MATEC Web of Conferences 184, 01020 (2018) https://doi.org/10.1051/matecconf/201818401020 Annual Session of Scientific Papers IMT ORADEA 2018

Comparative analysis of automatic and behaviour on the worldwide harmonized light duty test cycle

Norbert Bagameri1, Bogdan Varga1, Aron Csato1 and Dan Moldovanu1,*

1Technical University of Cluj-Napoca, Automotive and Transport Department, 400641 Cluj-Napoca, Romania

Abstract. The European Commission has been actively involved in the development of the World-wide harmonized Light duty Test Cycle (WLTC). The aim of that project was to develop a harmonized light duty test cycle, that represents the average driving characteristics around the world and to have a legislative world-wide-

harmonized procedure put in place from 2017 and onwards for determining the level of CO2 emissions. This work presents the results of the effect of automatic and manual transmissions as a of a light duty

vehicle on WLTC driving cycle. AVL Cruise software was used as simulation platform to analyse the CO2 level and fuel consumption of dynamic vehicle model using different type of . At first the simulation tool and the most influential parameters of the driving cycle procedure are described. In the second phase various components and modules for both dynamic models using automatic and manual transmission, as well as the respective input parameters, were defined. Analyses are based on a developed dynamic vehicle model in AVL Cruise. Finally, the simulation results were evaluated and presented for the two dynamic models according to a legislative driving cycle to provide the basis fuel consumption and exhaust gas emissions.

1 Introduction Recently research and development trends in the 2 Driving cycle procedure automotive industry have been focused on developing The European Union has developed a new test, called the vehicles with drivetrains that are strongly driven by Worldwide Harmonised Light Vehicle Test Cycle steadily increasing demands on improvements in fuel (WLTC). The WLTC has been developed with driving consumption, emissions and performance. The profile obtained from in use driving data and a test transportation sector is currently responsible for over 20% procedure more realistic in terms of vehicle mass and of emission of greenhouse pollutants, emissions that resistance to progress. The New European Driving cycle directly affect the climatic conditions of the planet. (NEDC) significantly differs from WLTC characterized Increased emissions in conjunction with achieving the  by a shorter duration and distance, longer idling and maximum degree of natural regeneration of the cruising time and lower speed and acceleration. Although environment lead to serious problems related to pollution WLTC driving cycle profile is more transient than NEDC, [1, 2]. Since the early phase of the automotive when these two cycles are tested under the same driving development, the interaction between the environment resistance. In WLTC are taking into account its minimum and the traffic has been represented by an ever-increasing and maximum unladen mass, which is defined as the number of legal standards related to reducing the exhaust vehicle’s standard weight without driver, fluid or any gas pollutants, hazardous substances and waste. The additional equipment, the maximum permissible weight, increasingly high traffic density, high demand of mobility the difference in rolling resistance between different and transportation adversely have a significant impact on versions, as well as the difference in aerodynamic the environment, causing the large societal problems such resistance expressed as the product of the drag coefficient as a rapid depleting petroleum resources, an increasing air and the frontal area between vehicle model with the best pollution and global warming [3]. and worst aerodynamics. Because pollutant emissions The European Union automobile industry welcomes the from vehicles are caused by combustion of a fuel shift to WLTC and has actively contributed to the  generally fossil fuels, increasing the efficiency and development of this new test cycle. effectiveness of vehicles drivetrain is constantly the focus

* Corresponding author: [email protected]

© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/). MATEC Web of Conferences 184, 01020 (2018) https://doi.org/10.1051/matecconf/201818401020 Annual Session of Scientific Papers IMT ORADEA 2018

of attention of researchers fro the autootive industry ransission ontroller of ual lutch ransission he oective of was to rovide a ore roust consists of shift state controller, which reselects the testasis and a rocedure which is ore reresentative of according to the current and desired vehicle seed, which actual onroad vehicle oeration significantly can e characteried y gearshift schedule differs fro , its ain differences affecting fuel consution include the test cycle and gearshifting seuence, vehicle ass definition, road load deterination, chassis dynaoeter reconditioning ,

 3 Simulation software package odelling various natural or artificial rocesses and henoena in engineering is achieved y alying and erforance of cole atheatical odels sing the ruise software siulations can e develoed, controlled and coordinated at the sae tie to achieve results and solutions to otiie and irove the

performance of vehicle’s technical system and are Fig. 2. AVL Cruise component model of the vehicle. analysed in ters of erforance and oerating efficiency n order to uantify and analyse the effect of This simulation model was developed based on an the drivetrain in the eissions and fuel consution on existing vehicle using technical data provided by the driving cycle siulations were erfored on two manufacturer to simulate and to put in evidence the different transissions Fig. 1 represents the WLTC advantages and disadvantages of the drivetrain powered a driving cycle. front drive vehicle equipped with manual transmission and with automatic dual transmission. After every component of the vehicle model is set up the model is tested on the WLTC driving cycle. The basic parameters of the vehicle model are given in Table 1. Table 1. DCT Vehicle model parameters

