Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 236
2017-09-19
Technical Paper
2017-01-2074
Thorsten Dillhoefer, Fatih Erdinc
Ever increasing process applications inspire us, as suppliers of aircraft, structural-assembly, and equipment to design innovative and modular, manufacturing cells in compliance with modern specifications. The result is the new flexible C-Frame Panel Assembly Cell (CPAC) Bulkhead riveting System. This paper describes how benchmarks for flexible automated drilling and fastening are being achieved with the CPAC.
2017-09-19
Technical Paper
2017-01-2088
Long Yu, Qingzhen Bi PhD, Yilian Zhang, Yuhan Wang
Abstract A novel normal measurement device for robotic drilling and countersinking has been developed. This device is mainly composed of three contact displacement sensors and a spherically compliant clamp pad. The compliance of the clamp pad allows it to be perpendicular to the part when the Multi-Function End Effector (MFEE) drives it to clamp the part surface prior to drilling, while the displacement sensors are used to measure the movement of the clamp pad relative to the MFEE. Once the sensors’ position is calibrated, the rotation angle of the clamp pad can be calculated by the displacement of the sensors. Then, the normal adjustment of MFEE is obtained, and the adjustment process can be achieved by the Rotation Tool Center Point (RTCP) function of robot. Thus, an innovative method based on laser tracker to identify the position of sensors is proposed.
2017-09-19
Technical Paper
2017-01-2094
Tyler Everhart
Abstract Electroimpact, in collaboration with Boeing, has developed an advanced robotic assembly cell, dubbed “The Quadbots.” Using Electroimpact’s patented Accurate Robot technology and multi-function end effector (MFEE), each robot can drill, countersink, inspect hole quality, apply sealant, and insert fasteners into the part. The cell consists of 4 identical machines simultaneously working on a single section of the Boeing 787 fuselage, two on the left, and two on the right. These machines employ “collision avoidance” a new feature in their software to help them work more synchronously. The collision avoidance software uses positional feedback from external safety rated encoders mounted to the motors on the robot. From this feedback, safe spaces, in the form of virtual boundaries can be created. Such that a robot will stop and wait if the adjacent robot is in, or going to move into its programmed work envelope.
2017-09-19
Technical Paper
2017-01-2077
John McClelland, Michael Morgan, Caroline McClory, Colm Higgins, Rory Collins, Adrian Murphy, Yan Jin
The need to drill several million holes per aircraft through composite and hybrid material stacks is a large challenge for the aerospace assembly process. The ability to produce high quality holes for the lowest tooling costs is at the forefront of requirements for aircraft assembly factories worldwide. Consequently, much research has been conducted into tool design and development, however, the effect of drilling platform characteristics has not been well covered in literature. Respectively, this research has compared the drilling abilities of a 5-axis precision CNC platform, a hybrid parallel kinematic machine and an articulated robotic arm fitted with a drilling module. In-process force measurement and post process hole and tool analysis methods were used to better understand the effect of static and dynamic platform characteristics on the achievable hole quality, cycle time and tool wear when drilling aerospace metal alloy stacks.
2017-09-19
Technical Paper
2017-01-2084
Karl-Erik Neumann
Abstract The evolving Aerospace manufacturing environment has created challenges that until now are not achievable with standard machine tools, large monumental gantry style machines and robots, or even manually operations. The solution is a lightweight, mobile/portable, and modular PKM (Parallel Kinematics Machine) solution, capable of machining to high tolerances, with minimal time and effort to relocate to a different area, at an affordable price With the carbon fiber PKM module mounted on a mobile platform, the module can simply be relocated using a standard pallet mover or forklift, to all areas in a factory. The module can also be removed from the mobile platform by two people, and mounted in a desired location and in any orientation “in hours”. The modularity of the PKM does not only make it possible to move it around in different production areas, but also makes it possible to reconstruct in an area that is not typically accessible by machines or robots.
