamic quality characteristics, a method to predict and analyze dynamic quality characteristics is proposed. Firstly, the time series of quality characteristics weight is constructed by obtaining the quality characteristics weight periodically; then they were processed to calculate the predicted weight by means of the least squares support vector machines regression model; Finally, through the predicted weight, the chart of dynamic trends with quality characteristics is constructed so as to provide the decision for product quality design. A case study of super-high-speed elevator was provided to prove the feasibility and effectiveness of the proposed method.In the fifth chapter, aiming at the fuzzy, subjective, uncertain course of quality comprehensive evaluation, a method to evaluate the elevator serial product quality is proposed. Through the predicted weight, the chart of dynamic trends with quality characteristics is constructed so as to provide the decision for product quality design. A case study of super-high-speed elevator was provided to prove the feasibility and effectiveness of the proposed method.In the sixth chapter, the theory and method discussed above are applied in elevator industry. The system of product quality characteristics and dynamic prediction and analysis has been developed and its main functions and the realized techniques are described and presented. The application and implement result of this system have proved that the theories and the methods have good practical value.In the seventh chapter, all achievements of the dissertation are summarized so as to put forward the further research.