scholarly journals Fast Synchronization Method of Comb-Actuated MEMS Mirror Pair for LiDAR Application

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1292
Author(s):  
Fahu Xu ◽  
Dayong Qiao ◽  
Changfeng Xia ◽  
Xiumin Song ◽  
Yaojun He
Keyword(s):  
Phase Synchronization ◽  
Low Cost ◽  
Three Dimensional ◽  
Micro Electro Mechanical System ◽  
Frame Rate ◽  
Lidar System ◽  
Synchronization Process ◽  
Synchronization Method ◽  
Mirror Pair ◽  
Set Up

MEMS-based LiDAR (micro-electro–mechanical system based light detection and ranging), with a low cost and small volume, becomes a promising solution for the two-dimensional (2D) and three-dimensional (3D) optical imaging. A semi-coaxial MEMS LiDAR design, based on a synchronous MEMS mirror pair, was proposed in our early study. In this paper, we specifically reveal the synchronization method of the comb-actuated MEMS mirror pair, including the frequency, amplitude, and phase synchronization. The frequency sweeping and phase adjustment are simultaneously implemented to accelerate the MEMS mirror synchronization process. The experiment is set up and the entire synchronization process is completed within 5 s. Eventually, a one-beam MEMS LiDAR system with the synchronous MEMS mirror pair is set up and a LiDAR with a field of view (FOV) of 60°, angular resolution of 0.2°, and frame rate of 360 Hz is obtained. The experimental results verify the feasibility of the MEMS mirror synchronization method and show a promising potential application prospect for the MEMS LiDAR system.

Optimum Design for the Frame of Open Type Abrasive Flow Polish Machine

2012 ◽  
Vol 497 ◽  
pp. 89-93
Author(s):  
Liang Liang Yuan ◽  
Ke Hua Zhang ◽  
Li Min
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Finite Element Methods ◽  
Optimization Design ◽  
Low Cost ◽  
Three Dimensional ◽  
Force Model ◽  
Optimization Analysis ◽  
Open Type ◽  
Set Up

In order to process heterotype hole of workpiece precisely, an open abrasive flow polish machine is designed, and the optimization design of machine frame is done for low cost. Firstly, basing on the parameters designed with traditional ways, three-dimensional force model is set up with the soft of SolidWorks. Secondly, the statics and modal analysis for machine body have been done in Finite element methods (FEM), and then the optimization analysis of machine frame has been done. At last, the model of rebuild machine frame has been built. Result shows that the deformation angle value of machine frame increased from 0.72′ to 1.001′, the natural frequency of the machine decreased from 75.549 Hz to 62.262 Hz, the weight of machine decreased by 74.178 Kg after optimization. It meets the strength, stiffness and angel stiffness requirement of machine, reduces the weight and cost of machine.

scholarly journals LOW-COST SIMULATOR ASSEMBLY FOR 3-DIMENSIONAL VIDEOSURGERY TRAINING

2018 ◽  
Vol 31 (3) ◽  
Author(s):  
Carlos Magno Queiroz da CUNHA ◽  
Douglas Marques Ferreira de LIMA ◽  
Francisco Julimar Correia de MENEZES
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Skills Training ◽  
Surgical Skills ◽  
3D Video ◽  
Training Methods ◽  
3 Dimensional ◽  
Set Up ◽  
Undergraduate Programs ◽  
Advanced Courses

ABSTRACT Background: Three-dimensional videosurgery is already a reality worldwide. The trainee program for this procedure should be done initially and preferably in simulators. Aim: Assemble low-cost simulator for three-dimensional videosurgery training. Methods: The simulator presented here was mounted in two parts, base and glasses. After, several stations can be inserted into the simulator for skills training in videosurgery. Results: It was possible to set up three dimensional (3D) video simulations with low cost. It has proved to be easy to assemble and allows the training surgeon of various video surgical skills. Conclusion: This equipment may be used in undergraduate programs and advanced courses for residents and surgeons. The acrylic box allows the visualization of the task executed by the tutor and even by other experienced students.

A Three-Dimensional Micro-Electro-Mechanical System (MEMS) Optical Switch Module Using Low-Cost Highly Accurate Polymer Components

2004 ◽  
Vol 43 (8B) ◽  
pp. 5824-5827 ◽  
Author(s):  
Tsuyoshi Yamamoto ◽  
Johji Yamaguchi ◽  
Nobuyuki Takeuchi ◽  
Akira Shimizu ◽  
Renshi Sawada ◽  
...  
Keyword(s):  
Mechanical System ◽  
Optical Switch ◽  
Low Cost ◽  
Three Dimensional ◽  
Micro Electro Mechanical System ◽  
Switch Module

Small-Scale Models for Testing Masonry Structures

2010 ◽  
Vol 133-134 ◽  
pp. 497-502 ◽  
Author(s):  
Alvaro Quinonez ◽  
Jennifer Zessin ◽  
Aissata Nutzel ◽  
John Ochsendorf
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Three Dimensional ◽  
Model Testing ◽  
Scale Model ◽  
Small Scale ◽  
Material Strength ◽  
Masonry Structures ◽  
Scale Models ◽  
Set Up

