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Viewing 1 to 30 of 18952
2016-05-01
Journal Article
2015-01-9147
Zhiyun Zhang, Miaohua Huang, Yupu Chen, Shuanglong Zhu
Abstract In the field of Electric Vehicle (EV), what the driver is most concerned with is that whether the value of the battery's capacity is less than the failure threshold because of the degradation. And the failure threshold means instability of the battery, which is of great danger for drives and passengers. So the capacity is an important indicator to monitor the state of health (SOH) of the battery. In laboratory environment, standard performance tests can be carried out to collect a number of related data, which are available for regression prediction in practical application, such as the on-board battery pack. Firstly, we make use of the NASA battery data set to form the observed data sequence for regression prediction. And a practical method is proposed to determine the minimum embedding dimension and get the recurrence formula, with which a capacity model is built.
2016-05-01
Journal Article
2015-01-9132
Husain Kanchwala, Harutoshi Ogai
Abstract Japan is suffering from the problem of an ageing society. In Kitakyushu city more than a quarter of people are aged above 65 years. The roads in this region are narrow with steep gradient and vulnerable roadbed. A big ratio of elderly people are living on their own. These characteristics make driving unsuitable. The problem is magnified by infrequent public transportation. A need-assessment survey for an autonomous vehicle at a community event suggested the applicability of small electric vehicle Toyota COMS. The vehicle is then equipped with features like automatic driving and platooning. The autonomous drive system is built to develop an intelligent transport system (ITS) using various sensors and actuators. Stereo camera and ultrasonic sensors were used to get a judgment of obstacle. Google earth and GPS were used to generate the target path using the Bezier curve method and optimized route is chosen.
2016-05-01
Journal Article
2015-01-9144
Marc-Olivier Lacerte, Gabriel Pouliot, Jean-Sébastien Plante, Philippe Micheau
Electric Vehicles (EVs) with single-ratio gearbox provide high levels of smoothness, but using multi-speed gearbox can provide significant benefits in terms of vehicle acceleration, top speed, powertrain cost, mass, and energy consumption. In particular, Automated Manual Transmissions (AMTs) have characteristics of smooth shifts without torque interruption when coupled to a torque bypass clutch. However, conventional friction clutches are not best suited as torque bypass clutches because of their limited controllability and because large amount of heat must be dissipated to slow down the motor during gearshifts. This paper studies the feasibility of a seamless AMT architecture for EVs and Hybrid Electric Vehicles (HEVs) using an eddy current torque bypass clutch that is highly controllable, robust, low cost, and has no wearable parts.
2016-04-15
Technical Paper
2015-01-9020
Emre Sert, Pinar Boyraz
Abstract Studies have shown that the number of road accidents caused by rollover both in Europe and in Turkey is increasing [1]. Therefore, rollover related accidents became the new target of the studies in the field of vehicle dynamics research aiming for both active and passive safety systems. This paper presents a method for optimizing the rear suspension geometry using design of experiment and multibody simulation in order to reduce the risk of rollover. One of the major differences of this study from previous work is that it includes statistical Taguchi method in order to increase the safety margin. Other difference of this study from literature is that it includes all design tools such as model validation, optimization and full vehicle handling and ride comfort tests. Rollover angle of the vehicle was selected as the cost function in the optimization algorithm that also contains roll stiffness and height of the roll center.
2016-04-05
Technical Paper
2016-01-1648
M. Kamel Salaani, Sughosh Rao, Joshua L. Every, David R. Mikesell, Frank Barickman, Devin Elsasser, John Martin
The rapid innovation underway with automated vehicle safety systems requires extensive evaluation and testing by system developers and regulatory agencies. The ability to evaluate heavy truck braking systems, complex, is made much more rapid, efficient, and economical through simulation employing the actual electronics and vehicle hardware. A hardware-in-the-loop pneumatic braking system was developed for this purpose by the National Highway Traffic Safety Administration. This paper describes the system in detail and includes some sample results of the testing.
