Automatic three-dimensional measuring method and automatic three-dimensional measuring system for high-precision blade of aviation engine

Abstract

The invention discloses an automatic three-dimensional measuring method for a high-precision blade of an aviation engine. The automatic three-dimensional measuring method comprises the following steps of (1) rectification: performing rectification on a design coordinate system of a design model and a measurement coordinate system of a workpiece entity; (2) path planning: planning a motion path of a distance sensor in a measuring process by using a data processing device so that a measured region of the workpiece entity is in a measurement range of the distance sensor; and (3) automatic measurement: sampling a front region and a reverse region of the workpiece entity by using the distance sensor to obtain a complete surface profile of the workpiece entity. The distance sensor serves as a measuring terminal, and position information of surface points of the measured region can be acquired; and moreover, by a three-axis motion mechanism, measurement on different regions of the workpiece entity can be realized, measured cloud data of points of density of a local range are automatically fused to the same coordinate system, and complete precise measurement on a workpiece and quality testing operation on the workpiece entity are realized.

Description

technical field [0001] The invention belongs to the field of precision measurement, and more specifically relates to a high-precision automatic three-dimensional measurement method and system for aeroengine blades. Background technique [0002] With the vigorous development of the domestic aerospace field, the three-dimensional measurement technology of aeroengine blades has more and more extensive application prospects in aerospace, weaponry and other fields. [0003] The proper functioning of each turbine in a modern airliner or military jet depends on the error-free function of more than a thousand turbine rotor blades and guide vanes. In such cases, the highest quality standard can only be measured in microns. Therefore, these highly complex components with irregular surface topography have very tight tolerances. [0004] Take the measurement of aerospace blades as an example. At present, most domestic enterprises still use manual inspection to measure blades. This met...

AI Technical Summary

Problems solved by technology

The time-of-flight method (also known as the light section method) uses a line laser to scan the surface of the free-form surface. One measurement can obtain the three-dimensional data points of a line on the measured surface, thereby improving the measurement efficiency, but its measurement accuracy is lower than that of aviation blades. Testing requirements

Moreover, the surface of the turbine blades of the aero-engine may have been forged, rolled or polished, and some parts are very bright. When using the time-of-flight method to measure the surface of highly reflective objects, the specular reflection on the surface of the object will greatly affect the measurement results

[0006] The structured light projection method is also used in the free-form surface measurement process. The measurement speed of the structured light projection method is faster than that of the time-of-flight method. One measurement can obtain three-dimensional data points in the projection area, but on the one hand, the measurement accuracy of the structured light projection method It is lower than the time-of-flight method. On the other hand, the accuracy of the measurement data obtained by measuring the highly reflective surface by the structured light projection method will also be affected.

[0007] To sum up: At present, contact three-dimensional coordinate measurement method, time-of-flight method, and structured light projection method have their own advantages, but none of them can meet the requirements of high precision, high resolution, and high efficiency for three-dimensional shape measurement of aeroengine blades at the same time.

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