scholarly journals Variability of Gravel Pavement Roughness: An Analysis of the Impact on Vehicle Dynamic Response and Driving Comfort

2021 ◽  
Vol 11 (16) ◽  
pp. 7582
Author(s):  
Vidas Žuraulis ◽  
Henrikas Sivilevičius ◽  
Eldar Šabanovič ◽  
Valentin Ivanov ◽  
Viktor Skrickij
Keyword(s):  
High Speed ◽  
Ambient Air ◽  
Dynamic Responses ◽  
Driving Safety ◽  
Vehicle Dynamic ◽  
Safe Driving ◽  
Evaluation Indexes ◽  
Road Pavement ◽  
Driving Speed ◽  
The Impact

Gravel pavement has lower construction costs but poorer performance than asphalt surfaces on roads. It also emits dust and deforms under the impact of vehicle loads and ambient air factors; the resulting ripples and ruts constantly deepen, and therefore increase vehicle vibrations and fuel consumption, and reduce safe driving speed and comfort. In this study, existing pavement quality evaluation indexes are analysed, and a methodology for adapting them for roads with gravel pavement is proposed. We report the measured wave depth and length of gravel pavement profile using the straightedge method on a 160 m long road section at three stages of road utilization. The measured pavement elevation was processed according to ISO 8608, and the frequency response of a vehicle was investigated using simulations in MATLAB/Simulink. The international roughness index (IRI) analysis showed that a speed of 30–45 km/h instead of 80 km/h provided the objective results of the IRI calculation on the flexible pavement due to the decreasing velocity of a vehicle’s unsprung mass on a more deteriorated road pavement state. The influence of the corrugation phenomenon of gravel pavement was explored, identifying specific driving safety and comfort cases. Finally, an increase in the dynamic load coefficient (DLC) at a low speed of 30 km/h on the most deteriorated pavement and a high speed of 90 km/h on the middle-quality pavement demonstrated the demand for timely gravel pavement maintenance and the complicated prediction of a safe driving speed for drivers. The main relevant objectives of this study are the adaptation of a road roughness indicator to gravel pavement, including the evaluation of vehicle dynamic responses at different speeds and pavement deterioration states.

scholarly journals Variability of Gravel Pavement Roughness: Analysis of the Impact on Vehicle Response and Driving Comfort

2021 ◽  
Author(s):  
Vidas Žuraulis ◽  
Henrikas Sivilevičius ◽  
Eldar Šabanovič ◽  
Valentin Ivanov ◽  
Viktor Skrickij
Keyword(s):  
High Speed ◽  
Ambient Air ◽  
Driving Safety ◽  
Safe Driving ◽  
Pavement Maintenance ◽  
Evaluation Indexes ◽  
Road Pavement ◽  
Driving Speed ◽  
Roughness Analysis ◽  
The Impact

The gravel road pavement has a lower construction cost but poorer performance than the asphalt surface. It also emits dust and deforms under the impact of vehicle loads and ambient air factors. The resulting ripples and ruts are constantly deepening, increasing vehicle vibrations and fuel consumption, reducing safe driving speed and comfort. In this article, existing pavement quality evaluation indexes are analysed, and a methodology for their adaptation for roads with gravel pavement is proposed. This article reports the measured wave depth and length of the gravel pavement profile by the straightedge method of a 160 m long road section in three road exploitation stages. The measured pavement elevation was processed according to ISO 8608, and vehicle frequency response has been investigated using simulations in MATLAB/Simulink. The applied International Roughness Index (IRI) analysis showed that a speed of 30-45 km/h instead of 80 km/h provides the objective results of IRI calculation on the flexible pavement due to a decreasing velocity of vehicle's unsprung mass on a more deteriorated road pavement state. The influence of the corrugation phenomenon of gravel pavement has been explored, identifying specific driving safety and comfort cases. Finally, an increase in the Dynamic Load Coefficient (DLC) at a low speed of 30 km/h on the most deteriorated pavement and a high speed of 90 km/h on the middle-quality pavement demonstrates the demand for timely gravel pavement maintenance and the complicated prediction of a safe driving speed for drivers.

