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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.

A new high speed forming process for fatigue rated index head rivets used in wing panel assembly using ball-screw based servo squeeze actuation has been developed. The new process is achieved using a combination of force and position control and is capable of forming to 40,000 lbs at rates of up to 200,000 lbs/second whilst holding the part location to within +/− 10 thousandths of an inch. Multi-axis riveting machines often have positioning axes that are also used for fastener upset. It is often the case that while a CNC is used for positioning control, another secondary controller is used to perform the fastener upset. In the new process, it has been possible to combine the control of the upset process with the machine CNC, thus eliminating any separate controllers. The fastener upset force profile is controlled throughout the forming of the rivet by using a closed loop force control system that has a load cell mounted directly behind the stringer side forming tool.

Aircraft assembly systems which require tooling or machinery to pulse or move between multiple positions within a factory can be positioned with high repeatability without high performance foundations or sweeping out large areas of floorspace. An example shows a system of large left and right-hand frames which are positioned at 3 sequential manufacturing steps and then recirculated to the start of production via a central return aisle. The frames are 41 ton actual weight and are 72′ long, similar to a rail car. The system achieves rectangular motion for the recirculation path. The supporting and moving system incorporates low-cost rail in a floor with minimal preparation and simple to use controls. The system is also easily reconfigured if the manufacturing system needs to be altered to meet rate or flow requirements.

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.

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.

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.

Electroimpact has developed a second generation of mobile robots with several improvements over the first generation. The frame has been revised from a welded steel tube to a welded steel plate structure, making the dynamic response of the structure stiffer and reducing load deflections while maintaining the same weight. The deflections of the frame have been optimized to simplify position compensation. The caster mechanism is very compact, offers greater mounting flexibility, and improved maneuverability. The mechanism uses a pneumatic airbag for both lifting and suspension. The robot sled has been improved to offer greater rigidity for the same weight, and dual secondary feedback scales on the vertical axis further improve the rigidity of the overall system. Maintenance access has been improved by rerouting the cable and hose trays, and lowering the electrical cabinet.

Electroimpact has recently produced a high-speed fuselage panel fastening machine which utilizes an all-electric, CNC-controlled squeeze process for rivet upset and bolt insertion. The machine is designed to fasten skin panels to stringers, shear ties, and other internal fuselage components. A high riveting rate of 15 rivets per minute was achieved on the first-generation E7000 machine. This rate includes drilling, insertion, and upset of headed fuselage rivets. The rivets are inserted by a roller screw-driven upper actuator, with rivet upset performed by a lower actuator driven by a high-load-capacity ball screw. The rivet upset process can be controlled using either position- or load-based feedback. The E7000 machine incorporates a number of systems to increase panel processing speed, improve final product quality, and minimize operator intervention.

Electroimpact's newest riveting machine features a track-style injector with Bomb Bay Ejection Doors. The Bomb Bay Ejection Doors are a robust way to eject fasteners from track style injector. Track style injectors are commonly used by Electroimpact and others in the industry. Using the Bomb Bay Doors for fastener ejection consists of opening the tracks allowing very solid clearing of an injector when ejecting a fastener translating to a more reliable fastener delivery system. Examples of when fastener ejection is needed are when a fastener is sent backwards, when there are two in the tube, or when a machine operator stops or resets the machine during a fastening cycle. This method allows fasteners to be cleared in nearly every situation when ejecting a fastener is required. Additional feature of Electroimpact's new injection system is integrated anvil tool change.

Over 1,200 large diameter holes must be drilled into the side-of-body join on a Boeing commercial aircraft's fuselage. The material stack-ups are multiple layers of primarily titanium and CFRP. Due to assembly constraints, the holes must be drilled for one-up-assembly (no disassembly for deburr). In order to improve productivity, reduce manual drilling processes and improve first-time hole quality, Boeing set out to automate the drilling process in their Side-of-Body join cell. Implementing an automated solution into existing assembly lines was complicated by the location of the target area, which is over 15 feet (4 meters) above the factory floor. The Side-of-Body Drilling machines (Figure 1) are capable of locating, drilling, measuring and fastening holes with less than 14 seconds devoted to non-drilling operations. Drilling capabilities provided for holes up to ¾″ in diameter through stacks over 4.5″ thick in a titanium/CFRP environment.

Starting in 2003 Electroimpact began development on a comprehensive kinematic and compensation software package for machines with large envelopes. The software was first implemented on Electroimpact's Automatic Fiber Placement (AFP) equipment. Implementation became almost universal by 2005. By systematically collecting tracker measurements at various machine poses and then using this software to optimize the kinematic parameters of the machine, we are able to reliably achieve machine positional accuracy of approximately 2x the uncertainty of the measurements themselves. The goal of this paper is to document some of the features of this system and show the results of compensation in the hope that this method of machine compensation or similar versions will become mainstream.

