ROV Viking SPEAR

2009 ◽  
Vol 43 (3) ◽  
pp. 85-97
Author(s):  
Ian Jasper ◽  
Ricardo Casaine ◽  
Stuart Cook ◽  
Nathan Grefe ◽  
Baxter Hutchinson ◽  
...  

AbstractLong Beach City College returns for our sixth year to enter the 2009 Marine Advanced Technology Education (MATE) remotely operated vehicle (ROV) competition with our latest ROV, the Viking SPEAR (Submarine Personnel Emergency Assistance ROV). The purpose of this ROV is to perform an underwater submarine rescue by inspecting it for damage, replenishing onboard air supplies, and delivering emergency materials to stranded crew members. This year’s ROV, designed in SolidWorks, is cut out of buoyant PVC, has a mass of 21 kg and is built to allow maximum water flow. The ROV is 38 cm high × 87 cm wide and 95 cm long. The major design focus was on redundancy and design functionality. The ROV has two, multi-functional pneumatic grippers, one at each end of the ROV, eight thrusters, and eight cameras covering all angles of viewing. A mating skirt is built into the existing frame design for easy docking on the submarine. These features allow the pilot to execute several tasks set forth by MATE in a timely fashion while providing the redundancy needed for a submarine rescue mission. In accomplishing the design and build of this ROV, the team created over 250 SolidWorks files, invested over 5,000 student hours, and corresponded daily utilizing the team’s online design forum. The entire project was heavily invested in computer aided design and manufacturing (CAD/CAM). The only system not designed by this team was the Fiber-Optic Video Link.

Author(s):  
A. N. Bozhko

Computer-aided design of assembly processes (Computer aided assembly planning, CAAP) of complex products is an important and urgent problem of state-of-the-art information technologies. Intensive research on CAAP has been underway since the 1980s. Meanwhile, specialized design systems were created to provide synthesis of assembly plans and product decompositions into assembly units. Such systems as ASPE, RAPID, XAP / 1, FLAPS, Archimedes, PRELEIDES, HAP, etc. can be given, as an example. These experimental developments did not get widespread use in industry, since they are based on the models of products with limited adequacy and require an expert’s active involvement in preparing initial information. The design tools for the state-of-the-art full-featured CAD/CAM systems (Siemens NX, Dassault CATIA and PTC Creo Elements / Pro), which are designed to provide CAAP, mainly take into account the geometric constraints that the design imposes on design solutions. These systems often synthesize technologically incorrect assembly sequences in which known technological heuristics are violated, for example orderliness in accuracy, consistency with the system of dimension chains, etc.An AssemBL software application package has been developed for a structured analysis of products and a synthesis of assembly plans and decompositions. The AssemBL uses a hyper-graph model of a product that correctly describes coherent and sequential assembly operations and processes. In terms of the hyper-graph model, an assembly operation is described as shrinkage of edge, an assembly plan is a sequence of shrinkages that converts a hyper-graph into the point, and a decomposition of product into assembly units is a hyper-graph partition into sub-graphs.The AssemBL solves the problem of minimizing the number of direct checks for geometric solvability when assembling complex products. This task is posed as a plus-sum two-person game of bicoloured brushing of an ordered set. In the paradigm of this model, the brushing operation is to check a certain structured fragment for solvability by collision detection methods. A rational brushing strategy minimizes the number of such checks.The package is integrated into the Siemens NX 10.0 computer-aided design system. This solution allowed us to combine specialized AssemBL tools with a developed toolkit of one of the most powerful and popular integrated CAD/CAM /CAE systems.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou

The computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication technique has become one of the hottest topics in the dental field. This technology can be applied to fixed partial dentures, removable dentures, and implant prostheses. This study aimed to evaluate the feasibility of NaCaPO4-blended zirconia as a new CAD/CAM material. Eleven different proportional samples of zirconia and NaCaPO4 (xZyN) were prepared and characterized by X-ray diffractometry (XRD) and Vickers microhardness, and the milling property of these new samples was tested via a digital optical microscope. After calcination at 950 °C for 4 h, XRD results showed that the intensity of tetragonal ZrO2 gradually decreased with an increase in the content of NaCaPO4. Furthermore, with the increase in NaCaPO4 content, the sintering became more obvious, which improved the densification of the sintered body and reduced its porosity. Specimens went through milling by a computer numerical control (CNC) machine, and the marginal integrity revealed that being sintered at 1350 °C was better than being sintered at 950 °C. Moreover, 7Z3N showed better marginal fit than that of 6Z4N among thirty-six samples when sintered at 1350 °C (p < 0.05). The milling test results revealed that 7Z3N could be a new CAD/CAM material for dental restoration use in the future.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1986
Author(s):  
Andreas Koenig ◽  
Julius Schmidtke ◽  
Leonie Schmohl ◽  
Sibylle Schneider-Feyrer ◽  
Martin Rosentritt ◽  
...  

The performance of dental resin-based composites (RBCs) heavily depends on the characteristic properties of the individual filler fraction. As specific information regarding the properties of the filler fraction is often missing, the current study aims to characterize the filler fractions of several contemporary computer-aided design/computer-aided manufacturing (CAD/CAM) RBCs from a material science point of view. The filler fractions of seven commercially available CAD/CAM RBCs featuring different translucency variants were analysed using Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), Micro-X-ray Computed Tomography (µXCT), Thermogravimetric Analysis (TG) and X-ray Diffractometry (XRD). All CAD/CAM RBCs investigated included midifill hybrid type filler fractions, and the size of the individual particles was clearly larger than the individual specifications of the manufacturer. The fillers in Shofu Block HC featured a sphericity of ≈0.8, while it was <0.7 in all other RBCs. All RBCs featured only X-ray amorphous phases. However, in Lava Ultimate, zircon crystals with low crystallinity were detected. In some CAD/CAM RBCs, inhomogeneities (X-ray opaque fillers or pores) with a size <80 µm were identified, but the effects were minor in relation to the total volume (<0.01 vol.%). The characteristic parameters of the filler fraction in RBCs are essential for the interpretation of the individual material’s mechanical and optical properties.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1401
Author(s):  
Doo-Bin Song ◽  
Man-So Han ◽  
Si-Chul Kim ◽  
Junyong Ahn ◽  
Yong-Woon Im ◽  
...  

This study investigated the fitting accuracy of titanium alloy fixed dental prostheses (FDP) after sequential CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) fabrication. A three-unit FDP model connecting mandibular second premolars and molars was prepared and scanned to fabricate titanium FDPs by CAD/CAM milling. A total of six FDPs were sequentially milled in one titanium alloy disk using a new set of burs every time (n = 4). The fitting accuracy of FDPs was mesiodistally evaluated by a silicone replica technique and the measurement was triplicated at four different locations: MO (marginal opening), MG (marginal gap), AG (axial gap), and OG (occlusal gap). Data were statistically analyzed using ANOVA and Tukey’s HSD test. The fitting accuracy of PMMA (polymethyl methacrylate) FDPs milled using the worn or new bur were evaluated by the same procedure (n = 6). The mean dimensions of titanium FDP for all measuring positions, except for AG, were significantly increased from the third milling. However, no difference was noted between the first FDP and the second FDP milled with the same set of burs. Severe edge chippings were observed in all milling burs. Detrimental effects of the worn burs on the fitting accuracy were demonstrated in the CAD/CAM-milled PMMA FDP. The results recommend proper changing frequency of cutting burs to achieve the quality of fit and predictable outcomes for dental CAD/CAM prostheses.


1999 ◽  
Vol 121 (4) ◽  
pp. 502-506 ◽  
Author(s):  
Q. J. Ge ◽  
M. Sirchia

This paper brings together the notion of analytically defined two-parameter motion in Theoretical Kinematics and the notion of freeform surfaces in Computer Aided Geometric Design (CAGD) to develop methods for computer aided design of two-parameter freeform motions. In particular, a rational Be´zier representation for two-parameter freeform motions is developed. It has been shown that the trajectory surface of such a motion is a tensor-product rational Be´zier surface and that such a kinematically generated surface has a geometric as well as a kinematic control structure. The results have not only theoretical interest in CAGD and kinematics but also applications in CAD/CAM and Robotics.


Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1170
Author(s):  
Giulio Marchesi ◽  
Alvise Camurri Piloni ◽  
Vanessa Nicolin ◽  
Gianluca Turco ◽  
Roberto Di Lenarda

Restorative materials are experiencing an extensive upgrade thanks to the use of chairside Computer-aided design/computer-assisted manufacturing (CAD/CAM) restorations. Therefore, due to the variety offered in the market, choosing the best material could be puzzling for the practitioner. The clinical outcome of the restoration is influenced mainly by the material and its handling than by the fabrication process (i.e., CAD/CAM). Information on the restorative materials performances can be difficult to gather and compare. The aim of this article is to provide an overview of chairside CAD/CAM materials, their classification, and clinically relevant aspects that enable the reader to select the most appropriate material for predictable success.


2020 ◽  
Vol 3 (2) ◽  
pp. 31-32
Author(s):  
Paul Brian S. Mendez ◽  
Rizalie N.E. Mibato

Dentistry has evolved from its origin to the present day, becoming almost entirely digitized and supervised. The digitalized dental laboratory saves time due to computer-aided design and computer-aided manufacture (CAD/CAM) technology, which will capture and display clients' tooth or teeth and gums on a 3D image on a computer screen sent to the lab.  It enables a dental lab technician to work faster and get the perfect design of the digital dental restoration. The main advantage of digitalization includes faster and improved efficiency on the turn-around time of devices, like crowns and bridges, and improved accuracy of procedures and manufactured gadgets. Digitalization Dental Laboratory (DDL) is the first to offer a digital dental lab in the city of Bacolod. The service allows laboratories to design the prosthesis digitally from in-house CAD software and email the design data provider or download the data file into a proprietary web host or server. The lab will cater to the digital needs of dental patients of the Multi-Specialty Dental Center (a sister company of DDL) and other dental clients.


2010 ◽  
Vol 139-141 ◽  
pp. 1299-1302
Author(s):  
Jian Xin Qiu ◽  
Yan Qiu Xu ◽  
Ying Li

The paper takes computer digital image processing as a foundation, laboratory analysis as the confirmation method, and takes garment industry production as the application production, researching the information characteristic of the clothing image design, the signal extraction, and the basic conversion rule in order to explore the computer-aided design of clothing pattern, apparel images (CAD), as well as the achievement of automatic laser cutting on complex design and apparel-hanging through the information technology. The topic emphatically discusses different graphic file format conversion technology and establishes the best craft parameter database that suits the laser cutting via the ACCESS software, while carrying on the shape error and precision analysis. The topic research conclusion will provide effective, reliable technology and the data support for the laser cutting craft in fashion industry. And it will enhance the laser processing efficiency of the fashion and the apparel hanging as well as guarantee the cutting quality to achieve the best effect.


1991 ◽  
Vol 7 (04) ◽  
pp. 234-247
Author(s):  
Bruce A. Carr ◽  
Thomas M. Houlihan ◽  
Michael A. Polini

The authors' company is a medium-sized engineering company specializing in naval ship repair. The bulk of corporate work centers on the Phased Maintenance (PM) of three classes of ships. Typically, each PM contract covers three to five different ships per class scheduled for 90-day Availabilities at approximately one-year intervals over a period of five years. The type of work to be performed during each Phased Maintenance Availability (PMA) falls into one of two categories: ship alterations or ship repairs. The first group, ship alterations, is characterized by detailed, long-lead engineering and planning efforts, typically beginning 540 days prior to the vessels's arrival. The second group, ship repairs, makes up the other end of the spectrum with short lead times and compressed service details. The majority of repair items are identified 60 days prior to an Availability, while some are not determined until after the vessel has arrived in the shipyard. The engineering department that services PMA work is composed of three disciplines: structural, mechanical and electrical. The mechanical discipline is further subdivided into the areas of machinery and piping/HVAC. While the nature of PMA work within each discipline is peculiar to the application, the process is similar in each. Reference information is gathered and verified, technical analysis is provided where necessary, and detailed drawings are prepared and submitted for Navy approval prior to shipyard production. All drawings are developed using two-dimensional drafting techniques at various sites by teams of computer-aided design (CAD) input operators utilizing color graphic workstations on a multi-shift basis as required by the workload. Completed drawings are transferred to the engineering site over a network link, where additional workstations are available for engineers to check and correct them as necessary


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