公开(公告)号：US09773190B2

公开(公告)日：2017-09-26

申请号：US14981815

申请日：2015-12-28

Applicant: NATIONAL CHUNG-SHAN INSTITUTE OF SCIENCE AND TECHNOLOGY

Inventor： Yi-Yuh Hwang ,  Guang-Sheen Liu ,  Chin-Der Hwang ,  Wei-Guo Chang ,  Chih-Ming Liao

IPC: G06K9/52 ,  G06T7/60 ,  G06K9/62 ,  G06T7/00 ,  G01D5/347 ,  G01D18/00 ,  G01B11/26 ,  G01D5/30 ,  G06K9/32 ,  G06K9/46 ,  G06K9/74 ,  G01B21/04 ,  G01B5/008 ,  G01B11/00

CPC classification number: G06K9/52 ,  G01B5/008 ,  G01B11/005 ,  G01B11/26 ,  G01B21/042 ,  G01D5/30 ,  G01D5/3473 ,  G01D18/00 ,  G06K9/32 ,  G06K9/4671 ,  G06K9/6201 ,  G06K9/74 ,  G06T7/60

Abstract: The present invention mainly provides a precision calibration method for being applied in a high-precise rotary encoder system, wherein the primary technology feature of the precision calibration method is that: using a laser speckle image capturing module to capture N frames of laser speckle image from an optical position surface of a rotary encoding body, and then using image comparison libraries and particularly-designed mathematical equations to calculate N number of image displacements, so as to eventually calculate N number of primary variation angles and sub variation angles corresponding to the N frames of laser speckle image. Therefore, after the rotary encoding body is rotated by an arbitrary angle, an immediate angle coordinate can be precisely positioned according to the primary variation angles, the secondary variation angles and the N number of image displacements.

公开(公告)号：US10189133B2

公开(公告)日：2019-01-29

申请号：US15388496

申请日：2016-12-22

Applicant: NATIONAL CHUNG SHAN INSTITUTE OF SCIENCE AND TECHNOLOGY

Inventor： Yi-Yuh Hwang ,  Wei-Guo Chang ,  Li-Chung Liu

IPC: B23Q11/00 ,  B23Q17/24 ,  G01B11/00 ,  G05B19/402

Abstract: A measurement, calibration and compensation system for machine tool includes a first positioning base; two first speckle image sensors for sensing speckle positions of an object holding unit at a first XY plane and a first XZ plane of the first positioning base before and after the machine tool is started for machining; a second positioning base; two second speckle image sensors for sensing speckle positions of a cutter holding unit at a second XY plane and a second YZ plane of the second positioning base before and after the machine tool is started for machining. Thus, the thermal expansion at all axes of the machine tool can be measured in a simplified and low-cost way, and the absolute positioning coordinates of all axes of the machine tool can be calibrated in real time to avoid reduced positioning accuracy due to the thermal expansion of the multi-axis machine tool.

公开(公告)号：US09671218B2

公开(公告)日：2017-06-06

申请号：US14578597

申请日：2014-12-22

Applicant: NATIONAL CHUNG SHAN INSTITUTE OF SCIENCE AND TECHNOLOGY

Inventor： Yi-Yuh Hwang ,  Wei-Guo Chang ,  Chin-Der Hwang ,  Guang-Sheen Liu ,  Wen-Jen Lin ,  Ping-Ya Ko

IPC: G01B11/02 ,  G01B11/00 ,  G01B9/02

CPC classification number: G01B11/002 ,  G01B9/02094

Abstract: A quick subpixel absolute positioning device and method are introduced. The method includes the steps of (A) capturing a real-time speckle pattern of a target surface; (B) providing a coarse-precision speckle coordinate pattern and a plurality of fine-precision speckle coordinate patterns, wherein the coarse-precision speckle coordinate pattern and the fine-precision speckle coordinate patterns include a coordinate value; (C) comparing the real-time speckle coordinate pattern with the coarse-precision speckle coordinate pattern by an algorithm and then comparing the real-time speckle coordinate pattern with the fine-precision speckle coordinate patterns to obtain a coordinate value, wherein each said coarse-precision speckle coordinate pattern corresponds to a set of fine-precision speckle coordinate patterns, and the fine-precision speckle coordinate patterns are obtained when the coarse-precision speckle coordinate pattern is captured again and then captured repeatedly according to a fixed fine-precision displacement distance. Accordingly, the subpixel positioning is attained by quick comparison and manifests high precision.