Reliability Analysis Design And Growth Technology Of CNC System With Comprehensive Application

Reliability is one of the main quality factors which determine the market value of brands. To a great extent, the cause that domestic high-end CNC products rely on imports is owing to the reliability gap at home and abroad.This dissertation is supported by the project "Research on CNC Reliability Design and Reliability Growth Technology", studies how to increase system reliability in the fields of reliability analysis design and growth technology, providing theoretical and technical supports for CNC reliability at all life cycle.As one of the high-reliability products, CNC is an integrated system of hardware and software. This paper starts from the basic analysis of CNC hardware and software characteristics, then analyzes the current reliability level of national CNC systems, introduces some views respectively from reliability allocation methodology, reliability growth technology, and field test planning.This dissertation proposes an approach of subsystem partitioning method based on hardware-software structure, which is easier to find reliability rules, collect statistical data and draw on research from similar fields. With a large number of fault data, the indicators of national CNC reliability, maintenance and availability, are analyzed, which show the exact gap comparing with foreign products. After that, a new time-based software reliability structure model is put forward, based on which model the availability index is solved as an example.This dissertation considers both the randomness and fuzziness, to realize the allocation of CNC failure rate target and allocate reasonable failure rate for each CNC subsystems. Then the allocation result is accepted by Monte Carlo simulation prediction method of the hardware-software system model. Taking the factor of hardware and software interaction reliability into consideration, a new concept of hardware-software cooperative reliability design is proposed.This dissertation creates a new hardware-software comprehensive reliability growth model named G.O.-AMSAA, then simulates and models the growth trend respectively using NHPP simulation data and field test data. Both the theoretical analysis and experimental data results show the validity and practicability of the model.This dissertation designs the kind of field test with'short censored time and large sample size", to compensate the lack of data collected by short-term experiment. This paper proposes a concept of fixed validity, and evaluates the current maintenance situation of national CNC systems using Markov chain model. In addition. this dissertation tries to solve the Failure-Free Test data with the subjective fuzzy method and an engineering instance is analyzed.This dissertation develops reliability aided software based on Matlab GUI, including data distribution type hypothesis testing module, reliability growth trend monitoring module and Monte Carlo reliability prediction module, which all show great application value in the specific samples.