Influences of Gesture-Based Mobile Phone Use While Driving

2021 ◽  
pp. 036119812110263
Author(s):  
Jianwei Niu ◽  
Yulin Zhou ◽  
Dan Wang ◽  
Xingguo Liu
Keyword(s):  
Mobile Phone ◽  
Lateral Position ◽  
Driving Safety ◽  
Control Technique ◽  
Steering Wheel ◽  
Secondary Tasks ◽  
Mobile Phone Use ◽  
Driving Speed ◽  
Gesture Control ◽  
The Impact

The use of mobile phones while driving has been a hot topic in the field of driving safety for decades. Although there are few studies on the influence of gesture control on in-vehicle secondary tasks, this study aims to investigate the impact of gesture-based mobile phone use without touching while driving from the perspective of multiple-resource workload owing to visual, auditory, cognitive, and psychomotor resource occupation. A novel gesture control technique was adopted for secondary task interactions, to recognize the gestures of drivers. An experiment was conducted to study the influences of two interaction modes, traditional touch-based mobile phone interaction and gesture-based mobile phone interaction, on driving behavior in three different cognitive level task groups. The results indicate that gesture-based mobile phone interaction can improve driving performance with regard to lateral position-keeping ability and steering wheel control; nevertheless, it has no significant impact on longitudinal metrics such as driving speed, driving speed variation, and throttle control variation. Gesture-based mobile phone interactions have a larger effect on secondary tasks with medium cognitive load but not on actual operation tasks. It was also verified that the performance of gesture-based mobile phone interaction was better in secondary mobile phone tasks such as switching (e.g., switching songs) and adjusting (e.g., adjusting volume) than the traditional interaction mode. This study provides the theoretical and experimental support for human–computer interaction using gesture-based mobile phone interactive control in future automobiles.

Impact Energy Measurement of a Hydraulic Breaker

2006 ◽  
Vol 326-328 ◽  
pp. 1669-1672
Author(s):  
Jong Won Park ◽  
Hyoung Eui Kim
Keyword(s):  
Construction Industry ◽  
Impact Energy ◽  
High Speed ◽  
Test System ◽  
Hydraulic Power ◽  
Construction Machinery ◽  
Road Pavement ◽  
Hydraulic Cylinders ◽  
The Impact ◽  
Test Process

A hydraulic breaker for construction machinery generally used for the destroying and disassembling of buildings, crashing road pavement, breaking rocks at quarry and so on. So the measurement of the impact energy of a hydraulic breaker is very important thing to prove its capability to manufacturers and customers. In this study, the test system for measuring the impact energy of a hydraulic breaker was designed and constructed. The test system was consisted with hydraulic cylinders for mounting a breaker, impact absorbing base and frames, pressure and flow sensors, high speed and accurate data acquisition system diesel engine driven hydraulic power unit. The test process of the developed system was carried by measuring guide for tool energy rating for hydraulic breakers which was developed by the CIMA (Construction Industry Manufacturers Association) USA. The developed test system can be applied to measure the impact energy for various kinds of hydraulic breakers.

scholarly journals Handling Stability of Tractor Semitrailer Based on Handling Diagram

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Ren Yuan-yuan ◽  
Zheng Xue-lian ◽  
Li Xian-sheng
Keyword(s):  
Rear Axle ◽  
Driving Safety ◽  
Nonlinear Characteristics ◽  
Vehicle Handling ◽  
Driving Speed ◽  
The Stability ◽  
The Impact ◽  
Better Than

Handling instability is a serious threat to driving safety. In order to analyze the handling stability of a tractor semitrailer, a handling diagram can be used. In our research, considering the impact of multiple nonsteering rear axles and nonlinear characteristics of tires on vehicle handling stability, the handling equations are developed for description of stability of tractor semi-trailer. Then we obtain handling diagrams so as to study the influence of driving speed, loaded mass, and fifth wheel lead on vehicle handling stability. The analysis results show that the handling stability of a tractor semi-trailer when the tractor has two nonsteering rear axles is better than that when the tractor has only one nonsteering rear axle. While the stability in the former case is slightly influenced by driving speed and loaded mass, the latter is strongly influenced by both. The fifth wheel lead is found to only slightly influence handling stability for both tractor semi-trailers. Therefore, to ensure the driving safety of tractor semi-trailers when the tractor has only one nonsteering rear axle, much stricter restraints should be imposed on driving speed, and the loaded mass must not exceed the rated load of the trailer.

