Vehicle Performance Evaluation Research Articles

Time dimension analysis: Comparison of Nanjing local driving cycles in 2009 and 2017

Driving cycles are widely used as standard measurement procedures for vehicle emissions and energy consumption assessment, especially for vehicle design optimization and performance evaluation of emerging vehicular technologies (HEV/EV), including standard driving cycles and non-standard driving cycles. Local driving cycles, as non-standard driving cycles, are mainly used in certain areas for in-use vehicle emission and fuel consumption assessment. However, whether these local driving cycles could represent the driving conditions in certain areas for a long time, and whether it is necessary to consider the year of development when comparing local driving cycles in different cities, these issues require more attention from researchers. In this paper, a practical local driving cycle construction methodology combing principal components analysis (PCA) and K-means clustering is proposed, and two local driving cycles for passenger cars in Nanjing are developed in 2009 and 2017, respectively. The same data acquisition and processing methods make the comparison between the two generated cycles more fair. Significant differences in driving parameters between Nanjing local driving cycles in 2009 and 2017 show the necessity of studying local driving cycles from time dimension and provide traffic management authority with some valuable advice on estimating road-based vehicle emission.

Performance Evaluation of Hybrid Electric Vehicles for Sustainable Transport System

The emissions from the internal combustion (IC) engine vehicle causes pollution which increases the carbon footprints in the environment which causes global warming. In ICE vehicle only 20 % of the energy produced by it is used to run the vehicle and rest 80 % of it get wasted. The emerging technology of Hybrid Electric vehicle (HEV) has become the feasible solution for the modern world as it lessens the carbon emission and augments the fuel performance of vehicle. The role of power electronic converters is very crucial in designing the configuration of HEVs. The performance of the converter is employed for realizing the features of electric traction motor drive. The paper analyses the performance of a small car powered by gasoline based internal combustion engine, series hybrid electric vehicle (SHEV) and parallel hybrid electric vehicle (PHEV) drive train. The simulation has been performed on Advanced Vehicle Simulator (ADVISOR) platform. Different types of HEVs configuration has been analyzed by considering three different driving schedules such as CYC_UDDS, CYC_NEDC and CYC_URBAN_INDIA. The gradability and acceleration test has also been carried out in all category of test vehicles and result is demonstrated by examining vehicle emission at each driving cycle.

Comparison of Strategies for Coupled Flow-Thermal Analysis of Thermal Protection System at Hypersonic Flight Condition

Coupled flow-thermal analysis is crucial for the performance evaluation and structural design of hypersonic vehicles. In this study, several strategies for computing the coupled flow-thermal response of air-breathing hypersonic flights in practical engineering are developed and compared. First, the basic direct correction method that amends wall heat flux via recovery temperature and wall temperature is proposed to approximate flow-thermal effects efficiently. Second, the improved DCM (IDCM) is further developed by interpolating the cold wall heat flux and the recovery temperature between adjacent trajectory points to improve computational accuracy. Third, the iteration solution method (ISM) that obtains solutions through mass and energy balances at a common interface by iterations between CFD analysis code and CSD analysis code is also presented. Thermal response and flow characteristics are compared through a test case of an air-breathing hypersonic vehicle. The results show that the thermal response tendencies are consistent by DCMs and ISM. However, for DCMs, the impact of hot wall on the flow characteristics is ignored, whereas it is fully considered in ISM; thus, the thickened boundary flow and complicated internal flow can be captured. However, while comparing computational efficiency, DCMs have a prominent advantage over ISM due to the decoupling algorithm and parallel strategy. Based on this, in the actual design process of an air-breathing hypersonic vehicle, the designers can select the proper flow-thermal analysis method according to the different design stages.

Developing a Standardized Performance Evaluation of Vehicles with Automated Driving Features

Developing a Standardized Performance Evaluation of Vehicles with Automated Driving Features

Road Noise Reduction of a Sport Utility Vehicle via Panel Shape and Damper Optimization on the Floor Using Genetic Algorithm

Road noise is always a major concern in automotive industries. The contribution of the floor of a automotive vehicle to road noise is large because of its large area and close location to chassis in terms of structure-borne noise. Therefore, the panel shape and damper of the floor should be carefully designed, which are effective on medium frequency region of the road noise. Because there are so many design options on the floor panels that experience high modal density and short wavelength at medium frequencies, traditional mode-decoupling approaches are no longer efficient. This study shows that a proposed optimization process based on a finite element model and a genetic algorithm is successful to reduce road noise at medium frequencies. Some background theories about the genetic algorithm and acoustic radiation efficiency in the frame of vibro-acoustics are explained to understand the optimization process. Vehicle performance evaluation and experimental study are given to validate this study. Finally, this verified process is applied to a sport utility vehicle (SUV) under development, whose road noise reduction is shown to be successful.

