Damping of idle engine speed oscillations using a reversible alternator

We consider the problem of damping the speed oscillations of an automotive engine crankshaft, using a reversible alternator, with a focus on the design of the controller. The reversible alternator is used to apply a control torque to the crankshaft that will improve the uniformity of its speed. One would then potentially use a lighter flywheel, or remove it altogether, thereby reducing engine size and weight. We have characterized the controllers that meet a variety of possibly competing performance specifications, leading to design charts. These charts are level curves of various controller performance metrics in a two-dimensional plane of controller design parameters. Simulation results suggest that engine speed oscillations can be substantially reduced by this method