2017-09-19
Technical Paper
2017-01-2087
Peter Mueller-Hummel, Alex Hjorten
Abstract This article characterizes the special features of machining composite in comparison to machining metal. Simplified theoretic models will demonstrate how CFRP should be machined without delamination, burn marks and cutting tool breakages. Different strategies can be chosen depending on the material removal rate. The paper will present, based on this analytical approach, how milling cutters should be designed for optimal trimming, and how a drill should be designed in order to avoid the entrance, inner and exit delamination. While entrance and exit delamination is well understood, the paper will focus more to the delamination inside the bore. The appearance and the avoidance of the so called "Volcano Effect" and the reason why holes in composite becomes smaller after a couple of days will be explained. The comparison between 4 different cutting tool technologies will prove and give a better understanding how to use this theoretical approach.
2017-07-10
Technical Paper
2017-28-1983
J Ronald Aseer, P Baskara Sethupathi, J. Chandradass, Renold Elsen
Abstract The utilization of unconventional machining methods such as electron beam machining, electrical discharge machinating, etc., have been increased in the manufacturing industry to create holes on the materials. In this paper, twist drill was used for drilling of Bahunia racemosa (BR)/ glass fiber composites and then the measurement of hole diameter error was analysed. The main objective was to establish a correlation between feed rate, cutting speed and drill tool with the induced hole diameter error in a composites. The drilling process was performed under various cutting speed, feed rates and different drilling tools with a point angle of 118°. A Coordinate measuring machine was used to examine the hole diameter error of drilling hole. Taguchi L9 (33) orthogonal array was used to determine the optimum levels of the parameters and analyze the effect of drilling parameters on hole diameter error.
2017-06-26
Solution Notes
SN-0001
Automating a manufacturing process often comes with substantial investment or sustained operational costs of complex subsystems. But, by reducing complexity and using technologically mature components, it is possible to develop viable scaled and robust automated solutions. For the past several years, aerospace manufacturers have endeavored to automate manufacturing processes as much as possible for both production efficiencies and competitive advantage. Automating processes like drilling, fastening, sealing, painting, and composite material production have reaped a wide range of benefits; from improving quality and productivity to lowering worker ergonomic risks. The results have improved supply chains from small component manufacturers all the way up to airframe assemblers. That said, automation can be very expensive, and difficult to introduce when a product is anywhere beyond the beginning of its life cycle.
2017-03-28
Journal Article
2017-01-0400
Theo Rickert
Abstract Hole drilling is a very common technique for measuring residual stresses. Adding an orbiting motion of the drill was found to improve hole quality in difficult to drill materials and has been in practice for decades. This study compares measurements using various orbiting amounts. Each measurement was repeated twice to evaluate measurement statistics. There is a distinct, though relatively small, effect of the hole shape when no orbiting is used. It disappears already when the hole is 50% larger than the tool size. Different orbiting amounts also produce systematically different results. These may be related to the absolute hole size.
2016-09-27
Technical Paper
2016-01-2101
Burak Deger, Fazli Melemez, Aykut Kibar lng
Abstract A hybrid drilling process of multi material stacks with one shot drilling recently emerge as an economical and time efficient method in aerospace industry. Even though the comprehensive experience and knowledge is available for the cutting parameters of composites and metals alone, significant gap exist for the hybrid drilling parameters. Determination of these parameters such as feed rate, spindle speed and pecking depth has vital importance so as to provide a robust and optimal process to ensure dimensionally high quality, burr and delamination free holes. Main challenge of hybrid drilling operation is to obtain required hole diameter with adequate homogeneity and repeatability. In this study, effect of cutting parameters on dimensional hole quality was investigated. In addition to the hole diameter tolerances, CFRP hole enlargement phenomena which is encountered as a specific drawback of metal-exit stack configurations is also addressed within the scope of this study.
