Driving cycle
Encyclopedia
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.
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 measurement
s 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
, 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.
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.
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.
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....
versus time.
Driving cycles are produced by different countries
Country
A country is a region legally identified as a distinct entity in political geography. A country may be an independent sovereign state or one that is occupied by another state, as a non-sovereign or formerly sovereign political division, or a geographic region associated with a previously...
and organizations to assess the performance of vehicles in various ways, as for example fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...
consumption and polluting
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
emissions.
Fuel consumption and emission
Exhaust gas
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline/petrol, diesel fuel, fuel oil or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack or propelling nozzle.It often disperses...
tests are performed on chassis dynamometers
Dynamometer
A dynamometer or "dyno" for short, is a device for measuring force, moment of force , or power. For example, the power produced by an engine, motor or other rotating prime mover can be calculated by simultaneously measuring torque and rotational speed .A dynamometer can also be used to determine...
. 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
Advisor
An advisor is normally a person with more and deeper knowledge in a specific area i.e. a specialist and may refer to:-Finances:*Commodity trading advisor, any person who engages in the business of advising others...
produced by AVL Engineering
AVL (Engineering Firm)
AVL, or Anstalt für Verbrennungskraftmaschinen List, is an Austrian-based automotive consulting firm as well as an independent research institute...
.
Some driving cycles are derived theoretically
Theory
The English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...
, as it is preferred in the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
, whereas others are direct measurement
Measurement
Measurement is the process or the result of determining the ratio of a physical quantity, such as a length, time, temperature etc., to a unit of measurement, such as the metre, second or degree Celsius...
s 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
FTP-75
On October 22, 1996, the final rule on Motor Vehicle Emissions Federal Test Procedure Revisions was published in the United States Federal Register. This rule revises the tailpipe emissions portion of the Federal Test Procedure for Light-duty vehicles and light-duty trucks .FTP is shown in...
, and the unofficial European Hyzem driving cycles are transient, whereas the official European NEDC
New European Driving Cycle
The New European Driving Cycle is a driving cycle consisting of four repeated ECE-15 driving cycles and an Extra-Urban driving cycle . The NEDC is supposed to represent the typical usage of a car in Europe, and is used, among other things, to assess the emission levels of car engines...
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
Drive cycle recognition
Drive Cycle Recognition is an advanced vehicle control strategy that uses past driving information, as well as a library of representative drive cycles to extrapolate future vehicle control parameters...
is applying to Hybrid Electric Vehicle.
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.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