The inertial measurement method is based on a simple law that states that the double integration of the acceleration gives its displacement. The track irregularity record obtained by the former inertial measurement system has a wave distrortion. It is casued by the nonlinear phase property of the analogue high-pass filter which stabilizes the integration. To solve the problem, two digital inertial measurement systems are proposed in this paper. As for the low-speed motorcar, the digital inertial system using variable CIC filter is described. This system can obtain 10 m versine signal directly. Following it, a system which could obtain the track waveform on the ground, is proposed for a high-speed test train. As a result of several examinations with a PC, it was confirmed that track irregularities obtained from the proposed digital systems don't accept the wave distortion. Equipment based on this study will be added on to the new track inspection car to be completed in September 2000.
展开▼
