- Driving cycle
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This article is part of the
Driving cycles series.Europe NEDC ECE 15 United States FTP 72 FTP 75 SFTP US06 SFTP SC03 Japan 10-15 Mode A driving cycle is a series of data points representing the speed of a vehicle versus time.
Driving cycles are produced by different countries and organizations to assess the performance of vehicles in various ways, as for example fuel consumption and polluting emissions.[1][2][3]
Fuel consumption and emission tests are performed on chassis dynamometers. Tailpipe emissions are collected and measured to indicate the performance of the vehicle.
Another use for driving cycles is in vehicle simulations. More specifically, they are used in propulsion system simulations (simulators designed specifically to model the drive system only and predict performance of internal combustion engines, transmissions, electric drive systems, batteries, fuel cell systems, etc.) An example of this type of vehicle simulator would be ADVISOR produced by AVL Engineering.
Some driving cycles are derived theoretically, as it is preferred in the European Union, whereas others are direct measurements of a driving pattern deemed representative.
There are two types of driving cycle: Transient driving cycles involve many changes, representing the constant speed changes typical of on-road driving. Modal driving cycles involve protracted periods at constant speeds. The American FTP-75,[4] and the unofficial European Hyzem driving cycles are transient, whereas the official European NEDC and the Japanese 10-15 Mode cycles are modal cycles.
The most common driving cycles are probably the European NEDC and the American FTP-75.
Driving cycle design is the core technology for these standard cycles. Optimization and Markov Chain are employed to design a driving cycle.
Driving cycle recognition is applying to Hybrid Electric Vehicle.
Contents
Data Collection
Data collection from the test road is the most important activity. Test road (e.g. city, highway, etc.) measured data are the inputs to the 'Drive Cycle' preparation activity.
The procedure involves instrumentation of the test vehicle to collect information while driving on the test road. There are two major types of data to be collected, Driver behavior and vehicle vs Road data. The vehicle vs road data are used to prepare the road drive cycle and the driver data to prepare the Driver model. for example, to calculate a vehicle's fuel consumption either in computer simulation or in chassis dynamo-meter which is going to be launched in India, it must run on an Indian road with an Indian Driver. Indian Drive Cycle with an European driver model does not give a fair comparison of the on road trials.
Driving Cycle Design
The "Drive-cycle" basically is the representative of the road. The need of a drive cycle is to reduce the expensive on road tests, time of test and fatigue of the test engineer. The whole idea is to bring the road to the test lab (a chassis dynamo-meter) or to the computer simulation.
Two kinds of drive cycle can be made. One is DISTANCE DEPENDENT (SPEED vs DISTANCE vs ALTITUDE) and the other one is TIME DEPENDENT (SPEED VS TIME VS GEAR SHIFT). The DISTANCE DEPENDENT is the actual replica of the test road. where as TIME DEPENDENT is the compressed version of the actual time taken to conduct the test on road. Examples of TIME DEPENDENT drive cycles are European NEDC cycle, FTP-75. TIME DEPENDENT drive cycles are used specifically for chassis dynamo meter testing because in a short time the results can be availed and repeated tests can be done easily.
Driving Cycle Recognition
Based on the type of application drive cycles are made. Drive cycle for passenger cars are different form commercial vehicle.
Driving Cycle Prediction
Reference
- ^ K. Brundell-Freij and E. Ericsson, Influence of street characteristics, driver category and car performance on urban driving patterns, Transportation Research D 10 (2005). [1]
- ^ E. Ericsson)[2], Variability in urban driving patterns, Transportation Research D 5 (2000)
- ^ E. Ericsson, Independent driving pattern factors and their influence on fuel-use and exhaust emission factors, Transportation Research D 6 (2001)[3]
- ^ FTP Driving Cycle, data:[4] picture:[5]
External links
- US EPA Dynamometer Driver's Aid - Examples of driving cycles and downloadable data sets
- Wheels: road load energy demand calculator - Online tool to calculate vehicle road load over a driving cycle
- What is an Indian driving cycle - The Hindu Article
- DieselNet - Introduction to various standard driving cycles
Categories:- Automotive technologies
- Hybrid vehicles
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