The impact of personality on driving safety among Chinese high-speed railway drivers

2016 ◽  
Vol 92 ◽  
pp. 9-14 ◽  
Author(s):  
Ming Guo ◽  
Wei Wei ◽  
Ganli Liao ◽  
Fulei Chu
Keyword(s):  
High Speed ◽  
Driving Safety ◽  
High Speed Railway ◽  
The Impact

scholarly journals Optimization of the auxiliary stopping area planning in the middle-to-high speed Maglev

2018 ◽  
Vol 4 (2) ◽  
pp. 141-151 ◽  
Author(s):  
Qingying Lai ◽  
Jun Liu ◽  
Lingyun Meng ◽  
Xiaofeng Chai ◽  
Qunyan Wang ◽  
...  
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Special Section ◽  
Construction Cost ◽  
Evaluation Indexes ◽  
Maglev System ◽  
Operation Process ◽  
Train Operation ◽  
The Impact ◽  
Area Planning

Background: The Auxiliary Stopping Area (ASA) is the special section that possesses power supply rail and personnel evacuation facilities, whose quantities and locations in a line are of great significance to reduce construction cost and improve transportation efficiency for the middle-to-high speed maglev. Aim: This paper focuses on optimizing the length and location of the ASA for the middle-to-high speed maglev system to improve the robustness of maglev line. Methods of the studies: Two evaluation indexes which reflect the ASA restricts on the train operation process was proposed. A model for optimizing the setting of the ASA is constructed, and solved by the genetic algorithm. Results: The result of numerical examples shows that the proposed method can effectively improve the performances of the ASA. Conclusion: This paper proposed two indexes to reflect the impact of station settings on train operations, which provides a method to optimize the ASA from qualitative optimization to quantitative optimization.

Study on Road Geometric Alignment Parameters Based on Vehicle Handling Stability Simulation

2013 ◽  
Vol 404 ◽  
pp. 273-279
Author(s):  
Xue Lian Zheng ◽  
Xian Sheng Li ◽  
Cheng Wu Jiao ◽  
Gang Bai ◽  
Yuan Yuan Ren
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Negative Influence ◽  
Vehicle Dynamic ◽  
Vehicle Handling ◽  
Horizontal Curves ◽  
Research Achievement ◽  
Vehicle Dynamic Model ◽  
Curve Radius ◽  
The Impact

Unreasonable road geometric alignment has a negative influence on vehicle handling stability, especially when vehicle drives with a high speed. For horizontal road alignment, radius and banking of circular curve are the most popular and important parameters. To investigate the influence of horizontal road alignment on vehicle handling stability, a 3 degrees-of-freedom vehicle dynamic model is established. Three road horizontal curves with different radius are established in Carsim environment to investigate the influence of curve radius on vehicle handling stability and four different banking curve roads are built to study the impact of road banking on vehicle roll stability. The research achievement will provide theoretical basis and technical support for road geometric alignment design.

Effect of unsteady aerodynamic loads on driving safety and comfort of trains running on bridges

2020 ◽  
Vol 23 (13) ◽  
pp. 2898-2910
Author(s):  
Yan Han ◽  
Ye Liu ◽  
Peng Hu ◽  
CS Cai ◽  
Guoji Xu ◽  
...  
Keyword(s):  
Dynamic Responses ◽  
Wind Loads ◽  
Driving Safety ◽  
Safe Driving ◽  
Average Speed ◽  
Aerodynamic Loads ◽  
Finite Element Software ◽  
Unsteady Aerodynamic ◽  
Multi Body ◽  
Assessment Results

In order to investigate the effects of unsteady aerodynamic loads on the driving safety and comfort of trains running on bridges, a three-dimensional and multi-body system model of train–track–bridge was established and the dynamic responses of the coupling system were calculated by combining the finite element software ANSYS with the multi-body dynamics software SIMPACK. The driving safety and comfort of a train running on a bridge under steady and unsteady aerodynamic loads were compared and analyzed. The effects of different crosswind speeds on the driving safety of the train running on the bridge under unsteady aerodynamic loads were studied. It is found that the index values of the driving safety and comfort of the train at the speed of 200–300 km/h without the wind loads are smaller (meaning safer) than those of the train under the wind loads. When the average speed of crosswind is 20 m/s, the driving safety assessment results of the train are better and its comfort assessment results are more conservative with considering the unsteady aerodynamic loads than the steady wind load case. When the average speed of crosswind is smaller than 10 m/s and the train speed is 250 km/h, the driving safety and comfort of the train on the bridge meet the requirements, and the level of stability can reach “good” or above. Through the analysis of driving safety of the train on the bridge under different crosswind speeds, the threshold values of safe driving were obtained, which can provide a better basis for the safe operation of trains on bridges.

