A turbocharger speed controller includes a rising rate limiter having an
input receiving a turbocharger speed signal and an output producing a
rate limited turbocharger speed signal, a high envelope filter having an
input receiving the rate limited turbocharger speed signal and an output
producing a filtered and rate limited turbocharger speed signal, a
turbocharger speed control signal generator having an input receiving the
filtered and rate limited turbocharger speed signal and an output
producing a turbocharger speed control signal based on comparison of the
filtered and rate limited turbocharger speed signal with a desired
turbocharger speed, and a swallowing capacity control mechanism
responsive to the turbocharger speed control signal to vary a swallowing
capacity of the turbocharger.