This paper presents a new metric for the nonuniformity of the torque random process of a reciprocating internal combustion engine. The proposed metric is derived from the torque 2N extrema which occur within each engine cycle for an N-cylinder engine. A 2N-dimensional vector is obtained for each cycle, which represents torque nonuniformity. The proposed metric is either the 11 or 12, norm for this vector. It is shown in this paper that this metric satisfies several properties which are desirable for quantitatively representing torque nonuniformity. Moreover, this metric is computed once each engine cycle and is, therefore, a quasi-real time measure of torque nonuniformity. This metric has several potential applications in electronic engine control systems.
