Research On Software Reliability Prediction Method Of Embedded CNC System

With the development of information technology,intelligence and networking,embedded technology is widely applied in all works of life.Because of its small volume,portability,low cost and high scalability,the embedded system has been widely used in the field of numerical control systems.However,the software design of the embedded CNC system is relatively autonomous,and the system is prone to crashes,trajectory deviations,program runaways and so on.The reliability of the system cannot be guaranteed.Therefore,it is very important to study the reliability of embedded system software.Reliability prediction is an important research content of reliability technology.Only by understanding the real levels of system reliability,and finding the locations of high failure and causes,can we further enhance and improve the reliability design.Based on government sponsored research of Wuhan Municipal Science and Technology Bureau,“Reliability and Quality Control of the Variable-speed Precision Numerical Control System”,this paper will take the multi-axis embedded CNC system as the object,and carry out the research of the embedded software reliability prediction method.The main contents are as follows:Firstly,the purpose and significance of this research was introduced.The research statuses of software reliability,CNC system reliability,software testing,fault location and mode,and influence analysis methods were presented and analyzed.Secondly,based on the modular design software testing method,the software of a certain CNC system was tested.According to the scale-adaptive wavelet analysis method,the fault location of the motor driving part of the embedded CNC system,which has a high frequency of failure,was located so that the corresponding measures can be taken in time.Then,the failure modes,causes and cause classifications of the certain embedded CNC system were classified.The FMECA analysis was found out by the collected data in the field tests.The weaknesses of the embedded CNC system were sought out and the effective improvement measures were put forward.Finally,the reliability prediction method was recommended.According to the characteristics of embedded CNC system,the reliability method of this paper was introduced.The model was predicted by the improved littlewood-Markov chain embedded CNC system.At last,the reliability of a certain type of embedded CNC system was predicted.