- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 6th International Conference on Systems and Informatics (ICSAI) - Shanghai, China (2019.11.2-2019.11.4)] 2019 6th International Conference on Systems and Informatics (ICSAI) - An electromagnetic and piezoelectric coupled energy harvester using cantilever beam for low frequency vibration
摘要： With the emergence of the Microsoft Kinect sensor, many developer communities and research groups have found countless uses and have already published a wide variety of papers that utilize the raw depth images for their specific goals. New methods and applications that use the device generally require an appropriately large ensemble of data sets with accompanying ground truth for testing purposes, as well as accurate models that account for the various systematic and stochastic contributors to Kinect errors. Current error models, however, overlook the intermediate infrared (IR) images that directly contribute to noisy depth estimates. We, therefore, propose a high fidelity Kinect IR and depth image predictor and simulator that models the physics of the transmitter/receiver system, unique IR dot pattern, disparity/depth processing technology, and random intensity speckle and IR noise in the detectors. The model accounts for important characteristics of Kinect’s stereo triangulation system, including depth shadowing, IR dot splitting, spreading, and occlusions, correlation-based disparity estimation between windows of measured and reference IR images, and subpixel refinement. Results show that the simulator accurately produces axial depth error from imaged flat surfaces with various tilt angles, as well as the bias and standard lateral error of an object’s horizontal and vertical edge.
关键词： simulation,Computer-aided design (CAD),Microsoft Kinect,infrared (IR) dot pattern,structured-light 3-D scanner,speckle noise
更新于2025-09-23 15:19:57
-
[IEEE OCEANS 2018 MTS/IEEE Charleston - Charleston, SC, USA (2018.10.22-2018.10.25)] OCEANS 2018 MTS/IEEE Charleston - High-resolution structured light D sensor for autonomous underwater inspection
摘要： Sensors that can provide detailed 3D data underwater are a prerequisite for enabling autonomous inspection of e.g. seafloor integrity, ocean habitats and subsea installations with unmanned underwater vehicles. Sonars are currently the primary source of 3D data on moving platforms subsea but have limited depth and lateral resolution. Several optical approaches exist such as passive stereo, which have problems with textureless objects, and LIDARs which are slow and provide low lateral resolution. In this work we explore the use of structured light, to achieve high-resolution 3D of objects in an underwater environment. We have adapted a Gray Code Phase Stepping (GCPS) structured light approach to be more robust to the contrast degradation caused by the scattering and attenuation of light in water. The robustness towards increasing water turbidity has been verified in pool experiments. We achieve a depth resolution ranging from 1.4mm to 6.4mm depending on the turbidity when imaging an object at 1.1m distance with a pixel resolution of 1280x1024 at a framerate of 8Hz.
关键词： underwater,turbidity,Gray code,Structured light,3D
更新于2025-09-19 17:15:36
-
Unsupervised texture reconstruction method using bidirectional similarity function for 3-D measurements
摘要： The developments of three-dimensional (3-D) imaging and display technology have created important demands for 3-D model with realistic texture. Due to texture misalignment and inconsistent illumination, texture reconstruction is subject to degradation like blurring, ghosting and color discontinuity. A composite weight texture blending approach is proposed to mitigate the artifacts. For inaccurate geometric model, bidirectional similarity function based multi-scale energy minimization method is proposed to correct texture misalignment. The average processing time of the proposed method is only 40% of existing method. The optical experiments demonstrate that photorealistic texture could be achieved for inaccurate geometric model and inconsistent illumination.
关键词： 3-D measurement,Structured light,Bidirectional similarity function,Texture reconstruction,Pinhole camera model
更新于2025-09-19 17:15:36
-
Structured Light from Lasers
摘要： Structured light is derived from the ability to tailor light, usually referring to the spatial control of its amplitude, phase, and polarization. Although a venerable topic that dates back to the very first laser designs, structuring light at the source has seen an explosion in activity over the past decade, fuelled by a modern toolkit that exploits the versatility of diffractive structures, liquid crystals, metasurfaces/metamaterials, and exotic laser geometries, as well as a myriad of applications that range from imaging, microscopy, and laser material processing to optical communication. Here, the recent progress in creating and controlling structured light is reviewed, with particular emphasis on structuring light at the source: structured light lasers. The various design approaches, including pump shaping, cavity geometries, and the use of custom intracavity optical elements, implemented in a variety of lasers from microchip solutions to high-power fibers are covered in a tutorial style. The history and latest developments in the field are reviewed, elucidating the various structured light patterns that have been created from lasers, including orbital angular momentum and vector states of light. Finally, the present challenges and limitations are highlighted, along with comments on likely future trends.
关键词： optical modes,random lasers,topological lasers,orbital angular momentum,vector beams,structured light
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Integration of Photovoltaic Systems into Smart Grids Demonstration of Solar-, Storage and E-Mobility Applications within a Secure Energy Information Network in Germany
摘要： With the emergence of the Microsoft Kinect sensor, many developer communities and research groups have found countless uses and have already published a wide variety of papers that utilize the raw depth images for their specific goals. New methods and applications that use the device generally require an appropriately large ensemble of data sets with accompanying ground truth for testing purposes, as well as accurate models that account for the various systematic and stochastic contributors to Kinect errors. Current error models, however, overlook the intermediate infrared (IR) images that directly contribute to noisy depth estimates. We, therefore, propose a high fidelity Kinect IR and depth image predictor and simulator that models the physics of the transmitter/receiver system, unique IR dot pattern, disparity/depth processing technology, and random intensity speckle and IR noise in the detectors. The model accounts for important characteristics of Kinect’s stereo triangulation system, including depth shadowing, IR dot splitting, spreading, and occlusions, correlation-based disparity estimation between windows of measured and reference IR images, and subpixel refinement. Results show that the simulator accurately produces axial depth error from imaged flat surfaces with various tilt angles, as well as the bias and standard lateral error of an object’s horizontal and vertical edge.
