Wheel-Rail Force Measurement Based on Wireless LC Resonance Sensing

Wheel-rail contact force measurement is one of the key issues in rolling stock monitoring. Traditional methods using strain gauges are a relative measurement, which requires strong bonding on the wheel webs with complicated telemetry transmission systems. This article proposes a wireless inductive–capacitive resonance sensing approach for noncontact measurement of wheel-rail contact forces. The proposed inductor–capacitor (
LC
) resonance sensor is low-cost, high sensitivity, and consists of a dual-layer rectangular inductance coil and a parallel capacitor. Validation using a standard dog-bone specimen tested on a universal testing machine was performed, with the resonant frequency of the proposed
LC
resonance sensor increasing monotonically with loading force. Investigation of the lift-off and aspect ratio of the inductance coil shows that lower lift-off and lower aspect ratio offer better sensitivity. The proposed
LC
resonance sensing with the LDC chip approach has great potential for rolling stock monitoring.