Comparative performance of electric vehicles using evaluation of mixed data

The electric vehicle (EV) technology has been getting momentum due to rapid depletion of fossil fuels and also in taking care of environment. Many manufacturers are investing a lot in electric vehicles for a particular outcome coming from it which can show a sign for replacement of conventional I.C engines. They are taking interest about the customer findings in a car. There are various factors which affect the performance of an electric vehicle such as battery capacity, charging time, price, driving range etc. As we know there are many electric vehicle models that are present in market with different combinations and this study is based on the performance evaluation of electric vehicles using multiple criteria decision making tool from customer point of view. This study highlights the best electric vehicle model in Asian market so that findings of an EV buyer can be fulfilled. Fuzzy analytic hierarchy process has been used to determine criteria weight whereas evaluation of mixed data has been used for performance evaluation and ranking. According to the study BYD E6 becomes the best electric vehicle model in Asian market.

Criterion for evaluating vehicle performance

The article proposes to evaluate the efficiency of an autonomous vehicle, taking into account not only the energy consumption for motion, but also the time of motion, i. e. both factors — efficiency and performance — should be taken into account. As a criterion for evaluating the efficiency of vehicles, authors propose the multiplication of efficiency on performance — the energy efficiency indicator (EEI). The best will be the vehicle with the highest EEI. The indicator should be calculated according to the specified technical characteristics of the vehicle laid down in the technical specifications. This criterion is suitable both for the evaluation of the vehicle during the design and during operation. At the same time, it is possible to evaluate and compare the EEI of technical vehicles not only of railway transport. The article presents the criterion values for water, rail and air transport. Proposed criterion makes it possible to evaluate the change in vehicle efficiency over time due to technical progress. Since 1953, the energy efficiency of a diesel locomotive has increased almost 3 times. To calculate the operational energy efficiency, it is necessary to obtain data on the actual performance of the vehicle. On railway transport, this is data on train work in t·km, speed and fuel consumption. The EEI assessment based on operating data will show how correctly the organization of vehicle operation is built, how non-stationary modes of the power plant and specific modes of traction influence the overall performance of the vehicle, how well the vehicle is selected for these operating conditions.

A Road-Holding Index Based on Ride Dynamics for High-Downforce Racing Cars

This work builds on some of the current industry techniques used in racing to evaluate vertical dynamics performance and propose a new methodology to evaluate vehicle performance. The proposed method creates a quantitative numerical index from the classic tyre vertical load variation frequency response function with some novelties that cover all peculiarities of high downforce race cars. In this method the aerodynamic forces are included as non-linear functions vs ride height and it is shown that they affect system stiffness and damping. As a result, the system response changes as a function of vehicle longitudinal speed. The importance of non-linear suspension rates in this kind of vehicle is also highlighted. The proposed index can also be customized for a certain vehicle speed range. A Formula 3 racecar model has been used as an application example.

A rolling resistance estimate using nonlinear finite element numerical analysis of a full three-dimensional tyre model

In accordance with the worldwide trend for developing energy-efficient vehicles and meeting environmental regulations, there exists a large potential for decreasing energy losses due to tyre rolling resistance and significantly reduce fuel consumption and greenhouse gas emissions and also improve tyre tread durability. To achieve a quantitative estimate of tyre rolling resistance force, in the present paper, we carry out rolling resistance modelling in order to introduce a comprehensive relation for predicting rolling resistance force variations with speed taking into account the most influential parameters. To accomplish this goal, full three-dimensional finite element modelling of a visco-hyperelastic inflated rubber tyre under the deformation of vertical loading is performed and validated by making use of available test data. Free rolling simulations are performed and rolling resistance diagrams at various vehicle speeds and inflation pressures are extracted by analysing the results. According to the simulation results, a general formula is suggested to predict the tyre rolling resistance force in terms of the influential factors such as velocity, inflation pressure and tyre load. Results obtained using the proposed equation compared with recorded coast down test data clearly indicate excellent agreement between the results, confirming the validity of the relation. The presented solution can be built into models for comprehensive techno-economic evaluation of vehicle performance and fuel economy where changes in velocity, load and inflation pressure can be considered.