2016-09-27
Journal Article
2016-01-2116
Peter Mueller-Hummel
Abstract Drilling holes into metal with MQL (Minimal Quantity Lubrication) is a normal procedure, because the drill is designed for drilling metal and the malleable capability of the metal compensates for the insufficient cutting capability of a worn out drill. Drilling composite materials using the same drill (designed for drilling metal) is a different procedure, because composite fibers are not malleable like metal at all. Due to this fact the tools become very hot trying to forge composite fibers like metal. The elastic behavior of the composite and the delamination inside the hole makes the tool temporary smaller than the diameter of the drill. The hole in the metal part of the stack remains slightly larger due to the heat and the thermal expansion rate. This paper shows how to drill metal and composite with the same diameter, so that achieving H8 quality is no longer a dream.
2016-09-27
Technical Paper
2016-01-2091
Raul Cano, Oscar Ibanez de Garayo, Miguel Angel Castillo, Ricardo Marin, Hector Ascorbe, Jose Ramon de los Santos
Abstract The aim of this paper is to present a robust and low-cost automatic system for drilling aluminum stacks, as well as an integral methodology for the design of tool trajectories and the control of the drilling process itself. The proposed system employs a high accuracy robotic arm, a commercial spindle head and a specially developed SCADA, which enables it to load tool trajectories designed by using any software application. Furthermore, this SCADA is useful to monitor the main parameters of the drilling process for anticipating problems related to the unexpected tool wear or for a quick response in case of tool collision. A special jig for positioning the stack to be drilled is designed to increase the robot accessibility. In this work, tests are performed for optimizing the cutting parameters of the robotic system in order to maximize the accuracy and the surface finishing of the holes.
2016-09-27
Technical Paper
2016-01-2089
Jose Guerra cEng, Miguel Angel Castillo
Abstract Aernnova experience on automatic drilling operations started in 1,999. The company signed a new contract with Embraer, to design, manufacture and assembly several structures of the model 170. It was big news for the company. But after that minute of pride, manufacturing engineering people of the company started to think about the process to assemble those big panels of the Horizontal Stabilizer, Vertical Stabilizer and Rear Fuselages in the best Quality and Cost. There were a lot of rows of rivets to install. Some ideas arisen, but the final decision was to forget the available processes at that time and think about to automate the drilling, countersink and riveting of the stringers, doublers and window frames to the panels. There were a lot of doubts, figures to do and obstacles, but the company took the decision of going ahead with that process. That step changed the state of the art at that time in the company.
2016-09-27
Technical Paper
2016-01-2095
Agata Suwala, Lucy Agyepong, Andrew Silcox
Abstract Reduction of overall drag to improve aircraft performance has always been one of the goals for aircraft manufacturers. One of the key contributors to decreasing drag is achieving laminar flow on a large proportion of the wing. Laminar flow requires parts to be manufactured and assembled within tighter tolerance bands than current build processes. Drilling of aircraft wings to the tolerances demanded by laminar flow requires machines with the stiffness and accuracy of a CNC machine while having the flexibility and envelope of an articulated arm. This paper describes the development and evaluation of high accuracy automated processes to enable the assembly of a one-off innovative laminar flow wing concept. This project is a continuation of a previously published SAE paper related to the development of advanced thermally stable and lightweight assembly fixture required to maintain laminar flow tolerances.
2016-09-27
Technical Paper
2016-01-2099
Peter Mueller-Hummel, Thomas Langhorst
Abstract On CNC Machines, drilling holes under perfect condition is possible. For drilling holes into titanium, composite and aluminum stacked materials the specific cutting condition can be selected. Furthermore surrounding conditions such as peck cycle, MQL and force and torque monitoring can be easily adapted. When drilling holes in the final assembly, CNC machine tools cannot be employed due to sizes and accessibility. Power Feed Units or Automated Drill Units ADUs are very handy, flexible and depending upon the jig extremely rigid. Whenever a machine tool does not fit, ADUs are highly recommended. In comparison to machine tools, conventional pneumatic ADUs can be used with one fixed set of feed, speed and micro peck only. Due to that a compromise in cutting condition has to be chosen in drilling stacked material with different layers.
