Tuning Principles of Control and Protection Strategies for a S.I. Engine

Engine effective torque is not only a preformance parameter but also a control parameter. Calibration of the developed torque of a s.i. engine requires a strategy and cartograms assemblies that allow the computer software to estimate the value of this injection parameter. Estimation is done by interpreting several engine operating parameters: the spark advance, enrichment, intake air flow, engine speed. Knowing the torque available for any speed and load allows inter-system exchanges between the engine electronic control unit and other control units of vehicle and possible use of security surveillance strategies for the powertrain. The achievement of an accurate estimation for the engine torque can influence and develop multiple areas: engine diagnostics, engine control starting from the developed torque, traction control and vehicle dynamic control. The paper contains a description of a calibration principle for estimating the engine torque and its use in the development of control and protection strategies.