关键词： simulation,Computer-aided design (CAD),Microsoft Kinect,infrared (IR) dot pattern,structured-light 3-D scanner,speckle noise
更新于2025-09-19 17:13:59
-
Development of an In-Situ Laser Machining System Using a Three-Dimensional Galvanometer Scanner
摘要： In this study, an in-situ three-dimensional (3D) laser machining system integrating laser measurement and machining was built using a 3D galvanometer scanner equipped with a side-axis industrial camera. A line structured light measurement model based on a galvanometer scanner was proposed to obtain the 3D information of the workpiece. A height calibration method was proposed to further ensure measurement accuracy, so as to achieve accurate laser focusing. In-situ machining software was developed to realize time-saving and labor-saving 3D laser processing. The feasibility and practicability of this in-situ laser machining system were veri?ed using speci?c cases. In comparison with the conventional line structured light measurement method, the proposed methods do not require light plane calibration, and do not need additional motion axes for 3D reconstruction; thus they provide technical and cost advantages. The in-situ laser machining system realizes a simple operation process by integrating measurement and machining, which greatly reduces labor and time costs.
关键词： Line structured light,Three-dimensional galvanometer scanner,In-situ laser machining,Three-dimensional measurement
更新于2025-09-12 10:27:22
-
In-process height control during laser metal deposition based on structured light 3D scanning
摘要： Laser metal deposition is an additive manufacturing process capable of layer by layer construction of solid parts. An incorrect deposition distance between nozzle and substrate can result in height deviations from the ideal building path. The error can be propagated along layers, leading to an irreversible defect. Maintaining an optimal distance between the nozzle and the substrate is therefore a critical aspect. This paper introduces an off-line geometric control system for in-process measurement and build path correction. A structured light based 3D scanner measures the build height from an external, fixed position, providing more precise results than moving measuring systems. The deposition is stopped in certain stages of the process and the piece is scanned generating a three-dimensional point cloud. Processing of the collected data allows the build height determination. A control algorithm was developed to take corrective actions in accordance with the measured error. The system enables an accurate control of the generated geometry and permits the comparison with the original computer design. This approach reduces the required human supervision during the process and the occurrence of non-valid parts. The effectiveness of the method was proved through the contrast of parts built with and without control, showing a more accurate reproduction of the generated solid parts when corrections are applied.
关键词： monitoring,Laser Metal Deposition (LMD),additive manufacturing,control,metrology,structured light,3D scanning
更新于2025-09-12 10:27:22
-
Influences of process conditions on stability of sensor controlled robot-based laser metal deposition
摘要： Robot-guided Laser Metal Deposition (LMD) process offers an efficient and resource-friendly production of big complex metals parts. In order to produce high-quality parts with minimum post-processing time, a highly stable process is required. The LMD process is characterized by numerous influencing physical parameters that lead to melt-pool instability, which results in shape irregularities in the component, followed by longer post-processing time. For process stability, control systems are necessary, which react to the occurring process and part deviations. The harsh environmental and process conditions impose high mechanical and thermal stresses on the sensors, which impact the accuracy of the system. In this paper, the factors influencing the accuracy of the sensors have been presented. The usability and stability of geometry control strategies with sensors have been evaluated against strategies without sensors. Additionally, the sensor system requirements for irregularity detection have been reported along with the guidelines developed for the implementation of a robust sensor control system for robot-based LMD processes.
关键词： Structured Light Sensor,Geometry Control,Sensor-Robot Control System,Sensors,Laser Metal Deposition
更新于2025-09-12 10:27:22
-
Controllable spatial array of optical needles with independent axial intensity distributions for laser microprocessing
摘要： Due to their high length to width ratio nondiffracting beams are usually perceived as “optical needles”. We construct an “optical needle” with an arbitrary longitudinal intensity distribution and change the spatial position of it in the focal region of a lens. Next, we introduce a spatial array of independent “optical needles” and report on physical limitations due to mutual interference of individual beams. We employ a spatial light modulator as a toy model of an actual geometrical phase element and experimentally observe controllable spatial arrays with various numbers and spatial separations of individual beam. Lastly, we examine the distortions caused by propagation through planar air-dielectric interface and attempt to compensate it.
关键词： Structured light,Focal lines,Diffraction,Optical Needle,Multiple focal spots,Optical engineering,Bessel beams
更新于2025-09-12 10:27:22
-
Vector Mathieu beam profile engineering for laser material processing applications
摘要： Beam profile engineering where a desired optical intensity distribution can be generated by an array of phase shifting elements is a promising approach in laser material processing. Scalar Mathieu beams have elliptical intensity distribution perceivable as “optical knives” in the transverse plane. They exhibit non-diffracting properties similar to Bessel beams, where a relatively long focal depth retains unchanging intensity distribution, which makes Mathieu beams a promising approach in laser processing. Here, we introduce additionally vector Mathieu beams with controllable polarization and investigate numerically their spatial spectra. Further, we attempt to generate individual components of vector Mathieu beams experimentally using SLMs. We report on our achievements in the control over the beam shape and dimensions along the propagation axis.
关键词： Spatial light modulator,Nondiffracting beams,Polarization,Mathieu beams,Structured light
更新于2025-09-11 14:15:04