Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6954677 | Mechanical Systems and Signal Processing | 2018 | 11 Pages |
Abstract
The present work proposes a novel capacitive absolute positioning sensor based on time grating. The sensor includes a fine incremental-displacement measurement component combined with a coarse absolute-position measurement component to obtain high-resolution absolute positioning measurements. A single row type sensor was proposed to achieve fine displacement measurement, which combines the two electrode rows of a previously proposed double-row type capacitive displacement sensor based on time grating into a single row. To achieve absolute positioning measurement, the coarse measurement component is designed as a single-row type displacement sensor employing a single spatial period over the entire measurement range. In addition, this component employs a rectangular induction electrode and four groups of orthogonal discrete excitation electrodes with half-sinusoidal envelope shapes, which were formed by alternately extending the rectangular electrodes of the fine measurement component. The fine and coarse measurement components are tightly integrated to form a compact absolute positioning sensor. A prototype sensor was manufactured using printed circuit board technology for testing and optimization of the design in conjunction with simulations. Experimental results show that the prototype sensor achieves a ±300â¯nm measurement accuracy with a 1â¯nm resolution over a displacement range of 200â¯mm when employing error compensation. The proposed sensor is an excellent alternative to presently available long-range absolute nanometrology sensors owing to its low cost, simple structure, and ease of manufacturing.
Keywords
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Physical Sciences and Engineering
Computer Science
Signal Processing
Authors
Hongji Pu, Hongzhong Liu, Xiaokang Liu, Kai Peng, Zhicheng Yu,