Parameters Value ehicle ass g ngine dislaceent c Fig. 1. WLTC driving cycle. ngine aiu ower ngine aiu seed r 4 Model description ngine nertia g inal drive ratio In the following paragraph provide a description of the lutch inertia g drivetrains used for vehicles: with manual transmission lutch inertia g and automatic transmission. The vehicle model includes rontal area the various sub-models. The vehicle model is a structure rag coefficient that has been developed to simulate accurately the two types of drivetrains. They are not different in the Final drive is a gear step with fixed ratio. It can be used as arrangement of components of the drivetrain. The a transmission step of the differential also called final developed model consists of components that exist in drive unit. A drive will be transferred to a power vehicles, such as the internal combustion engine, take of torque of the transmission step by considering the transmission, control and program of the transmission, transmission, the mass moments of inertia, and the brake system, system, and the respective moment of loss [4, 5]. The gear ratios of the transmissions connections among them which can be either mechanical are given in the Table 2. or electrical. Each component is described by several parameters and is configurable in such a way that it can Table 2. ear ratio represent a vehicle for this study. The main components of the simulation model with reference to Fig. 2, are the Gear Gear ratio internal combustion engine and the attached mechanical consumer, manual/automatic transmission together with st the controller that controls the operation of the gearbox nd rd such as the gearshift schedule, the differential together th with the final drive, the brakes, the cockpit, the vehicle th body, the electrical system which includes the battery and th other modules essential for initiating the simulation. he

2 MATEC Web of Conferences 184, 01020 (2018) https://doi.org/10.1051/matecconf/201818401020 Annual Session of Scientific Papers IMT ORADEA 2018

The driver should imitate the behaviour of a real driver as operates freent ear chanes more operations over well as possible. Everything that would normally be the cycle than the manal transmission controlled by a real driver, such as turning the steering wheel, stepping on the gas, brake and clutch pedal, shifting on the manual transmission is controlled by the virtual driver. s the driver controls the cltch pedal it is necessary to epress the cltch position as a fnction of time drin cltch enaement phase

5 Drivetrain of the vehicle o different transmission types ere evalated one of the is the conventional manal transmission hich has a limited nmer of ears maimm p to si and the atomatic transmission sin to cltches one for the odd ears and one for the even ears n case of the manal transmission the entire synchroniation process can e Fig. 4. ariation of the fel consmption drin drivin cycle divided in nine staes tae free travel from netral position hich has no tore transfer his stae can also start from a disenaement from a previos ear called In the simulation carried out with AVL Cruise WLTC here as start of disenaement tae einnin of the regulation fixed points, the total CO emissions were contact amon strt and synchroniation rin initiatin found higher by 6 % higher for the case using automatic the indein process or preselectin tae indein dual clutch transmission than using the manual process conclded tae contact of synchroniation transmission vehicle when compared to the WLTC CO rin ith the sleeve cone initiatin the synchroniation emissions curve. phase tae end of synchroniation rin locin and einnin of rin and ear trn de to cone friction tae second free travel tae tip contact of the sleeve aainst the ear cltch asher n this stae is possile to detect the dole mp phenomena tae end of ear anlar movement tae fll enaement n the folloin in i the shiftin schedle is presented for the pshift and donshift process

Fig. 5. ariaton of emissions over the drivin cycle Fig. 3. hiftin stratey for pshift and donshift

n the i it can e seen that the maimm vale of the 6 Simulation and results emissions is and it is achieved sin the manal transmission de to the hiher load of the internal imlation ere performed to investiate the vehicle fel comstion enine and different ear shift stratey of the consmption and emission over time ased drivin cycle transmission he simlation is a method sed to verify a model hich represents the ehavior of a physical system he maimm distance is meters and averae speed of mh maimm acceleration ms and total time is seconds he fel economy for dal cltch transmission is loer ith than the manal transmission over the drivin cycle de to the elimination of tore interrption that is associated ith manal transmission he earo proram is the same for the manal and dal cltch transmission and the ear shiftin time is ms for manal transmission and ms for dal cltch transmission e to the different orin conditions of the earoes the atomatic transmission

3 MATEC Web of Conferences 184, 01020 (2018) https://doi.org/10.1051/matecconf/201818401020 Annual Session of Scientific Papers IMT ORADEA 2018

Fig. 6. ariaton of emissions over the drivin Fig. 8. ariaton of enine poer necessary for proplsion cycle the vehicel

t is seen in the fire that especially there is a sinificant 7 Conclusion increase in the emission in the hih speed area of the drivin cycle de to the hiher temperatre into the imlation softare can sinificantly redce the time comstion chamer and hiher speed of the internal reired for developin ne technoloies and control comstion enine sin a loer ear ratio strateies in the atomotive field he overall system enineerin model is sed to compare the to drivetrains topoloies poered y the same enines drin drivin cycle his investiation focses on evalation of the fel consmption emissions of the considered vehicle confiration inally simlation reslts demonstrates the differences of sin to type of drivetrains for the vehicle and the importance of considerin also the atomatic dal cltch transmission in order to achieve loer fel consmption and emissions

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