Functional Safety Design And Evaluation Of CNC System

Modern CNC systems is becoming more and more powerful,and the electrical structure is becoming more and more complex,which not only improves the manufacturing efficiency and precision,but also increases the risk of electrical system failure.How to ensure the safety of human-computer interaction in the whole manufacturing process has become a new research direction of numerical control system.The research on functional safety technology in China is still in the theoretical research stage,and there is no experience in the field of functional safety of CNC system.This paper studies the functional safety technology of numerical control system,focusing on the safety PLC of numerical control system.In this paper,the functional safety requirements of CNC system are analyzed from the whole,and the risk assessment technology of functional safety is used to analyze the CNC system,and the potential hazards of the CNC system are analyzed from multiple dimensions,and the functional safety objectives are derived.By comparing the advantages and disadvantages of different schemes,the safety-related system architecture of CNC system based on safety PLC is designed.Secondly,the hardware and software system of safety PLC,the core component of safety-related system,was studied.Hardware architecture of 1oo1 D was designed and implemented,which can support the safety function of SIL3 level at the highest.The failure mode and diagnosis of safety PLC are analyzed from bottom to top by using FMEDA.The functional safety standard of soft PLC: PLCopen Safety standard is studied.The Safety function control block library of PLCopen Safety standard is realized on HPAC platform,and the Safety development platform is constructed.Then,the software architecture and modules of CNC system safety PLC are designed and implemented on HPAC.Then the theory of functional safety modeling and evaluation was studied,and the Markov modeling of the system was carried out to verify the hardware safety integrity of the safety function.Finally,the functional testing software was designed,and the experimental platform is built to test the software and hardware functions of the system,which verified the safety function of the designed safety PLC.