Workpiece surface shape measuring system and method

Abstract

The embodiment of the invention provides a workpiece surface shape measuring system and a workpiece surface shape measuring method. According to the invention, the measuring stability of a capacitivesensor is high. Meanwhile, the complex linear correction of data is not required white the linear measurement can be well achieved. Moreover, surface oil contamination and other impurities do not influence the capacitive sensor, so that the measurement result of the capacitive sensor cannot be influenced. Meanwhile, the working surface of the capacitive sensor is a circular region and has a certain sampling area. Therefore, local large deviation errors in a primary sampling area can be homogenized. As a result, the accidental high point of the measurement result of the capacitive sensor is reduced and a reasonable surface shape peak valley value is obtained. The surface shape error measurement is greatly facilitated.

Description

technical field [0001] The invention relates to the technical field of advanced manufacturing of space optical systems, in particular to a workpiece surface shape measurement system and method. Background technique [0002] Ultra-precision turning is a high-efficiency optical component processing method, which can simultaneously obtain nanometer surface roughness and submicron surface shape accuracy. Generally speaking, the optical components after ultra-precision turning can directly meet the requirements for the use of infrared band components. However, ultra-precision turning optical components cannot meet the surface shape requirements of optical components in the visible light band. Especially for mirrors with large diameter or large diameter-to-thickness ratio, large surface shape errors will be introduced due to factors such as machine tool guideway errors, thermal deformation during processing, and clamping stress. [0003] The in-situ detection system equipped wit...

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Problems solved by technology

[0003] The in-situ detection system equipped with a single-point diamond lathe is mainly a contact ball probe, which has poor accuracy, low measurement efficiency, and is easy to scratch the surface of the component

At the same time, the surface of the aluminum alloy reflector is very soft, and the pressure of the measuring head causes the mirror to deform elastically, thus introducing measurement errors

Chinese patent CN205580399U proposes a measurement method of laser three-dimensional scanning. Although this method can realize non-contact measurement, the presence of impurities such as oil on the ultra-precision turning surface will interfere with the laser, and the scattering of the laser on the reflective mirror will also introduce measurement errors.

Chinese patent CN102305601A proposes a method of using a grating projection device to project sinusoidal grating fringes on the surface of the measured object, and the image acquisition device obtains the deformed fringe pattern modulated by the surface of the measured object, and then restores the method of the three-dimensional shape of the surface of the measured object, but this The resolution of the method is not high, and it is only suitable for the measurement of surface errors above the micron level

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