Development of a simple instantaneous torque measurement system on a rotating shaft

Abstract

This publication presents a simple and inexpensive torque measuring system for rotating shafts with sampling frequencies up to 40kHz. This work was done as part of a project whose aim was to determine the mechanical friction of a motored engine. The presented method can be applied to any rotating shaft. The proposed system makes use of a full-bridge strain gauge system coupled to a custom electronic amplifier which makes use of only one reference supply rail and hence eliminates the need for two batteries. The developed system also features a one pulse per revolution indicator using an infra-red sensor which gives a reference point for the start and end of a cycle. The Arduino data acquisition system used in this study was inexpensive and commercially available, hence making this measurement system easily obtainable whilst still having the advantage of a compact system able to achieve decent sampling rates.