Calculation of resistance to motion of a high-speed train using acceleration measurements in irregular coasting conditions

Abstract

The resistance to motion of the Korean high-speed train has been calculated and evaluated using train speed measurements gathered from coasting tests in the speed range from 30 to 300 km/h under various track conditions. Several test runs of the Korean high-speed train, with consists of seven cars, have been performed on the Seoul-Busan high-speed line since August 2002. A modified method for regression and the normal regression method have been employed to calculate the running resistance of the train to eliminate the error due to the irregular test conditions of slope, train speed, and coasting distance, and the validity and robustness of the calculation methods have been discussed extensively in this paper. The initial estimation of resistance to motion for the Korean high-speed train based on the general resistance to motion equation for the Train à Grande Vittesse train has been compared with the results obtained from the coasting test measurements.

In the present study, curve fits of the acceleration data using a second-order polynomial show that the low-speed region error is relatively high, however fixing the constant and low-order coefficients can generate more robust curve-fitting results. The actual resistance to motion of the Korean high-speed train is lower than the estimated value based on the resistance to motion equation for the Korea Train Express train, especially in the high-speed region.