2016-04-05
Technical Paper
2016-01-1676
Wenchao Liu, Guoying Chen, Changfu Zong, Chunshan Li
The driving range of the pure electric vehicles (PEVs) greatly restricts the development of PEVs. The vehicles waste a lot of energy on account of automobiles frequently braking under the city cycle.The regenerative braking system can convert the braking kinetic energy into the electrical energy and then returns to the battery, so the energy regeneration could prolong the driving range of the PEVs. To be for high-efficient braking energy recovery, regenerative braking force and friction braking force must be reasonably distributed, in the meantime, we must take the assignment of the front axle and rear axle’s braking force for the braking safety and stability of vehicles. This paper proposes a four-wheel-drive PEV model with an electric-hydraulic brake system, on the basis of which is an additional regenerative braking system.
2016-04-05
Technical Paper
2016-01-1612
Francesco Mariani, Francesco Risi, Nicola Bartolini, Francesco Castellani, Lorenzo Scappaticci
Aerodynamics of formula vehicles covers one of the most important roles in the development of racing cars. At the speeds which usually reach the formula cars, the driver's neck can be subjected to stresses resulting from the aerodynamic forces acting on the helmet; developing an aerodynamic project that takes into account the comfort of the driver without thereby affecting the performance can be undoubtedly considered a challenging activity. The aim of the present work is to develop a zero-pitching-moment-helmet for formula racing cars optimizing the shape and the location of some aerodynamic appendices to be applied on it. The goal is pursued adopting an approach based on both experimental and numerical activities. At earliest stage the aerodynamic configuration of an existing helmet was examined; trough a testing campaign in the wind tunnel facilities of Perugia University, pressures acting on the helmet were scanned at various speeds and data about aerodynamic drag were collected.
2016-04-05
Technical Paper
2016-01-1620
Jeff Howell, Sumit Panigrahi
Side force has an influence on the behaviour of passenger cars in windy conditions. It increases approximately linearly with yaw angle over a significant range of yaw for almost all cars and the side force derivative, (the gradient of side force coefficient with yaw angle), is similar for vehicles of a given category and size. The shape factors and components which affect side force for different vehicle types are discussed. The dominant influence on side force, for most cars, however, is shown to be the vehicle height which is consistent with slender wing theory if the car and its mirror image are considered. This conjecture is supported by data showing the side load distribution along vehicles. This simple theory applies to 1-box and 2- box shapes, covering most MPVs, hatchbacks and SUVs, but does not adequately represent the side forces on notchback and fastback car shapes.
2016-04-05
Technical Paper
2016-01-0310
John R. Wagner, Xinran Tao
The pursuit of greater fuel economy in internal combustion engines requires the optimization of all subsystems including thermal management. The reduction of cooling power required by the electromechanical coolant pump, radiator fan(s), and thermal valve demands real time control strategies. To maintain the engine temperature within prescribed limits for different operating conditions, a continual estimation of the heat removal needs and synergistic operation of the cooling system components must be accomplished. Reduced thermal management power consumption can be achieved by avoiding unnecessary overcooling efforts which are often accommodated by extreme thermostat valve positions. In this paper, an optimized nonlinear controller for a military MATV engine cooling system will be presented. The prescribed engine coolant temperature will be tracked while minimizing the pump, fan(s), and valve power usage.
2016-04-05
Technical Paper
2016-01-0437
Bin Tang
In order to ensure that coach drivers have good manipulation and road feeling at different speeds, variable assist characteristic of electronically controlled hydraulic power steering system (ECHPS) in a coach was designed based on drivers’ preferred steering torque. Two degrees of freedom vehicle model, steering system model and model of steering resistance moment were established for following simulation. The design method of assist characteristic was proposed. Feature points of assist characteristic curves were calculated via coach drivers’ preferred steering torque and steering resistance moment at different speeds by means of simulation. For realization of the variable assist characteristic, the optimization model of rotary valve parameters was put forward, with the minimum of quadratic sum of the difference between assisted oil pressure under characteristic speed and characterized assisted oil pressure defined as objective function.
