Author:

Keywords:

FM_affiliated, LMSD, MOD/ISMA

Abstract:

This article investigates the viability of using a smartphone’s rolling shutter camera as a cost-effective tool for rotational speed measurement. The smartphone is pointed to the side of the rotating shaft, on which a zebra pattern is pasted. As a consequence of the rolling shutter effect, the zebra pattern is deformed. This deformation depends on the pose of the shaft with respect to the camera, the intrinsic camera parameters and the rotational speed of the shaft. A novel method is proposed to measure this speed using an extended perspective projection model and an optimization algorithm. This method is designed to measure constant and varying speeds, even above the Nyquist limit related to the camera’s frame rate, and to be robust against variations in the pose of the shaft with respect to the camera. The method is validated using simulations and on an in-house test rig and shows promising results making it possible to develop a smartphone application to measure the rotational speed of a shaft in the close future.