Experiments may be used to verify numerical and analytical results, but large-scale model testing is associated with high costs and lengthy set-up times. In contrast, small-scale model testing is inexpensive, non-invasive, and easy to replicate over several trials. This paper proposes a new method of masonry model generation using three-dimensional printing technology. Small-scale models are created as an assemblage of individual blocks representing the original structure’s geometry and stereotomy. Two model domes are tested to collapse due to outward support displacements, and experimental data from these tests is compared with analytical predictions. Results of these experiments provide a strong understanding of the mechanics of actual masonry structures and can be used to demonstrate the structural capacity of masonry structures with extensive cracking. Challenges for this work, such as imperfections in the model geometry and construction problems, are also addressed. This experimental method can provide a low-cost alternative for the collapse analysis of complex masonry structures, the safety of which depends primarily on stability rather than material strength.

scholarly journals OptiJ: Open-source optical projection tomography of large organ samples

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pedro P. Vallejo Ramirez ◽  
Joseph Zammit ◽  
Oliver Vanderpoorten ◽  
Fergus Riche ◽  
Francois-Xavier Blé ◽  
...  
Keyword(s):  
Open Source ◽  
Low Cost ◽  
Three Dimensional ◽  
Optical Projection Tomography ◽  
Optical Components ◽  
Adult Mice ◽  
Optical Projection ◽  
Set Up ◽  
Imagej Plugin ◽  
Lung Lobes

Abstract The three-dimensional imaging of mesoscopic samples with Optical Projection Tomography (OPT) has become a powerful tool for biomedical phenotyping studies. OPT uses visible light to visualize the 3D morphology of large transparent samples. To enable a wider application of OPT, we present OptiJ, a low-cost, fully open-source OPT system capable of imaging large transparent specimens up to 13 mm tall and 8 mm deep with 50 µm resolution. OptiJ is based on off-the-shelf, easy-to-assemble optical components and an ImageJ plugin library for OPT data reconstruction. The software includes novel correction routines for uneven illumination and sample jitter in addition to CPU/GPU accelerated reconstruction for large datasets. We demonstrate the use of OptiJ to image and reconstruct cleared lung lobes from adult mice. We provide a detailed set of instructions to set up and use the OptiJ framework. Our hardware and software design are modular and easy to implement, allowing for further open microscopy developments for imaging large organ samples.

scholarly journals Affordable Three-Dimensional Printed Heart Models

2021 ◽  
Vol 8 ◽  
Author(s):  
Gorka Gómez-Ciriza ◽  
Tomás Gómez-Cía ◽  
José Antonio Rivas-González ◽  
Mari Nieves Velasco Forte ◽  
Israel Valverde
Keyword(s):  
3D Printing ◽  
Medical Training ◽  
Low Cost ◽  
Three Dimensional ◽  
Point Of View ◽  
Cardiac Device ◽  
Three Dimensional Printing ◽  
Average Production ◽  
Set Up ◽  
Dimensional Printing

This is a 7-years single institution study on low-cost cardiac three-dimensional (3D) printing based on the use of free open-source programs and affordable printers and materials. The process of 3D printing is based on several steps (image acquisition, segmentation, mesh optimization, slicing, and three-dimensional printing). The necessary technology and the processes to set up an affordable three-dimensional printing laboratory are hereby described in detail. Their impact on surgical and interventional planning, medical training, communication with patients and relatives, patients' perception on care, and new cardiac device development was analyzed. A total of 138 low-cost heart models were designed and printed from 2013 to 2020. All of them were from different congenital heart disease patients. The average time for segmentation and design of the hearts was 136 min; the average time for printing and cleaning the models was 13.5 h. The average production cost of the models was €85.7 per model. This is the most extensive series of 3D printed cardiac models published to date. In this study, the possibility of manufacturing three-dimensional printed heart models in a low-cost facility fulfilling the highest requirements from a technical and clinical point of view is demonstrated.

scholarly journals GEOMATIC ARCHAEOLOGICAL RECONSTRUCTION AND A HYBRID VIEWER FOR THE ARCHAELOGICAL SITE OF CÁPARRA (SPAIN)

2018 ◽  
Vol XLII-2 ◽  
pp. 1105-1111 ◽  
Author(s):  
C. Tejeda-Sánchez ◽  
A. Muñoz-Nieto ◽  
P. Rodríguez-Gonzálvez
Keyword(s):  
Cross Sections ◽  
Low Cost ◽  
Three Dimensional ◽  
3D Models ◽  
Site Survey ◽  
Topographic Survey ◽  
Cad Models ◽  
Close Range ◽  
Archaeological Reconstruction ◽  
Set Up

