Laser angle interferometry system possessing standard angle rotating platform and its measurement method

Abstract

The invention relates to a laser angle interferometry system provided with a turntable with standard angle and a measuring method, which resolves problems that measuring range of the existing laser angle interferometer is small, initial zero error and error of reflector constant A influences the measurement accuracy. A laser head (1) is fixed at an angle interferometer (2), a top wall (4) of the turntable with standard angle is connected with an angle reflector (3), wherein laser emitted from the laser head (1) projects to the angle reflector (3), the top wall (4) of the turntable is in tight fit with a spindle (9), a chassis of the turntable (5) is in movable fit with the spindle (9), the top wall (4) of the turntable and the chassis of the turntable can be rotated relatively, further the chassis of the turntable is connected with a turntable to be measured (6) via a bolt (7). When measuring, the top wall (4) of the turntable and the angle reflector (3) can rotate in identical angle in opposite directions in sequence with respect to integer of the turntable to be measured (6), the chassis of the turntable (5), the top wall of the turntable (4) and the angle reflector (3), ensuring laser beam is not deviated from the angle reflector (3), reading each readout of the laser angle interferometer after rotating in sequence, and obtaining measured value of each arbitrary angle by calculating.

Description

Technical field: [0001] The invention relates to a system and a method for measuring angles by laser interferometry. Background technique: [0002] Laser angle interferometer is mainly used for angle measurement, including precision angle detection of rotary table, CNC machine tool turntable and other devices. [0003] The principle of traditional laser angle interferometer is shown in Figure 1. [0004] The laser light emitted by the laser head 1 is divided into two paths in the angle interferometer 2, pointing to the two angle prisms in the angle reflector 3 respectively. When the angle reflector rotates from the original position E to the F position, the corresponding rotation angle is α, The optical path of the laser passing through the two angular prisms changes δ, and the rotation angle of the angular reflector is obtained by the following formula: [0005] α=arcsin(δ / A) [0006] A is the angular reflector constant, which is the distance between the ...

AI Technical Summary

Problems solved by technology

[0009] 2. The error caused by the initial zero position: the laser angle interferometer requires that the laser beam be perpendicular to the conical point connecting the two angled prisms of the angle reflector at the beginning of the measurement, which is often difficult to achieve in actual operation

[0010] 3. Inaccurate angle reflector constant A will cause large measurement errors: Figure 4 shows the influence of different angle reflector constant A (corresponding to curves 1 and 2) on the measurement. Due to the different values ​​of A, for the same optical path change δ Different angle measurement results α 1 and alpha 2

[0015] To sum up, the small range of the laser angle interferometer limits the application range, and the initial zero error α 0 and the error of the angle mirror constant A is an important factor affecting the measurement accuracy, which is a problem that needs to be solved in actual use

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