Improving Speed and Accuracy of Gasoline and Diesel Engine Testing via Closed-Loop Combustion Control Mahle Powertrain Limited

Format:

Conference/Event

Author/Creator:

Cains, Cains, author.

Contributor:

Pates, David

Warth, Marco

Conference Name:

SAE 2012 World Congress & Exhibition (2012-04-24 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

To improve the speed and accuracy of engine testing, the spark(gasoline)/injection (diesel) timing can be optimized based on thelocation of the 50% mass fraction burn point (α50) rather than thetraditional approach of "sweeping" timing to find themost efficient point. Results from both gasoline and diesel enginesshow that setting α50 to around 8° ATDC gives optimum efficiencyfor most circumstances. An exception is the case of highly unstablecombustion, where the misfire rate may also be strongly dependenton timing. For diesel engines this method is effective in findingthe timing for best efficiency but in practice the chosen injectiontiming may be driven more by the need to optimize emissions.This technique has been implemented by incorporating a burnangle controller into the MAHLE Flexible ECU (MFE), a powerful andhighly adaptable engine controller. The MFE includes the burn anglecalculation (based on cylinder pressure signals) as well as themain control strategy in a single robust unit, allowing forstraightforward test bed or vehicle operation of gasoline anddiesel engines. The burn angle controller also takes account ofknock and cylinder pressure limitations.A high octane fuel demonstrator car was developed using the MFEfor the remapping of spark and other parameters. Optimum sparktiming was found by the burn angle controller while operating theengine at different loads and speeds on a chassis dynamometer,without needing to remove the engine from the vehicle. The remappedengine delivered 15-20% more torque at low to medium speeds thanthe baseline engine (at the same boost pressure), while reducingfuel requirement due to lower exhaust temperatures. This could befelt as much stronger vehicle performance and improved flexibilityin high gears

Notes:

Vendor supplied data

Publisher Number:

2012-01-0902

Access Restriction:

Restricted for use by site license