2016-04-05
Technical Paper
2016-01-1671
Dejian Han, Zhen Yan, Feng Xiao, Shaokun Li MD
In the context of the global energy crisis and environmental degradation, electric vehicles (EVs) have been gaining a lot of focus and attention as they run clean and are environment friendly. The electric vehicle with in-wheel motors is a promising form of EV, which is driven by four in-wheel motors. Under this mode, the driving and brake torques of each of wheel can be controlled independently. Stability control of the vehicle requires the vehicle to travel along an ideal trajectory and remain the ideal state all the time. Direct yaw moment control (DYC) has a high ability to maintain the vehicle stability in critical situation. For four-wheel independently driven (4WD) electric vehicle with in-wheel motors (IWMs), direct DYC system can work more flexibly and efficiently than internal combustion engine vehicles, because the driving/braking torque of each wheel can be controlled accurately. In this paper, a hierarchical direct yaw moment controller is developed.
2016-04-05
Technical Paper
2016-01-1680
Suresh Abasaheb Patil, Indrajit Dinkar More
With the cut-throat competition in automotive industry and sky rocketing expectations from potential customers, ride comfort is one of the most critical factors to evaluate the automobile performance and has been an interesting topic for researchers for many years. Automobile designers give an abundant attention to the isolation of vibrations in the car, in order to provide a comfortable ride for the passengers. The ride characteristics affect not only the comfort of the crew, work performance and physical health, but also directly or indirectly affect the vehicle's power, economy and handling performance. Ride Comfort is the general sensation of noise, vibration and motion inside a driving vehicle, experienced by both the driver as well as the passengers. Ride comfort optimization goes beyond the pure ISO 2631 Whole body vibration certification testing as it affects the comfort, safety and health of the passengers subjected to it.
2016-04-05
Technical Paper
2016-01-1183
The modeling and simulation of high Pressure Hydrogen All Electrochemical Decentralized RefUeling Station (PHAEDRUS) is investigated in this paper. The main goal is to develop and validate a new concept for 100 MPa hydrogen refueling station enabling self-sustained infrastructure roll-out for early vehicle deployment volumes, showing the applicability of the electrochemical hydrogen compression (EHC) technology in combination with an on-site anion exchange membrane (AEM) electrolyser, storage units, pre-cooling and a dispensing system. The electrolyser and the compressor are modeled using the electrochemical equations and the conservation of mole balance. The main water flows, electro-osmotic drag and diffusion are added in the electrolyser model and the effect of hydrogen back diffusion is included in the compressor model. The storage is modeled thermodynamically using the energy balance equation.
2016-04-05
Technical Paper
2016-01-0528
Anthony Padden
Driven by the need to reduce emissions, today’s automotive industry is strongly focused on improving vehicle efficiency by reducing weight through metal-to-plastic conversion. Around the globe, new and upcoming legislation is placing ever-tighter limits on vehicle emissions and carbon footprints during the manufacturing process. Weight reduction is a focus area to accomplish these targets. One such vehicle technology that is currently undergoing drastic weight reduction is the steering module. The shift from a conventional hydraulic power steering (HPS) system to electric power steering (EPS) is becoming more popular because it leads to improved fuel economy and lower CO2 emissions. Further weight reduction at the component level a serious challenge as the incremental costs outweigh the incremental benefits, when one sticks to conventional material choices.
2016-04-05
Technical Paper
2016-01-1628
Gurdeep Singh Pahwa, Baskar Anthonysamy, Karan shah
Lateral Stability is a major concern for Pick – Up segment vehicle. The high yaw rate or tail sway reduces the confidence of the driver during the lane change manoeuvre. The concept architecture of vehicle plays an important role to produce the stable vehicle. High yaw rate or tail sway during cornering were reported during proto vehicle validation. Tested vehicle configuration was Double Wish Bone Suspension with antiroll bar in front and rear rigid axle suspension with leaf spring anti-roll bar. The feedback was critically analysed on the vehicle with the simulation of field conditions. Since the vehicle was still under validation team, solution for the feedback required was quick and within boundary condition (maximum possible allowable limits of modification) of no major change in the suspension design as it was affects homologation cycle.
