RU2689897C1 - Method for measurements introduction during monitoring local residual deformations of the ship hull - Google Patents

Abstract

FIELD: shipbuilding.

SUBSTANCE: invention relates to shipbuilding and ship repair and can be used in assessing technical condition of ship hulls. Method of measurements introduction during the monitoring of local residual deformations of the ship hull consists in that due using a laser scanner or laser tracker, a three-dimensional model of the damaged ship hull structure is constructed. Parameters of operational defects are determined by analyzing constructed model and theoretical drawing and data of design drawings of the respective areas, their comparison with standard values.

EFFECT: following invention provides a reduction in labor intensity and objectivity in measuring in the course of monitoring local residual deformations of the ship hull.

1 cl, 7 dwg

Description

The invention relates to the field of shipbuilding and ship repair and can be used in assessing the technical condition of ship hulls.

Known laser scanner or laser tracker with a projector (US 86384469, G01B 11/24, G01B 21/14, publ. January 28, 2014), which is a coordinate measuring device with a three-dimensional coordinate system, and includes a light source that emits light a beam in the medium; and a data capture component that captures a light beam reflected back to the laser scanner or tracker from the environment.

This laser scanner or laser tracker with a projector has the disadvantage that it only allows to build a three-dimensional model of the object under test, in particular the ship hull, but not to determine the parameters of the hull's operational defects in the form of residual deformations, as for the hull areas with double curvature such parameters of operational defects as arrows of deflection of elements of hull structures cannot be determined.

Known laser-optical systems used to build mathematical models in assessing the strength and carrying capacity of the actual geometry (Dulnev AI, Tumashik GA, Tyutyukov VE Experience in building mathematical models to assess the strength of the shells on the basis of measurement data , obtained by laser-optical systems // Proceedings of the Krylovsky State Research Center. - 2014. - Issue 82 (366). P. 37-44).

These systems and models have the disadvantage that they only allow to evaluate the effect of construction defects in the form of shell structures on their carrying capacity. They cannot be used for the inspection of ship hull structures during their operation, as they do not allow determining the parameters of operational defects in the form of residual deformations in areas of the hull with double curvature, since they do not contain information about the vessel hull geometry.

As the closest analogue adopted method of measurement in the course of monitoring local residual deformations of the hull of the vessel (Patent for invention No. 2380273, IPC В63В 9/00, publ. 01/27/2010), carried out using tools, templates and layouts, with a preliminary assessment residual deformation values and their error for a given type of defect in a significant amount of statistical material, taking into account the margin of error in determining the above statistical error estimate in relation to the deflection needle of the corrugation, buhtin and Myatin

A significant disadvantage of this method is that it does not allow to determine the arrows of the deflection of the hull structures in areas with double curvature. In addition, this method is characterized by large laboriousness of measurements using tools, as well as the impossibility of eliminating the influence of the human factor at the expert assessment stage, as a result of which not all unacceptable hull defects can be detected, which adversely affects the operational safety of ships.

The invention solves the problem of reducing labor intensity and ensuring objectivity in conducting measurements while monitoring local residual deformations of the ship hull by building a three-dimensional model of the hull with operational defects and finding deviations of the actual surface points at the deformation sites from the corresponding points in the theoretical and structural drawings of the hull.

To solve the problem in the method of measurement during the monitoring of local residual deformations of the ship hull, including the definition of parameters of operational defects, such as arrows of deflection of dents, buhtin, corrugations, and their comparison with standard values, it is proposed to preliminarily clean the hull of the vessel, after which the surface hulls optically scan, process data and create a three-dimensional model of the hull surface with operational defects. It is proposed to compare the three-dimensional model with the data of a theoretical drawing of the ship hull for the hull areas containing operational defects and the data of the design drawings of the respective areas. It is proposed to determine the actual deflection arrow as the distance between the points of the theoretical drawing and the corresponding points of the constructed three-dimensional model of the hull in the area of the operational defect. In addition, it is additionally proposed to determine the length of the operational defect by finding its boundary, beyond which the distance between the corresponding points of the theoretical drawing and the constructed three-dimensional model does not exceed the magnitude of the manufacturing error of the ship’s hull relative to its theoretical drawing.

On the attached graphic materials depicted:

in fig. 1 is a flowchart for processing scan results;

in fig. 2 - model of the bow of the vessel;

in fig. 3 - software product interface window;

in fig. 4 - displaying the scan result in the interface window;

in fig. 5 - the result of integrating the surface of the defect in the design documentation;

in fig. 6 - model of values falling out of tolerance;

in fig. 7 is a flowchart of the measurement process.

The method of measurement during the monitoring of local residual deformations of the hull of the vessel is as follows. The vessel, which requires the assessment of the technical condition of the hull structures, is placed in the dock, where the hull is cleaned of fouling, damaged paintwork and scale. After that, a laser scanner or laser tracker is placed in the dock, which optically scans the vessel's hull surface. Scan data is collected, stored and sent to the processor, where it is processed to create a three-dimensional image of the vessel hull surface with operational defects in the form of residual deformations, such as dents, coils and shirring (Fig. 1). In the block for determining the actual parameters of operational defects, the created three-dimensional model is compared with the data of the theoretical hull drawing for hull areas containing operational defects and the design drawings of the respective areas. After that, the parameters of existing operational defects, such as deflection and length, are determined, and in the regulatory base block they are compared with the allowable values presented, for example, in (Rules of Classification Surveys of Ships in Operation / Russian Maritime Register of Shipping. - St. Petersburg: RMRS , 2014. - 350 p.). Based on this comparison, if the parameters of the operational defect exceed the permissible values, the conclusion is made about the need to eliminate the defect. To determine the actual deflection arrow, the distance between the points of the theoretical drawing and the corresponding points of the constructed model in the area of the operational defect is determined on the basis of the three-dimensional model constructed from the scan results and the theoretical drawing. The length of the operational defect is determined by finding its boundary, beyond which the distance between the corresponding points of the theoretical drawing and the three-dimensional model constructed based on the scan results does not exceed the magnitude of the error in the manufacture of the ship’s hull relative to its theoretical drawing.

