Development and Validation of Engine Models Via Automated Dynamometer Tests

An automated engine dynamometer test procedure is developed and mathematical models for the main engine control variables are derived from the resulting data base. The new procedure involves sequential testing at many speed/load conditions for various combinations of air fuel ratio, spark timing and exhaust gas recirculation. The total testing time required for generating the data base of more than 2000 test points is less than twelve hours.

An independent transient speed/load test is also conducted for the purpose of validating the engine models. The measured and model predicted data are compared for this test which corresponds to a segment of the EPA urban schedule.