2016-04-05
Technical Paper
2016-01-1678
Etsuo Katsuyama, Ayana Omae
Vehicles equipped with in-wheel motors (IWMs) are capable of independent control of the driving force at each wheel. These vehicles can also control the motion of the sprung mass by driving force distribution using the suspension reaction force generated by IWM drive. However, one disadvantage of IWMs is an increase in unsprung mass. This has the effect of increasing vibrations in the 4 to 8 Hz range, which is reported to be uncomfortable to vehicle occupants, thereby reducing ride comfort. This research aimed to improve ride comfort through driving force control. Skyhook damper control is a typical ride comfort control method. Although this control is generally capable of reducing vibration around the resonance frequency of the sprung mass, it also has the trade-off effect of worsening vibration in the targeted mid-frequency 4 to 8 Hz range. This research aimed to improve mid-frequency vibration by identifying the cause of this adverse effect through the equations of motion.
2016-04-05
Technical Paper
2016-01-1677
Hiroshi Himeno, Etsuo Katsuyama, Takao Kobayashi
Electric vehicles (EVs) are attracting attention due to growing awareness of environmental issues such as fossil fuel depletion and global warming. In particular, a wide range of research has examined how direct yaw moment controls (DYCs) can enhance the handling performance of EVs equipped with multiple in-wheel motors (IWMs) or the like. Recently, this research has focused on reducing energy consumption through driving force distribution control. The first report proposed a method to minimize energy consumption through an efficient DYC for extending the cruising range of a vehicle installed with four IWMs, and described the vehicle behavior with this control. Since motors allow high design flexibility, EVs can be developed with a variety of drive systems. For this reason, various driving force distribution control methods can be considered based on the adopted system.
2016-04-05
Technical Paper
2016-01-1627
Liangxiu Zhang, Guangqiang Wu
In order to improve robustness and stability of the autonomous vehicle at high speed, a path tracking approach using combined front steering and differential braking control is investigated in this paper. Bicycle model with 3 degrees of freedom is established and linear time-varying path tracking predictive model using front steering as its control input is derived. Based on the theory of model prediction, path tracking using linear time-varying model predictive control can be transformed into online quadratic programming problem with constraints. Target front steering angle can be obtained from online moving optimization. Then the direct yawing control is adopted to treat two types of differential braking control. The first one researches steady-state yaw rate gain of linear 2 degrees of freedom vehicle model, and designs differential braking stable controller based on reference yaw rate.
2016-04-05
Technical Paper
2016-01-1670
Qian Wang, Beshah Ayalew, Amandeep Singh
Multi-axle land vehicles with drive actuation on more than one axle offer improved stability and traction on various road surfaces. This is possible via the optimization of load distribution and maximization of the utilization of individual tire-road contacts by exploiting the redundancy of the drive system. This paper outlines a real-time hierarchical control optimization algorithm for multi-axle driven land vehicles with independent hub motor wheel drives and/or front axle active steering. At the top level, the driver’s input such as pedal position or steering wheel position are interpreted into desired global state responses based on a reference model. Then, a locally linearized rigid body model is used to design a linear quadratic regulator that generates the desired global control efforts that can closely track the desired state responses.
2016-04-05
Technical Paper
2016-01-1188
Stuart Chubbock, Ralph Clague
Fuel cell hybrid vehicles offer a high-efficiency and low-emission alternative to internal combustion engines (ICE). The fuel cell is silent, vibration free and zero emissions at point of use allowing the vehicle control system engineer considerably greater flexibility than with an ICE. They are no longer constrained by the need to maintain discrete power levels to minimise the noise intrusion, or switch the ‘engine’ off at low vehicle speeds to reduce noise and vibration. This paper presents simulation work comparing the performance of a typical a B-segment electric vehicle with either a fuel cell or an ICE range extender over a number of real-world drive cycles. Intelligent Energy’s ‘Gen4’ air cooled fuel cell system is detailed as the fuel cell range extender, a typical 660cc gasoline engine is used for comparison.
2016-04-05
Technical Paper
2016-01-1189
Arya Yazdani, Mehran Bidarvatan
Power split in Fuel Cell Hybrid Electric Vehicles (FCHEVs) have been controlled using different strategies ranging from rule-based to optimal control. Dynamic Programming (DP) and Model Predictive Control (MPC) are two common optimal control strategies used in optimization of the power split in FCHEVs with a trade-off between global optimality of the solution and on-line implementation of the controller. In this paper, both control strategies are developed and tested on a FC/battery vehicle model and the results are compared in terms of energy consumption. In addition, the effects of the MPC prediction horizon length on the controller performance are studied. Results show that using the DP strategy, up to 12% less total energy consumption is achieved compared to MPC for a charge-sustaining mode in Urban Dynamometer Driving Schedule (UDDS) drive cycle.
