419 research outputs found

    Electric-drive vehicle emulation using advanced test bench

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    Vehicle electrification is considered to be the most promising approach toward addressing the concerns on climate change, sustainability, and rapid depletion of fossil fuel resources. As a result electric-drive vehicle (EDV) technology is becoming the subject of many research studies, from academia and research laboratories to automotive industries and their suppliers. However, a crucial step toward the success of EDV implementation is developing test platforms that closely emulate the behavior of these vehicles. In this dissertation, a new approach for emulating an EDV system on a motor/dynamometer test bench is investigated. Two different methods of emulation are discussed which are based on predefined drive cycle and unpredictable driving behavior. MATLAB/Simulink is used to model the test bench and simulations are carried out for each case. Experimental test bench results are also presented to validate hardware-in-the-loop (HIL) real-time performance for each method. Furthermore, to provide a more realistic approach towards EDV emulation a braking system suitable for motor/dynamometer architecture is proposed. The proposed brake controller represents a very close model of an actual EDV braking system and takes into account both regenerative and friction braking limitations. Finally, the challenges and restrictions of using a full scale test bench are outlined. To overcome these limitations, the development of an educational small scale hybrid electric vehicle (HEV) learning module is discussed which provides an ideal test platform to simulate and study both electric and HEV powertrains --Abstract, page iv

    Design, Modelling and Verification of Distributed Electric Drivetrain

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    The electric drivetrain in a battery electric vehicle (BEVs) consists of an electric machine, an inverter, and a transmission. The drivetrain topology of available BEVs, e.g., Nissan Leaf, is centralized with a single electric drivetrain used to propel the vehicle. However, the drivetrain components can be integrated mechanically, resulting in a more compact solution. Furthermore, multiple drivetrain units can propel the vehicle resulting in a distributed drive architecture, e.g., Tesla Model S. Such drivetrains provide an additional degree of control and topology optimization leading to cheaper and more efficient solutions. To reduce the cost, the drivetrain unit in a distributed drivetrain can be standardized. However, to standardize the drivetrain, the drivetrain needs to be dimensioned such that the performance of a range of different vehicles can be satisfied. This work investigates a method for dimensioning the torque and power of an electric drivetrain that could be standardized across different passenger and light-duty vehicles. A system modeling approach is used to verify the proposed method using drive cycle simulations. The laboratory verification of such drivetrain components using a conventional dyno test bench can be expensive. Therefore, alternative methods such as power-hardware-in-the-loop (PHIL) and mechanical-hardware-in-the-loop (MHIL) are investigated. The PHIL test method for verifying inverters can be inexpensive as it eliminates the need for rotating electric machines. In this method, the inverter is tested using a machine emulator consisting of a voltage source converter and a coupling network, e.g., inductors and transformer. The emulator is controlled so that currents and voltages at the terminals resemble a machine connected to a mechanical load. In this work, a 60-kW machine emulator is designed and experimentally verified. In the MHIL method, the real-time simulation of the system is combined with a dyno test bench. One drivetrain is implemented in the dyno test bench, while the remaining are simulated using a real-time simulator to utilize this method for distributed drivetrain systems. Including the remaining drivetrains in the real-time simulation eliminates the need for a full-scale dyno test bench, providing a less expensive method for laboratory verification. An MHIL test bench for verification of distributed drivetrain control and components is also designed and experimentally verified

    Model-in-the-loop development for fuel cell vehicle

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    In this paper, the work on developing and validating a model-in-the-loop (MIL) simulation environment for a group of prototype fuel cell vehicles is presented. The MIL model consists of a vehicle plant model and an integrated vehicle system controller model. First, the vehicle simulation plant model is functionally validated with a simple vehicle system controller (VSC) model and then improved to satisfy the input output interface and fidelity requirements. The developed MIL system is then verified for basic functionality against the simple VSC controller model and shows uniform correlation results. It is further validated against vehicle dynamometer test data and demonstrates satisfactory consistency. A rapid model building approach which is suitable for model-based controller design process was also discussed. This approach enabled the developers to use model-to-code algorithms unlike many comparable simulation models. © 2011 AACC American Automatic Control Council

