Experimental Road Test of a Noncontacting Method of Measuring I-C Engine Torque Nonuniformity

This paper presents the experimental results of measurement of the nonuniformity in diesel engine torque. Measurements were made for an engine driving a water brake dynamometer as well as for a diesel engine (with a manual transmission) in an actual vehicle on roads of varying surface quality. These nonuniformity measurements are a measure of engine performance and have potential application in electronic engine control, maintenance/diagnostic functions and can serve as an indicator of incipient failure of the engine or of certain components.

The instrumentation includes a noncontacting (magnetic field system) sensor which can be mounted on the engine with minimal modification. The computation of the nonuniformity index can be implemented with an 8-bit or 1-6-bit microcomputer

This paper presents the theory of the method, explains the necessary instrumentation, and gives results of the experimental study.