2016-04-05
Technical Paper
2016-01-1255
David Mackanic, Eduardo D. Marquez, James Dennington, Jacob McClean, Kaitlyn Wheeler, Douglas Nelson
The Hybrid Electric Vehicle Team (HEVT) of Virginia Tech has completed several modeling and testing stages to develop models that represent the P3 PHEV powertrain the team is building as part the EcoCAR 3 competition. The model development process consists of several major steps. First, Model-in-the-Loop (MIL) testing is conducted to validate a conventional vehicle model against data provided by General Motors, down-select a desired powertrain configuration, and generate initial vehicle technical specifications (VTS). HEVT is pursuing a performance powertrain that balances high performance with minimal energy consumption. Initial MIL modeling results yield an IVM-60 mph time of 4.9 seconds and an overall UF-weighted 4-cycle energy consumption of 560 Wh/km. MIL modeling provides an initial reference to compare subsequent vehicle modeling.
2016-04-05
Technical Paper
2016-01-1615
Thomas Blacha, Misha Marie Gregersen, Moni Islam, Henry Bensler
The aerodynamic optimization of an AUDI Q5 vehicle is presented using the continuous adjoint approach within the OpenFOAM framework. All calculations are performed on an unstructured automatically generated mesh. The primal flow, which serves as input for the adjoint method, is calculated using the standard CFD process at AUDI. It is based on DES calculations using a Spalart-Allmaras turbulence model. The transient results of the primal solution are time averaged and fed to a stationary adjoint solver using a frozen turbulence assumption. From the adjoint model, drag sensitivity maps are computed and measures for drag reduction are derived. The predicted measures are compared to CFD simulations and to wind tunnel experiments at 1:4 model scale. In this context, general challenges, such as convergence and accuracy of the adjoint method are discussed and best practice guidelines are demonstrated.
2016-04-05
Technical Paper
2016-01-1247
Kevin L. Snyder, Jerry Ku
The objective of the research into modeling and simulation was to provide an iterative improvement to the Wayne State EcoCAR 2 team's math-based design tools for use in evaluating different outcomes based on hybrid powertrain architecture tweaks, controls code development and testing. This paper includes the results of the team's work in the EcoCAR 2 competition for university student teams to create and test a plug-in hybrid electric vehicle for reducing petroleum oil consumption, pollutant emissions, and Green House Gas (GHG) emissions. Plant model validations and advancements brought the vehicle plant model directionally closer to the actual vehicle's experimental data and achieved a significant error reduction in 10 of 11 metrics detailed in the research. The EcoCAR 2 competition events provided the opportunity for the team to get experimental data of the vehicle's behavior on the vehicle chassis dyno and the vehicle on road testing from General Motors proving ground test tracks.
2016-04-05
Technical Paper
2016-01-1668
Hideki Fukudome
Measures to help preserve the environment have become an essential part of vehicle development. Vehicles powered by electric motors such as hybrid and fuel-cell vehicles are an effective way of helping to reduce greenhouse gas emissions. Furthermore, in addition to environmental friendliness, motor drive allows torque to be controlled freely with high response and precision, adopting both forward and reverse rotation. As a result, motors can be used to achieve enable a high degree of controllability even for functions related to ride comfort and handling performance. In addition, in-wheel motors (IWMs), i.e., motor units that are installed inside the wheels of the vehicle, greatly increase the freedom of part layout. Consequently, IWMs have the potential to revolutionize vehicle development, including the way that vehicles are manufactured, in a way not feasible with conventional vehicle configurations.
2016-04-05
Technical Paper
2016-01-1674
Takao Kobayashi, Etsuo Katsuyama, Hideki Sugiura, Eiichi Ono, Masaki Yamamoto
Various kinds of direct yaw moment controls have been developed to enhance vehicle handling performance. Simultaneously, there have been innovations of the driving force distribution mechanism. Recently, an in-wheel motor has been proposed as the most efficient system. However, since one of the difficult issues in developing electric vehicles is to improve the mileage per charge, it is necessary to construct a new control algorithm capable of conserving and saving energy. Therefore, the purpose of this paper is to study the cornering resistance and dissipation power on tire contact patch, and to develop an efficient direct yaw moment control during acceleration and deceleration while turning. To optimize the cornering efficiency reasonably, our method to formulate the cornering resistance in steady state cornering was extended to so-called quasi steady state cornering that includes acceleration and deceleration.