2016-09-27
Journal Article
2016-01-2126
Ali Mohamed Abdelhafeez, Sein Leung Soo, David Aspinwall, Anthony Dowson, Dick Arnold
Abstract Despite the increasing use of carbon fibre reinforced plastic (CFRP) composites, titanium and aluminium alloys still constitute a significant proportion of modern civil aircraft structures, which are primarily assembled via mechanical joining techniques. Drilling of fastening holes is therefore a critical operation, which has to meet stringent geometric tolerance and integrity criteria. The paper details the development of a three-dimensional (3D) finite element (FE) model for drilling aerospace grade aluminium (AA7010-T7451 and AA2024-T351) and titanium (Ti-6Al-4V) alloys. The FE simulation employed a Coupled Eulerian Lagrangian (CEL) technique. The cutting tool was modelled according to a Lagrangian formulation in which the mesh follows the material displacement while the workpiece was represented by a non-translating and material deformation independent Eulerian mesh.
2016-09-27
Technical Paper
2016-01-2096
Simon Schnieders, Dirk Eickhorst
Abstract Drilling of high-strength titan material and composites in combination creates complex challenges in order to achieve required productivity and quality. Long spiral chips are characteristically for the titan drilling process, which leads to e.g. chip accumulation, high thermomechanical load, surface damages and excessive tool wear. The basic approach is the substitution of today’s peck drilling as current solution to this problem and the implementation of a vibration assisted drilling, so called micro-peck-drilling-process, to generate a kinematic chip breakage in a significant more efficient way. To meet perfectly the requirements regarding rates, quality and automation level, Broetje-Automation as system integrator has investigated and developed the implementation of different alternative high-performance systems and methods to approach the optimal oscillation movement of the tool.
2016-09-27
Technical Paper
2016-01-2097
Sylvain Laporte, Cosme De Castelbajac, Mathieu Ladonne
Abstract The Vibration Assisted Drilling (VAD) process has been implemented in Automated Drilling Equipment (ADE) on an industrial scale since 2011. Today more than 11000 ADEs are currently used on aircraft assembly lines. As well as drawing up a short report on the use of this new process, the authors make an assessment on new challenges that VAD has to face up. Indeed production rates are increasing and ADE manufacturers improve their technologies, one of the most recent and major development concerning the electrical motorization of the machines. These evolutions are as many opportunities for the VAD provided you have a clever understanding as well as an expert knowledge of the process. Thus the authors propose a new dynamic model of the whole VAD system which integrates the behavior of the part, cutting tool/material pair and the machine. The confrontation of model results and experimental validation tests demonstrates the relevance of the works.
2016-09-27
Technical Paper
2016-01-2136
Oliver Pecat, Tebbe Paulsen, Philipp Katthöfer, Ekkard Brinksmeier, Sascha Fangmann
Abstract Insufficient chip extraction often leads to disruptions of automated drilling processes and will have a negative impact on the surface qualities. One opportunity to avoid chip accumulation is based on a kinematically enforced chip breakage caused by sinusoidal axial oscillations of the drilling tool. Recent investigations have shown that the quality of chip extraction is, amongst others, considerably depending on the chip shape and mass which are defined by the cutting parameters feed, amplitude and frequency. So far only mechanical systems in the form of tool holders have been available on the market, which are restricted to a fixed frequency (oscillation frequency is coupled to the spindle speed). In the present study a spindle with magnetic bearings was used which allows to adjust the oscillation frequency independent of the spindle speed and therefore enables all opportunities to affect the generated chip shapes.
