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Viewing 121 to 150 of 19741
2014-09-16
Technical Paper
2014-01-2248
Santiago Droll
In contemporary industries the demand for very accurate robots is continuously growing. Yet, robot vendors are limited in the achievable accuracy of their robots, as they have no means to provide a direct end-effector feedback. Therefore, most approaches aim to identify an accurate model of the robotic system, thus providing compensation factors to correct the deflections. Models, however, are unable to represent the real physical system in a sufficient manner for path correction. The non-linearities in robotic systems are difficult to model and the dynamics cannot be neglected. A better approach is, therefore, to use direct end-effector position and orientation feedback from an external sensor as, e.g. a Leica laser tracker. The measured data can directly be compared to the nominal data from the path interpolator. Hence, the data are independent of the kinematic robot model. The residual errors can be used to calculate correction values in Cartesian space, which are mapped to each individual robot joint, thus providing a fast path correction algorithm.
2014-09-16
Technical Paper
2014-01-2234
Nelson W. Sorbo, Jason J. Dionne
Abstract The use of composite materials and composite stackups (CO-Ti or CO-Al) in aerospace and automotive applications has been and will continue to grow at a very high rate due to the high strength and low weight of the materials. One key problem manufacturers have using this material is the ability to efficiently drill holes through the layers to install fasteners and other components. This is especially true in stackups of CFRP and titanium due to the desire of drilling dry for the CFRP layer and the need for cooling when drilling the high strength Ti layer. By using CO2 through tool cooling, it is possible to protect both layers. Through work supported by the National Science Foundation (NSF) and Department of Energy (DOE) it is shown that CO2 through tool cooling productivity can be significantly increased while maintaining required hole tolerances in both the composite and Ti layers. Improvements in tool life have been demonstrated when compared to either emulsion or dry drilling.
2014-09-16
Technical Paper
2014-01-2253
Ralf Schomaker, Richard Pedwell, Björn Knickrehm
Abstract As a result of the increasing use of fibre reinforced plastic (FRP) components in a modern commercial aircraft, manufacturers are facing new challenges - especially with regards to the realisation of significant build rates. One challenge is the larger variation of the thickness of FRP components compared with metal parts that can normally be manufactured within a very narrow thickness tolerance bandwidth. The larger thickness variation of composite structures has an impact on the shape of the component and especially on the surfaces intended to be joined together with other components. As a result, gaps between the components to be assembled could be encountered. However, from a structural point of view, gaps can only be accepted to a certain extent in order to maintain the structural integrity of the joint. Today's state of the art technologies to close gaps between FRP structures comprise shimming methods using liquid and solid shims. Another option is the use of peelable shims that offer significant economic benefits compared with liquid and solid shims.
2014-09-16
Technical Paper
2014-01-2273
James Cunov, Charles J. Habermann
Abstract The ever increasing use of composites for aircraft components presents opportunities for new ways to process these parts. There are myriad benefits for use of composites in achieving aircraft performance goals. However, composites come with unique challenges as well. Some of these challenges impact the ability to produce accurate parts. Traditionally, such parts have been trimmed only while clamped in dedicated rigid tools that secure the part in the nominal shape. This results in significant investment in tooling design, production, maintenance, storage and, handling. As an alternative, PaR has developed its Adaptive Manufacturing System that incorporates a Robotic Fixture and Precision Motion Machine with an Integrated Process Head. The Robotic Fixture allows the entire family of parts to be managed with one fixture that remains within the machine footprint. The fixture is programmed to command 38 individual robots to assume appropriate poses and end effector configurations to accommodate over 400 different parts in the family that range in length from 0.5 to 20 meters.
2014-09-16
Technical Paper
2014-01-2274
Riley HansonSmith, Alan Merkley
Abstract The Boeing Company is striving to improve quality and reduce defects and injuries through the implementation of lightweight “Right Sized” automated drill and fasten equipment. This has lead to the factory adopting Boeing developed and supplier built flex track drill and countersink machines for drilling fuselage circumferential joins, wing panel to spar and wing splice stringers. The natural evolution of this technology is the addition of fastener installation to enable One Up Assembly. The critical component of One Up Assembly is keeping the joint squeezed tightly together to prevent burrs and debris at the interface. Traditionally this is done by two-sided machines providing concentric clamp up around the hole while it is being drilled. It was proposed that for stiff structure, the joint could be held together by beginning adjacent to a tack fastener, and assemble the joint sequentially using the adjacent hole clamp up from the previous hole to keep the joint clamped up. This process would significantly decrease the costs and complexity that is usually associated with two sided equipment involved in One Up drilling and fastening.
