scholarly journals Construction of Three-Dimensional Road Surface and Application on Interaction between Vehicle and Road

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Lu Yongjie ◽  
Huai Wenqing ◽  
Zhang Junning
Keyword(s):  
Quantitative Description ◽  
Three Dimensional ◽  
Point Contact ◽  
Estimation Method ◽  
Road Surface ◽  
Surface Model ◽  
Dynamical Process ◽  
Contact Points ◽  
Box Counting Dimension ◽  
The Impact

The quantitative description is given to three-dimensional micro and macro self-similar characteristics of road surface from the perspective of fractal geometry using FBM stochastic midpoint displacement and diamond-square algorithm in conjunction with fractal characteristics and statistical characteristics of standard pavement determined by estimation method of box-counting dimension. The comparative analysis between reconstructed three-dimensional road surface spectrum and theoretical road surface spectrum and correlation coefficient demonstrate the high reconstruction accuracy of fractal reconstructed road spectrum. Furthermore, the bump zone is taken as an example to reconstruct a more arbitrary 3D road model through isomorphism of special road surface with stochastic road surface model. Measurement is taken to assume the tire footprint on road surface to be a rectangle, where the pressure distribution is expressed with mean stiffness, while the contact points in the contact area are replaced with a number of springs. Two-DOF vehicle is used as an example to analyze the difference between three-dimensional multipoint-and-plane contact and traditional point contact model. Three-dimensional road surface spectrum provides a more accurate description of the impact effect of tire on road surface, thereby laying a theoretical basis for studies on the dynamical process of interaction of vehicle-road surface and the road friendliness.

scholarly journals DETECTION OF CRACKS IN PAVED ROAD SURFACE USING LASER SCAN IMAGE DATA

2016 ◽  
Vol XLI-B1 ◽  
pp. 559-562 ◽  
Author(s):  
J. Choi ◽  
L. Zhu ◽  
H. Kurosu
Keyword(s):  
Image Segmentation ◽  
Background Subtraction ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Image Data ◽  
Road Surface ◽  
Surface Model ◽  
Rolling Ball ◽  
The Difference ◽  
Paved Road

In the current study, we developed a methodology for detecting cracks in the surface of paved road using 3D digital surface model of road created by measuring with three-dimensional laser scanner which works on the basis of the light-section method automatically. For the detection of cracks from the imagery data of the model, the background subtraction method (Rolling Ball Background Subtraction Algorithm) was applied to the data for filtering out the background noise originating from the undulation and gradual slope and also for filtering the ruts that were caused by wearing, aging and excessive use of road and other reasons. We confirmed the influence from the difference in height (depth) caused by forgoing reasons included in a data can be reduced significantly at this stage. Various parameters of ball radius were applied for checking how the result of data obtained with this process vary according to the change of parameter and it becomes clear that there are not important differences by the change of parameters if they are in a certain range radius. And then, image segmentation was performed by multi-resolution segmentation based on the object-based image analysis technique. The parameters for the image segmentation, scale, pixel value (height/depth) and the compactness of objects were used. For the classification of cracks in the database, the height, length and other geometric property are used and we confirmed the method is useful for the detection of cracks in a paved road surface.

scholarly journals DETECTION OF CRACKS IN PAVED ROAD SURFACE USING LASER SCAN IMAGE DATA

2016 ◽  
Vol XLI-B1 ◽  
pp. 559-562
Author(s):  
J. Choi ◽  
L. Zhu ◽  
H. Kurosu
Keyword(s):  
Image Segmentation ◽  
Background Subtraction ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Image Data ◽  
Road Surface ◽  
Surface Model ◽  
Rolling Ball ◽  
The Difference ◽  
Paved Road

In the current study, we developed a methodology for detecting cracks in the surface of paved road using 3D digital surface model of road created by measuring with three-dimensional laser scanner which works on the basis of the light-section method automatically. For the detection of cracks from the imagery data of the model, the background subtraction method (Rolling Ball Background Subtraction Algorithm) was applied to the data for filtering out the background noise originating from the undulation and gradual slope and also for filtering the ruts that were caused by wearing, aging and excessive use of road and other reasons. We confirmed the influence from the difference in height (depth) caused by forgoing reasons included in a data can be reduced significantly at this stage. Various parameters of ball radius were applied for checking how the result of data obtained with this process vary according to the change of parameter and it becomes clear that there are not important differences by the change of parameters if they are in a certain range radius. And then, image segmentation was performed by multi-resolution segmentation based on the object-based image analysis technique. The parameters for the image segmentation, scale, pixel value (height/depth) and the compactness of objects were used. For the classification of cracks in the database, the height, length and other geometric property are used and we confirmed the method is useful for the detection of cracks in a paved road surface.

