High-precision absolute linear encoder based on a standard calibrated scale

This paper presents the full research and development cycle of a high-precision absolute linear encoder based on a standard calibrated scale. Already available and used in industry standard scales of invar alloy were employed in the study. The scales have incremental indexes with 1 mm spacing intervals without an absolute code. However, the existing technical task is to measure the absolute position in the range of 2 m with accuracy less than 5μm. For that, the developed encoder rationally combines magnetic measuring channel for the index numbering and an optical channel for the precise estimation of the encoder position. First, for the development, a simulation was performed to synthesize and analyze an image of an index. This image was used to develop a real-time double-threshold image processing algorithm to estimate the index position. Later the developed image processing algorithm was veriThis paper presents the full research and devel