    Real time full circuit driving simulation system

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    Thesis (MScEng)--Stellenbosch Universit, 2004.ENGLISH ABSTRACT: The requirements regarding the quality of engines and vehicles have increased constantly, requiring more and more sophisticated engine testing. At the same time, there is a strong demand to reduce lead time and cost of development. For many years steady state engine testing was the norm using standard principles of power absorption. Since the mid 1980's increasing importance has been attached to the optimisation of transient engine characteristics and the simulation of dynamic real world driving situations on engine test stands. This has led to the use of bi-directional DC or AC regenerative dynamometers a practice now known as dynamic engine testing. Interfacing a computer with vehicle simulation software to an engine on a dynamic test stand and using "hardware in the loop" techniques, enables the simulation of real world driving situations in a test facility. In dynamic engine testing a distinction can be made between simulation testing and transient testing. In simulation testing the set point values are predetermined whereas in transient testing a model generates set point values in real time. Speeds and loads are calculated in real time on the basis of real time measurements. The model can be in the form of a human or driver simulation. This project involved the application of dynamic engine testing to simulating a racing application. It is termed Real Time Full Circuit Driving Simulation System due to the simulation of a race car circling a race track, controlled by a driver model and running the engine on a dynamic test bench in real time using "hardware in the loop" techniques. By measuring the simulated lap times for a certain engine configuration on the test bench in real time, it is possible to select the optimal engine set-up for every circuit. The real time nature of the simulation subjects the engine on the test bench to similar load and speed conditions as experienced by its racing counterpart in the race car yielding relevant results. The racing simulation was achieved by finding a suitable dynamic vehicle model and a three dimensional race track model, developing a control strategy, programming the software and testing the complete system on a dynamic test stand. In order to verify the simulation results it was necessary to conduct actual track testing on a representative vehicle. A professional racing driver completed three flying laps of the Killarney racing circuit in a vehicle fitted with various sensors including three axis orientation and acceleration sensors, a GPS and an engine control unit emulator for capturing engine data. This included lap time, vehicle accelerations, engine speed and manifold pressure, an indicator of driver input. The results obtained from the real time circuit simulation were compared to actual track data and the results showed good correlation. By changing the physical engine configuration in the hardware and gear ratios in the software, comparative capabilities of the system were evaluated. Again satisfactory results were obtained with the system clearly showing which configuration was best suited for a certain race track. This satisfies the modem trend of minimizing costs and development time and proved the value of the system as a suitable engineering tool for racing engine and drive train optimisation. The Real Time Full Circuit Driving Simulation System opened the door to further development in other areas of simulation. One such area is the driveability of a vehicle. By expanding the model it would be possible to evaluate previously subjective characteristics of a vehicle in a more objective manner.AFRIKAANSE OPSOMMING: Die vereistes om die kwaliteit van enjins en voertuie te verhoog, word daagliks hoër. Meer gesofistikeerde enjintoetse word daarom vereis. Terselfdertyd is dit 'n groot uitdaging om die tydsduur en koste van ontwikkeling so laag as moontlik te hou. Gestadigde toestand enjintoetse, wat op die prinsiep van krag absorpsie werk, was vir baie jare die norm. Vanaf die middel tagtigerjare het die optimering van dinamiese enjinkarakteristieke en die simulasie van werklike bestuursituasies op enjintoetsbanke van al hoe groter belang geword. Die gevolg was die gebruik van twee rigting wisselof gelykstroomdinamometers en staan vandag bekend as dinamiese enjintoetsing. Deur 'n rekenaar met simulasiesagteware aan 'n enjin op 'n dinamiese toetsbank te koppel, word die moontlikheid geskep om enige werklike bestuursituasies van 'n voertuig te simuleer in die enjintoetsfasiliteit. Dinamiese enjintoetse kan opgedeel word in simulasietoetse en oorgangstoestandtoetse. By laasgenoemde genereer 'n "bestuurdersmodel" die beheerwaardes intyds deur te kyk na intydse metings terwyl by simulasietoetse die beheerwaardes vooraf bepaal word. Die "bestuurder" kan in die vorm van 'n persoon of rekenaarsimulasie wees. Die projek behels die toepassing van dinamiese enjintoetse vir renbaansimulasie en staan bekend as'n Intydse, Volledige Renbaansisteem weens die simulasie van 'n renmotor om 'n renbaan, onder die beheer van 'n bestuurdersmodel. Dit geskied terwyl die enjin intyds op 'n dinamiese enjintoetsbank loop en gekoppel is aan die simulasie. Deur die intydse, gesimuleerde rondtetye te analiseer, word die moontlikheid geskep om die enjinkonfigurasie te optimeer vir 'n sekere renbaan. Dit is bereik deur die keuse van 'n gepaste dinamiese voertuigmodel, 'n driedimensionele renbaanmodel, ontwikkeling van 'n beheermodel, programmering van die sagteware en integrasie van die dinamiese enjintoetsstelsel. Die simulasieresultate verkry is gestaaf deur werklike renbaantoetse. 'n Professionele renjaer het drie rondtes van die Killarney renbaan voltooi in 'n verteenwoordigende voertuig wat toegerus was met verskeie sensors o.a. drie as versnellings- en orientasiesensors, GPS en 'n enjinbeheereenheidemmuleerder vir die verkryging en stoor van enjindata. Die sensors het data versamel wat insluit rondtetyd, voertuigversnellings, enjinspoed en inlaatspruitstukdruk. Die korrelasie tussen die simulasie waardes en werklik gemete data was van hoë gehalte. Deur die fisiese enjinkonfigurasie te verander in die hardeware en ratverhoudings in die sagteware, is die vergelykbare kapasiteite van die renbaansimulasie geevalueer. Die resultate was weer bevredigend en die simulasie was in staat om die beste enjinkonfigurasie vir die renbaan uit te wys. Dit bevredig die moderne neiging om koste en ontwikkelingstyd so laag as moontlik te hou. Sodoende is bewys dat die stelsel waarde in die ingenieurswêreld het. 'n Intydse, Volledige Renbaansisteem die skep die geleentheid vir verdere ontwikkeling op verskeie terreine van simulasie. Een so 'n veld is die bestuurbaarheid van 'n voertuig. Deur die model verder te ontwikkel word die moontlikheid geskep om voorheen subjektiewe karakteristieke van 'n voertuig meer wetenskaplik te analiseer

