A rational approach for optimization of road upgrading

2010 ◽  
Vol 37 (11) ◽  
pp. 1462-1470 ◽  
Author(s):  
Anastasios Mouratidis ◽  
Grigorios Papageorgiou
Keyword(s):  
Ride Comfort ◽  
Cost Benefit ◽  
Management Policy ◽  
Rational Approach ◽  
Ride Quality ◽  
The Road ◽  
Optimal Intervention ◽  
Four Levels ◽  
Operational Criteria ◽  
High Level

Roads designed and constructed in the 1950s and 1960s far from cover present-day traffic needs and require maintenance and renewal. A common practice of upgrading aged two-lane roads consists of pavement resurfacing, but this practice often proves insufficient at providing a high serviceability level and risks being inefficient. An existing aged and distressed road may need more radical upgrading operations. The optimum upgrading strategy must be envisaged with regards to prevailing operational criteria such as road safety, ride comfort, and serviceability. In this context, a systematic approach to the upgrading issue has been elaborated aiming at introducing all significant factors to the processing algorithm designating the optimal intervention in each case. The proposed model is meant to determine and recommend the appropriate strategy for each part of the road network and provide a high level of service and avoid unnecessary expenses. Within this scope, this rational strategy proceeds to an exhaustive assessment of examined roads with respect to their performance and defines improvement priorities in accordance with an innovative management policy. The model distinguishes four levels of “upgrading” activities, with each adopted with respect to the road condition, traffic features, ride quality, and environmental considerations. The option derived is supposed to provide the best cost–benefit upgrading solution.

scholarly journals AVERAGE SPEED ENFORCEMENT SYSTEM EFFICIENCY ASSESSMENT MODEL

2017 ◽  
Vol 12 (1) ◽  
pp. 64-69
Author(s):  
Laura Jateikienė ◽  
Audrius Vaitkus
Keyword(s):  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Assessment Model ◽  
Vehicle Speed ◽  
Main Road ◽  
Average Speed ◽  
The Road ◽  
Traffic Law Enforcement ◽  
High Level ◽  
Speed Enforcement

Accidents are one of the leading cause of death all over the world. Speed has been identified as a factor in road accidents, influencing both the risk of accidents and the severity of the accidents. However, speeding is one of the most frequent violations of traffic rules by the road users. Many results of studies showed that the implementation of speed cameras significantly reduced the vehicle speed and the number of accidents near camera sites. One issue regarding speed enforcement by a speed camera is that a reduction in speed is obtained only on a short section of a road. The results of scientific research analysis suggest that this issue can be overcome by the employment of average speed enforcement system (hereafter system), which is a relatively new approach to traffic law enforcement. Until now, Lithuania had no methodology for selecting road sections to be installed with the system. The purpose of this paper is to develop a model for the assessment of safety impact of the system and to perform economic estimation of a system of Lithuanian main road sections selected under this model. The analysis of international practice helped to develop this model, which joins accident indicators, road and traffic parameters. A cost-benefit analysis of the system, implemented on main road sections and selected by suggested model, shows a high level of payback. The implementation of the system would pay back in one year of service.

scholarly journals Road Roughness Estimation Based on the Vehicle Frequency Response Function

Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 89
Author(s):  
Qingxia Zhang ◽  
Jilin Hou ◽  
Zhongdong Duan ◽  
Łukasz Jankowski ◽  
Xiaoyang Hu
Keyword(s):  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Gaussian White Noise ◽  
Estimation Method ◽  
Time Shift ◽  
Ride Quality ◽  
The Road ◽  
Road Roughness ◽  
Measured Response

Road roughness is an important factor in road network maintenance and ride quality. This paper proposes a road-roughness estimation method using the frequency response function (FRF) of a vehicle. First, based on the motion equation of the vehicle and the time shift property of the Fourier transform, the vehicle FRF with respect to the displacements of vehicle–road contact points, which describes the relationship between the measured response and road roughness, is deduced and simplified. The key to road roughness estimation is the vehicle FRF, which can be estimated directly using the measured response and the designed shape of the road based on the least-squares method. To eliminate the singular data in the estimated FRF, the shape function method was employed to improve the local curve of the FRF. Moreover, the road roughness can be estimated online by combining the estimated roughness in the overlapping time periods. Finally, a half-car model was used to numerically validate the proposed methods of road roughness estimation. Driving tests of a vehicle passing over a known-sized hump were designed to estimate the vehicle FRF, and the simulated vehicle accelerations were taken as the measured responses considering a 5% Gaussian white noise. Based on the directly estimated vehicle FRF and updated FRF, the road roughness estimation, which considers the influence of the sensors and quantity of measured data at different vehicle speeds, is discussed and compared. The results show that road roughness can be estimated using the proposed method with acceptable accuracy and robustness.

