98%
921
2 minutes
20
This paper takes industrial robot disordered object grasping as its research background and proposes an object recognition method based on binocular laser three-dimensional (3D) scanning imaging for the characteristics of grasping objects with complex structures, single surface colors, and scattered stacking. First, to address the issue of incomplete data in the 3D reconstruction of stacked scenes caused by self-obscuration and mutual occlusion of objects, this paper proposes a binocular laser scanning 3D imaging method that utilizes a rapid fusion of multi-source point cloud data. Secondly, this paper reports improved point cloud matching of a pose estimation algorithm based on the point pair feature (PPF) to achieve accurate pose estimation of scattered stacked objects. In the offline training stage, the hidden point removal (HPR) method is introduced to impose visibility constraints, eliminating interference from occluded points and achieving a more accurate global description of the model. In the online matching stage, farthest point sampling (FPS) is applied to the scene point cloud to improve the uniformity of the sampling results. Through Hough voting, candidate poses are quickly obtained. The rough estimation of the object pose was completed by adjusting the grasping pose screening strategy to remove the mismatched poses. Finally, the iterative closest point (ICP) algorithm is used to optimize the poses and obtain more accurate pose results. The experimental results demonstrate that the object information reconstruction completeness of the proposed method is significantly improved compared with the original binocular vision and monocular laser vision system, and the recognition time and average error are reduced compared to the original PPF algorithm. Furthermore, the matching success rate is 100% in 20 cluttered scenes. In the actual grasping experiments, the success rate of grasping is 93.3%, which verifies the proposed method's effectiveness for cluttered occlusion.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/AO.534520 | DOI Listing |
J Refract Surg
September 2025
Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio.
Purpose: To report a case of acute and transient accommodative insufficiency after laser in situ keratomileusis (LASIK) due to coronavirus disease 2019 (COVID-19).
Methods: Case report and literature review.
Results: A 36-year-old man complained of acute blurred near vision 7 days after uneventful bilateral hyperopic LASIK, concurrent with the onset of COVID-19 infection.
Clin Ophthalmol
August 2025
NVISION Eye Centers, Rowland Heights, CA, USA.
Purpose: To evaluate cataract surgery outcomes following mix-and-match implantation of a trifocal and extended-depth-of-focus (EDOF) intraocular lens (IOL).
Setting: Single center, private practice.
Design: Single arm, non-interventional, ambispective study.
J Clin Med
August 2025
Department of Ophthalmology, LMU University Hospital, LMU Munich, 80336 Munich, Germany.
: To evaluate the safety and efficacy of the simultaneous implantation of a monofocal capsular bag-fixated and a trifocal supplementary sulcus-fixated intraocular lens (duet procedure) in eyes with co-existing pathologies undergoing cataract or refractive lens surgery. : In total, 80 eyes of 40 consecutive patients, who underwent refractive lens exchange or cataract surgery and received the duet procedure due to minor co-pathologies, were included in this retrospective case series. Preoperative assessment comprised slit-lamp biomicroscopy, optical biometry, posterior-segment optical coherence tomography, corneal endothelial specular microscopy, corneal tomography, manifest refraction and distance and near visual acuity testing.
View Article and Find Full Text PDFNanomaterials (Basel)
July 2025
Xi'an Key Laboratory of Active Photoelectric Imaging Detection Technology, Xi'an Technological University, Xi'an 710021, China.
Optical materials are widely used in large optical systems such as lithography machines and astronomical telescopes. However, optical materials inevitably produce subsurface damage (SSD) during lapping and polishing processes, degrading the laser damage threshold and impacting the service life of the optical system. The large surface roughness of the lapped optical materials further increases the difficulty of the nondestructive detection of SSD.
View Article and Find Full Text PDFSpaceborne telescopes are vital components in space-based gravitational wave (GW) detection observatories, utilized for receiving and emitting laser signals to facilitate heterodyne interferometric displacement measurements. The coupling of wavefront aberrations with tilt-to-length (TTL) noise in space gravitational wave telescopes is a pivotal factor impacting measurement accuracy and warrants thorough attention. This research endeavors to achieve a telescope design with high optical path stability by reducing non-geometric TTL coupling noise, aiming to keep such noise beneath the threshold of 0.
View Article and Find Full Text PDF