Ride Comfort Level Research Articles

Fundamental Study on the Effect of High-frequency Vibration in the Vertical and Lateral Directions on Ride Comfort

To develop a more suitable method of evaluating the ride comfort of railway vehicles, including high-speed trains, a fundamental study was conducted on passenger sensitivity to various frequencies of vibration with respect to ride comfort. Experiments were performed on 54 subjects using an electrodynamic vibration system that can generate vibrations in the frequency range of 1 to 80 Hz in the vertical and lateral directions. The results of the experiments indicated that the subjects tended to experience greater discomfort when exposed to high-frequency vibrations than presumed by Japan's conventional Ride Comfort Level assessment method.

358129 FUNDAMENTAL STUDY ON THE EFFECT OF HIGH FREQUENCY VIBRATION ON RIDE COMFORT(Vehicle,Technical Session)

To develop a more suitable method of evaluating ride comfort of high speed trains, a fundamental study was conducted on sensitivity of passengers to various frequencies of vibration with respect to ride comfort. Experiments were performed on 55 subjects using an electrodynamic vibration system that can generate vibrations in the frequency range of 1 to 80 Hz in the vertical direction. Results of experiments indicated that the subjects tend to experience greater discomfort when exposed to high frequency vibrations than that presumed by the conventional Japanese ride comfort assessment method, the "Ride Comfort Level."

Development of a Vibration Simulator for Railway Vehicles with Field-Portable Actuators (2nd Report, Excitation Tests of an Actual Commuter Vehicle)

Bending vibration characteristics of railway vehicles have been investigated in general under excitation tests, in which a carbody was directly excited by a shaker. It is however very difficult with their results to evaluate the ride comfort of passengers under a condition that the vehicle runs on a certain track. The authors are therefore developing a “vertical vibration simulator” for railway vehicles. The simulator consists of a excitation system equipped with linear actuators, the elastic supporting device installed between wheels and rails, and analytical techniques to estimate the power spectral density (PSD) and the ride comfort level (Lr) which feature the ride comfort. In this paper, we describe the excitation tests performed using an actual commuter car and the estimated PSD and LT are compared with what substantially measured under the running conditions.

Vertical Vibration Suppression of Railway Vehicle by Using Variable Coefficient Axle Dampers

In order to improve vertical ride comfort aboard railway vehicles, it has recently become essential to suppress vertical bending vibration of carbody. In many cases, the resonant frequency of the system which consists of bogie frame and axle springs is close to the one of the first mode bending vibration of carbody. Therefore, suppressing the vibration of bogie frames near their resonant frequency effectively reduces the vibration of carbody. In this paper, we propose a method to suppress this vibration by controlling damping force of axle dampers, which are installed between bogie frames and wheel sets. The semi-active controller that is applied to determine the optimal damping force is designed based on the sky-hook control theory. Both numerical simulations using a vehicle model with 16 degrees of freedom and excitation tests using a carbody with variable coefficient axle dampers on rolling stock testing plant are carried out. In results, we show that the control method effectively reduces the power spectral density (PSD) of acceleration on the floor and the ride comfort level (LT) can be improved by about 3 dB.

A604 RIDE COMFORT AND ABILITY TO WORK IN TILTING TRAINS REPORT FROM A TRAIN STUDY CARRIED OUT WITH NSB, NORWAY

Short train journeys, good ride comfort and good ability to work in a train are some of the main requirements for the potential train passenger. High speed, especially in curves, often means decreased ride comfort and ability to work. Before introducing a new tilting train, the Norwegian State Railways wanted to compare its performance in terms of estimated comfort, work ability and possible motion sickness with a non-tilting train. This study argues that a tilting train will offer almost as good ride comfort levels estimated by subjects, while maintaining higher speed in curves.