Method and apparatus for laser projection, and machining method

Patent metadata

Field	Value
Publication number	US-9644942-B2
Application number	US-201314079515-A
Country	US
Kind code	B2
Filing date	Nov 13, 2013
Priority date	Nov 29, 2012
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A laser projection method including the steps of: irradiating, from a laser projection unit, a workpiece that is a measurement object, with a laser while controlling a plurality of mirror angles; imaging the workpiece with a stereo camera, extracting a contour of the workpiece, and calculating a three-dimensional coordinate; calculating a positional relationship between the laser projection unit and the workpiece by comparing the calculated three-dimensional coordinate of the workpiece contour with the minor angle; and performing coordinate transformation of CAD data information and drawing CAD data from the laser projection unit to the workpiece, based on the positional relationship between the laser projection unit and the workpiece. The machining method including the steps of: selecting a component of a tool; assembling the component; imaging the tool assembled; and determining whether or not a desired tool has been assembled.

First claim

The invention claimed is:

1. A laser projection method comprising:
irradiating, from a laser projection unit, a laser on a workpiece at at least three different positions on the workpiece, which is a measurement object, by controlling respective angles of a plurality of mirrors;
storing the angles at which each of the plurality of mirrors are disposed when each of the at least three different positions are irradiated on the workpiece;
measuring three-dimensional coordinates of the at least three positions with a stereo camera;
calculating a positional relationship between the laser projection unit and the workpiece by comparing the at least three three-dimensional coordinates with the stored angles of the plurality of mirrors;
performing coordinate conversion of Computer Aided Design (CAD) data based on the positional relationship between the laser projection unit and the workpiece to generate data for irradiating the laser; and
controlling the angles of the plurality of mirrors and irradiating the laser on the workpiece to draw on the workpiece based on the generated data for irradiating the laser.

2. The laser projection method according to claim 1 , further comprising the steps of:
comparing a three-dimensional coordinate of said CAD data with the three-dimensional coordinate of an actual contour of said workpiece and indicating this comparison result.

3. The laser projection method according to claim 2 ,
wherein said comparison result is indicated on a display.

4. A laser projection apparatus comprising:
a laser projection unit to irradiate a laser on a workpiece at at least three different positions on the workpiece, which is a measurement object, by respectively controlling a plurality of mirror angles;
a memory to store the angles at which of each of the plurality of mirrors are disposed when each of the at least three different positions are irradiated on the workpiece;
a coordinate calculation unit to measure three-dimensional coordinates of the at least three positions with a stereo camera;
a relative positional relationship calculation unit to calculate a positional relationship between the laser projection unit and the workpiece by comparing the at least three three-dimensional coordinates with the stored angles of the plurality of mirrors; and
a CAD data conversion unit to perform coordinate conversion of Computer Aided Design (CAD) data based on the positional relationship between the laser projection unit and the workpiece to generate data for irradiating the laser,
wherein the laser projection unit controls the angles of the plurality of mirrors and irradiates the laser on the workpiece to draw on the workpiece based on the generated data for irradiating the laser.

Assignees

• Mitsubishi Hitachi Power Sys

Inventors

• Nakano Hiroyuki
• Seya Nobuhisa
• Igarashi Daisuke
• Igarashi Kazuhiro
• Maekawa Youhei
• Numayama Katsuto

Classifications

• G05B2219/45165

  Laser machining · CPC title

• B23Q17/2428

  for measuring existing positions of tools or workpieces · CPC title

• B23Q17/2233

  for adjusting the tool relative to the workpiece · CPC title

• G01B11/2545 Primary

  with one projection direction and several detection directions, e.g. stereo · CPC title

• G01B11/25

  by projecting a pattern, e.g. {one or more lines,} moiré fringes on the object (G01B11/255 takes precedence {; image analysis for depth or shape recovery G06T7/50}) · CPC title