Estimations for train speed based on two-frequency CW and initial experiments on railway environments

Abstract

Estimation methods based on two-frequency continuous wave modulation (2FCW) for the train speed which are not affected by idling and slide of wheels are presented. The initial experimental results on the railway environments are also shown. The proposed methods obtained stable estimation results even in the situation where there exists shielding objects. The nonlinear least square method with an unknown quantity had the smallest standard deviation in the environment where the height of ballast track bed was not changed. The nonlinear least square method with two unknowns had the smallest bias errors between the estimation results and GPS speedometer.