scholarly journals Entropy Based Classification of Road-Profiles

2010 ◽  
Author(s):  
S. C¸ag˘lar Bas¸lamıs¸lı ◽  
Selis O¨nel
Keyword(s):  
Nonlinear Damping ◽  
Operating Parameters ◽  
Vertical Acceleration ◽  
Vehicle Speed ◽  
Mean Square ◽  
The Road ◽  
Dirt Road ◽  
Asphalt Road ◽  
Acceleration Signals

In this study, the Shannon entropies of six different road-profiles ranging from “very good asphalt road” to “dirt road (terrain)” were calculated. Results indicate that each type of road has a well defined entropy value and that the entropies of roads ranging from “very good asphalt” to “dirt road (terrain)” lie on a nearly linear locus. A second approach presented in this paper consists in measuring the sprung mass vertical acceleration of a vehicle running over segments of roads of different qualities and calculating the entropies of the acceleration signals. This procedure has been applied to assess the influence of nonlinear damping and vehicle speed. It has been seen that it is possible to identify the type of the road surface through the calculation of entropy if the vehicle operating parameters are known. Finally, it is observed that the locus of entropy values is concave on the plot of acceleration entropy versus root mean square (RMS) acceleration.

scholarly journals Smartphone monitoring of in-ambulance vibration and noise

2021 ◽  
pp. 095441192098599
Author(s):  
Tom Partridge ◽  
Lorelei Gherman ◽  
David Morris ◽  
Roger Light ◽  
Andrew Leslie ◽  
...  
Keyword(s):  
Transport Systems ◽  
Vertical Acceleration ◽  
Vehicle Speed ◽  
Noise Levels ◽  
The Road ◽  
Neonatal Transport ◽  
Mass Data ◽  
Transport Team ◽  
Vertical Accelerations ◽  
Noise Vibration

Transferring sick premature infants between hospitals increases the risk of severe brain injury, potentially linked to the excessive exposure to noise, vibration and driving-related accelerations. One method of reducing these levels may be to travel along smoother and quieter roads at an optimal speed, however this requires mass data on the effect of roads on the environment within ambulances. An app for the Android operating system has been developed for the purpose of recording vibration, noise levels, location and speed data during ambulance journeys. Smartphone accelerometers were calibrated using sinusoidal excitation and the microphones using calibrated pink noise. Four smartphones were provided to the local neonatal transport team and mounted on their neonatal transport systems to collect data. Repeatability of app recordings was assessed by comparing 37 journeys, made during the study period, along an 8.5 km single carriageway. The smartphones were found to have an accelerometer accurate to 5% up to 55 Hz and microphone accurate to 0.8 dB up to 80 dB. Use of the app was readily adopted by the neonatal transport team, recording more than 97,000 km of journeys in 1 year. To enable comparison between journeys, the 8.5 km route was split into 10 m segments. Interquartile ranges for vehicle speed, vertical acceleration and maximum noise level were consistent across all segments (within 0.99 m . s−1, 0.13 m · s−2 and 1.4 dB, respectively). Vertical accelerations registered were representative of the road surface. Noise levels correlated with vehicle speed. Android smartphones are a viable method of accurate mass data collection for this application. We now propose to utilise this approach to reduce potential harmful exposure, from vibration and noise, by routing ambulances along the most comfortable roads.

scholarly journals Road Vehicle-Bridge Interaction considering Varied Vehicle Speed Based on Convenient Combination of Simulink and ANSYS

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Helu Yu ◽  
Bin Wang ◽  
Yongle Li ◽  
Yankun Zhang ◽  
Wei Zhang
Keyword(s):  
Reaction Force ◽  
Sudden Change ◽  
Vertical Direction ◽  
Dynamic Responses ◽  
Force Model ◽  
Vertical Acceleration ◽  
Vehicle Speed ◽  
Road Vehicle ◽  
The Road ◽  
Bridge Model

In order to cover the complexity of coding and extend the generality on the road vehicle-bridge iteration, a process to solve vehicle-bridge interaction considering varied vehicle speed based on a convenient combination of Matlab Simulink and ANSYS is presented. In this way, the road vehicle is modeled in state space and the corresponding motion equations are solved using Simulink. The finite element model for the bridge is established and solved using ANSYS. The so-called inter-history iteration method is adopted to realize the interaction between the vehicle model and the bridge model. Different from typical method of road vehicle-bridge interaction in the vertical direction, a detailed longitudinal force model is set up to take into account the effects of varied vehicle speed. In the force model, acceleration and braking of the road vehicle are treated differently according to their mechanical nature. In the case studies based on a simply supported beam, the dynamic performance of the road vehicle and the bridge under varied vehicle speeds is calculated and discussed. The vertical acceleration characteristics of the midpoint of beam under varied vehicle speed can be grouped into two periods. The first one is affected by the load transform between the wheels, and the other one depends on the speed amplitude. Sudden change of the vertical acceleration of the beam and the longitudinal reaction force are observed as the wheels move on or off the bridge, and the bridge performs different dynamic responses during acceleration and braking.

