Design and laboratory-based proof-of-concept verification of electromagnetic energy harvesting device for multi-state monitoring of large-diameter TBM gauge cutters

• Proposed an embedded electromagnetic energy harvesting device for 19-inch edge disc cutters . • Introduced planetary gear speed increase mechanism and dedicated energy management circuit. • Optimized the structural configuration and key parameters through FEM simulation. • Developed an independent experimental platform for the electromagnetic energy harvesting device . • The device meets the power requirements of real-time monitoring. To meet the future-oriented multi-state online monitoring demands for the disc cutters of large-diameter full-face rock tunnel boring machines (hereinafter referred to as TBM), this study proposes an electromagnetic energy harvesting self-powering scheme that can be embedded inside the disc cutter, addressing the challenge of wired power supply for the cutter condition monitoring system. Focusing on the 19-inch gauge cutter used in TBMs with cutterhead diameters exceeding 14 m, and without altering its existing structure, the design of a built-in electromagnetic energy harvesting device is completed. Through theoretical electromagnetic modeling and finite element simulation, key variables such as the configuration and spatial arrangement of permanent magnets and coil parameters are optimized. Simulation results indicate that the optimized electromagnetic energy harvesting component can generate a peak induced electromotive force of 25 V, theoretically meeting the power consumption requirements of the monitoring system. Furthermore, an experimental test platform was constructed for validation. Tests demonstrate that the variation trend of the output induced electromotive force from the device is consistent with simulation predictions. The device can fully charge a lithium battery within 150 min and maintains stable output waveform during continuous operation for 2000 s. The proposed electromagnetic energy harvesting solution effectively overcomes the limitations of wired power supply for the disc cutter condition monitoring system, providing critical hardware support for the construction of a high-precision TBM digital twin model.