2015-09-15
Technical Paper
2015-01-2489
Philippe Le Vacon, Thomas Buisson, Fabien Albert
This paper presents an innovative solution of portable drilling machine, lightweight and low cost, dedicated to drilling operations on single and double curved aircraft structure. Aircraft Standard drilling process mainly uses drilling templates combined with Automated Drilling Units (ADU) which is a very efficient solution. However, the management of templates and ADUs is a time consuming and costly task in regards to the large quantity of existing references spread over every aircraft production sites. Therefore, to help reducing those costs and also workload, the concept of the Numerical Template (NCT) has been designed, using classic and robust mechanical devices, hand-held, lightweight and universal. NCT architecture concept could led to a family of NCT with different dimensions of frame parts(X,Y,Z), fitted to the targeted area geometry. The system is able to guaranty an accuracy of ± 0.5 mm and a normality of ±0.5°.
2015-09-15
Journal Article
2015-01-2501
Cosme de Castelbajac, Sylvain Laporte, Julian Lonfier, Emmanuel Puviland
Abstract Over the last few years, many aircraft production lines have seen their production rate increase. In some cases, to avoid bottlenecks in the assembly lines, the productivity of processes needs to be improved while keeping existing machine-tools. In this context, the case of drilling machine-tools tends to require particular attention, especially when multi-material parts are drilled. In such instances, the Vibration Assisted Drilling (VAD) process can be a way to improve productivity and reliability while keeping quality standards. This article presents a case of a drilling/countersinking process for stainless steel and titanium stack parts. Firstly, the article assesses the feasibility and benefits of using Vibration Assisted Drilling and Countersinking with the current cutting-tools.
2015-09-15
Technical Paper
2015-01-2509
Eric Reid
Abstract The Boeing Company has developed a mobile robotic drilling and fastening system for use in assembly processes on the lower panel of a horizontally fixtured wing. The robotic system, referred to as Lower-panel Drilling and Fastening System (LPDFS), was initially developed as part of an initiative to minimize facilities costs by not requiring costly foundation work. It is designed to operate with a high level of autonomy, minimizing operator intervention, including that required for machine setup and tool changes. System design enables positioning the work piece at a lower ergonomic height for concurrent manual processes. In all aspects of design, the system will maintain maximum flexibility for accommodating future manufacturing changes and increases in production rate, while meeting the strict accuracy requirements characteristic of aircraft manufacturing.
2015-09-15
Technical Paper
2015-01-2513
Hans-Juergen Borchers, Kadir Akkuş, Cagatay Ucar
Abstract This paper will discuss the process of drilling large diameter holes within high quality requirements using a Robot positioning concept. This Robot end-effector system provides flexibility to handle different aircraft sections due to its Robot arm design. The material configuration that will be discussed in this paper is a mixed material stack of CFRP and Aluminum. The diameter range is from 7.9 mm to 15.9mm. This paper will focus on the largest diameter (Ø15.9mm). It addresses the process forces to be handled and the solutions. This paper will take an integrated look at the whole process including machine, spindle, cutting tool design and process conditions. Only this integrated view to all process related items enables running an innovative and effective process. The maximum stack size of 40 mm is another condition that requires a specific process to control the chip size to avoid an impact to the material. Here different concepts have been taken under consideration.
2015-09-15
Technical Paper
2015-01-2490
Sylvain Guerin, Sylvain da Costa
The quality requirement for drilling operation in aerospace industry associated to the different material layers of the recent aircraft design is one of the most challenging issues for manufacturing engineers who want to design system for one-shot drilling operation. We have developed and validated in production a handheld electrical tool which is able to accurately monitor the drilling parameter and to adjust the drilling conditions to specific material in the stack-up. This “Smart Driller” achieves quality and performances equivalent to those obtained by the most advanced heavy automated drilling systems at a small portion of weight and cost.
2015-09-15
Technical Paper
2015-01-2517
Sean Holt, Rider Clauss
Abstract Electroimpact has developed a novel method for accurately drilling and countersinking holes on highly convex parts using an articulated arm robotic drilling system. Highly curved parts, such as the leading edge of an aircraft wing, present numerous challenges when attempting to drill normal to the part surface and produce tight tolerance countersinks. Electroipmact's Accurate Robot technology allows extremely accurate positioning of the tool point and the spindle vector orientation. However, due to the high local curvature of the part, even a small positional deviation of the tool point can result in a significantly different normal vector than expected from an NC program. An off-normal hole will result in an out of tolerance countersink and a non-flush fastener.
