Neural network based on-line detection of drill breakage in micro drilling process

The breakage of drill bit often occurs in micro drilling process because of the very small drill diameter. So on-line detection of drill breakage plays an important role in micro drilling process. In this paper, a method for the on-line detection of the drill breakage in micro drilling process based on neural network is presented. The characteristic of the drilling torque during the drilling process is studied first. Five features extracted from the drilling torque signal and the drilling conditions are input to a neural network for the detection of the drill breakage. A three-layer backpropagation neural network with five input nodes, ten hidden nodes and one output node is applied here. The results show that the presented neural network based method can effectively detect the drill breakage in micro drilling process.