With the rise of Industry 4.0, smart factory is fast becoming a key concept in infrastructure. To realize the autonomous production system, it is necessary to ensure the parts are properly manufactured. 3D scanners are expected to play a vital role in quality assessment in smart factories. Especially, amplitude-modulated continuous-wave laser scanners benefit from high accuracy and high sensitivity which are suitable for industrial inspection. However, due to the limited dynamic range of receiver electronics, such laser scanners fail to obtain the data points in 3D measurement of highly reflective objects. This impairment deteriorates the performance of conversion of 3D point clouds to solid data for shape inspection, 3D modeling, reverse engineering etc. We coped with receiver saturation by adopting a high-speed polarizationindependent variable optical attenuator in our laser scanner. With such a lase scanner, we have succeeded in prevention of data loss due to receiver saturation.
Amplitude-modulated continuous-wave laser scanners can realize 3D measurement with high longitudinal resolution. With installation of focusing optics in the laser scanning system, the high lateral resolution can be realized, which is enhanced by the focused beam spot size <100 um. However, the depth-of-focus of the focusing optics is generally several cm. The 3D data of the defocused objects are contaminated by aliases distributed by integer times of the half cycle of the periodical modulation. Aliasing is an impairment inherent in the amplitude-modulated continuous-wave scheme. We experimentally recovered the defocused data drastically by synthesizing those aliases. The ranging area can be elongated by at least ten times with such data processing compared with the depth of focus. Our results will contribute to highprecision industrial inspection for Industry 4.0.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.