scholarly journals 3-D Shape Reconstruction of Non-Uniform Reflectance Surface Based on Pixel Intensity, Pixel Color and Camera Exposure Time Adaptive Adjustment

2020 ◽  
Author(s):  
Jianhua Wang ◽  
Yanxi Yang ◽  
Yuguo Zhou
Keyword(s):  
Exposure Time ◽  
Three Dimensional ◽  
Estimation Method ◽  
Shape Reconstruction ◽  
Color Information ◽  
Pixel Intensity ◽  
Light Interference ◽  
Novel Approach ◽  
Pixel Color ◽  
The Impact

Abstract Three-dimensional (3-D) surface reconstruction of reflective objects and colored objects is a challenge. To this end, we proposed a novel approach. First, a new method of pixel matching between the projected image and the captured image is proposed. Then, we analyzed the impact of color texture and reflective surface on the captured image quality, and proposed a black-and-white (B/W) camera-based color information extraction method, an object surface reflectance and ambient light interference estimation method. Finally, the pixel color, pixel intensity and exposure time can be adaptively adjusted according to the color information and reflectivity of the measured objects. Experiments verified that the proposed method can not only obtain high-quality captured images, but also has a smaller number of additional images and a wider range of applications than existing methods.

Wheel/Rail Two-Point Contact Geometry With Back-of-Flange Contact

2007 ◽  
Author(s):  
Hiroyuki Sugiyama ◽  
Yoshihiro Suda
Keyword(s):  
Dimensional Analysis ◽  
Three Dimensional ◽  
Point Contact ◽  
Numerical Procedure ◽  
Contact Geometry ◽  
Light Rail ◽  
Contact Algorithm ◽  
Rail Vehicle ◽  
Contact Points ◽  
Contact Formulation

In this investigation, a numerical procedure that can be used for the three-dimensional analysis of wheel and rail contact geometry is developed using the constraint contact formulation. The locations of contact points are determined for given lateral and yaw displacements of a wheelset when one-point contact is considered for each wheel, while these two displacements are no longer independent when the two-point contact occurs. A systematic procedure for predicting the flange as well as the back-of-flange contact points is developed and used for the two-point contact analysis of wheel and rail. Numerical results that involve tread, flange, and back-of-flange contacts are presented in order to demonstrate the use of the contact algorithm developed in this investigation. In particular, the back-of-flange contact is discussed for assessing contact configurations of wheel and grooved rail in Light Rail Vehicle (LRV) applications.

Three-Dimensional Rigid-Body Collisions With Multiple Contact Points

1995 ◽  
Vol 62 (3) ◽  
pp. 725-732 ◽  
Author(s):  
D. B. Marghitu ◽  
Y. Hurmuzlu
Keyword(s):  
Special Class ◽  
External Surface ◽  
Three Dimensional ◽  
Kinematic Chain ◽  
Coefficient Of Restitution ◽  
Kinematic Chains ◽  
Contact Points ◽  
Differential Formulation ◽  
Impact Energies ◽  
The Impact

This article deals with three-dimensional collisions of rigid, kinematic chains with an external surface while in contact with other surfaces. We concentrate on a special class of kinematic chain problems where there are multiple contact points during the impact process. A differential formulation based algorithm is used to obtain solutions that utilize the kinematic, kinetic, and the energetic definitions of the coefficient of restitution. Planar and spatial collisions of a three-link chain with two contact points are numerically studied to compare the outcomes predicted by each approach. Particular emphasis is placed on the relation between the post and pre-impact energies, slippage and rebounds at the contact points, and differences among planar and nearly planar three-dimensional solutions.

scholarly journals Application of LiDAR Data for the Modeling of Solar Radiation in Forest Artificial Gaps—A Case Study

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 821
Author(s):  
Leszek Bolibok ◽  
Michał Brach
Keyword(s):  
Solar Radiation ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Management Decision ◽  
Surface Model ◽  
Lidar Data ◽  
Size And Shape ◽  
Hemispherical Photographs ◽  
Actual Shape ◽  
The Impact