2014-09-16
Technical Paper
2014-01-2270
Jason Rediger, Joseph Malcomb, Craig Sylvester
Abstract A new portable floor drilling machine, the 767AFDE, has been designed with a focus on increased reach and speed, ease-of-use, and minimal weight. A 13-foot wide drilling span allows consolidation of 767 section 45 floor drilling into a single swath. A custom CNC interface simplifies machine operations and troubleshooting. Four servo-driven, air-cooled spindles allow high rate drilling through titanium and aluminum. An aluminum space frame optimized for high stiffness/weight ratio allows high speed operation while minimizing aircraft floor deflection. Bridge track tooling interfaces between the machine and the aircraft grid. A vacuum system, offline calibration plate, and transportation dolly complete the cell.
2014-09-16
Technical Paper
2014-01-2272
Todd Rudberg, Justin Nielson, Mike Henscheid, Joshua Cemenska
Abstract The Automated Fiber Placement (AFP) machine layup run time in large scale AFP layup cells consumes approximately 30% of the entire part build time. Consequentially, further reductions to the run time of the AFP machine part programs result in small improvements to the overall cycle time. This document discusses how Electroimpact's integrated system and cell design reduces the overall cycle time by reducing the time spent on non-machine processes.
2014-09-16
Technical Paper
2014-01-2255
Joseph R. Malcomb
Abstract Automated countersink measurement methods which require contact with the workpiece are susceptible to a loss of accuracy due to cutting debris and lube build-up. This paper demonstrates a non-contact method for countersink diameter measurement on CFRP which eliminates the need for periodic cleaning. Holes are scanned in process using a laser profilometer. Coordinates for points along the countersink edge are processed with a unique filtering algorithm providing a highly repeatable estimate for major and minor diameter.
2014-09-16
Technical Paper
2014-01-2265
Lutz Neugebauer
The demand of fulfilling increasing Prime Customer requirements forces Tier 1 suppliers to continually improve their system solutions. Typically, this will involve integration of “state of the art” tools to afford the Tier 1 supplier a throughput and cost advantage. The subject “Production Optimization Approach” addresses the machine and process optimization of automated fastening machines in operation at customer factories. The paper will describe and focus on the main aspects of production optimization of existing machines to meet and exceed the required customer production and reporting criteria. Furthermore, the paper will present existing examples based on use of the established diagnostic tools
2014-09-16
Technical Paper
2014-01-2252
Lucas Irving, Svetan Ratchev, Atanas Popov, Marcus Rafla
Abstract The replacement for the current single-aisle aircraft will need to be manufactured at a rate significantly higher that of current production. One way that production rate can be increased is by reducing the processing time for assembly operations. This paper presents research that was applied to the build philosophy of the leading edge of a laminar flow European wing demonstrator. The paper describes the implementation of determinate assembly for the rib to bracket assembly interface. By optimising the diametric and the positional tolerances of the holes on the two bracket types and ribs, determinate assembly was successfully implemented. The bracket to rib interface is now secured with no tooling or post processes other than inserting and tightening the fastener. This will reduce the tooling costs and eliminates the need for local drilling, de-burring and re-assembly of the bracket to rib interface, reducing the cycle time of the operation. Ultimately, self-indexing components mean that the there is more flexibility as to what point in production the bracket can be attached to the rib.
2014-09-16
Technical Paper
2014-01-2242
Samuel Baha II
Hybrid (bolted/bonded) joining is becoming one of the innovative joining processes for light weight structures in the transport industry, especially in the aerospace industry where weight reduction and high joining requirements are permanent challenges. Combining the adhesive bonding with the mechanical joining -riveting for instance- can lead to an enhancement of the properties of the joint compared to the wide established riveting, as a result of a synergistic load bearing interaction between the fastener and the adhesive bondline. The influence of the rivet installation process on a hybrid joint regarding the joint stress state, the change of the bondline thickness as well as its effects on the joint performance and load transfer are some of the factors that drive the users to a better understanding of the hybrid joining process. This paper deals therefore on one hand with the numerical simulation of the rivet installation process in an adhesively bonded joint to understand the phenomena occurring during the installation process and on the other hand with the investigation of the load transfer depending on the joint parameters.