Previous Flex Track drilling systems move along two parallel tracks that conform to the contour of a work piece surface. Until recently, applications have been limited to relatively simple surfaces such as the cylindrical mid-body fuselage join of a commercial aircraft. Recent developments in the state of the art have introduced the 5-axis variant which is capable of precision drilling on complex contours. This paper presents solutions to two positioning challenges associated with this added functionality: the ability to align the spindle axis normal to an angled drilling surface while maintaining accuracy in tool-point position, the ability to maintain synced motion between dual drives on complex track profiles.

Precision hole inspection is often required for automated aircraft assembly. Direct contact measurement has been proven reliable and accurate for over 20 years in production applications. At the core of the hole measurement process tool are high precision optical encoders for measurement of diameter and countersink depth. Mechanical contact within the hole is via standard 2-point split ball tips, and diametric data is collected rapidly and continuously enabling the system to profile the inner surface at 0 and 90 degrees. Hole profile, countersink depth, and grip length data are collected in 6 seconds. Parallel to the active process, auto-calibration is performed to minimize environmental factors such as thermal expansion. Tip assemblies are selected and changed automatically. Optional features include concave countersink and panel position measurement.

Automated Fiber Placement (AFP) machines typically consist of 3 linear and 3 rotary axes of motion in order to manufacture complex shapes. These axes are generally orthogonal and semi-coupled. In these designs, a linear axis move will not affect the rotary axes orientation whereas a rotary axis move will affect the Tool Center Point (TCP) location with respect to the linear axes position. The wide range of motion required to maintain the compaction-axis normality needed for carbon fiber layup tends to prevent all of the rotational axes from passing through the TCP. The location and arrangement of these rotational axes has a great effect on the AFP machine performance and controllability during high speed layup. This paper presents a unique kinematic AFP axes design consisting of replacing the 3 orthogonal rotary axes with 3 tool-center-point-intersecting coupled-axes which decouple the linear axes from the rotary axes.

Wing and fuselage aircraft structures require large precise tools for assembly. These large jigs require periodic re-certification to validate jig accuracy, yet metrology tasks involved may take the tool out of service for a week or more and typically require highly specialized personnel. Increasing the time between re-certifications adds the risk of making out-of-tolerance assemblies. How can we reduce jig re-certification down time without increasing the risk of using out-of-tolerance tooling? An alternative, successfully tested in a prototype tool, is to bring automated metrology tools to bear. Specifically, laser tracker measurements can be automated through a combination of off-the-shelf & custom software, careful line-of-sight planning, and permanent embedded targets. Retro-reflectors are placed at critical points throughout the jig. Inaccessible (out of reach) tool areas are addressed through the use of low cost, permanent, shielded repeatability targets.

Incorporation of laser projectors in AFP machine cell controller reduces ply boundary inspection time, on-part course identification and part probing.

The Electromagnetic Bolt Inserter (EMB) is a new tool that combines functions that on previous machines were performed by two tools, a bolt inserter followed by an EMR. By combining the operations of two tools in one the processing time for the wing spar is reduced. The tool incorporates quality checks for bolt length, stake height and bolt insert height.

As part of a Composite Wing Manufacture Program, Electroimpact was asked to design and develop a small portable milling machine for machining CFRP. The machine needed to be light so it could be lifted by two operators, robust to the production environment, and stiff enough to allow it to cut a 15 mm deep 3/8\mi slot through composite material (CFRP), in one pass, with no delamination. The machine also needed to be capable of performing a 30 mm deep finishing cut, in one pass, with 3 μm or better surface finish. Specialist Polycrystalline Diamond (PDC) roughing cutters were developed for the cutting process to reduce cutting loads and vibration while maximizing cutter life. The machine also needed to be capable of cutting along a 2 axis path. Electroimpact successfully introduced the machine in to the production environment in October 2011, within a 12 month development window.

The handheld (HH) electromagnetic riveter (EMR) has proven to be an effective means of installing up to 7/16\mi diameter rivets in aircraft components. These devices are currently installing rivets on Boeing and Airbus planes all over the world. They are also very popular in China and Japan. However, there have always been difficulties with stringer access. A new version of lightweight driver with interchangeable offset tooling was created to alleviate this problem. In addition, a disposable plastic wedge has been incorporated at the base of the offset ram to prevent stringer damage during the recoil.

Flex Track Systems are seeing increased usage in aerospace applications for joining large assemblies, such as fuselage sections. Previous systems were limited to work pieces that allowed the tracks to follow a gentle radius of curvature, limiting the locations where the system could be used. This paper describes a new 5-Axis Flex Track System developed to expand the usage of the systems, allowing them to process work pieces containing complex and irregular contours. Processing complex contours is accomplished through the addition of A and B axes providing normalization in multiple directions. These new systems are configured with the latest multi-function process capabilities allowing drilling, hole quality measurement, and temporary or permanent fastener installation.