Quantitative visualization of physical barriers for vulnerable pedestrians based on photogrammetry

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Koki Taniguchi ◽  
Satoshi Kubota ◽  
Yoshihiro Yasumuro
Keyword(s):  
Effective Means ◽  
Three Dimensional ◽  
Road Surface ◽  
Geographical Information ◽  
Web Based ◽  
Content Type ◽  
Wheelchair Users ◽  
Digital Twin ◽  
The Road ◽  
Physical Barriers

Purpose The purpose of this study is to propose a method for vulnerable pedestrians to visualize potential obstacles on sidewalks. In recent years, the number of vulnerable pedestrians has been increasing as Japanese society has aged. The number of wheelchair users is also expected to increase in the future. Currently, barrier-free maps and street-view applications can be used by wheelchair users to check possible routes and the surroundings of their destinations in advance. However, identifying physical barriers that pose a threat to vulnerable pedestrians en route is often difficult. Design/methodology/approach This study uses photogrammetry to create a digital twin of the three-dimensional (3D) geometry of the existing walking space by collecting photographic images taken on sidewalks. This approach allows for the creation of high-resolution digital elevation models of the entire physical sidewalk surface from which physical barriers such as local gradients and height differences can be detected by uniform image filtering. The method can be used with a Web-based data visualization tool in a geographical information system, permitting first-person views of the ground and accurate geolocation of the barriers on the map. Findings The findings of this study showed that capturing the road surface with a small wide-angle camera while walking is sufficient for recording subtle 3D undulations in the road surface. The method used for capturing data and the precision of the 3D restoration results are described. Originality/value The proposed approach demonstrates the significant benefits of creating a digital twin of walking space using photogrammetry as a cost-effective means of balancing the acquisition of 3D data that is sufficiently accurate to show the detailed geometric features needed to navigate a walking space safely. Further, the findings showed how information can be provided directly to users through two-dimensional (2D) and 3D Web-based visualizations.

scholarly journals Living in the clouds: conceptual reconstructions of harbour structures

2018 ◽  
Vol 8 (4) ◽  
pp. 405-419
Author(s):  
Elizabeth Anne Shotton
Keyword(s):  
Three Dimensional ◽  
Point Clouds ◽  
Heritage Management ◽  
Historical Narrative ◽  
Web Based ◽  
Content Type ◽  
Terrestrial Lidar ◽  
Sea Levels ◽  
Rising Sea Levels ◽  
Scan Data

Purpose The harbours of Ireland, under threat from deterioration and rising sea levels, are being documented using terrestrial LiDAR augmented by archival research to develop comprehensive histories and timeline models for public dissemination. While methods to extract legible three-dimensional models from scan data have been developed and such operational formats for heritage management are imperative, the need for this format in interpretive visualisations should be reconsidered. The paper aims to discuss these issues. Design/methodology/approach Interpretive visualisations are forms of history making, where factual evidence is drawn together with conjecture to illustrate a plausible account of events, and differentiation between fact and conjecture is the key to their intellectual transparency. A procedure for superimposing conjectural reconstructions, generated using Rhinoceros and CloudCompare, on original scan data in Cyclone and visualised on a web-based viewer is discussed. Findings Embellishing scan data with conjectural elements to visualise the evolution of harbours is advantageous for both research and public dissemination. The accuracy and density of the scans enables the interrogation of the harbour form and the irregular details, the latter in danger of generalisation if translated into parametric or mesh format. Equally, the ethereal quality of the point cloud conveys a sense of tentativeness, consistent with a provisional hypothesis. Finally, coding conjectural elements allows users to intuit the difference between fact and historical narrative. Originality/value While various web-based point clouds viewers are used to disseminate research, the novelty here is the potential to develop didactic representations using point clouds that successfully capture a provisional thesis regarding each harbour’s evolution in an intellectually transparent manner to enable further inquiry.

scholarly journals Mobile Laser Scanning Data for the Evaluation of Pavement Surface Distress

2020 ◽  
Vol 12 (6) ◽  
pp. 942 ◽  
Author(s):  
Maria Rosaria De Blasiis ◽  
Alessandro Di Benedetto ◽  
Margherita Fiani
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Road Traffic ◽  
Single Point ◽  
Three Dimensional ◽  
Point Clouds ◽  
Road Surface ◽  
Important Indicator ◽  
The Road ◽  
Laser Systems

