Linear capacitive encoder and position determing method

Abstract

Embodiments of the present invention provide a capacitive linear encoder that can enable incremental displacement measurement with a differential configuration and determine absolute position of a movable plate by digitally encoding pitch bars disposed in a single linear transmitter line on a static plate of the encoder. The encoder further includes a signal generator, a controller, an incremental processing module and an absolute processing module. The encoder can offer both incremental and absolute measurement modes and combine robustness with high measurement resolution.

Description

technical field [0001] Embodiments of the invention relate to linear encoders and corresponding methods of position determination, and more particularly to linear capacitive encoders that can provide absolute position measurement and relatively high measurement resolution. Background technique [0002] In existing manufacturing environments, linear encoders (which can be used to measure motion displacement) are widely used for speed and position control of motors. In general, encoders use one of two types of measurement schemes: absolute and incremental. [0003] Absolute encoders provide immediate absolute position measurement when the system is initialized or restarted after a shutdown, without first using a reset routine. However, absolute encoders are generally more costly and larger than incremental encoders. [0004] In contrast, incremental encoders calculate the absolute position by measuring relative displacement and require a reference point for this calculation....

AI Technical Summary

Problems solved by technology

First, encoder resolution and accuracy are limited by analog-based absolute position detection methods

Secondly, in order to detect the absolute position, the encoder uses a multi-track structure, which is relatively large in size and expensive to manufacture

Third, the untethered capacitive encoders described above only provide incremental position information

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