Visualization and analysis use to be the final steps in Geomatics. This paper shows the workflow followed to set up a hybrid 3D archaeological viewer. Data acquisition of the site survey was done by means of low-cost close-range photogrammetric methods. With the aim not only to satisfy the general public but also the technicians, a large group of Geomatic products has been obtained (2d plans, 3d models, orthophotos, CAD models coming from vectorization, virtual anastylosis, and cross sections). Finally, all these products have been integrated into a three-dimensional archaeological information system. The hybrid archaeological viewer designed allows a metric and quality approach to the scientific analysis of the ruins, improving, thanks to the implementation of a database, and its potential for queries, the benefits of an ordinary topographic survey.

scholarly journals A Study of Correction to the Point Cloud Distortion Based on MEMS LiDAR System

2021 ◽  
Vol 11 (5) ◽  
pp. 2418
Author(s):  
Dongbing Guo ◽  
Chunhui Wang ◽  
Baoling Qi ◽  
Yu Zhang ◽  
Qingyan Li
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Scanning Speed ◽  
Correction Method ◽  
Micro Electro Mechanical System ◽  
Imaging Systems ◽  
Lidar System ◽  
Active Imaging ◽  
Scanning Lidar ◽  
Coordinate Correction

Active imaging technology can perceive the surrounding environment and obtain three-dimensional information of the target. Among them, light detection and ranging (LiDAR) imaging systems are one of the hottest topics in the field of photoelectric active imaging. Due to the small size, fast scanning speed, low power consumption, low price and strong anti-interference, a micro-electro-mechanical system (MEMS) based micro-scanning LiDAR is widely used in LiDAR imaging systems. However, the imaging point cloud will be distorted, which affects the accurate acquisition of target information. Therefore, in this article, we analyzed the causes of distortion initially, and then introduced a novel coordinate correction method, which can correct the point cloud distortion of the micro-scanning LiDAR system based on MEMS. We implemented our coordinate correction method in a two-dimensional MEMS LiDAR system to verify the feasibility. Experiments show that the point cloud distortion is basically corrected and the distortion is reduced by almost 72.5%. This method can provide an effective reference for the correction of point cloud distortion.

Improving the Quality of Low-Cost GPS Receiver Data for Monitoring Using Spatial Correlations

2016 ◽  
Vol 10 (2) ◽  
Author(s):  
Li Zhang ◽  
Volker Schwieger
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Single Frequency ◽  
Spatial Correlations ◽  
Gps Receivers ◽  
Engineering Geodesy ◽  
Monitoring Applications ◽  
Set Up ◽  
Metal Wall

AbstractThe investigations on low-cost single frequency GPS receivers at the Institute of Engineering Geodesy (IIGS) show that u-blox LEA-6T GPS receivers combined with Trimble Bullet III GPS antennas containing self-constructed L1-optimized choke rings can already obtain an accuracy in the range of millimeters which meets the requirements of geodetic precise monitoring applications (see [For this purpose, several adjoined stations with low-cost GPS receivers and antennas were set up next to the metal wall on the roof of the IIGS building and measured statically for several days. The time series of three-dimensional coordinates of the GPS receivers were analyzed. Spatial correlations between the adjoined stations, possibly caused by multipath effect, will be taken into account. The coordinates of one station can be corrected using the spatial correlations of the adjoined stations, so that the quality of the GPS measurements is improved.The developed algorithms are based on the coordinates and the results will be delivered in near-real-time (in about 30 minutes), so that they are suitable for structural health monitoring applications.

scholarly journals Three-dimensional modeled environments versus 360 degree panoramas for mobile virtual reality training

2021 ◽  
Author(s):  
K. A. Ritter ◽  
Terrence L. Chambers
Keyword(s):  
Virtual Reality ◽  
Low Cost ◽  
Three Dimensional ◽  
3D Models ◽  
Breakdown Time ◽  
Virtual Field ◽  
Actual Environment ◽  
Vr Training ◽  
Set Up ◽  
Normalized Gain

AbstractVirtual field trip is a way of providing users with some knowledge and exposure of a facility without requiring them to physically visit the location. Due to the high computational costs that are necessary to produce virtual environments (VEs), the potential for photorealism is sacrificed. Often these three-dimensional (3D) modeled applications use an unrealistic VE and, therefore, do not provide a full depiction of real-world environments. Panoramas can be used to showcase complex scenarios that are difficult to model and are computationally expensive to view in virtual reality (VR). Utilizing 360° panoramas can provide a low-cost and quick-to-capture alternative with photorealistic representations of the actual environment. The advantages of photorealism over 3D models for training and education are not clearly defined. This paper initially summarizes the development of a VR training application and initial pilot study. Quantitative and qualitative study then was conducted to compare the effectiveness of a 360° panorama VR training application and a 3D modeled one. Switching to a mobile VR headset saves money, increases mobility, decreases set-up and breakdown time, and has less spatial requirements. Testing results of the 3D modeled VE group had an average normalized gain of 0.03 and the 360° panorama group, 0.43. Although the 3D modeled group had slightly higher realism according to the presence questionnaire and had slightly higher averages in the comparative analysis questionnaire, the 360° panorama application has shown to be the most effective for training and the quickest to develop.

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