Artificial canopy gaps (forest openings) are frequently used as an element of regeneration cutting. The development of regeneration in gaps can be controlled by selecting a relevant size and shape for the gap, which will regulate the radiation microclimate inside it. Based on the size and shape of a gap computer models can assess where solar radiation is decreased or eliminated by the surrounding canopy. The accuracy of such models to a large extent depends on how the modeled shape of a gap matches the actual shape of the gap. The aim of this study was to compare the results of modeling solar radiation availability by applying Solar Radiation Tools (SRT) that use a different digital surface model (DSM) for a description of the shape of a studied gap, with the results of the analysis of 27 hemispherical photographs. The three-dimensional gap shape was approximated with the use of simple geometrical prisms or airborne laser scanning (LiDAR) data. The impact of two variations of exposure (automatic and manual underexposure) and two variations of automatic thresholding on the congruence of SRT and Gap Light Analyzer (GLA) results were studied. Taking into account information on differences in height between trees surrounding the gap enhanced the results of modeling. The best results were obtained when the boundary of the gap base estimated from LiDAR was expanded in all directions by a value close to a mean radius of the crowns of surrounding trees. Modeling of radiation conditions on the gap floor based on LiDAR data by an SRT program is efficient and more time effective than taking hemispherical photographs. The proposed solution can be successfully applied as a trustworthy source of information about light conditions in gaps, which is needed for management decision-making in silviculture.

scholarly journals Three-Dimensional Evolution of Mesoscale Anticyclones in the Lee of Crete

2020 ◽  
Vol 7 ◽  
Author(s):  
Artemis Ioannou ◽  
Alexandre Stegner ◽  
Franck Dumas ◽  
Briac Le Vu
Keyword(s):  
Numerical Model ◽  
Vertical Structure ◽  
Three Dimensional ◽  
Wind Forcing ◽  
Water Model ◽  
Mountain Range ◽  
Dynamical Process ◽  
Ekman Pumping ◽  
Spatio Temporal ◽  
The Impact

Motivated by the recurrent formation of mesoscale anticyclones in the southeast of Crete, we investigated with a high resolution model the response of the ocean to orographic wind jets driven by the Cretean mountain range. As shown in the dynamical process study of Ioannou et al. (2020) which uses a simplified shallow-water model, we confirm here, using the CROCO (Coastal and Regional Ocean COmmunity) model, that the main oceanic response to the Etesian wind forcing is the formation of mesoscale anticyclones. Moreover, we found that the intensity of the wind-induced Ekman pumping acting on the eddies, once they are formed, modulates their intensity. Among the various coastal anticyclones formed during summer and fall 2015, only one of them will correspond to a long lived structure (M_IE15) which is similar to the Ierapetra Eddy detected in 2015 (O_IE15) on the AVISO/DUACS products. Thanks to the DYNED-Atlas data base, we were able to perform a quantitative comparison of the vertical structure of such long-lived anticyclone between the numerical model and the in-situ measurements of the various Argo profilers trapped inside the eddy core. Even without assimilation or any nudging, the numerical model was able to reproduce correctly the formation period, the seasonal evolution and the vertical structure of the O_IE15. The main discrepancy between the model and the altimetry observations is the dynamical intensity of the anticyclone. The characteristic eddy velocity derived from the AVISO/DUACS product for the O_IE15 is much lower than in the numerical model. This is probably due to the spatio temporal interpolation of the AVISO/DUACS altimetry products. More surprisingly, several coastal anticyclones were also formed in the model in the lee of Crete area during summer 2015 when the Etesian winds reach strong values. However, these coastal anticyclones respond differently to the wind forcing since they remain close to the coast, in shallow-waters, unlike the M_IE15 which propagates offshore in deep water. The impact of the bottom friction or the coastal dissipation seems to limit the wind amplification of these coastal anticyclones.

scholarly journals Driving Safety Analysis Using Grid-Based Water-Filled Rut Depth Distribution

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jiao Yan ◽  
Hongwei Zhang ◽  
Bing Hui
Keyword(s):  
Water Depth ◽  
Three Dimensional ◽  
Element Model ◽  
Road Surface ◽  
Driving Safety ◽  
Vehicle Speed ◽  
Adhesion Coefficient ◽  
The Road ◽  
Left And Right ◽  
The Impact