2014-09-16
Technical Paper
2014-01-2241
Jamie Skovron, Laine Mears, Durul Ulutan, Duane Detwiler, Daniel Paolini, Boris Baeumler, Laurence Claus
Abstract A state of the art proprietary method for aluminum-to-aluminum joining in the automotive industry is Resistance Spot Welding. However, with spot welding (1) structural performance of the joint may be degraded through heat-affected zones created by the high temperature thermal joining process, (2) achieving the double-sided access necessary for the spot welding electrodes may limit design flexibility, and (3) variability with welds leads to production inconsistencies. Self-piercing rivets have been used before; however they require different rivet/die combinations depending on the material being joined, which adds to process complexity. In recent years the introductions of screw products that combine the technologies of friction drilling and thread forming have entered the market. These types of screw products do not have these access limitations as through-part connections are formed by one-sided access using a thermo-mechanical flow screwdriving process with minimal heat. The friction drilling, thread forming process, hereto referred to as “FDS” is an automated continuous process that allows multi-material joining by utilizing a screw as both the tool and the fastener.
2014-09-16
Technical Paper
2014-01-2240
Joshua Norman, Cesar Moreno, Zhiyu Wang, James Mann, Christopher Saldana
Abstract The beneficial effects of contact disruption in modulation-assisted machining of aerospace alloys have been well documented, but sources for such improvements are not well understood. This study explores the underlying nature of differences that occur in energy dissipation during conventional and modulation-assisted machining by characterizing the relationship between controllable process parameters and their effects on chip formation. Simultaneous in situ force and tool position measurements are used to show that the forces in modulation-assisted machining can be described by empirical force models in conventional machining conditions. These models are found to accurately describe plastic dissipation over a range of modulation conditions and configurations, including in cases where energy expenditure decreases with the application of modulation. These observations suggest that the underlying response in modulation-assisted machining is analogous to that of conventional machining.
2014-09-16
Technical Paper
2014-01-2271
Ryan Haldimann, Daniel Orf
Abstract In an attempt to be more flexible and cost effective, Aerospace Manufacturers have increasingly chosen to adapt a manufacturing style which borrows heavily from the Automotive industry. To facilitate this change in methodologies a system for locating robots has been developed which utilizes cameras for both locating and guidance of a mobile platform for a robot with drilling and fastening end effector.
2014-09-16
Technical Paper
2014-01-2230
Ruiqiang Lu
Abstract With the development of many new technologies in aircraft manufacturing area and the increasing competition of the global market, aircraft manufacturing enterprises have to reduce their production time and increase the cost-efficiency, with the consideration of high speed response to the changes inside enterprises or in the environment. Production scheduling is a significant process in manufacturing, especially for complicated part or component processing. This paper proposes an agent based multi-objective optimization approach for production scheduling based on Genetic Algorithms. It aims to minimize the total production cost and simultaneously reducing the emission released during production, and the delivery time and equipment constraints are satisfied as well. The new approach is tested in a virtual plant for turbine blade manufacturing. Experimental results show that a group of Pareto optimal solutions are obtained, which can be provided to the decision maker of the manufacturer to select according to different actual conditions.
2014-09-16
Technical Paper
2014-01-2258
Sylvain Laporte, Etienne Gueydon, Alain Auffret, Cosme De Castelbajac
Abstract In today's aircraft assembly process several new features make drilling operations very challenging according to production requirements. Parts are made of thin or thick multi-material stacks with a large scope to cover and complex assembly sequences. In addition, the current ramp-up in aircraft programs involves to improve productivity while keeping process quality and reliability. In this context robotic solution meets perfectly all these requirements as it is flexible, reconfigurable, fast and agile. Among the possible end-effectors, the Barrel Multi-Function End Effector (BMFEE) appears to be the most flexible solution to allow many different process configurations. The latest developments have been focused on the drilling equipment of this BMFEE. In fact the drilling process efficiency can be constantly improved especially in terms of reliability, quality and productivity. Therefore vibration-assisted drilling system has been integrated into the BMFEE drilling module. This innovative drilling process allows breaking up the metallic chips in such a way that jamming is avoided.