Road wetness quantification via tyre spray

2018 ◽  
Vol 233 (1) ◽  
pp. 28-37 ◽  
Author(s):  
Bernhard Schmiedel ◽  
Frank Gauterin ◽  
Hans-Joachim Unrau
Keyword(s):  
Vehicle Dynamics ◽  
Autonomous Vehicles ◽  
Water Film ◽  
Significant Loss ◽  
Vehicle Speed ◽  
The Road ◽  
Acceleration Sensors ◽  
On The Road ◽  
Wheel Arch

Road wetness can lead to a significant loss in tyre traction. Although a driver can easily distinguish between dry and wet roads, the thickness of a water film on the road (wetness) and its impact on the vehicle dynamics are more difficult for a driver to classify. Furthermore, autonomous vehicles also need a graded classification of road conditions. There are known sensors, which are able to classify road conditions, but these are either not able to quantify the road wetness or are not suitable for mass production. Therefore, this work analyses a method to measure the road wetness by analysing tyre spray with plain acceleration sensors at positions like wheel arch liner or side skirt. It discusses influences of vehicle speed, road wetness, tyres, road structure and sensor positioning. The results show that a quantification of road wetness is possible, but it relies on the sum of all boundary conditions.

scholarly journals Analisa Koefisien Gesek Kinetis Terhadap Struktur Permukaan Jalan Akibat Beban Dinamik Mobil

2018 ◽  
Vol 1 (1) ◽  
pp. 047-051
Author(s):  
Muhammad Nuh Hudawi Pasaribu ◽  
Muhammad Sabri ◽  
Indra Nasution
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Surface Texture ◽  
Road Surface ◽  
Vehicle Speed ◽  
Kinetic Friction ◽  
The Road ◽  
Road Condition ◽  
Asphalt Road ◽  
The Coefficient Of Friction

Tekstur permukaan jalan umumnya terdiri dari aspal dan beton. Kekasaran tekstur permukaan jalan dapat disebabkan oleh struktur perkerasan dan beban kendaraan. Kekasaran tekstur permukaan jalan, bebandan kecepatan kendaraan akan mempengaruhi koefisien gesek. Untuk mengetahui nilai koefisien gesek dilakukan penelitian dengan melakukan variasi beban mobil (Daihatsu Xenia, Toyota Avanza, Toyota Innova dan Toyota Yaris) terhadap kontak permukaan jalan (aspal dan beton) dan kecepatan kendaraan. Hasil penelitian menunjukkan bahwa massa, lebar kontak tapak ban terhadap permukaan jalan dan kecepatan sangat mempengaruhi nilai koefisien gesek kinetis. Koefisien gesek kinetis yang terbesar untuk ketiga kontak permukaan jalan (aspal lama IRI 10,1, Aspal baru IRI 6,4 dan beton IRI 6,7) dengan menggunakan mobil Daihatsu Xenia terjadi pada kondisi jalan beton yaitu 0,495 pada kecepatan 35 Km/Jam. Koefisien kinetis jalan beton > 52 % dibandingkan jalan aspal pada parameter IRI yang sama (6-8).Koefisien gesek kinetis > 0,33 diperoleh di jalan beton pada kecepatan 30 – 40 Km/Jam   The texture of road surface generally consists of asphalt and concrete. The roughness of the road surface texture could be caused by the structure of the pavement and the load of the vehicles. Roughness of road surface texture, load and speed of vehicles would affect to the coefficient of friction. This research was carried out to find out the value of the coefficient of friction by using various load of cars (Daihatsu Xenia, Toyota Avanza, Toyota Innova and Toyota Yaris) on road surface contact (asphalt and concrete) and vehicle speed. The result showed the mass, the width of the tire tread contact to the road surface, and speed very influenced the coefficient value of kinetic friction. The biggest kinetic friction coefficient for all three road surface contacts (IRI 10.1 old asphalt, IRI 6.4 and IRI 6.7) using the Daihatsu Xenia was on the concrete road condition i.e. 0.495 on a speed of 35 km/hour. The concrete road kinetic coefficient was >52% compared to the asphalt road in the same IRI parameter (6-8). The kinetic friction coefficient >0.33 was obtained on the concrete road on a speed of 30 - 40 km/hour.

scholarly journals Cortical Activity Linked to Clocking in Deaf Adults: fNIRS Insights with Static and Animated Stimuli Presentation

2021 ◽  
Vol 11 (2) ◽  
pp. 196
Author(s):  
Sébastien Laurent ◽  
Laurence Paire-Ficout ◽  
Jean-Michel Boucheix ◽  
Stéphane Argon ◽  
Antonio Hidalgo-Muñoz
Keyword(s):  
Near Infrared ◽  
Brain Activity ◽  
Time Estimation ◽  
Cognitive Effort ◽  
Deaf People ◽  
Vehicle Speed ◽  
Neural Basis ◽  
Functional Near Infrared Spectroscopy ◽  
The Road ◽  
Deaf Adults

