CN2525471Y - Multiple structure light light plane aligning indicator - Google Patents

Abstract

The utility model relates to a multiple structure light light plane aligning indicator for detecting straightness, coaxiality and other form and position errors of a cylinder class workpiece in a structure-light vision detecting system. The aligning indicator consists of an aligning device, a CCD vidicon and a computer; the aligning device consists of a base, splints, translucent and semi-reflecting glass and bolts; two splints are placed upright on two ends of the base and clamp two pieces of translucent and semi-reflecting glass, and the translucent and semi-reflecting glass is fixed by bolts; the space between two splints is 18 cm. The utility model has simple structure, effectively increased quantity of ellipse fitting data, improved ellipse fitting precision, simple and reasonable structure design, convenient use and operation and high aligning precision; the adopted principles are simple and easy to understand.

Description

Multi-structured light plane alignment indicator device

Technical field: The utility model relates to a multi-structured light plane alignment indicator device for detecting shape and position errors such as straightness and coaxiality of cylindrical workpieces in a structured light visual inspection system.

Background technology: In the machining and manufacturing industry, some cylindrical workpieces, such as long steel pipes, long bars, etc., usually need to measure and evaluate their straightness, coaxiality and other shape and position errors. In this kind of shape and position error measurement, structured light three-dimensional vision detection has broad application prospects, and its biggest feature is non-contact, large measurement range and fast speed. Line structured light sensors are generally used in the measurement, and multiple line structured light sensors are arranged along the axis of the cylindrical workpiece. The structured light plane projected by the sensor intersects the surface of the cylindrical workpiece, forming multiple structured light strips and ellipses on the surface of the workpiece. arc. By ellipse fitting the points on the ellipse arc of these light strips, the center coordinates of multiple cross-sections along the axial direction of the workpiece can be obtained, and then the evaluation of parameters such as straightness and coaxiality can be realized. Unfortunately, due to the constraints of the structure of the line-structured light sensor, the field of view of the CCD, and other factors, the arc length of the ellipse formed by the light bar is often short, accounting for only a small part of the ellipse contour line where it is located. And in the actual measurement, the measurement data inevitably contains various noises, which makes the accuracy of the center positioning by using the short light bar ellipse arc for ellipse fitting cannot meet the measurement accuracy requirements. Using a sensor group composed of multiple sensors to measure the same section of the workpiece at the same time can increase the length of the light bar ellipse arc and the amount of data involved in ellipse fitting. On the premise of ensuring coplanarity, use multiple light bar ellipse arcs The accuracy of ellipse fitting must be much higher than that of using only one light bar ellipse arc. However, in actual measurement, it is difficult to ensure that the elliptical arcs of multiple light bars of the same sensor group are coplanar. Usually, the way people deal with it in actual measurement is: take a piece of white paper, place it in two different positions, and use eyes to observe the light stripes formed on the white paper by multiple structured light planes emitted by the same sensor group. Whether these two different positions coincide to determine whether they are coplanar. The accuracy of this processing method is obviously very low, and it will introduce considerable errors in the actual measurement results, and it will not achieve the original intention of improving the accuracy of ellipse fitting.

Summary of the invention: In order to realize the high-precision coplanarity of multiple structured light planes of the same line structured light sensor group, so as to realize the coplanarity of multiple structured light strips formed on the workpiece surface, the purpose of this utility model is to provide a structure Simple, easy to use, high alignment precision multi-structured light plane alignment indicator device to solve the problem of high-precision coplanarity of multiple structured light planes of the same line structured light sensor group, in order to achieve high-precision workpiece shape The structured light 3D visual detection of errors provides guarantee. The technical solution of the utility model is that the alignment indicating device is composed of an alignment device 1, a CCD camera 2 and a computer 3; Stand on both ends of the base, clamp two pieces of translucent and semi-reflective glass, and fix the semi-transparent and semi-reflective glass with screws. The distance between the two splints is 18cm. The utility model has the advantages of simple structure, simple and reasonable structure design, convenient use and operation; the adopted principle is simple and easy to understand, and the alignment precision is high.

Description of drawings:

Figure 1 is a schematic diagram of measuring the straightness of steel pipes using a line structured light sensor;

Fig. 2 is the structural representation of the utility model;

Fig. 3 is a schematic diagram of the alignment device of the present invention.

The two line structured light sensors 4 in the structured light vision detection system constitute a measurement sensor pair. The structured light light plane emitted by the light sensor 4 intersects the alignment device 1 to form a structured light strip pattern 5 . The CCD camera 2 is used to acquire the image information of the structured light strip pattern 5 on the alignment device. The computer 3 is used to process the image acquired by the CCD camera 2, calculate and indicate whether the two structured light planes emitted by the light sensor 4 have been aligned and overlapped.

The alignment device 1 is designed based on the principle that two non-coincident straight lines in the same plane uniquely determine the plane. A splint 8 is provided at both ends of the base 9, and is fixed on the base 9 by screws. The semi-transparent and semi-reflective glass 7 is clamped in the splint 8, and fixed with screws 6 to communicate with the light sensor 4 in the structured light visual detection system. The light planes of the structured light intersect to form straight light bars. The thickness of the two pieces of semi-transparent and semi-reflective glass is less than 4mm, making the error caused by the refraction of light negligible. The distance between them is 18cm, and on the premise of ensuring high alignment accuracy, the overall alignment device is compact and easy to carry and use.

Adjust the position of the line structured light sensor 4 and the position of the alignment device 1 so that the structured light plane emitted by the structured light sensor intersects with the two pieces of transflective glass 7 of the alignment device 1 to form four linear structured light strips Pattern 5. Adjust the position of the CCD camera 2 so that the two pieces of transflective glass of the alignment device 1 are completely within its field of view and can form a clear image. Among the four structured light strip patterns 5, the two on the same piece of semi-transparent and semi-reflective glass form a group, a total of two groups. When the images formed by these two groups of structured light straight line light strip patterns 5 on the image plane of the CCD camera overlap simultaneously, it means that the two structured light light planes emitted by the two line structured light sensors 4 have already been spaced. To coincide, that is, to align.

Claims (2)

1. aim at indicating device by alignment device, video camera, computing machine, the multi-structured light optical plane formed for one kind, it is characterized in that, alignment device is made up of base, clamping plate, semi-transparent semi-reflecting glass and screw, two clamping plates stands on the two ends of base, two blocks of semi-transparent semi-reflecting glass of clamping, and with screw semi-transparent semi-reflecting glass is fixed.

2. multi-structured light optical plane according to claim 1 is aimed at indicating device, it is characterized in that the spacing of two clamping plates is 18cm.

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