A method for determining the modal parameters of a road or rail vehicle and indirectly characterizing the road or rail profile

Abstract

A pole (λ n ) and the mode vector (ψ n ), the vehicle is provided with at least two wheels and is in operation, by analyzing the movement or velocity or acceleration (output of the system) of said vehicle taken in specified measurement points, wherein said poles and Mode vectors are determined based on a mathematical model describing the interaction between the road or rail and the vehicle, by fitting data related to the output of the system, characterized in that the vehicle is assumed to travel at a constant speed moving on a straight track or on a curve with a constant radius; assuming that the vehicle is moving on a uniform and traversed surface, the roughness of which has a Gaussian distribution and that the at least two wheels are on a profile or in relation to Move over multiple contours parallel to each other; assume that inputs induced by road or track surfaces on the vehicle cannot be traced back to the white noise sequence and are temporally and / or spatially correlated relative to each other.

Description

technical field [0001] The present invention relates to a method for estimating modal parameters of a road / rail vehicle system under operating conditions and indirectly characterizing the statistical properties of the roughness of rolling profiles on road / rail surfaces. [0002] It is tentatively summarized that the methods described below can be applied to road or rail vehicle systems, and thus the terms road surface and track surface, road profile and track profile, road and track or railway are interchangeable throughout the text. [0003] For an explanation of all acronyms used, see the list at the end of the specification. Background technique [0004] The field of application of the invention is the operating modal analysis OMA applied in the case of road / rail vehicle systems, and the characterization of the roughness of the profile of the road / rail surface. [0005] OMA is a technique commonly used to perform experimental identification of structures in operational s...

AI Technical Summary

Problems solved by technology

[0086] Problem 1: Loads have a pattern that can be traced back to one of colored noise, where the amplitude generally decreases with frequency, the form of which depends on the characteristics of the road / track profile (equations (9) and (10)) and on Some of the wheels (via H in equation (15) fr (ω) description): Therefore, Assumption 1 of NExT is invalid

[0087] Problem 2: Inputs acting on wheels positioned on the same axis are spatially dependent (by Γ in Equation (14) m (ω) description) is interested, and the input applied to the wheels with a common rolling profile but arranged on different axes is time-dependent (by the description) while for loads related to wheels that do not have a common rolling profile and belong to different axes, there is a spatial and temporal dependence: Assumption 2 of NExT is therefore invalid

In contrast, application US2014 / 257629A1 proposes an approach based on a single-suspension model of the vehicle, which algorithm does not allow proper consideration of the effects associated with the correlation of road inputs

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