## Measurement and analysis technology

## Manufacturing Technology

# Development of a highly accurate non-contact shape and displacement measurement system

Keyword: Shape and displacement measurement system, Grating projection method, High accuracy, Calibration method

## Organizations Involved

☐ Yoshiharu Morimoto, Prof. and Motoharu Fujigaki, Assoc. Prof., Faculty of Systems Engineering, Wakayama University

☐ Shien Ri, Research Fellowship for Young Scientists, Japan Society for the Promotion of Science

☐ Ryoichi Takesako, General Manager, Planning and Developing Division, Nippon Gijutsu Center Co., LTD.

## 【Abstract】

Wakayama University has been studying non-contact shape and displacement measurement principles. Nippon Gijutsu Center Co., Ltd has been developing non-contact 3D measurement equipment using laser beams and also has techniques and know-how in development of optical systems and software. In order to realize the commercialization of the ideas of Wakayama University's, a prototype model was manufactured. The equipment can measure an object with a height of 50 mm in a 150 mm field of view to an accuracy of 3 $ \mu $ m.

## [Summary of the technology transfer]

●Technological Impact

• Our Fourier transformation phase-shifting method allows highly accurate phase analysis of the projected grating.

• Lens distortion aberration can be entirely removed by a calibration method that obtains the visual line of each pixel of a camera using the reference plane.

• By developing shape measurement equipment with these methods, it is possible to measure an object with a height of 50 mm in a 150 mm field of view to an accuracy of 3 $ \mu $ m.

• Measurement can be performed in a short time (several 10's of seconds).

• For an object with different reflectances and colors, affect can be reduced by a fringe pattern measured data combination method that uses an evaluated value.

• It is useful for metal bodies with halation.

• Miniaturization and lightening of the equipment has been achieved.

• Social Impact

• Product inspection used to take a long time. Using our technique, it can be performed in a short time.

• By developing inexpensive equipment, medium and small companies can easily adopt it.

• If this equipment is adopted in many industries, they can save time and cost which leads to an advance in delivery date and quality improvement.

• Accordingly, this contributes to an increase in Japanese industries' international competitiveness.

## Project Background

·Mr. R. Takesako found that Wakayama University was doing research on shape measurement by an internet search.

• When the prototype was presented at an exhibition, visitors showed interest. This confirmed interest in its development.

## Funding History

1. 1998, 1999 Grants-in-Aid for Scientific Research "Grant-in-Aid for Encouragement of Scientists"

The prototype model (Compact and lightweight)

2. 2000 JST "Technology processing"

3. 2006 JST "Original modeling program"

## I ntellectual property protection

Patent acquisition: Domestic 15

「Method and equipment for shape

measurement, Patent No. 2913021, etc.

Patent application: Domestic 16

Measuring an aluminum part.

(Measurement of the steep parts

can be performed.)

## Turning point in the Project

OFunding by JST original modeling project was a big factor of success.

OFor general purpose measurement equipment, it is very important to confirm needs concurrently with development.