Intelligent Sensorless Monitoring Dual System to Detect the Tool Condition in CNC Milling Machines

Tool state in the CNC milling machines will determine the product quality. An efficient tool state monitoring system will protect machinery from severe damages. For determining the state of the cutting tools in a milling machine there is a great variety of models in the industrial market, however those systems are not available for all companies because of their high costs and requirements of modifying the machining tool in order to attach the system sensors in the machine. This paper presents a sensorless intelligent dual system which classifies the cutters status in a CNC milling machine. The tool state is mainly determined through the analysis of the cutting forces drawn from the spindle motors currents. The tool classification is made by a Supervised SOM (Self Organized Maps), a MLP (Multilayer Perceptron) or both, achieving a reliability of 98%.