Real-time side-slip angle measurements using digital image correlation

In vehicle dynamics there are many parameters that are desired for vehicle control and modelling. One of the most important parameters for handling and stability is the vehicle side-slip angle. The ability to directly measure the vehicle side-slip in real-time will aid and improve many driver assist systems such as stability control schemes and roll-over mitigation, especially over rough terrain.Commercial side-slip angle solutions are available but they are prohibitively expensive and are only suitable for use during vehicle development and performance evaluation. They are also restricted to small side-slip angles and give unsatisfactory results at low speeds and over uneven terrain. Previous research has proven that digital image correlation can be used to accurately measure vehicle side-slip angle over rough off-road terrain using inexpensive, off-the-shelf cameras. However, side-slip angle calculations were performed in post processing from pre-recorded footage and not implemented in real time due to the large computational times of the novel algorithms developed.This paper describes the improvements made to the algorithms that enable real-time implementation. The side-slip angle is measured using a single camera pointing downwards to the terrain and digital image correlation. The sensor is tested on a flat surface using a rig that allows for validation. The maximum sampling frequency and accuracy are investigated. The system is shown to measure accurately and in real-time up to 100 km/h speeds.

A flexible multi-disciplinary environment for performance, life-cycle cost, and safety evaluation of suborbital vehicles

Suborbital vehicles are innovative and unconventional aerospace concepts that are characterized by a high level of complexity and a lack of optimized baseline. The present focuses on the development of a flexible multi-objective modeling and simulation environment that provides the capabilities to rapidly evaluate the flying, economic, and safety performance of suborbital vehicles at a conceptual design level. One of the goals of this environment is to enable the exploration of large design spaces and facilitate the mapping between high-level requirements and the identified optimized concept. The environment is broken down into six modules: weight/size, aerodynamics, trajectory, propulsion, economics, and safety. By leveraging empirical models, physics-based approaches, and surrogate modeling techniques, it enables the rapid and parametric assessment and optimization of a multitude of design concepts. It is the first environment of this sort to support informed design space exploration of suborbital vehicles and allow for new trends to be identified and crucial observations to be made.

Generation of a driving cycle for battery electric vehicles：A case study of Beijing

Driving cycle, which is widely adopted as a standard measurement procedure for evaluation of fuel economy, emission and driving range, can facilitate vehicle design and performance evaluation of emerging vehicular technologies. However, all current popular driving cycles are developed based on the operation characteristics of conventional vehicles, while the driving characteristics of battery electric vehicles could be quite different, which means traditional driving cycles may not be suitable for evaluating and improving battery electric vehicles. Thus it is important to develop a new driving cycle, which is consistent with real-world situations of battery electric vehicles for the development of new energy auto industry. In this study, the real-world operation data of battery electric vehicles in Beijing are collected with high frequency and the usage and driving characteristics of battery electric vehicles are analyzed based on the real-world data and compared with several standard cycles, such as New European Driving Cycle, Federal Test Procedure-75, and Japan 10–15. Then the Beijing driving cycle is developed using statistic and Markov chain method. The following evaluation proves the new developed driving cycle represents the real-world driving well, which establishes a solid foundation for accurate performance evaluation of battery electric vehicles at least in Beijing.

Vehicle performance evaluation in side impact (MDB) using ES-II dummy

Side impact collision is one of the leading causes of death. Protection of people during lateral collision is challenging because of relatively small space available to restraint occupant compared to front. Hence, it is imperative to protect the occupants in side collision. It is a function of vehicle type and restraints for side protection. This paper focuses on evaluation of injury parameters of the ES II dummy during the lateral collision of different vehicles with different spaces, sections and materials. Thus the comparison will enable us to understand the sensitivity of space, B-pillar section and material which affects the injury parameters. This study will help automotive engineers to design side impact crashworthy vehicles.

A study on the construction of Hefei urban driving cycle for passenger vehicle

NEDC is widely used in China, however, it is not really appropriate for the current Chinese road conditions. In order to construct the driving cycle of Hefei, this paper take the urban roads in Hefei as the research object, using principal component analysis (PCA) to reduce the dimensionality of the kinematic parameters and k-means clustering method to classify kinematics segments. According to the length of time and the correlation of each class, some kinematic segments were selected to form the synthetic driving cycle. Through the error analysis, it can be seen that the synthetic driving cycle represents the real-world driving well, which establishes a solid foundation for accurate performance evaluation of passenger vehicles in Hefei.

Analysis of European Emission & Energy Consumption Calculation Software

Build a calculation model to measure the energy consumption of vehicle emissions, we can economically and easily achieve family type certification under multiple operating conditions and performance evaluation of specific vehicles. During the development of working conditions in Europe, the standard emission energy consumption estimation models for light vehicles and heavy vehicles were respectively developed. This paper conducts in-depth research on these calculation models, comprehensively introduces the overall process of model measurement method , explains in detail the technical details of working conditions conversion, refers to the calibration method of certification institutions, promotes the steady development of China's vehicle test and testing system, and provides technology for emission calibration. Support and guide motor vehicles to a cleaner, environmentally friendly and economical direction.