Running safety evaluation of high-speed train subject to the impact of floating ice collision on bridge piers

2021 ◽  
pp. 095440972110100
Author(s):  
Penghao Li ◽  
Zhonglong Li ◽  
Zhaoling Han ◽  
Shengyang Zhu ◽  
Wanming Zhai ◽  
...  
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Dynamic Responses ◽  
Impact Loads ◽  
High Speed Train ◽  
Train Track ◽  
Railway Bridges ◽  
Running Safety ◽  
Track Bridge ◽  
The Impact

In Northeast China and the areas along Sichuan-Tibet railway, collision between floating ice and piers of railway bridges seriously threatens the train operation safety. The safety of high-speed train running on the bridge subject to the impact of floating ice collision is rarely assessed considering the spatial interaction of the train-track-bridge-ice system. To evaluate the running safety and ride comfort of trains and the structural stability of railway bridges under the collision between floating ices and piers, a train-track-bridge (TTB) dynamic interaction model considering the impact of floating ice is established. Using the refined finite element model, the collision process of floating ice on bridge pier is simulated, and the impact loads are employed as the excitation input of the TTB dynamics model. Taking a 5 × 32 m simply-supported bridges as a case study, the influence of bridge structural parameters on the floating ice collision system is investigated, and then the dynamic responses of the TTB system induced by the floating ice impact loads are analyzed in detail. Finally, the effect of the ice impact loads on the running safety of the high-speed train is revealed. Results show that under the floating ice impact loads, the angle of the pier sharp-nose (APSN) and lateral stiffness of foundations are the key parameters that influence the dynamic responses of the bridge, and an improperly small lateral stiffness of foundation would lead to an instability of bridge structure. The influence of ice impact loads on the dynamic responses of the train is remarkable. The lateral vibration acceleration, derailment factor and lateral wheel rail force caused by the ice impact loads are all greater than those caused by the track irregularity, while the wheel unloading rate is slightly smaller. In addition, the running speed of train is also closely related to the running safety and ride comfort when the collision occurs. When the train speed exceeds 400 km/h, the train passing through the bridge would have the possibility of derailment.

scholarly journals Analysis of the lateral slope’s impact on the calculation of water-filled rut depth

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243952
Author(s):  
Jiao Yan ◽  
Hongwei Zhang ◽  
Bing Hui
Keyword(s):  
Moving Average ◽  
Driving Safety ◽  
Calculation Error ◽  
Accurate Calculation ◽  
Safe Driving ◽  
Cloud Data ◽  
Evaluation Indexes ◽  
Key Points ◽  
Matlab Programming ◽  
Transportation Agencies

Accurate calculation of the water-filled rut depth is critical for assessing hydroplaning potential. Nevertheless, due to the difficulty in collecting and calculating the water-filled rut depth, most transportation agencies do not use i, especially in the case of lateral slopes, although water-filled rut depth is a key parameter that impacts driving safety. Contributions of this paper are development of a methodology to reliably compute the water-filled rut depth and quantitatively evaluate the influence of lateral slope on the water-filled rut depth. The proposed method include: 1) acquisition of the high-resolution 3D point cloud data of rut, 2) smooth processing of rut profile through moving average method with Matlab programming, 3) water-filled rut depth computation at different lateral slopes with the assistance of key points based on rut sections. With the variation of water-filled rut depth (ΔWD), its change rate (δWD), and the calculation error between the rut depth and the water-filled rut depth (Δn) as evaluation indexes, the variation law of water-filled rut depth under different lateral slopes is analyzed when considering the severity level and rut shape of the rut profile. Results show that: 1) the increase in lateral slope leads to the reduction of water-filled rut depth; 2) the water-filled rut depth is affected by the rut shape, including rut side wall’s slope and the key points’ elevation. The accurate calculation of the water-filled rut depth can provide reliable suggestions for safe driving.

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