2015-09-15
Technical Paper
2015-01-2500
Brigitte Vasques
The drilling of multi layers composite stacks remains a common process in aerospace industry. Research of productive solutions such as one shot and dry drilling operations to avoid reaming and lubrication are contemplated by aerospace customers on titanium multi layers composite applications. Those solutions permit to reduce the number of finishing operation and drilling time. Special ADEs (Advanced Drilling Equipment) machines are used to drill aircraft components in limited access areas. Parameters such as cutters, ADE machines type, rigidity clamping, cutting conditions, speed, feed, chip fragmentation and extraction are related and influence the holes quality. Titanium (TA6V) thickness and cutting configuration influence the cutter wear development. In this work, ADE and specific cutter geometries developed by Apex are used for the one shot dry drilling of titanium. Carbide cutters have been chosen for their resistance to the heat developed by titanium drill.
2015-09-15
Journal Article
2015-01-2502
Jeremy Jallageas, Matthieu Ayfre, Mehdi Cherif, Jean-Yves K'nevez, Olivier Cahuc
Abstract This study investigates the self-adjusted cutting parameter technique to improve the drilling of multi-stacked material. The technique consists in changing the cutting strategy automatically, according to the material being machined. The success of this technique relies on an accurate signal analysis, whatever the process setting. Motor current or thrust force are mostly used as incoming signals. Today, analyses are based on the thresholding method. This consists in assigning lower and upper limits for each type of material. The material is then identified when the signal level is stabilized in between one of the thresholds. Good results are observed as long as signal steps are significantly distinct. This is the case when drilling TA6V-CFRP stacks. However, thrust force level remains roughly unchanged for AA7175-CFRP stacks, leading to overlapping thresholds. These boundary limits may also change with tool geometry, wear condition, cutting parameters, etc.
2015-09-15
Technical Paper
2015-01-2510
Ryan Haldimann
Abstract Accurate measurement of countersinks in curved parts has always been a challenge. The countersink reference is defined relative to the panel surface which includes some degree of curvature. This curvature thus makes accurate measurements very difficult using both contact and 2D non-contact measurements. By utilizing structured light 3D vision technologies, the ability to very accurately measure a countersink to small tolerances can be achieved. By knowing the pose of the camera and projector, triangulation can be used to calculate the distance to thousands of points on the panel and countersink surface. The plane of the panel is then calculated using Random Sample Consensus (RANSAC) method from the dataset of points which can be adjusted to account for panel curvatures. The countersink is then found using a similar RANSAC method.
2015-09-15
Technical Paper
2015-01-2508
Jason Rediger, Kyle Fitzpatrick, Rob McDonald, Daniel Uebele
Abstract An improved aircraft assembly line incorporates fully automated robotic tool change. Ten machine tools, each with two onboard 6-axis robots, drill and fasten airplane structural components. The robots change 100% of the process tooling (drill bits, bolt anvils, hole probes, and nosepieces) to allow seamless transition across the entire range of hole and fastener sizes (3/16″-7/16″). To support required rate, total tool change time (including automatic calibration) is less than 80 seconds. This paper describes the robots and their end effector hardware, reliability testing, and simulations for both mechanical clearance and cycle time estimation.
2015-01-01
Journal Article
2014-01-9105
Akram Faqeeh, Ahmed Sherif El-Gizawy
The present paper aims at optimization of multiple quality characteristics (dimensional accuracy and surface roughness) in dry drilling Ti-6Al-4V using TiAlN-coated carbide tool while the controllable factors are spindle speed and feed rate. To do so, desirability methodology is used to explore optimum conditions for concurrent optimization of the addressed quality characteristics. Central composite design (CCD) is used for experimentation. In order to create reliable models describing the process behavior, response surface methodology (RSM) is used.
Viewing 1 to 30 of 236

Filter