scholarly journals Vehicle Specific Power: An Alternative to Evaluate the Dynamics of Real-Driving Tests

2021 ◽  
Author(s):  
Andre Luiz Silva Forcetto ◽  
Orlando Salvo Junior ◽  
Francisco Fernando Maciel Filho ◽  
Maria de Fatima Andrade ◽  
Flavio Guilherme Vaz de Almeida Filho
Keyword(s):  
Vehicle Dynamics ◽  
Air Pollutants ◽  
Laboratory Tests ◽  
Specific Power ◽  
Dynamic Parameters ◽  
The Road ◽  
Actual Operation ◽  
Road Grade ◽  
Dynamic Metrics ◽  
Engine Power

Abstract Vehicles are an important source of air pollutants and greenhouse gases. Their emissions are controlled since the 1970’s by laboratory tests, but divergences are often found between the results and real-world emissions. Real Driving Emissions procedure was implemented in many countries, in order to evaluate the vehicle closer to actual operation. In order to reduce the dispersion of the results, some dynamic parameters, such as speed and acceleration, are controlled, but the influence of the road grade has not being taken into account. This paper presents an alternative for the dynamic metrics, based on the Vehicle Specific Power, that allows evaluating more accurately the vehicle dynamics and representing better both the up-and-downhill effect as well the low engine power driving requirement, even when the regulatory parameters are into their limits.

scholarly journals Striated Tire Yaw Marks—Modeling and Validation

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4309
Author(s):  
Wojciech Wach ◽  
Jakub Zębala
Keyword(s):  
Vehicle Dynamics ◽  
Linear Equations ◽  
Tire Model ◽  
Vehicle Accidents ◽  
The Road ◽  
Variable Curvature ◽  
Macro Scale ◽  
On The Road ◽  
Multi Body ◽  
Non Linear Equations

Tire yaw marks deposited on the road surface carry a lot of information of paramount importance for the analysis of vehicle accidents. They can be used: (a) in a macro-scale for establishing the vehicle’s positions and orientation as well as an estimation of the vehicle’s speed at the start of yawing; (b) in a micro-scale for inferring among others things the braking or acceleration status of the wheels from the topology of the striations forming the mark. A mathematical model of how the striations will appear has been developed. The model is universal, i.e., it applies to a tire moving along any trajectory with variable curvature, and it takes into account the forces and torques which are calculated by solving a system of non-linear equations of vehicle dynamics. It was validated in the program developed by the author, in which the vehicle is represented by a 36 degree of freedom multi-body system with the TMeasy tire model. The mark-creating model shows good compliance with experimental data. It gives a deep view of the nature of striated yaw marks’ formation and can be applied in any program for the simulation of vehicle dynamics with any level of simplification.

On the Road Profile Estimation from Vehicle Dynamics Measurements

2021 ◽  
Author(s):  
Angelo Domenico Vella ◽  
Antonio Tota ◽  
Alessandro Vigliani
Keyword(s):  
Vehicle Dynamics ◽  
The Road ◽  
Road Profile ◽  
On The Road ◽  
Profile Estimation

Road profile identification with an algebraic estimator

2018 ◽  
Vol 233 (4) ◽  
pp. 1139-1155 ◽  
Author(s):  
Maroua Haddar ◽  
S Caglar Baslamisli ◽  
Riadh Chaari ◽  
Fakher Chaari ◽  
Mohamed Haddar
Keyword(s):  
Vehicle Dynamics ◽  
Operational Calculus ◽  
Algebraic Theory ◽  
Piecewise Constant Function ◽  
Piecewise Constant ◽  
The Road ◽  
Road Profile ◽  
Vertical Displacements ◽  
Profile Reconstruction ◽  
Unsprung Mass

In order to isolate the propagation of unwanted vibrations to passengers and improve vehicle maneuverability, it is common practice to predict road profile roughness in the scope of active suspension design. An algebraic estimator designed for the estimation of the road profile excitation has been investigated in this study based on vehicle dynamics responses. An approximation of road profile excitation by a piecewise constant function has been proposed using the operational calculus method and the differential algebraic theory. The proposed technique allows for the usage of cheap instrumentation with a small number of sensors and employs a straightforward calibration process. Accurate approximation of the road profile was obtained from the measurement of sprung mass and unsprung mass vertical displacements. The performance and robustness of the proposed algebraic predictor is compared with an augmented Kalman estimator. Numerical results are provided to analyze the effectiveness and the limitations of the proposed algorithm for road profile reconstruction. Furthermore, a comparison with real profile was studied.