2014-09-16
Technical Paper
2014-01-2236
Julian Lonfier, Côme De Castelbajac
Abstract As aircraft programs currently ramp up, productivity of assembly processes needs to be improved while keeping quality, reliability and manufacturing cost requirements. Efficiency of the drilling process still remains an issue particularly in the case of CFRP/metal stacks: hot and long metallic chips are difficult to remove and often damage the surface of CFRP holes. Low frequency axial vibration drilling has been proposed to solve this issue. This innovative drilling process allows breaking up the metallic chips in such a way that jamming is avoided. This paper presents a case of CFRP/Ti6Al4V drilling on a CNC machine where productivity must be increased. A comparison is made between the current regular process and the MITIS drilling process. First the analysis and comparison method is presented. The current process is analyzed and its limits are highlighted. Then the vibration process is implemented and its performances are studied. Both processes are compared according to the following criteria: chip morphology, thrust force, power consumption, tool life, cycle time, holes quality and manufacturing costs.
2014-09-16
Technical Paper
2014-01-2263
Eric Barton, Dan Hasley, Joey Jackson
Abstract The following is a unique case study expounding on automatic fastening technology designed and engineered to ramp up a Tier 2 supplier that had no experience with automatic fastening, to efficiently produce a large volume of fuselage panel assemblies with demanding process requirements in a very short amount of time. The automation technology integrated for the skin to stringer & skin to window frame fastening were two GEMCOR G12 five-axis CNC All-Electric fastening systems coupled with a Cenit offline part programming system. This joint solution served as a launch vehicle for Center Industries to efficiently supply the full rate of fuselage panel assemblies for a large volume commercial aircraft program without having any automatic riveting experience. The aero structure sourced to Center Industries has tight manufacturing tolerances & quality requirements without room for error or scrap whereby Drivmatic® fastening with CNC positioning and offline part programming was the feasible approach.
2014-09-12
Article
High-performance metamaterial antennas could be compact, lightweight, conformable, and stealthy.
2014-09-11
Standard
AMS4351
This specification covers an aluminum alloy in the form of plate products from from 1.000 to 6.000 inches (152.40 mm) in thickness. 7065-T7651 may be used in aerospace applications requiring high strength and good fracture toughness, good resistance to stress-corrosion cracking and to exfoliation corrosion, but usage is not limited to such applications.
2014-09-11
Standard
AMS4361
This specification covers an aluminum alloy in the form of plate products from 1.000 to 6.000 inches (152.40 mm) in thickness. 7065-T7451 may be used in aerospace applications requiring high strength and fracture toughness, high resistance to stress-corrosion cracking and good resistance to exfoliation corrosion, but usage is not limited to such applications.
2014-09-11
Standard
AS4228C
Scope is unavailable.
2014-09-09
Standard
J176_201409
This SAE Standard applies to off-road self-propelled work machines as categorized in SAE J1116. Fast fill fueling typically applies to self-propelled machines with a fuel capacity over 380 L, although fast fill fueling can be used on machines with smaller fuel capacity.
2014-09-09
WIP Standard
J78
This SAE Standard covers the dimensional and general specifications, including performance requirements, for carbon steel self-drilling tapping screws suitable for use in general applications. It is the objective of this document to insure that carbon steel self-drilling tapping screws, by meeting the mechanical and performance requirements specified, shall drill a hole and form or cut mating threads in materials into which they are driven without deforming their own thread and without breaking during assembly. Appendix A is included to provide a recommended technique for measuring the case depth on the screws.
2014-09-09
WIP Standard
ARP1917B
This Aerospace Recommended Practice (ARP) clarifies terms used in Aerospace materials and process specifications. The terms clarified in this ARP are not intended to supersede those terms for which clarification is already provided in existing specifications.
2014-09-08
Article
The Walmart Advanced Vehicle Experience is a prototype tractor-trailer developed to demonstrate the possibilities of future transport, and the truck is not the only place where innovation reigns. The trailer body is built almost exclusively with carbon fiber, and it incorporates other technologies such as advanced adhesives and low-profile LED lighting.
2014-09-05
Article
Days before Tesla on Sept. 4 announced it has selected Nevada as the state in which it will build a large "Gigafactory' battery plant, Lux Research opined that the savings in lithium-ion battery costs owing to high-volume efficiencies will not be as much as the automaker expects it to be.
2014-09-05
Standard
AMS3217/7A
This specification covers a high strength fluorosilicone (FVMQ) rubber stock in the form of molded test slabs.
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