Research And Application Of Instruction Domain Oscilloscope For CNC Machine Tool Based On Bridge Intelligent Slave

The working condition monitoring of CNC machine tool is of great significance for improving production efficiency,ensuring processing quality,and reducing maintenance costs.The traditional condition monitoring and fault diagnosis of CNC machine tools are often analyzed in time-domain and frequency-domain simply,which does not associate the real-time machining task information of the machine tool with the CNC machine tool data,and there is a problem of misjudgment in the data analysis and processing of the CNC machine tool.This thesis designs and implements the instruction domain oscilloscope of CNC machine tool based on Huazhong 8 CNC system and intelligent slave to monitor the condition of the CNC machine tool in instruction-domain.The main work of this thesis includes the following aspects:Firstly,based on the demand analysis,aiming at the complexity of traditional CNC machine tool data instruction domain alignment method,an easy-to-implement and high-precision data synchronization acquisition and instruction domain alignment scheme is proposed,which is based on the Huazhong 8 CNC system and intelligent slave.Based on the IEC 61131-3 standard,HPAC software platform,OPC UA specification and LabVIEW,the CNC machine tool instruction domain oscilloscope is designed to implement the overall scheme.The instruction domain oscilloscope,which is realized by OPC UA as the data exchange standard,is independent of the platform and can realize more secure and reliable access to industrial field data.Then,carry on the function development to the intelligent slave.The interconnection between Huazhong 8 CNC system based on NCUC bus and intelligent slave based on Ether CAT bus is realized.The timestamp is acquired and upload it to Huazhong 8 CNC system,which provides high-precision timestamp for the CNC machine tool to realize high-precision signal capture and precise control in high-speed and high precision machining and accurate tracing of important analog signals.Based on the ping-pong double buffer mechanism,the CNC machine tool internal data such as the G code line number and high-speed data such as the vibration signal of the external sensor in the execution of the work task of the CNC machine tool are synchronously collected and aligned in instruction domain.The time error of the alignment is no more than 1ms.Based on the OPC UA client/server architecture,the communication protocol of instruction domain oscilloscope is designed and implemented,and OPC UA server is realized and integrated into script layer.The data of CNC machine tool is mapped to OPC UA server address space by shared data access API and server object method supported by script layer,so that instruction domain oscilloscope can obtain CNC machine tool data for further analysis and visualization.Furthermore,the instruction domain oscilloscope of CNC machine tool is realized based on LabVIEW,and it is used as OPC UA client to communicate with the OPC UA server in the script layer.It subscribes address space nodes and monitors the changes of node variable data,and analyzes and visualizes CNC machine tool data after obtaining it to realize online monitoring of CNC machine tool condition,and stores CNC machine tool data to support offline analysis function.Finally,experiments are designed to verify the timestamp,synchronous data acquisition and instruction domain alignment,and instruction domain oscilloscope.