The Time Domain Simulation of Non-Stationary Road Roughness

2013 ◽  
Vol 423-426 ◽  
pp. 1238-1242
Author(s):  
Hao Wang ◽  
Xiao Mei Shi
Keyword(s):  
Power Spectrum ◽  
Time Domain ◽  
Ride Comfort ◽  
Time History ◽  
Random Excitation ◽  
Power Spectrum Density ◽  
The Road ◽  
Road Roughness ◽  
Spectrum Density ◽  
History Of

The input of road roughness, which affects the ride comfort and the handling stability of vehicle, is the main excitation for the running vehicle. The time history of the road roughness was researched with the random phases, based on the stationary power spectrum density of the road roughness determined by the standards. Through the inverse Fourier transform, the random phases can be used to get the road roughness in time domain, together with the amplitude. Then, the time domain simulation of the non-stationary random excitation when the vehicle ran at the changing speed, would also be studied based on the random phases. It is proved that the random road excitation for the vehicle with the changing speed is stationary modulated evolution random excitation, and its power spectrum density is the stationary modulated evolutionary power spectrum density. And the numerical results for the time history of the non-stationary random inputs were also provided. The time history of the non-stationary random road can be used to evaluate the ride comfort of the vehicle which is running at the changing speed.

Analysis of the energy harvesting potential–based suspension for truck semi-trailer

2018 ◽  
Vol 233 (11) ◽  
pp. 2955-2969 ◽  
Author(s):  
Mohamed AA Abdelkareem ◽  
Mina MS Kaldas ◽  
Mohamed Kamal Ahmed Ali ◽  
Lin Xu
Keyword(s):  
Ride Comfort ◽  
Simulation Analysis ◽  
Conflict Analysis ◽  
Driving Safety ◽  
Dissipated Energy ◽  
Ride Quality ◽  
Surface Model ◽  
Long Distance ◽  
Class C ◽  
The Right

As the articulated trucks are mainly used for long distance transportations, the design of the suspension system became a major concern and a research hotspot not only for ride comfort and driving safety but also for energy consumption. Therefore, the objective of this study is to conduct a comprehensive parametrical–based conflict analysis between the ride comfort and road holding together with the potential power of the shock absorbers. The simulation analysis is performed using a 23 degree-of-freedom full truck semi-trailer mathematical model with random road surface model. The bounce and combined excitation modes for the truck model are applied to present the pro and contra of the simplified and realistic analysis. The bounce mode is applied for a road Class C and truck driving speed of 20 m/s, while the combined mode is performed with the same truck-speed but considering a Class C road for the left track and Class D road for the right track considering the time delay between the truck axles. The truck dynamics including the mean potential power, average dynamic tire load and bounce, and pitch and roll accelerations is comprehensively combined in the conflict analysis–based suspension and driving parameters. The obtained simulation results showed that the articulated truck suspension should be designed considering a realistic excitation condition. In contrast to the bounce mode, under the combined road input, the tractor ride quality and road handling performances are improved when a heavily damped suspension is considered. Furthermore, the otherwise dissipated energy through the damping events can reach an overall value between 2 and 4 kW.

scholarly journals Mathematical Modelling of Two-Wheeler Suspension system in a wavy road

2019 ◽  
Vol 8 (11) ◽  
pp. 3630-3635
Keyword(s):  
Ride Comfort ◽  
Health Hazard ◽  
Suspension System ◽  
Vehicle Body ◽  
Continuous Exposure ◽  
Potential Health ◽  
Suspension Spring ◽  
The Road ◽  
Potential Health Hazard ◽  
Two Wheeler

Two wheelers like motorbikes and scooters are one of the major transports in India. In major cities and towns, it is most common private transport as it is fast and easy approach to the destination. But the prolonged drive in the two-wheeler leads to the potential health hazard and musco-skeletal disorder due to continuous exposure to the vibration caused during the ride and force transmitted to the vehicle body due to road irregularities. It is a challenge of automobile engineers to design a promising suspension system to overcome the risk of ride comfort during continuous driving. In this research, two-wheeler suspension system is modelled with a condition of bump and valley in a wavy road. The road surface is assumed to be wavy and the response of new suspension spring with different materials (stainless steel, tungsten and polymeric) along with viscous damper is analyzed and compared. By this analysis, it will be proposed to industry to modify the suspension system to improve its efficiency and reduce force transmitted to the human body to improve the ride comfort

scholarly journals Brake systems: a mind of their own

2021 ◽  
pp. 27-34
Author(s):  
Michael Ellims
Keyword(s):  
Failure Modes ◽  
Electronic Control ◽  
Hydraulic Systems ◽  
Control Software ◽  
The Road ◽  
Current Production ◽  
On The Road ◽  
High Level ◽  
Electronic Sensors ◽  
Systems Failure