The question of the possible impact of deafness on temporal processing remains unanswered. Different findings, based on behavioral measures, show contradictory results. The goal of the present study is to analyze the brain activity underlying time estimation by using functional near infrared spectroscopy (fNIRS) techniques, which allow examination of the frontal, central and occipital cortical areas. A total of 37 participants (19 deaf) were recruited. The experimental task involved processing a road scene to determine whether the driver had time to safely execute a driving task, such as overtaking. The road scenes were presented in animated format, or in sequences of 3 static images showing the beginning, mid-point, and end of a situation. The latter presentation required a clocking mechanism to estimate the time between the samples to evaluate vehicle speed. The results show greater frontal region activity in deaf people, which suggests that more cognitive effort is needed to process these scenes. The central region, which is involved in clocking according to several studies, is particularly activated by the static presentation in deaf people during the estimation of time lapses. Exploration of the occipital region yielded no conclusive results. Our results on the frontal and central regions encourage further study of the neural basis of time processing and its links with auditory capacity.

Road Feel Design for Vehicle Steer-by-Wire System Based on Joystick

2013 ◽  
Vol 336-338 ◽  
pp. 734-737
Author(s):  
Hong Yu Zheng ◽  
Ya Ning Han ◽  
Chang Fu Zong
Keyword(s):  
Computer Simulation ◽  
Control Strategy ◽  
Vehicle Speed ◽  
Control Module ◽  
Matlab Simulink ◽  
The Road ◽  
Steering Feel ◽  
Steer By Wire ◽  
Simulation Results ◽  
Wire System

In order to solve the problem of road feel feedback of vehicle steer-by-wire (SBW) system based on joystick, a road feel control strategy was established to analyze the road feel theory of traditional steer system, which included return, assist and damp control module. By verifying the computer simulation results with the control strategy from software of CarSim and Matlab/Simulink, it shows that the proposed strategy can effective get road feel in different vehicle speed conditions and could improve the vehicle maneuverability to achieve desired steering feel by different drivers.

On kinematic waves II. A theory of traffic flow on long crowded roads

1955 ◽  
Vol 229 (1178) ◽  
pp. 317-345 ◽  
Keyword(s):  
Traffic Flow ◽  
Functional Relationship ◽  
Vehicle Speed ◽  
Main Road ◽  
The Road ◽  
Traffic Distribution ◽  
Kinematic Waves ◽  
The Subject ◽  
The Mean ◽  
Starting Flow

This paper uses the method of kinematic waves, developed in part I, but may be read independently. A functional relationship between flow and concentration for traffic on crowded arterial roads has been postulated for some time, and has experimental backing (§2). From this a theory of the propagation of changes in traffic distribution along these roads may be deduced (§§2, 3). The theory is applied (§4) to the problem of estimating how a ‘hump’, or region of increased concentration, will move along a crowded main road. It is suggested that it will move slightly slower than the mean vehicle speed, and that vehicles passing through it will have to reduce speed rather suddenly (at a ‘shock wave’) on entering it, but can increase speed again only very gradually as they leave it. The hump gradually spreads out along the road, and the time scale of this process is estimated. The behaviour of such a hump on entering a bottleneck, which is too narrow to admit the increased flow, is studied (§5), and methods are obtained for estimating the extent and duration of the resulting hold-up. The theory is applicable principally to traffic behaviour over a long stretch of road, but the paper concludes (§6) with a discussion of its relevance to problems of flow near junctions, including a discussion of the starting flow at a controlled junction. In the introductory sections 1 and 2, we have included some elementary material on the quantitative study of traffic flow for the benefit of scientific readers unfamiliar with the subject.

scholarly journals Traffic Analysis and Pavement Technology as a Tool for Urban Noise Control

2015 ◽  
Vol 61 (4) ◽  
pp. 107-126 ◽  
Author(s):  
K. J. Kowalski ◽  
A. J. Brzeziński ◽  
J. B. Król ◽  
P. Radziszewski ◽  
Ł. Szymański
Keyword(s):  
Urban Space ◽  
Urban Traffic ◽  
Vehicle Speed ◽  
Noise Emission ◽  
Noise Barriers ◽  
Technical Improvement ◽  
Protection Measures ◽  
The Road ◽  
Road Pavement ◽  
Acoustic Conditions

Traffic related noise is currently considered as an environmental pollution. Paper presents results of multidirectional study attempting to serve urban traffic without the need to erect noise barriers interfering urban space. Initial concept of the road expansion included construction of 1000 m of noise barriers dividing city space. Improvement in the acoustic conditions after construction completion is possible due to the applied noise protection measures: vehicle speed limit, smooth of traffic flow, use of road pavement of reduced noise emission and the technical improvement of the tramway.

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