An Online Estimator for Heavy Vehicle's Mass and Road Grade

2006 ◽  
Author(s):  
M. McIntyre ◽  
A. Vahidi ◽  
D. Dawson
Keyword(s):  
Accurate Estimate ◽  
Control Area ◽  
Area Network ◽  
Heavy Duty ◽  
Two Stage ◽  
Estimation Strategy ◽  
The Road ◽  
Control Area Network ◽  
Road Grade ◽  
Stage Estimation

This work proposes a two stage estimation strategy to determine a heavy duty vehicles's mass and road grade. The estimation strategy uses standard signals available through the vehicle control area network. The first stage of this approach utilizes an adaptive least-squares estimation strategy to determine the vehicle's mass. Due to the time varying nature of the road grade, a nonlinear estimator is then developed that provides a more accurate estimate of the road grade. An estimation analysis is provided for both stages that proves, under a set of qualifying conditions, both the mass and road grade can be estimated. The validity of this two stage approach is verified using experimental data.

scholarly journals Evaluating the Effects of One-Way Traffic Management on Different Vehicle Exhaust Emissions Using an Integrated Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jieyu Fan ◽  
Kun Gao ◽  
Yingying Xing ◽  
Jian Lu
Keyword(s):  
Traffic Management ◽  
Integrated Approach ◽  
Exhaust Emissions ◽  
Traffic Emissions ◽  
Specific Power ◽  
Emission Measurement ◽  
Emission Rates ◽  
Vehicle Exhaust ◽  
Emission Data ◽  
The Road

One-way traffic management is a recognized traffic organization to improve traffic efficiency and safety, but its effects on different traffic emissions remains unclear. This paper aims to investigate the impacts of one-way traffic management on three typical vehicle exhaust emissions including Carbonic Oxide (CO), Hydrocarbon Compounds (HC), and Nitrogen Oxides (NOx) in a traffic system using an integrated approach. Field experiment was conducted to collect the vehicular emission data under different traffic conditions using the onboard portable emission measurement system. An instantaneous emission model (i.e., Vehicle Specific Power) is calibrated using the collected field emission data and is incorporated into the microscopic traffic simulation tool VISSIM for quantifying the emissions before and after one-way traffic management through simulation. Two scenarios based on real networks and traffic demands of peak hours in part areas of Shanghai are developed for simulation and evaluation. The results show that in the intersections, the emission rates of COHC, NOx after one-way traffic management is significantly reduced by 20.46%, 21.29% and 21.06%, respectively. In the road sections, the emission rates of CO, HC, NOx in the road sections decrease by 23.38% and 26.29%. The overall CO, HC, NOx emissions in the studied network reduce by 21.34%, 22.29% and 23.77% separately due to one-way traffic management. The results provide insights into the derivative effects of one-way traffic management on traffic emissions in the intersections, road sections and network levels, and thus support scientific traffic management for promoting the sustainability of transport system.

scholarly journals Practical Approach for Developing Lateral Motion Control of Autonomous Lane Change System

2020 ◽  
Vol 10 (9) ◽  
pp. 3143 ◽  
Author(s):  
Jaemin Baek ◽  
Changmook Kang ◽  
Wonhee Kim
Keyword(s):  
Vehicle Dynamics ◽  
Low Cost ◽  
Computation Time ◽  
Practical Approach ◽  
Lane Changes ◽  
The Road ◽  
Control Units ◽  
Vision Sensors ◽  
Lateral Offset ◽  
Change System

In this paper, we present a practical approach to address the vehicle lateral control problem. The proposed method can overcome practical problems associated with vehicle lane changes on highways. The vehicle state with respect to the road, which is called lateral offset, jumps in camera vision sensors when the vehicle changes lanes. Thus, in this study, we solve the state jump problem by translating it into a new domain called the cylinder domain. In addition, we proposed the design of a parameter-varying controller to overcome the nonlinear term of vehicle dynamics by considering it as a varying parameter. The proposed method does not consider the lateral offset jump when changing lanes. Furthermore, its significant advantage in terms of computation time makes it suitable for implementation in low-cost electronic control units (ECUs). The proposed algorithm is validated using MATLAB/Simulink with the vehicle dynamics analysis program CarSim.

The Value of Reclaimed Rubber in Tread Stock

1929 ◽  
Vol 2 (4) ◽  
pp. 517-524
Author(s):  
C. W. Sanderson
Keyword(s):  
Laboratory Tests ◽  
Relative Cost ◽  
The Road ◽  
Different Types

Abstract The road abrasion value has been determined on a series of tread stocks containing from 0 to 100 per cent. reclaim hydrocarbon. There is a close check between the road value as determined on two different types of road tests. The value of reclaim in this test is shown to vary from 25 to 42 per cent. of the value of new rubber, being higher for the all reclaim stock. The relative cost per unit of abrasion is shown to be above rubber at all points for 20-cent rubber. For 40-cent rubber it is lower than rubber when used above 50 per cent. reclaim hydrocarbon. The relative values for laboratory tests are compared to the road value. The tensible, lamination tear, and the 30 per cent. slip abrasion seem to give the best indication of road value.

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