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.
Modern demands for railway track measurements require high accuracy (about 2-5 mm) of rails placement along the track to ensure smooth, safe and fast transportation. As a mean for railways geometry measurements we suggest a stereoscopic system which measures 3D position of fiducial marks arranged along the track by image processing algorithms. The system accuracy was verified during laboratory tests by comparison with precise laser tracker indications. The accuracy of ±1.5 mm within a measurement volume 150×400×5000 mm was achieved during the tests. This confirmed that the stereoscopic system demonstrates good measurement accuracy and can be potentially used as fully automated mean for railway track inspection.
Design of optical-electronic devices and systems involves the selection of such technical patterns that under given initial requirements and conditions are optimal according to certain criteria.1-5 The original characteristic of the OES for any purpose, defining its most important feature ability is a threshold detection. Based on this property, will be achieved the required functional quality of the device or system. Therefore, the original criteria and optimization methods have to subordinate to the idea of a better detectability. Generally reduces to the problem of optimal selection of the expected (predetermined) signals in the predetermined observation conditions. Thus the main purpose of optimization of the system when calculating its detectability is the choice of circuits and components that provide the most effective selection of a target.
Level crossing – one of the most dangerous sections of the road network, where railway line crosses motor road at the same level. The collision of trains with vehicles at a level crossing is a serious type of road traffic accidents. The purpose of this research is to develop complex optical electronic control system of vehicles location in the dangerous zone of level crossing. The system consists of registration blocks (including photodetector, lens, infrared emitting diode), determinant devices and camera installed within the boundaries of level crossing. The system performs detection of objects (vehicles) by analysing the time of the object movement opposite to the registration block and level of the reflected signal from the object. The paper presents theoretical description and experimental research of main principles of the system operation. Experimental research of the system model with selected optical-electronic components have confirmed the possibility of metal objects detection at the required distance (0.5 – 2 m) with different values of background illuminance.
In this paper we introduce a system for deflection measurement of floating dry docks. The system contains two measurement channels observing opposite directions of the dock. It also includes set of reference marks, an industrial computer and a display. Each channel contains CMOS camera with long focal-length lens. Reference marks are implemented as IR LED arrays with 940 nm working wavelength for better performance within bad weather conditions (e.g. fog, rain, high humidity etc.). In the paper we demonstrate results of an analysis of different optical schemes for coupling the oppositely directed channels of the measurement unit and show that the scheme with two image sensors with separated lenses is an optimal option, because it allows usage of nonequidistant location of reference marks and demonstrates the least value of parasitic shift caused by rotations of the measuring unit. The developed system was tested both on specially-designed setup and in real infrastructure of a floating dry dock. The conducted tests proved that a measuring error of the system is smaller than ± 1.5 mm within the measurement range of ± 150 mm when deflection of 100 m dock is measured. Obtained results showed that the system demonstrates an ability to work in a harsh environment including poor weather conditions.
System that will allow visual and measuring control of blades is proposed. It based on triangulation method of measurement. This method implies using of elements described below: a receiving unit, source of structured light, processing and control unit, the monitor and power supply unit. Geometrical characteristics of the system are calculated. As a result we got numbers of receiving units and sources of structured light needed to monitor blade along its entire length. Theoretical error of system measurement is calculated. It depends on distance to the object, the base between receives unit and sources of structured light, resolution and physical size of image receive. Surface of blade is not flat this fact entails changing distance from object to receive unit. So the error of measurement will be different. The interval for researching was chosen from 90 to 130 mm. Error of measurement have steady upward trend from 0,08 to 0,017 mm all period between chosen distances. The physical model of control method is developed. As a result of its working picture of illuminated metal object was obtained. The program written in MatLab processes experimental picture, find lines of structure light and calculate dislocations of it. Then use this information to make a three-dimensional model of object.
Piston-cylinder assemblies are used in various actuator applications in all branches of industry, such as construction
technology. It is often important for the operator to know the condition of the piston rod in the pressure-operated
cylinder. A large number of operating cycles by this piston can lead to premature failure and breakage of the entire
cylinder; this is conditioned by a high chance of splitting of the piston rod due to its elongation during the operating
process. Therefore, it is necessary to know their operating lifetimes, for which purpose endurance tests are conducted.
Since the pistons are located in hard-to-reach place, monitoring their operation via the contact method while there are in
motion is not considered possible. In such situations, a non-contact method is used to monitor to moving parts, which is
conducted on the basis of imaging sensors. The authors of this article have developed a new system for conducting
endurance test on piston mechanism in a cylindrical valve. This system makes it possible to observe the shift of the
reciprocating piston in real time, automate the process of recording data and promptly and accurately measure the
parameters of the shift of the piston via a non-contact method and increase the reliability of the data received.
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