The surface conditions of road pavements, including the occurrence and severity of distresses present on the surface, are an important indicator of pavement performance. Periodic monitoring and condition assessment is an essential requirement for the safety of vehicles moving on that road and the wellbeing of people. The traditional characterization of the different types of distress often involves complex activities, sometimes inefficient and risky, as they interfere with road traffic. The mobile laser systems (MLS) are now widely used to acquire detailed information about the road surface in terms of a three-dimensional point cloud. Despite its increasing use, there are still no standards for the acquisition and processing of the data collected. The aim of our work was to develop a procedure for processing the data acquired by MLS, in order to identify the localized degradations that mostly affect safety. We have studied the data flow and implemented several processing algorithms to identify and quantify a few types of distresses, namely potholes and swells/shoves, starting from very dense point clouds. We have implemented data processing in four steps: (i) editing of the point cloud to extract only the points belonging to the road surface, (ii) determination of the road roughness as deviation in height of every single point of the cloud with respect to the modeled road surface, (iii) segmentation of the distress (iv) computation of the main geometric parameters of the distress in order to classify it by severity levels. The results obtained by the proposed methodology are promising. The procedures implemented have made it possible to correctly segmented and identify the types of distress to be analyzed, in accordance with the on-site inspections. The tests carried out have shown that the choice of the values of some parameters to give as input to the software is not trivial: the choice of some of them is based on considerations related to the nature of the data, for others, it derives from the distress to be segmented. Due to the different possible configurations of the various distresses it is better to choose these parameters according to the boundary conditions and not to impose default values. The test involved a 100-m long urban road segment, the surface of which was measured with an MLS installed on a vehicle that traveled the road at 10 km/h.

Optimal Active Control of Vehicle Suspension System Including Time Delay and Preview for Rough Roads

2002 ◽  
Vol 8 (7) ◽  
pp. 967-991 ◽  
Author(s):  
Javad Marzbanrad ◽  
Goodarz Ahmadi ◽  
Yousef Hojjat ◽  
Hassan Zohoor
Keyword(s):  
Ride Comfort ◽  
Three Dimensional ◽  
Suspension System ◽  
Road Surface ◽  
Vehicle Suspension ◽  
Control Force ◽  
Preview Control ◽  
The Road ◽  
Road Surface Roughness ◽  
Vehicle Suspension System

An optimal preview control of a vehicle suspension system traveling on a rough road is studied. A three-dimensional seven degree-of-freedom car-riding model and several descriptions of the road surface roughness heights, including haversine (hole/bump) and stochastic filtered white noise models, are used in the analysis. It is assumed that contact-less sensors affixed to the vehicle front bumper measure the road surface height at some distances in the front of the car. The suspension systems are optimized with respect to ride comfort and road holding preferences including accelerations of the sprung mass, tire deflection, suspension rattle space and control force. The performance and power demand of active, active and delay, active and preview systems are evaluated and are compared with those for the passive system. The results show that the optimal preview control improves all aspects of the vehicle suspension performance while requiring less power. Effects of variation of preview time and variations in the road condition are also examined.

scholarly journals ROAD SURFACE DETECTION FROM MOBILE LIDAR DATA

2018 ◽  
Vol IV-5 ◽  
pp. 95-101 ◽  
Author(s):  
M. Yadav ◽  
B. Lohani ◽  
A. K. Singh
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Test Site ◽  
Road Surface ◽  
Lidar Data ◽  
Rural Roads ◽  
The Road ◽  
Surface Detection ◽  
Rural Road ◽  
Data Points