2016-04-05
Technical Paper
2016-01-1252
Arjun Khanna, Sam Yacinthe, Jason Ward, M.J. Yatsko, Shawn Midlam-Mohler
Vehicle modeling is important to vehicle development as it allows for initial vehicle architecture investigation and validation. A well designed vehicle model will be critical to hybrid supervisory control refinement and development. The Ohio State University EcoCAR 3 team designing a plug-in hybrid electric vehicle (PHEV) post-transmission parallel 2016 Chevrolet Camaro. With the end-goal of reducing the environmental impact of the vehicle, the Ohio State Camaro has been designed with a 44-mile all-electric range. It also features an 18.9 kWh Li-ion energy storage system, a 119 kW 2.0L GDI I4 engine that runs on 85% ethanol (E85) fuel, a 5-speed automated manual transmission, and a 150 kW peak electric machine. This report details the model and controls development process followed by the Ohio State team during Year 1 of the competition. The focus will be on overall development of a vehicle model, initial simulation results, and supervisory controls development.
2016-04-05
Technical Paper
2016-01-1257
Sam Yacinthe, Arjun Khanna, Jason Ward, M.J. Yatsko, Shawn Midlam-Mohler
The design of a performance hybrid electric vehicle includes a wide range of architecture possibilities. A large part of the design process is identifying reasonable vehicle architectures and vehicle performance capabilities. The Ohio State University EcoCAR 3 team designed a plug-in hybrid electric vehicle (PHEV) post-transmission parallel 2016 Chevrolet Camaro. With the end-goal of reducing the environmental impact of the vehicle, the Ohio State Camaro has been designed with a 44-mile all-electric range. It also features an 18.9 kWh Li-ion energy storage system, a 119 kW 2.0L GDI I4 engine that runs on 85% ethanol (E85) fuel, a 5-speed automated manual transmission, and a 150 kW peak electric machine. This report details the design and modeling process followed by the Ohio State team during Year 1 of the competition. The process included researching the customer needs of the vehicle, determining team design goals, initial modeling, and selecting a vehicle architecture.
2016-04-05
Technical Paper
2016-01-1186
Dong Hao, Yongping Hou, Jianping Shen, Liying Ma
The vehicular fuel cell (FC) stack is unavoidably impacted by the vibration in the real-world due to the road unevenness. However, impacts of vibration on FC stack have yet to be completely investigated. In this work, the mechanical integrity and gas-tightness of the stack are investigated through a 200 hours strengthen road vibration test. The excitation spectra applied in the vibration test are simulated by the acceleration signals of the stack, which are previously measured in a vehicle vibration test. The load signals of the vehicle vibration test are iterated through a road simulator from vehicle acceleration signals which are originally sampled in the strengthened road of the ground prove. Frequency sweep test is conducted before and after the vibration test. During the vibration test, mechanical structure inspection and pressure maintaining test of the stack are carried out at regular intervals.
2016-04-05
Technical Paper
2016-01-1581
Felix Wittmeier, Armin Michelbach, Jochen Wiedemann, Victor Senft
With its recent wind tunnel upgrade, FKFS installed the first interchangeable 3-belt / 5-belt-system in a full scale automotive wind tunnel. With the 5-belt-system, which today is a state-of-the-art ground simulation technique, the system is ideally suited for day to day passenger car development work. The 5-belt system offers high flexibility, quick access to the underfloor and vehicle fixation, and setting the vehicle’s ride height by the restraint device. The first results of the 5-belt-system have already been presented in SAE 2015-01-1557. The 3-belt system on the other hand, offers a much more sophisticated ground simulation technique which is necessary especially for sports and racing cars. For such vehicles with low ground clearance, it is important to have a more accurate ground simulation, in order to capture the same aerodynamic modes of action and response as on the road.
Viewing 1 to 30 of 18952