Wear tolerant hydraulic / pneumatic piston position sensing using optical sensors
US10365370B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Jul 3, 2017 |
| Grant date | Jul 30, 2019 |
| Priority date | — |
| Expiry date | Jul 15, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2210/52
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to using a self calibrating and recalibrating 230, 925 optical sensors piston rod displacement. Self calibration enables field calibration of uncalibrated 230, 925 optical sensors. During operation, recalibration enables detecting and correcting for wear and damage of the 200 piston rod and/or 230, 925 optical sensors. 210 Calibration positions on the surface of the 200 piston rod are imaged by 230 optical sensors using laser or darkfield lenses designed for optical computer mice. Natural surface patterns can be used in locations where 210 calibration positions are required, which reduces or eliminates the need for marked 210 calibration positions. Marked 210 calibration positions are spatially unique encoded sequences used to determine the piston rod absolute position. Storing only the significant features of 210 calibration positions saves significant memory. The reduced memory requirements of each 210 calibration position enables the use of closely spaced or continuous 210 calibration positions. Multiple 210 calibration position features and multiple 230, 925 optical sensors together collectively provide immunity to localized 208 surface damage. Pro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.