Design Of Wireless Monitoring System For Self Sensing Tool Wear

Intellectualization is the development direction of manufacturing automation.The basis of intellectualization is information acquisition and processing.Real time physical information acquisition in cutting process is one of the basic requirements to realize intellectualization.Among them,tool wear is an important factor affecting machining accuracy and part quality.The real-time monitoring technology for tool wear is gradually developed.However,in the process of practical application,the existing tool wear monitoring equipment often has some problems,such as low acquisition accuracy,large equipment volume,complex wiring,large workload of early data calibration and so on.Therefore,seeking an effective tool wear monitoring method is of great significance to ensure good product quality,minimize tool failure and optimize production cost.This paper takes the machine clamp turning tool as the research object,and designs a wear monitoring system that pastes the vibration sensor on the tool surface and connects the wireless transmission signal module.Firstly,through the structural design of the wireless vibration signal acquisition device,determine the vibration sensor model,and program the software of the developed acquisition device,and then verify the feasibility of the wireless vibration acquisition system through experiments,Finally,the support vector machine regression model is used to predict the actual tool wear value,and the effectiveness of the model is verified.The main research contents of this paper are as follows :(1)The theory of wireless monitoring system is studied and the system is built.The theoretical research of wireless monitoring system includes: wireless communication technology,wireless sensor network and basic theory of data processing.According to the theoretical knowledge,the wireless monitoring system based on WiFi technology is designed,and the sensor model,signal wireless transmission module and other devices are determined.A wireless vibration signal transmission system is built.The system uses the special software of wireless module for algorithm programming to realize the collection and transmission control of tool vibration signal.(2)Experiments verify the feasibility of the wireless monitoring system.The experiment of bar cylindrical turning is carried out.The wireless vibration signal acquisition device designed in this paper is used to collect signals,and compared with the signals collected by the wired vibration signal acquisition device,the relevant error value is less than 3.61%,which verifies that the wireless vibration signal acquisition device is feasible.Then,the vibration signal is processed in time-frequency domain and feature extraction,and the feature vector which can effectively reflect the tool wear state is obtained.(3)The prediction model of tool wear value is established and its effectiveness is analyzed.The wear value of the tool flank after cutting is measured and output as the model,and then the feature vector extracted from the feature is used as the model input to establish the support vector machine regression model.The model prediction simulation is carried out with Mtalab software,and the accuracy of the prediction result is 94.38%,which realizes the prediction of tool wear value.