    Energy Management System For Three-Wheel Light Electric Vehicle Using Multi-Sources Energy Models

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    Hybrid electric vehicles, plug-in hybrid electric vehicles, battery electric vehicles, fuel-cell vehicles are just a few technologies that are being researched worldwide today. Applying renewable energy such as battery, fuel cell and super-capacitor in the electric vehicle is a smart and ideal solution. However, battery as a single-source in electric vehicle has many disadvantages such as limited travel distance and longer charging time. Besides, battery reduces its electrical characteristics through high current flow, high temperature, self-discharge and low battery capacity level. Fuel cell has low power response during sudden energy demand and requires an expensive infrastructure for refueling. In case of light fuel cell vehicle, small tank is practical for exchange tank. In super-capacitor side, it cannot support enough energy for a single powered electric vehicle purposes, however can be used as secondary power supply. Thus, an intelligent energy management system (EMS) of various sources is necessary to counterbalance the drawback of the sources. To solve the problem, the objective of the research is to develop an intelligent EMS which can conduct multi-sources for three wheel light electric vehicle (LEV). A rule-based control algorithm which contains eight states in EMS is designed to control power switches and to ensure sufficient energy is delivered to the load. The work of this research begins by electrical analysis in PSPICE simulation which focuses in circuit design and testing the state condition. A close loop vehicle system implemented with intelligent EMS is designed in MATLAB/Simulink. The simulation model is simulated with a real three wheel scooter specification which has capacity of 5.4 kW DC machine. To show effectiveness of the developed vehicle system, the performance and efficiency of the vehicle simulation is compared with standard drive cycle such as ECE-47 and ECE-15. To justify the simulation model, a scaled-down lab test bench model is designed using dSPACE DS 1104. The LEV model with 18 W load power is implemented in the developed test bench prototype. As a result, the vehicle system specification for the lab test bench model is reduced accordingly to the ratio of load power. The power specifications of the multi-source models such as 30 W for fuel cell, 3 Ah for rechargeable sealed lead acid battery and 100F for super-capacitors have been used. An EMS hardware is designed to offer a bridge between MATLAB/Simulink and dSPACE DS 1104. In the EMS hardware design, the switching relay is used for selection of the sources and current transducers which are used for measuring load current and battery capacity. All input and output signals from the EMS hardware design are connected to the dSPACE DS 1104 for data presentation in graphical user interface. For the uphill simulation test, using ECE-47 drive cycle, multi-source energy models shows that the power effectiveness is 94.6% where as for the battery, as a single-source, it is 84.9%. The lab test bench model also proved that in extension of 33% of speed ECE-47 drive cycle, the energy efficiency of multi-source LEV is 80.2% which is better performance than that of combustion engine energy efficiency of 29.2%. Therefore, the system equipped with an intelligent control algorithm has promising potential in vehicle energy management applications for the future

    A hardware-anywhere-in-the-loop simulator for dynamic real-time analysis of electric propulsion systems

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    This work introduces a low-level real-time vehicle simulator with hardware-anywhere-in-the-loop (HAIL) capability. Vehicle dynamics are simulated on a high-performance workstation running a real-time operating system. The vehicle’s battery pack is both modeled in simulation and interfaced externally, providing the option of establishing a baseline performance in the simulation, and then evaluating candidate battery packs against these results. This simulation test bed is applied to an electric vehicle and an unmanned underwater vehicle, two vehicle types that present very different loads to the batteries. The HAIL platform is validated against the verified simulated performance of both vehicle models, achieving an error of less than 2% across 25 trials. This paves the way for expansion to include an electric drive and dynamometer, as well as peripheral power electronics systems

