Review of optical measurement techniques for measuring three-dimensional topography of inner-wall-shaped parts

Inner-wall-shaped parts refer to special parts with semi-closed structures, such as bearings and pipes, that are widely used in various fields. Three-dimensional (3D) topography reflects the geometric characteristics and surface quality of a part, so it is essential to measure it. Optical measurement techniques are efficient, non-destructive, and have become the main methods for measuring such parts. This paper evaluates the optical measurement techniques that meet the 3D topography measurement requirements of inner-wall-shaped parts in different frequency bands. The key points, advantages, and disadvantages of the different measurement techniques and their improvement directions in terms of systems and algorithms are analyzed systematically. The relevant processing algorithms adapted to topography features are also introduced. Finally, this review tries to determine the future development trends of 3D topography measurement technology for inner-wall-shaped parts according to the current research and application status.