An active contour is used to track a target in a sequence recorded by a walking robot in an unstructured scene . The deformations of the contour are analysed in order to extract the robot’s egomotion, from which we compute the epipolar geometry that guides the matching between different views of the scene. The results prove that the proposed solution is a promising alternative to the prevalent ...

Car body acceleration is an important factor affecting track safety and ride comfort, which are two primary aspects of railway systems. Though track level is an important source of wagon body acceleration, no quantitative relation between them is available and the aim of this paper is to propose a method to address this issue. To do so, car body acceleration is determined using a 10 DOF simulat...

the aim of this paper is to show the importance of analytic hyperbolic geometry introduced in [9]. in [1], ungar and chen showed that the algebra of the group sl(2,c) naturally leads to the notion of gyrogroups and gyrovector spaces for dealing with the lorentz group and its underlying hyperbolic geometry. they defined the chen addition and then chen model of hyperbolic geometry. in this paper,...

Abstract We investigate numerically the dynamical reactions of a moving wheelset model to real measured track irregularities. The background is examine whether dynamics are suitable as input inverse problem: determine true geometry from reactions. It known that method works well for vertical position rails but computed lateral often flawed. find motion may differ geometry. cases investigated cl...

The motion error of a multi-rotor unmanned aerial vehicle (UAV) leads to severe image blurring for mini synthetic aperture radar (SAR) systems. along-track displacement usually is compensated in advance through real-time pulse repetition frequency (PRF) adjustment. And then, only the cross-track considered traditional compensation (MOCO) algorithms. However, instantaneous range expression based...

With dynamic behaviour different from that of traditional discretely supported tracks, continuously embedded rail systems (ERSs) have been increasingly used in railway bridges, level crossings, trams, and high-speed lines. However, studies on ERSs limited, none them addressed the wheel-rail impact-induced response, although impact is a main cause ERS degradation. This paper studies, numerically...

Today’s railway transport is built upon high-performance infrastructure. Cost-effective yet sustainable infrastructure presumes tracks with a precise and durable geometry. At ballasted tracks, the geometry created restored through tamping machines, which position track panel compact ballast beneath sleepers. It commonly agreed that compaction plays an important role in long-term stability of tr...

investigations on vibration behaviors of railway track systems were attempted in this research. this was made by conducting a comprehensive field investigation into the free vibration of track systems and response of tracks to train moving loads. in-situ modal analysis was used in a railway track field as an efficient method of investigating dynamic properties of railway track systems. natural ...

Tracks are critical and expensive railroad asset, requiring frequent maintenance. The stress from heavy car axle loads increases the risk of deviations uniform track geometry. Irregularities in geometry, such as warping, can cause an excessive harmonic rocking condition that lead to derailments, traffic delays, associated financial losses. This article presents approach enhance location identif...