Method for measuring orthogonality of orthogonal axis system

A method for measuring orthogonality of an orthogonal axis system of an instrument, comprising:

• placing the instrument on a bearing surface, flatness of the bearing surface being less than a first preset threshold;
• making perpendicularity between a first rotary axis and the bearing surface smaller than a second preset threshold value;
• intercepting a second rotary axis along an interception plane to obtain a first virtual cross section of the second rotary axis, the interception plane passing through a specific point of the bearing surface and being orthogonal to the bearing surface and a projection of the second rotary axis on the bearing surface, and measuring the first virtual cross section to obtain a geometric center of the first virtual cross section as a first position;
• rotating a second rotary device to enable the second rotary axis to rotate with a preset angular degree, the preset angular degree being an odd multiple of 180°, using the interception plane to intercept the second rotary axis to obtain a second virtual cross section of the second rotary axis, and measuring the second virtual cross section to obtain a geometric center of the second virtual cross section as a second position;
• and
• determining whether the orthogonality between the first rotary axis and the second rotary axis meets requirements based on the first position and the second position;
• wherein:
• spatial coordinates of an arbitrary point on an axial line of the first rotary axis are obtained as a third position;
• a distance between the first position and the second position is set as a first distance;
• a distance from the third position to the interception plane is set as a second distance;
• a mismatch angle is obtained based on the first distance and the second distance;
• if the mismatch angle is less than a preset angle, the orthogonality between the first rotary axis and the second rotary axis meets requirements;
• and
• if the mismatch angle is not less than the preset angle, the orthogonality between the first rotary axis and the second rotary axis does not meet requirements;
• and
• wherein:
• the instrument comprises a first rotary device having the first rotary axis and the second rotary device having the second rotary axis;
• the second rotary device is provided on the first rotary device and is rotatable around the first rotary device;
• and
• the orthogonal axis system is formed by the first rotary axis and the second rotary axis.