Self-powered wireless sensor system application for cutting process con-trol
In the article a self-powered wireless sensor used for milling operation control is presented. Source of vibrations suitable for energy harvesting and generation has been accurately identified, experimental work on CNC machine performed and was determined that the highest amplitude vibrations for the milling tool are present during its tooth contact with the workpiece. During investigation it was determined that based on feed rate and number of teeth on the cutter, the frequency of tooth contact with workpiece is in the range of 150 – 300 Hz, based on that a piezoelectric cantilever with natural frequency falling within this frequency range scope has been chosen. In order to increase the efficiency of energy generation by the piezoelectric transducer adjustment of its natural frequency by adding proof mass for course control and connection of piezoelectric layers for fine tunning has been proposed. Proposed energy generation, storage and wireless signal representing tool condition transmition circuit for the device. Experiments were performed, that allowed to record milling tool‘s wear during machining and evaluate energy generation dependence on set milling parameters. Designed and validated prototype device is suitable for control of milling process and can be efectivelly used to increase milling accuracy of thin-walled workpieces.