Closed Loop Turbocharger Control with Transient Wastegate Functions

Conventional turbocharger boost controls, using either a simple mechanical wastegate or a knock-based electronically-controlled strategy, have had some weaknesses in the areas of transient response, performance with a cold” engine, and in the interaction of the boost and knock control strategies. A controller for boost pressure, integrated with the controls for spark and fuel scheduling, can use common controller inputs (engine speed, throttle position, engine temperatures, and manifold pressure) to control the complete engine with greater stability, improved performance, reduced turbocharger lag, more successful spark knock control, and improved throttle response compared to conventional systems.