The wave-dissipating blocks are stacked on the breakwater as a protective structure to protect beaches, ports, and harbors from the erosion of waves. However, the motion and corrosion of sea waves also cause irreversible damage to the blocks, causing these structures to sink and even ablate. Therefore, regular supplementary work is required to maintain the height of the breakwater. This study aims to accurately estimate the number of supplemental blocks and their stacking poses using a physics engine. In addition, we propose an estimation algorithm of new block poses stacked on the existing block models derived from UAV and MBES scanned points.

We propose two-wavelength FMCW-Digital Holography (DH) for three-dimensional shape measurement, which is a combination of FMCW-DH and two-wavelength method. By choosing the corresponding beat frequency in the frequency domain, the complex amplitude of hologram for each wavelength can be selected, independently. Therefore, the optical system achieves a common path for two-wavelength beams and requires no mechanical moving parts. In addition, it is possible to reconstruct the object waves by effectively utilizing the whole pixels of the image sensor. In this study, the proposed technique was applied to measure the surface profile of the metallic plates having the known step height and the measurement accuracy was evaluated.

Operators of refuse incineration plants require high decision-making skills to operate the refuse crane while recognizing the amount and type of garbage in the refuse pits. However, they are faced with the problem of a declining domestic workforce. We have been working on the automatic operation of the refuse crane, and have developed a technology for recognizing garbage in the refuse pits and judging the operation to replace the operators. In this presentation, we introduce a real-time measurement technology for the garbage amount in the refuse pits, and a method for interpolating and removing outliers from the measured point clouds.

Precise 6-DOF alignment of lenses and sensors is essential for the manufacture of high-performance cameras. The conventional 2D chart method requires multiple imaging with different focal points, so time and accuracy are problems. In this report, 6-DOF alignment error is obtained from a 3D chart image. Since it needs only one image, it is a high speed and accurate. Furthermore, the roof-type 3D chart can simultaneously measure SFR (spatial frequency response) at 100 or more points. Experiments have shown that it is 3 times faster and more accurate than conventional methods.