Control design for active engine damping using a starter/alternator

In this paper, different control schemes for active damping of engine crankshaft oscillations using a supplemental torque source are designed and analyzed. The controller synthesis is based on the classical idea of the periodic disturbance rejection by increasing the loop gain over the disturbance frequency range. The techniques under consideration include a classical lead-lag compensator, a variable “inverse” notch filter, H_∞ synthesis, and a PID control. The notch filter with high frequency lead compensation shows a superior performance compare to others feedback based control techniques. The starter/alternator active flywheel system implementation results are also presented and discussed