Economic performance evaluation of natural gas vehicles and their fuel infrastructures

The transition from high carbon-intensity to low carbon-intensity transport fuels entails the development of energy efficient and cost-effective decarbonisation pathways. In this paper, 14 potential natural and renewable gas supply pathways and natural gas vehicles (NGVs) have been selected and evaluated with regards to well-to-tank (WTT) fuel production costs and break-even vehicle added investment costs. NGVs are evaluated for both road- and maritime transport applications with three types of gas engines; dedicated, dual fuel, and high pressure direct injection (HPDI) engines. The results indicate that owing to the alternate gas distribution mechanisms and filling stations configuration there exist a substantial fuel production cost differences between the selected gas pathways. Despite its long-distance shipping and distribution, imported LNG showed significant production cost advantage over compressed natural gas (CNG) and liquefied renewable natural gas (LRNG) pathways. Evaluating the current economic performances, all NGVs are found to be competitive corresponding to gasoline cars, but not compared to diesel cars due to the lower price gap between CNG and diesel. In the heavy-duty vehicle and passenger vessel segments, however, owing to the high price gap between LNG and diesel/marine gas oil (MGO), all NGVs and LNG passenger vessels showed high competitiveness compared to their conventional counterparts.

Economic performance evaluation of natural gas vehicles and their fuel infrastructures

The transition from high carbon-intensity to low carbon-intensity transport fuels entails the development of energy efficient and cost-effective decarbonisation pathways. In this paper, 14 potential natural and renewable gas supply pathways and natural gas vehicles (NGVs) have been selected and evaluated with regards to well-to-tank (WTT) fuel production costs and break-even vehicle added investment costs. NGVs are evaluated for both road- and maritime transport applications with three types of gas engines; dedicated, dual fuel, and high pressure direct injection (HPDI) engines. The results indicate that owing to the alternate gas distribution mechanisms and filling stations configuration there exist a substantial fuel production cost differences between the selected gas pathways. Despite its long-distance shipping and distribution, imported LNG showed significant production cost advantage over compressed natural gas (CNG) and liquefied renewable natural gas (LRNG) pathways. Evaluating the current economic performances, all NGVs are found to be competitive corresponding to gasoline cars, but not compared to diesel cars due to the lower price gap between CNG and diesel. In the heavy-duty vehicle and passenger vessel segments, however, owing to the high price gap between LNG and diesel/marine gas oil (MGO), all NGVs and LNG passenger vessels showed high competitiveness compared to their conventional counterparts.

Prediction of the wheel profile wear using railroad vehicle dynamics simulation: Comparison of simulation and test results

Wear is a fundamental problem in the railroad vehicle design and performance evaluation. Slight changes in the profile shape result in significant impact on the contact geometry characteristics of ...

Performance evaluation of unmanned aerial vehicles in automatic power meter readings

Typically, the electric power companies employ a group of power meter readers to collect data on the customers energy consumption. This task is usually carried out manually, which can lead to high cost and errors, causing financial losses. Some approaches have tried to minimize these problems, using strategies such as discovering the minimal route or relying on vehicles to perform the readings. However, errors in the manual readings can occur and vehicles suffer from congestion and high fuel and maintenance costs. In this work, we go further and propose an architecture to the Automatic Meter Reading (AMR) system using Unmanned Aerial Vehicles (UAV). The main challenge of the solution is to design a robust and lightweight protocol that is capable of dealing with wireless communication collisions. Therefore, the main contribution of this work is the design of a new protocol to ensure wireless communication from UAV to the power meters. We validated and evaluated the architecture in an urban scenario, with results showing a decrease of time and distance when compared to other approaches. We also evaluated the system proposed with Linear Flight Plan, the Ant Colony Optimization and Guided Local Search metaheuristic. Our mechanism attains an improvement of 98% in reducing the message collisions and reducing the energy consumption of the power meters.

A multi-domain modelling and verification procedure within MBSE approach to design propulsion systems for road electric vehicles

The paper deals with the model based systems engineering (MBSE) approach, focused on the designing process of propulsion systems for road electric vehicles. In particular, the paper adopts multi-domain Modelling, in accordance with a top-down approach. The process, in fact, starts from the main requirement analysis of the road electric vehicle which is considered as reference. Then, a wide range of parameters, related to the characteristics of propulsion system components and resistance forces, are evaluated to build a parametric model of the propulsion system running on a road. In this way, a procedure for the evaluation of vehicle performance is accomplished within the developed simulation environment. Therefore, the procedure allows all the requirements to be satisfied, under different operative conditions, through an iterative procedure of verification for the imposed parameters. The tested operative conditions are represented in this paper by standard driving cycles, expressed in terms of vehicle speed and autonomy requirement.