A laser measuring head device with variable measuring range and its curved surface measuring method

Abstract

The invention discloses a laser measuring head device with variable measuring range and a curved surface measuring method thereof. Existing complex surface measurement methods to solve overrange are inefficient. The device of the invention comprises a sensor main board, a laser measuring head, a first interface, a second interface, a third interface, a fourth interface, a first prism frame, a first right-angle prism, a second prism frame and a second right-angle prism. The invention realizes the change of the measurement range by changing the measuring optical path around the laser measuring head, without changing the internal structure of the laser measuring head, so that a single laser measuring head can realize multiple measuring ranges; the variable-range secondary measurement method solves the problem of laser Contradiction between probe range and accuracy.

Description

Technical field [0001] The invention belongs to the technical field of laser non-contact precision measurement of the surface shape of an object, and specifically relates to a laser probe device with a variable range and a curved surface measurement method. Background technique [0002] Complex curved parts are widely used in aerospace equipment, ship propulsion devices, motor vehicles, optical instruments and other fields, such as aero engine blades, ship propellers, automobile covers, Fresnel prisms, etc. As a functional component, the geometric shape of the curved surface on the part has a great influence on the realization of its function, so the geometric shape of the functional curved surface needs to be precisely tested. [0003] At present, surface measurement methods are mainly divided into two types: contact and non-contact. The non-contact measurement method has the advantages of fast speed, no contact force, convenient measurement device, and great flexibility, which is...

AI Technical Summary

Problems solved by technology

However, when using this method, if there is an over-range phenomenon, the system cannot identify whether the surface to be measured exceeds the upper limit or the lower limit of the range. In order to avoid collision between the laser probe and the surface to be measured, the vertical axis of the measuring machine needs to move upward first. If the upward movement cannot make the surface to be measured return to the range, then move downward to bring the surface to be measured back to the range. The reciprocating adjustment process will affect the measurement efficiency

In addition, if the overall height difference of the surface to be measured changes greatly, or there are many sudden changes in the surface that the height difference exceeds the range, the measuring machine needs to perform range regression operations frequently during the measurement process, which will seriously affect the measurement efficiency

[0009] Method (2) is more effective for slowly changing surfaces, but if there are many sudden changes in the height difference beyond the range range on the surface to be measured, the system still needs to perform range regression operations frequently

[0010] Method (3) can better solve the problem of over-range, but requires three-dimensional shape sensors to intervene in the measurement process, which directly increases the measurement cost, and the integration of multiple sensors requires calibration and data fusion processing, making the measurement process relatively more cumbersome

In addition, the 3D shape sensor obtains a large amount of scattered point cloud data, and the data processing has high requirements for computer hardware and algorithm design, and the processing process is relatively complicated.

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