Establishment And Application Of A Monitoring And Feedback System For Precision Internal Grinding

Intelligent machining is the ultimate goal of machining. Currently, researchers and producersof different types of machine tool all set it as a research direction, concentrating on theupgrades of existing products. In the Research area of internal grinding, CNC precisioninternal grinder, the key equipment for the machining of Media-small Holes, has thefollowing questions in machining. They can not monitor the entire grinding processeffectively. They can not judge the dressing quality online, They can not identify and dealwith the sudden failure of Machine tool in order to reduce the damage in time.In this background, we established a monitoring and feedback system for precision internalgrinder based on Labview to solve the problems mentioned above. Acoustic EmissionTechnology was used to monitor the grinding process and collect status information. Afteranalyzing and extracting useful information of internal grinding process, we can realize thosefunctions of the automatic tool setting of internal grinding, anti-collision of grinding processand the monitoring of dressing. Meanwhile, processed monitoring information will betransmitted to the control system of precision CNC internal grinder online. Then, CNCgrinder can adjust the grinding state by controlling the grinding spindle, X and Z-axis servosystem to realize the feedback control of the grinding process as well as improving the qualityand efficiency of grinding.To test the performance of the monitoring feedback system (control software and application),we use the experimental method to research the selection of AE sensor, automatic tool settingof internal grinder. By experiments, the control program of monitoring and feedback systemwas demonstrated to be effective. In addition, PLC control program of CNC internal grinderwas also edited and tested. By studying the monitoring and feedback system of internal grinder, we get the followingresults:1. A monitoring and feedback system for precision internal grinding was established.2. On the research platform of CNC internal grinder, the resonant frequency of AE sensorshould be selected in the range of150-300KHz; bandwidth should be selected in the range of0-500KHz. The most suitable installation location of AE sensor is the bracket of grindingspindle.3, In the process of tool setting of grinding, feeding rate and spindle speed affect the strengthand the time domain and frequency domain characteristics of acquired AE signal. Andcharacteristic values of AE signal have features of short rising time and irreversible. Inaddition, feed rate and spindle speed are closely related to the characteristic curve of AEsignal. The spindle speed affects characteristic value of AE signal, the feeding rate affects therising time of AE signal’s characteristic curve.4. RMS average, ring-down count, and wavelet packet analysis can extract characteristicinformation of the process of internal grinding. And monitoring system and PLC cancommunicate with each other using VISA serial communication method.Finally, this paper can provide a reference for the monitoring of internal grinding process.