Development of Advanced Automated Mapping and Calibration Techniques
Inclusive Dates: 07/01/04 Current
Background - The objective of this project is to develop, implement, and demonstrate an advanced, transient engine calibration technique on a modern, port-injected, spark-ignited gasoline engine. The technique is to be automatic in nature, such that great time and cost savings may be realized when calibrating the engine. The typical automotive spark-ignited engine has only two main actuators: ignition timing and Exhaust Gas Recirculation (EGR) rate. In a move to promote better fuel economy and better performance, additional actuators like cam phasers that control the relative position of the camshaft in relation to the crankshaft are being used. Initially only one phaser on the intake camshaft was utilized, but more engine manufacturers are moving toward dual camshaft phasers with phasers on the intake and exhaust camshaft. A full factorial calibration with four actuators may take 10 to 20 times as long. Therein lies the need for an automated mapping routine to run the engine, log engine performance parameters, make intelligent decisions, and pick the best operating point in a minimum amount of time.
Approach - A major automotive manufacturer has supplied a V6 engine for use on this project. The engine represents one of the most advanced engines available in the marketplace today. It has distributor-less ignition, EGR, and dual independent camshaft phasers. This represents one of the most difficult platforms currently available to achieve optimum mapping and calibration. An SwRI Rapid Prototyping Electronic Control System (RPECS®) will be used to read and record test cell information, control engine parameters, transition the engine from one operating point to the next, and make decisions on which transition is next. Initially, offline models will be used to select the operation condition that best trades off emissions, fuel economy, and performance. As the work progresses, the models will be transitioned to run real-time to further reduce the operating time necessary for calibration.
Accomplishments - The RPECS has been built, and software is being written that will control the engine and log data. The models to select the optimum operating condition have been written. The engine is scheduled to be received shortly and will be installed in a light-duty motoring test cell. Engine installation is expected to begin as soon as the engine is received, and baseline data will be recorded within four weeks of installation.