Proposal of rail-gauge-widening detection method using existing tachometer generator on vehicles

Excessive rail-gauge widening may cause derailment. To prevent this, not only periodic inspection but also condition monitoring by a commercial train is desirable. To achieve this in a low cost way, this study proposes to use pre-installed tachometer generators on the train. When the train has axle beam type bogies, the signal amplitude from the tachometer generator reflects the lateral displacement of wheelset from the bogie. Therefore, when the displacement of the wheelset is affected by the rail-gauge widening, that can be detected by the amplitude of signal from the tachometer generator. To verify the effectiveness of the method, 10mm rail-gauge-widening was simulated on a test track. Through the comparison of the results between default and widened condition, it is confirmed that the rail-gauge-widening can be detected by the amplitude of the signal from the tachometer generator.