Format

Send to

Choose Destination
See comment in PubMed Commons below
Sensors (Basel). 2011;11(12):11856-70. doi: 10.3390/s111211856. Epub 2011 Dec 20.

Characterization of a low-cost optical flow sensor when using an external laser as a direct illumination source.

Author information

1
Department of Computer Science and Industrial Engineering, University of Lleida, Jaume II, 69, Lleida 25001, Spain. dfont@diei.udl.cat

Abstract

In this paper, a low cost optical flow sensor is combined with an external laser device to measure surface displacements and mechanical oscillations. The measurement system is based on applying coherent light to a diffuser surface and using an optical flow sensor to analyze the reflected and transferred light to estimate the displacement of the surface or the laser spot. This work is focused on the characterization of this measurement system, which can have the optical flow sensor placed at different angles and distances from the diffuser surface. The results have shown that the displacement of the diffuser surface is badly estimated when the optical mouse sensor is placed in front of the diffuser surface (angular orientation >150°) while the highest sensitivity is obtained when the sensor is located behind the diffuser surface and on the axis of the laser source (angular orientation 0°). In this case, the coefficient of determination of the measured displacement, R(2), was very high (>0.99) with a relative error of less than 1.29%. Increasing the distance between the surface and the sensor also increased the sensitivity which increases linearly, R(2) = 0.99. Finally, this measurement setup was proposed to measure very low frequency mechanical oscillations applied to the laser device, up to 0.01 Hz in this work. The results have shown that increasing the distance between the surface and the optical flow sensor also increases the sensitivity and the measurement range.

KEYWORDS:

displacement; external laser source; optical mouse sensor; oscillatory motion

PMID:
22247696
PMCID:
PMC3252013
DOI:
10.3390/s111211856
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Multidisciplinary Digital Publishing Institute (MDPI) Icon for PubMed Central
    Loading ...
    Support Center