Event-based estimation of indicated torque for IC engines using sliding-mode observers

Abstract

This paper investigates the estimation of indicated torque in internal combustion engines. A crank-angle-based model is used to design a nonlinear event-based observer. This observer is able to estimate the unknown system input, that is, the indicated torque, from one or more measurements of crankshaft angular velocity. The crank-angle-based formulation is the obvious choice for the direct implementation of such an observer, because the crankshaft angular velocity signal is sampled uniformly at discrete crank angle intervals. Most of the work done so far has relied on time-based approaches. The paper also proves the convergence of the observer, describes how to design the observer gain, and includes experimental results.