<p><strong>Abstract.</strong> The accurate three-dimensional road surface information is highly useful for health assessment and maintenance of roads. It is basic information for further analysis in several applications including road surface settlement, pavement condition assessment and slope collapse. Mobile LiDAR system (MLS) is frequently used now a days to collect detail road surface and its surrounding information in terms three-dimensional (3D) point cloud. Extraction of road surface from volumetric point cloud data is still in infancy stage because of heavy data processing requirement and the complexity in the road environment. The extraction of roads especially rural road, where road-curb is not present is very tedious job especially in Indian roadway settings. Only a few studies are available, and none for Indian roads, in the literature for rural road detection. The limitations of existing studies are in terms of their lower accuracy, very slow speed of data processing and detection of other objects having similar characteristics as the road surface. A fast and accurate method is proposed for LiDAR data points of road surface detection, keeping in mind the essence of road surface extraction especially for Indian rural roads. The Mobile LiDAR data in <i>XYZI</i> format is used as input in the proposed method. First square gridding is performed and ground points are roughly extracted. Then planar surface detection using mathematical framework of principal component analysis (PCA) is performed and further road surface points are detected using similarity in intensity and height difference of road surface pointe in their neighbourhood.</p><p>A case study was performed on the MLS data points captured along wide-street (two-lane road without curb) of 156<span class="thinspace"></span>m length along rural roadway site in the outskirt of Bengaluru city (South-West of India). The proposed algorithm was implemented on the MLS data of test site and its performance was evaluated it terms of recall, precision and overall accuracy that were 95.27%, 98.85% and 94.23%, respectively. The algorithm was found computationally time efficient. A 7.6 million MLS data points of size 27.1<span class="thinspace"></span>MB from test site were processed in 24 minutes using the available computational resources. The proposed method is found to work even for worst case scenarios, i.e., complex road environments and rural roads, where road boundary is not clear and generally merged with road-side features.</p>

scholarly journals Comparison of algorithms for road surface temperature prediction

2018 ◽  
Vol 2 (3) ◽  
pp. 212-224
Author(s):  
Bo Liu ◽  
Libin Shen ◽  
Huanling You ◽  
Yan Dong ◽  
Jianqiang Li ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Prediction Method ◽  
Temperature Data ◽  
Road Surface ◽  
Machine Learning Algorithms ◽  
Gradient Boosting ◽  
Data Set ◽  
Content Type ◽  
The Road ◽  
Road Surface Temperature

Purpose The influence of road surface temperature (RST) on vehicles is becoming more and more obvious. Accurate predication of RST is distinctly meaningful. At present, however, the prediction accuracy of RST is not satisfied with physical methods or statistical learning methods. To find an effective prediction method, this paper selects five representative algorithms to predict the road surface temperature separately. Design/methodology/approach Multiple linear regressions, least absolute shrinkage and selection operator, random forest and gradient boosting regression tree (GBRT) and neural network are chosen to be representative predictors. Findings The experimental results show that for temperature data set of this experiment, the prediction effect of GBRT in the ensemble algorithm is the best compared with the other four algorithms. Originality/value This paper compares different kinds of machine learning algorithms, observes the road surface temperature data from different angles, and finds the most suitable prediction method.

Computational modelling methods for sports bra–body interactions

2020 ◽  
Vol 32 (6) ◽  
pp. 921-934
Author(s):  
Liang Ruixin ◽  
Joanne Yip ◽  
Winnie Yu ◽  
Lihua Chen ◽  
Newman Lau
Keyword(s):  
Contact Pressure ◽  
Computer Aided Design ◽  
Effective Means ◽  
Three Dimensional ◽  
Pressure Sensors ◽  
Computational Modelling ◽  
The Body ◽  
Fe Modelling ◽  
Content Type ◽  
Static Contact

PurposeThe breasts are mainly fatty and connective tissues with no muscles that directly support them, so wearing sports bras is one of the most effective means of alleviating the discomfort of breast movement and potential injury during vigorous physical exercise. However, the design and development processes of traditional sports bras are time-consuming and costly. Hence, a novel method of simulating the static contact pressure between a sports bra and women’s body based on the finite element (FE) and artificial neural network (ANN) models is developed in this study to contribute to the design considerations of sports bras.Design/methodology/approachThree-dimensional FE models of a female subject and sports bras with different fabric properties are developed to determine the amount of contact pressure exerted onto the body. The FE results are then verified by measuring the amount of pressure exerted by the sports bra on the skin with pressure sensors. The Taguchi technique is used to effectively reduce the number of trials from 625 to only 25 cases. These 25 results obtained through FE modelling are then used to provide the training set for the ANNs. Finally, a comparison between the FE and ANN results is carried out.FindingsA novel model of the static contact pressure between a sports bra and human subject based on the FE and ANN methods is presented in this paper. The root mean square error values show that there is only a small difference between the FE and ANN results.Originality/valueThe ANN function established in this study can be used to predict the mechanical behaviours of breasts and has a fundamental impact on the computer-aided design of functional garments in general.