At the same time, the obtained three-dimensional model makes it possible to determine the location area for each of the existing operational defects (middle part of the body, extremities, spreads, etc.), which makes it possible to compare the parameters of these defects with the corresponding standard values. It should be noted that in order to carry out dent defect detection in accordance with the current regulatory documents (Rules of Classification Surveys of Vessels in Operation / Russian Maritime Register of Shipping. - SPb .: RMRS, 2014. - 350 p.), The system should contain data on the location of the hull links in the design the basis of the design drawings in conjunction with the data of the theoretical drawing, which, in particular, is necessary to determine the distance from the beam section with the maximum deflection to the nearest undeformed support. Such supports may be perpendicular beams of the frame set, deck, platform, bulkhead, etc. At the same time, the use of theoretical drawing data allows defining the arrows of the hull connections in areas with double curvature.

As an example of the implementation of the proposed method of measurement in the course of monitoring local residual deformations of the hull, consider the case of fault detection of the outer skin of the bow of the vessel with a defect in an area with a complex loss.

Upon receipt of the technical assignment for flaw detection by the department of plazvom preparation, the design documentation was sent in the form of a three-dimensional model of the nasal tip (Fig. 2).

After receiving the technical specifications and arrival at the site, the operators install a laser tracker with a projector (or laser scanner). To do this, select the installation location of the device, allowing you to cover the entire area of flaw detection. For the installation of the system itself, a tripod stand is mounted, the scanning device is attached to it with a clamping screw and is brought to a position close to the horizon. At the same time, the second operator starts the computer with the pre-installed software SpatialAnalyzer and, via the Bluetooth connection protocol, connects to the device. To do this, select the function "Device" - "Add a device." The brand of the scanning device is selected and the “Start interface” button is pressed. When the device is ready, an interface window appears on the main screen (Fig. 3).

When the device and the computer are ready for operation, the operator, using the device interface, turns on the laser pointing function “Device” - “Laserpointer” - “ON”. After that, he makes a preliminary manual guide to the defect and presses the “Thask” button or the F7 key, thereby starting the process of recording the results. The process itself lasts about 15-20 minutes. Upon completion of the measurements, the scan result presented in FIG. four.

After receiving the results, they must be transferred from the SpatialAnalyzer environment to the AutoCAD environment. For this, the SpatialAnalyzer function “File” - “Export” - “DFX File” is used. Thus, the results are converted into readable format for AutoCAD. To insert a drawing into the design documentation, use the AutoCAD Insert feature - Import. After importing, a defect surface is created from the obtained points using the “Surface” - “Network” function. As a binding of the obtained surface to the three-dimensional model, the intersection point of the joint and the groove of the sheet of the outer skin is used. The results of the model information are presented in FIG. five.

Using the AutoCAD software product, two models are combined: a model of a body with a defect and a theoretical model provided by the department of plasma training. Using the function “Surface” - “Subtraction”, a three-dimensional model is obtained with the deviation of the defect geometry from the construction values. The resulting model is shown in FIG. 6

Such a model is easy to analyze in order to determine the zone in which deviations are beyond the allowable values in accordance with (Rules of Classification Surveys of Ships in Operation / Russian Maritime Register of Shipping. - SPb .: RMRS, 2014. - 350 p.), And outputting information largest plot to be repaired (in case of deflection of standard values). The model itself is sent to the department of platform training for further analysis. The whole process of measuring can be represented in the form of a flowchart (Fig. 7).

Thus, the proposed method of measuring during the monitoring of local residual deformations of the ship hull allows, unlike the closest analogue, to automatically scan all hull defects belonging to the class of residual deformations, to determine the actual parameters of operational defects and compare them with the allowable values , which significantly reduces the time required to assess the technical condition of the hull, reduces the cost of this operation, and also eliminates the possibility the occurrence of errors related to the human factor.

Claims (1)

The method of measurement during the monitoring of local residual deformations of the ship hull, including the determination of parameters of operational defects, such as dents, deflection arrows, bukhtin, corrugations, and their comparison with standard values, characterized in that the ship hull is cleaned beforehand scan, process data and create a three-dimensional model of the vessel hull surface with operational defects, which is compared with the theoretical hull drawing data vessel for hull areas containing operational defects and design data of the respective areas, and the actual deflection arrow is defined as the distance between the points of the theoretical drawing and the corresponding points of the constructed three-dimensional model of the hull in the area of the operational defect, in addition, the length of the operational defect is additionally determined the boundaries beyond which the distance between the corresponding points of the theoretical drawing and the constructed three second model does not exceed the value of a manufacturing error the hull with respect to the theoretical drawing.

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