The water accumulated in the rutted road sections poses a threat to the safety of vehicles. Water-filled ruts will cause partial or complete loss of the friction between tires and the road surface, leading to driving safety hazards such as hydroplaning and sliding. At present, the maximum water depth of left and right ruts is mostly adopted to analyze the safety of water-filled ruts, ignoring the uneven change of ruts in the driving direction and the cross-section direction, which cannot fully reflect the actual impact of asymmetric or uneven longitudinal ruts on the vehicle. In order to explore the impact of water-filled ruts on driving safety, a three-dimensional (3D) tire-road finite element model is established in this paper to calculate the adhesion coefficient between the tire and the road surface. Moreover, a model of the 3D water-filled rut-adhesion coefficient vehicle is established and simulated by the dynamics software CarSim. In addition, the influence of the water depth difference between the left and right ruts on the driving safety is quantitatively analyzed, and a safety prediction model for the water-filled rut is established. The results of the case study show that (1) the length of dangerous road sections based on vehicle skidding is longer than that based on hydroplaning, and the length of dangerous road sections based on hydroplaning is underestimated by 9.4%–100%; (2) as the vehicle speed drops from 120 km/h to 80 km/h, the length of dangerous road sections obtained based on vehicle sliding analysis is reduced by 93.8%. Therefore, in order to ensure driving safety, the speed limit is controlled within 80 km/h to ensure that the vehicle will not skid. The proposed method provides a good foundation for the vehicles to actively respond to the situation of the water-filled road section.

Underwater Structure from Motion for Cameras Under Refractive Surfaces

2019 ◽  
Vol 31 (4) ◽  
pp. 603-611 ◽  
Author(s):  
Xiaorui Qiao ◽  
◽  
Atsushi Yamashita ◽  
Hajime Asama
Keyword(s):  
3D Reconstruction ◽  
Structure From Motion ◽  
Three Dimensional ◽  
Estimation Method ◽  
Reconstruction Technique ◽  
Camera System ◽  
Light Refraction ◽  
Camera Pose Estimation ◽  
Geometric Reconstruction ◽  
The Impact

Structure from Motion (SfM), as a three-dimensional (3D) reconstruction technique, can estimate the structure of an object by using a single moving camera. Cameras deployed in underwater environments are generally confined to waterproof housings. Thus, the light rays entering the camera are refracted twice; once at the interface between the water and the camera housing, and again at the interface between the camera housing and air. Images captured from scenes in underwater environments are prone to, and deteriorate, from distortion caused by this refraction. Severe distortions in geometric reconstruction would be caused if the refractive distortion is not properly addressed. Here, we propose a SfM approach to deal with the refraction in a camera system including a refractive surface. The impact of light refraction is precisely modeled in the refractive model. Based on the model, a new calibration and camera pose estimation method is proposed. This proposed method assists in accurate 3D reconstruction using the refractive camera system. Experiments, including simulations and real images, show that the proposed method can achieve accurate reconstruction, and effectively reduce the refractive distortion compared to conventional SfM.

Three-Dimensional Quantification of Multi-Point Contact Loads During Lumbar Spinal Manipulation

2004 ◽  
Author(s):  
Maruti R. Gudavalli ◽  
Robert M. Rowell
Keyword(s):  
Spinal Manipulation ◽  
Force Plate ◽  
Three Dimensional ◽  
Point Contact ◽  
Time Data ◽  
Rib Cage ◽  
Contact Points ◽  
Contact Loads ◽  
Pelvic Support ◽  
Hand Contact

The objective of this study was to measure the complete three-dimensional loads at each of the support contacts namely both hand contacts, and the support loads at the rib cage and the pelvis during chiropractic treatments for low back pain. Two small force transducers were used to measure hand contact loads, and a specially instrumented force plate table was used for measuring support loads. A doctor of chiropractic delivered fourteen spinal manipulations to the lumbar spines of five subjects during a period of three weeks. The results showed that there are three dimensional loads at each of the four contact points. The loads at the thrusting hands reached as high as 382N. For the stabilizing hands the maximum loads were 160N. The support loads reached as high as 727N at the pelvic support and 660N at the rib cage support. This study reports for the first time data on the loads at each of the hand contact points and the support locations during chiropractic spinal manipulation.

Sign in / Sign up

Export Citation Format

Share Document