    Development of an Optimal Controller and Validation Test Stand for Fuel Efficient Engine Operation

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    There are numerous motivations for improvements in automotive fuel efficiency. As concerns over the environment grow at a rate unmatched by hybrid and electric automotive technologies, the need for reductions in fuel consumed by current road vehicles has never been more present. Studies have shown that a major cause of poor fuel consumption in automobiles is improper driving behavior, which cannot be mitigated by purely technological means. The emergence of autonomous driving technologies has provided an opportunity to alleviate this inefficiency by removing the necessity of a driver. Before autonomous technology can be relied upon to reduce gasoline consumption on a large scale, robust programming strategies must be designed and tested. The goal of this thesis work was to design and deploy an autonomous control algorithm to navigate a four cylinder, gasoline combustion engine through a series of changing load profiles in a manner that prioritizes fuel efficiency. The experimental setup is analogous to a passenger vehicle driving over hilly terrain at highway speeds. The proposed approach accomplishes this using a model-predictive, real-time optimization algorithm that was calibrated to the engine. Performance of the optimal control algorithm was tested on the engine against contemporary cruise control. Results indicate that the “efficient” strategy achieved one to two percent reductions in total fuel consumed for all load profiles tested. The consumption data gathered also suggests that further improvements could be realized on a different subject engine and using extended models and a slightly modified optimal control approach

    Model Based Automotive System Integration: Fuel Cell Vehicle Hardware-In-The-Loop

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    abstract: Over the past decade, proton exchange membrane fuel cells have gained much momentum due to their environmental advantages and commutability over internal combustion engines. To carefully study the dynamic behavior of the fuel cells, a dynamic test stand to validate their performance is necessary. Much attention has been given to HiL (Hardware-in-loop) testing of the fuel cells, where the simulated FC model is replaced by a real hardware. This thesis presents an economical approach for closed loop HiL testing of PEM fuel cell. After evaluating the performance of the standalone fuel cell system, a fuel cell hybrid electric vehicle model was developed by incorporating a battery system. The FCHEV was tested with two different control strategies, viz. load following and thermostatic. The study was done to determine the dynamic behavior of the FC when exposed to real-world drive cycles. Different parameters associated with the efficiency of the fuel cell were monitored. An electronic DC load was used to draw current from the FC. The DC load was controlled in real time with a NI PXIe-1071 controller chassis incorporated with NI PXI-6722 and NI PXIe-6341 controllers. The closed loop feedback was obtained with the temperatures from two surface mount thermocouples on the FC. The temperature of these thermocouples follows the curve of the FC core temperature, which is measured with a thermocouple located inside the fuel cell system. This indicates successful implementation of the closed loop feedback. The results show that the FC was able to satisfy the required power when continuous shifting load was present, but there was a discrepancy between the power requirements at times of peak acceleration and also at constant loads when ran for a longer time. It has also been found that further research is required to fully understand the transient behavior of the fuel cell temperature distribution in relation to their use in automotive industry. In the experimental runs involving the FCHEV model with different control strategies, it was noticed that the fuel cell response to transient loads improved and the hydrogen consumption of the fuel cell drastically decreased.Dissertation/ThesisMasters Thesis Engineering 201

    Towards a Common Software/Hardware Methodology for Future Advanced Driver Assistance Systems

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    The European research project DESERVE (DEvelopment platform for Safe and Efficient dRiVE, 2012-2015) had the aim of designing and developing a platform tool to cope with the continuously increasing complexity and the simultaneous need to reduce cost for future embedded Advanced Driver Assistance Systems (ADAS). For this purpose, the DESERVE platform profits from cross-domain software reuse, standardization of automotive software component interfaces, and easy but safety-compliant integration of heterogeneous modules. This enables the development of a new generation of ADAS applications, which challengingly combine different functions, sensors, actuators, hardware platforms, and Human Machine Interfaces (HMI). This book presents the different results of the DESERVE project concerning the ADAS development platform, test case functions, and validation and evaluation of different approaches. The reader is invited to substantiate the content of this book with the deliverables published during the DESERVE project. Technical topics discussed in this book include:Modern ADAS development platforms;Design space exploration;Driving modelling;Video-based and Radar-based ADAS functions;HMI for ADAS;Vehicle-hardware-in-the-loop validation system
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