Instrumented Wheelset Wheel/Rail Force Measurement by Blind Signal Separation

The measure of wheel/rail force has great significance on vehicle dynamics, derailment mechanism, the theory of wheel/rail contact and the vehicle security measurement. The instrumented wheelset is now the most direct and most precise technology of measuring the wheel/rail force, which takes the wheel as the detecting sensor of wheel/rail force and realizes continuous measurement of wheel/rail force by measuring the strain on several places on the wheel plate. This paper makes the Blind Signal Separation (BSS) algorithm apply to the process of the instrumented wheelset strain signal. BSS is new method of signal processing, which can reconstruct the source signal through observational signal based on the statistics characteristic of the source signal on condition that the source signal and the transport channel parameters are unknown. The wheel/rail force is changing and non-stationary and the plate strain which is produced by the wheel/rail force is modulated by the wheel rotating angle. As a result, the strain signal is complex. This paper analyzed the characteristic of the instrumented wheelset's strain signal, developed the way to extract the strain harmonic of wheel/rail force based on Blind Signal Separation algorithm, researched the applicability of the algorithm in all cases, and completed the detecting method of wheel/rail force. Then, according to the simulation of wheelset's finite element model, proved the validity by means of the Blind Signal Separation algorithm. Finally, proposed some problems which need to be solved and the development direction next step.