Brake systems fitted to current production vehicles are not the relativity straightforward hydraulic systems that many people expect. Rather they have evolved into complex systems which are on their own deliberately capable of affecting the behaviour of a vehicle. Crucially they depend on computers, software and electronic sensors to allow them to form a model of how the vehicle is expected to behave on the road and how it is actually behaving. Like any artefact they can, and do fail. This paper provides a high-level overview of the braking systems currently in place, how these systems act and present some examples of how they have failed in practice. Index words: vehicles; vehicle electronics; electronic control; software; brake systems; failure modes

Studies in beef production I. The effects of level of feeding and of breed on the growth and fattening of spring born cattle

1959 ◽  
Vol 53 (1) ◽  
pp. 78-101 ◽  
Author(s):  
A. J. Brookes ◽  
John Hodges
Keyword(s):  
Growth Rate ◽  
Marked Improvement ◽  
Live Weight ◽  
Moderate Level ◽  
Food Conversion ◽  
Beef Industry ◽  
Points Of View ◽  
The Difference ◽  
Four Levels ◽  
High Level

1. The sources of calves for rearing for beef are discussed and the dependence of the beef industry upon the dairy industry demonstrated.2. An experiment designed to compare the effects of four levels of feeding on the growth rate, conformation, economy of food conversion and type of carcase produced, of three breeds of spring-born steers, Hereford, Dairy Shorthorn and Friesian, is described. The levels of feeding are high or moderate in the calf stage, each followed by high or moderate feeding in subsequent winters.3. The results on growth and time of fattening are given and discussed.4. The calves fed on a high level were almost twice the weight of those fed on a moderate level at 8 months old.5. The well-reared calf had an advantage over the moderately reared calf for the rest of its life.6. Although calves which had been reared moderately showed a marked improvement in growth rate when subsequently fed on a higher level they did not reach the weight of calves fed well throughout at 2 years old.7. The level of feeding in the calf stage had little effect upon the time of fattening provided that the level of feeding in the winter periods of subsequent life was on a high level.8. When subsequent feeding was on a moderate level in the winter months, the calf reared well initially fattened on grass a year earlier than the moderately reared animal.9. The high-moderate treatment is shown to be the most satisfactory from many points of view. On this treatment a minimum of concentrates is used in the production of beef.10. The moderate-moderate cattle may be too heavy for present-day requirements when finished off grass at 3½ years old.11. Cattle which were fed on a high level in winter from 8 to 14 months put on less live weight in the following summer than those fed moderately. A live-weight gain of about 1 lb. a day in winter would appear to be satisfactory if the cattle are to make good use of grass in the following summer.12. These main feeding treatment effects applied to the three breeds used.13. The Friesians were heavier than Dairy Shorthorns or Herefords as calves, and the live weight at most ages was in descending order Friesians, Dairy Shorthorns, Herefords.14. The growth rate of Friesian steers was higher than that of the other two breeds at most stages of life, but the difference between Dairy Shorthorns and Herefords was negligible.15. The Herefords finished earlier than the Dairy Shorthorns and Friesians when fattened in yards or on grass.16. There was some indication (Brookes, 1954) that husk and ringworm caused less trouble with cattle which had been well reared than with those moderately reared.

Influence of the road profile accuracy on disturbance compensation in active suspension systems

2021 ◽  
Vol 69 (6) ◽  
pp. 485-498
Author(s):  
Felix Anhalt ◽  
Boris Lohmann
Keyword(s):  
Ride Comfort ◽  
Feedforward Control ◽  
Active Suspension ◽  
Disturbance Compensation ◽  
Critical Factors ◽  
The Road ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Road Profile ◽  
Profile Accuracy

Abstract By applying disturbance feedforward control in active suspension systems, knowledge of the road profile can be used to increase ride comfort and safety. As the assumed road profile will never match the real one perfectly, we examine the performance of different disturbance compensators under various deteriorations of the assumed road profile using both synthetic and measured profiles and two quarter vehicle models of different complexity. While a generally valid statement on the maximum tolerable deterioration cannot be made, we identify particularly critical factors and derive recommendations for practical use.

Sign in / Sign up

Export Citation Format

Share Document