This paper describes the development of a transverse deflection measuring system for floating dry docks. The system consists of a set of reference marks and a measurement unit. When the measurement is performed in outside for the inspection of real structures, the influence of external conditions can lead to change the position and the direction of a measurement unit. In this case, the deflection of the object cannot be measured because the effect of the camera movement is included in the measured deflection. The aim of the work is to analyze and estimate the rotation parameters of the measurement unit relative to an arbitrary axis. The result of the estimation rotation parameters can be used to compensate the error caused by the rotation of the measurement unit in the development of electro-optical system for transverse deflection measuring system for floating dry docks.
An influence of external conditions can lead to a random rotation of the base unit of the electro-optical deflectometer. This will affect the variation of the image coordinates of the control elements in relation to base position, and, as a result, will cause the error in determining the deflection of the analyzed structure. The changes in the position of the image coordinates of the reference marks before and after the base unit rotation of the electro-optical deflectometer was estimated with the help of elements of vector algebra and matrix analysis. The results of the analysis show that errors in the assignment of the coordinates of the control elements are affected not only by the angle of rotation, but also by the position of rotation axis around which the base unit rotates.
An electro-optical system for deflection measurement of floating docks is represented in this paper. This system contains
a base unit with two measurement channels observing opposite directions of the dock. It also includes a set of reference
marks and an industrial computer. The measurement unit contains of a camera with long focal-length lens and a beam
splitter. The effect of the beam splitter turning point on the image position of the reference mark on the camera is
analyzed as well in this paper.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.