Development of Synthetic Drive Cycle for Fuel Economy Prediction Nissan Ashok Leyland Technologies Limited

Format:

Conference/Event

Author/Creator:

A N Prasad, A N Prasad, author.

Contributor:

D, Balakrishnan

Manickam, Murali

Saravanan, N.

Conference Name:

SAE 2012 Commercial Vehicle Engineering Congress (2012-10-02 : Rosemont, Illinois, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

With growing fuel prices and global warming, fuel economyimprovement and reduced emissions are becoming order of the day.Automobile manufacturers around the world are in increasingpressure to achieve the same, also keeping in account the stifftimelines required in the product developmental cycle. Condensedduty cycle that is representative of several days of actual reallife running is developed for quicker fuel economy tuning on achassis dynamometer. This paper presents a new methodology toobtain a synthetic drive duty cycle, which matches engine operatingconditions of the actual real life cycle accurately and therebyproviding a more accurate match in fuel economy.Drive duty cycle (vehicle velocity profile) used in this studyis extracted from the instrumented vehicle in the real trafficcondition (peak/lean hour) of major cities in India at differentlocation/load conditions. Each recorded trip is further dividedinto micro trips. Several principal components such as averagevelocity, percentage of times in acceleration, deceleration, cruise& idle, shift pattern closeness, (which is a measure of numberof shifts from one of the above-mentioned state to the other),etc., of the entire trip and individual micro trips are evaluated.The synthetic drive duty cycle is derived by minimizing theobjective function, which is created from a selected set of theprincipal components. An optimization algorithm that reduces theobjective function coded in MATLAB is used to create the syntheticduty cycle by suitably clubbing the micro trips such that there areno repetitions. The synthetic cycle and the full trip data are bothanalyzed for fuel economy in AVL-CRUISE software. From theAVL-CRUISE simulation results, fuel economy and engine operatingpoints of condensed and real-world cycle are compared. Principalcomponents that yield the closest match not only in fuel economybut also on engine operating points repeatedly are identified andpresented.With the identified objective function from a optimal set ofprincipal components, the engine operating point plots and hencethe fuel economy values matches very well with that of the entiretrip to within ±3% and the total development time is reduced toless than 1/6th of the time consumed otherwise. This methodologyprovides repeatable and reproducible results consistently. Someof the factors affecting the data obtained from different cyclesare discussed and possible methodologies to develop syntheticcycles across different vehicle categories/platforms aresuggested

Notes:

Vendor supplied data

Publisher Number:

2012-01-2048

Access Restriction:

Restricted for use by site license