Multi-input observer for estimation of compressor flow

This paper presents a formulation and an application of a high-gain multi-input observer to estimate the compressor flow in turbocharged gasoline engines. Such an observer is desired in vehicles lacking a mass air flow sensor yet in which compressor flow needs to be known; for instance, it is desired in order to apply a reference governor for surge constraint avoidance. In this application, a fast estimate of the compressor flow is required so that the reference governor can take action before the compressor goes into surge. The multi-input observer uses pressure measurements and cylinder flow to estimate the compressor flow. This paper presents the derivation of the observer and both simulation and experimental results showing its feasibility in estimating the compressor flow.Copyright © 2013 by ASME