Battery-free Digital Tooling Head using Wireless Power Transmission

This study demonstrates a battery-free digital tooling head (BF-DTH) for real-time monitoring of a rotating machine tool. As tooling heads include more digital electronics and consume more power with improved functionalities, replacement and management of batteries become major issues. A BF-DTH using wireless power transmission is proposed to resolve these issues. The BF-DTH is composed of a transmitter/receiver (TX/RX) coil pair, converters, a wireless microcontroller and thermal sensor. The microcontroller, powered by a wirelessly transmitted and converted DC voltage, measures the tool’s temperature and continuously transmits data from the rotating BF-DTH to an external wireless terminal. The delivered RX power was measured to be 32 mW at 15% efficiency, with the RX converter providing a constant DC voltage regardless of spindle speeds of up to 1200 RPM. The BF-DTH system could be effectively used for emerging smart factory applications, where smart DTHs consume moderate to high power.