scholarly journals Solving traffic congestion consequences regarding e-taxi parking by identifying a suitable location for the e-taxi station: geo-spatial and AHP approaches

2020 ◽  
Vol 2 (2) ◽  
pp. 55-68
Author(s):  
Mazed Parvez
Keyword(s):  
Expert Opinion ◽  
Traffic Congestion ◽  
Road Network ◽  
Secondary Data ◽  
Geographical Information ◽  
Primary Data ◽  
Content Type ◽  
The Road ◽  
On The Road ◽  
Suitable Location

Purpose The quantity of e-taxi in Bangladesh is increasing day by day, especially in the municipality area. With the increase of this e-taxi quantity, it becomes hard to provide parking space for these consequences the illegal parking on road. This parking consequences traffic congestion on the road and obstructs the free flow of traffic. So, this paper aims to investigate the present scenario of this e-taxi parking problem and provides a solution by finding out a suitable location for an e-taxi station by the analytic hierarchy process (AHP) approach. Design/methodology/approach For the study, both primary and secondary data were collected. Primary data on existing parking points on the road of e-taxi which consequences traffic congestion are collected from the Municipality area. Secondary data on the existing road network of the Pabna Municipality has collected from the MIDP data also from the literature review. For the suitability analysis process for establishing an e-taxi station, six variables were determined. These variables are determined from the previous studies and the expert opinion survey. The six variables are land use of the study area, road network of the study area, proximity to the office area, proximity to the educational facilities, proximity from the market and finally,proximity from the hospital. After the selection of the variables ranking value was determined from the expert opinion. Then using The AHP method final weight value is determined and, finally, with the assist of geographical information system. Findings From the resulting total 4,285 spots were found as optimally suitable spots are found which is almost 21% of the suitable spot. No mostly suitable spots are found from the GIS analysis. The moderately suitable spots were found in the prime number of 14,817 spots, almost 75% of the suitable spot. Likely the most suitable spots no partly suitable spots were found but the number of very few suitable spots was found in the number of 918, 4% of the suitable spot. A total of 20,020 spots was found as suitable for the construction of E-taxi station. Originality/value Finding out a suitable spot for e-taxi stand the traffic congestion can be solved, accident risk can be minimized during loading and unloading of passengers and the municipality authority can find a permanent solution for the traffic congestion problem.

Model of the wheel motion state under path constraints based on the Darboux frame in 3D space

2018 ◽  
Vol 35 (8) ◽  
pp. 2883-2903 ◽  
Author(s):  
He Zhang ◽  
Shaowei Yang ◽  
Zhengfeng Ma
Keyword(s):  
Rigid Body Dynamics ◽  
Geometric Design ◽  
Road Surface ◽  
Surface Model ◽  
Content Type ◽  
Rolling Velocity ◽  
The Road ◽  
Geometry Design ◽  
Road Geometry ◽  
Darboux Frame

Purpose Existing three-dimensional (3D) road-surface models use approximation methods such as a set of discrete triangular patches and cannot accurately describe changes in the geometrically designed elements along the road. This paper aims to construct a 3D road-surface model with combinations of geometric design invariants and apply the proposed model to analyse the state of motion of a wheel’s centre. Design/methodology/approach In this paper, the 3D road surface is modelled as a continuous function with combinations of geometric design invariants. By introducing the theories of differential geometries and rigid body dynamics, a wheel-road model wherein a wheel fixed to a Darboux frame moves along a curved road surface is constructed, and the wheel time-dependent properties of the velocity, angular velocity and acceleration at an arbitrary point of the surface are described using road geometry design invariants. Findings This paper adopts the Darboux frame to study the instantaneous spin-rolling motion of a wheel. It is found that the magnitudes of the spin-rolling velocity, the acceleration and the geometric invariants of the road surface, including the geodesic curvature, the normal curvature and the geodesic torsion, determine the instantaneous states of motion of a wheel. Originality/value This work provides a theoretical foundation for future studies of wheel motion states, such as the relationship between road geometry design invariants and driving safety, vehicle lane changing and other vehicle microbehaviours. New insights are gained in the areas of road safety and vehicles incorporating artificial intelligence.

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.

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