Ultra-precise 3D aiming and measuring sensor based on differential astigmatism and defocus detection

Abstract

The invention belongs to the technical field of precision instruments and measurement and discloses an ultra-precision three-dimensional collimation and measurement sensor based on differential astigmatism defocus detection. The sensor consists of a differential astigmatism defocus detection unit, a flexible hanging mechanism, a precision regulating mechanism and a shell, wherein the flexible hanging mechanism consists of a rigid cross, an elastic membrane, a reflector support and a measurement needle and is used for transmitting the displacement of the measurement needle to a reflector at a high displacement transmission rate; the differential astigmatism defocus detection unit consists of digital video disks (DVD) laser head and reflectors and used for performing high-precision differential detection on the displacement of the reflectors; and the precision regulating mechanism consists of movable wedge-shaped blocks and driven wedge-shaped blocks and used for performing high-precision zero focus on the DVD laser head in an initial state. According to the sensor, the maximum measurable depth-to-width ratio can reach or exceed 40:1, and the resolution is nanoscale; the sensor is convenient to decouple and has high anti-interference capability; and the effective sensor is provided for high-precision measurement of inner cavity parts such as deep holes and narrow slots with the large depth-to-width ratio.

Description

technical field [0001] The invention belongs to the technical field of precision instruments and measurement, in particular to an ultra-precise three-dimensional aiming and measuring sensor based on differential astigmatism and defocus detection. Background technique [0002] High-precision probes / sensors are key components of various precision coordinate measuring machines, length measuring machines, and size and shape measuring instruments. In recent years, with the development of inner cavity parts such as slots and deep blind holes with large aspect Wide application has put forward higher requirements for the measurable depth and measurement accuracy of the aiming and measuring sensors. The scanning sensor has outstanding advantages such as high precision and simultaneous aiming and measurement. It is the core technical unit of ultra-precision measuring instruments and equipment, and is strictly prohibited from abroad. [0003] In principle, the scanning aiming and meas...

AI Technical Summary

Problems solved by technology

[0007] The invention provides an ultra-precise three-dimensional aiming and measuring sensor based on differential astigmatism and defocus detection, which solves the contradiction between the resolution and the lateral size of the sensor and the common mode interference existing in the existing displacement sensor based on astigmatism and defocus detection It is difficult to eliminate, there are problems such as inter-axis coupling, and the measurable depth of the sensor is improved. It is suitable for various sizes and shapes of measuring instruments and equipment, especially for high precision of inner cavity parts such as deep holes and slots with a large aspect ratio. The purpose of the measurement is to provide an effective sensor

Images