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Automated collar and nut installation requires complex hardware on the wet side of the spar or wing panel. Wet side automatic tool changers are becoming common but an operator is often required to connect electrical, pneumatic and fastener feed system components. This is unacceptable in a lights-out cell, and any fully automatic solution must be reliable while satisfying demanding design requirements. Figure 1 Wet side anvil for nut installation. The 737 Spar Assembly Line (SAL) is a new lights-out machine cell at the Boeing factory in Renton, Washington. The SAL machines are equipped with a unique fully automatic tool changer (ATC). The wet side ATC interface is designed to automatically connect conventional as well as more unique services such as fastener feed. The fastener feed ATC module, called the “spinner,” rotates with the machine’s wet side rotary axis (C axis). It consists of a stack of rotors that rotate inside of a stationary annulus.

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.

A simple, open, post and index system is used for final alignment and joining of the fuselage and wings of a new passenger business jet. 19 manually actuated axes precisely move the wings, forward, and rear fuselage sections into position. Movement is accomplished with industrial jacking screws and positions recorded with precision linear potentiometers. Wing sweep, angle of attack, and dihedral are monitored and controlled. The axes positions are downloaded to data files for verification and data archiving. The Gulfstream G150 Join Cell's open architecture enhances access to fasten the main aircraft structure while maintaining flight critical geometry.

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.

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.

Electroimpact has produced a new in-process inspection system for use on drilling and fastening systems. The system uses a high-accuracy, non-contact, laser system to measure the flushness of installed fasteners. The system is also capable of measuring part normality and providing feedback to the machine for correction. One drawback to many automatic inspection systems is measurement error. Many sources of measurement error exist in a production environment, including drilling chips, lubrication, and fastener head markings. Electroimpact’s latest system can create a visualization of the measured fastener for the operator to interpret. This allows the operator to determine the cause of a failed measurement, thus reducing machine downtime due to false negatives. Electroimpact created a custom C# WPF application that queries the point-cloud data and analyzes the raw data. A custom “circle Hough transform” scoring algorithm is used to find the center of the nosepiece (pressure foot).

Electroimpact and Kawasaki Heavy Industries (KHI) have produced a new riveting process for the forming of Briles type rivets in Boeing 777 and 777X fuselage assemblies. The Briles rivet is typically used for fuselage assembly and is unique in that it has a self-sealing head. Unlike conventional headed rivets such as the NAS1079, this fastener does not require aircraft sealant under the head to be fluid tight. This unique fastener makes for a difficult fastening process due to the fact that interference must be maintained between the hole and fastener shank, as well as along the sides of the fastener head. Common issues with the formed fasteners include gapping under the fastener head and along the shank of the fastener. Electroimpact has employed a host of different technologies to combat these issues with Briles fastening. First, Electroimpact’s patented “Air Gap” system allows the machine to confirm that the head of the rivet is fully seated in the countersink prior to forming.

Traditionally, automated fiber placement (AFP) motion platforms use rack and pinion drive trains coupled through a gearbox to a rotary motor. Extensive use of non-contact linear motors on a new AFP motion platform produces a quiet, low-maintenance system without sacrificing precision. A high-rail gantry arrangement allows dynamic performance improvements to machine acceleration and speed, while lowering power consumption costs and capital expenses. The seventh axis incorporated into the machine arrangement effectively produces an effective “five sides of a cube” work envelope, permitting complex spar and panel fabrication.

Large diameter, tightly toleranced fastener patterns are commonplace in aerospace structures. Satisfactory generation of these holes is often challenging and can be further complicated by difficult or obstructed access. Bespoke tooling and drill jigs are typically used in conjunction with power feed units leading to a manual, inflexible, and expensive manufacturing process. For 777X flap production, Boeing and Electroimpact collaborated to create a novel, automated solution to generate the fastener holes for the main carrier fitting attachment pattern. Existing robotic automation used for skin to substructure assembly was modified to utilize extended length (up to 635mm), bearing-supported drill bar sub-assemblies. These Long Assembly Drills (LADs) had to be easily attached and detached by one operator, interface with the existing spindle(s), supply cutting lubricant, extract swarf on demand, and include a means for automatically locating datum features.

The decision to replace a successful automated production system at the heart of a high volume aircraft factory does not come easily. A point is reached when upgrades and retrofits are insufficient to meet increasing capacity demands and additional floor space is simply unavailable. The goals of this project were to increase production volume, reduce floor space usage, improve the build process, and smooth factory flow without disrupting today’s manufacturing. Two decades of lessons learned were leveraged along with advancements in the aircraft assembly industry, modern machine control technologies, and maturing safety standards to justify the risk and expense of a ground-up redesign. This paper will describe how an automated wing spar fastening system that has performed well for 20 years is analyzed and ultimately replaced without disturbing the high manufacturing rate of a single aisle commercial aircraft program.

Aircraft manufacturers are seeking automated systems capable of positioning large structural components with a positional accuracy of ±0.25mm. Previous attempts at using coordinated arm robots for such applications have suffered from the use of low accuracy robots and minimal systems integration. Electroimpact has designed a system that leverages our patented Accurate Robot technology to create an extensively automated and comprehensively integrated process driven by the native airplane component geometry. The predominantly auto-generated programs are executed on a single Siemens CNC that controls two Electroimpact-enhanced Kuka 6 axis robots. This paper documents the system design including the specification, applicable technologies, descriptions of system components, and the comprehensive system integration. The first use of this system will be the accurate assembly of production empennage panels for the Boeing 777X, 787 and 777 airplanes.

Previously given Paper 09ATC-0232 delivered at the SAE Aerotech conference in Seattle in 2009 reports on the E6000 machine installing slug rivets with the EMR. Paper 2015-01-2491given at the SAE conference in Seattle in 2015 reports on index head rivets being installed with screw driven squeeze process. This paper reports on the screw driven squeeze process installing unheaded slug rivet which is a more complex process. We also report on improvements to the fixture automation.

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.

A fully automated off-line cartridge filling station has been commissioned to support the new Boeing SAL production cell. The filing station uses automated fastener feed technology that is typically found on the machines themselves. Incorporating this technology off-line in place of the traditional manual handling processes extends the benefits of automation beyond the main manufacturing cell. A single operator is able to keep up with the demand of eight production fastening machines while maintaining the highest levels of accuracy and quality. Additional benefits to this application of automation include reduction of the operators exposure to risks associated with manual handling and repetitive tasks.

A frame-clip riveting end effector has been developed for installing 3.97mm (5/32) and 4.6mm (3/16) universal head aluminum rivets. The end effector can be mounted on the end of a robot arm. The end effector provides 35.6 kNt (8000 lbs) of rivet upset. Rivets can be installed fifteen millimeters from the IML. The clearance allowed to rivet centerline is 150 millimeters. The riveting process features a unique style of rivet fingers for the universal head rivet. These fingers allow the rivet to be brought in with the ram. This differentiates from some styles of frame-clip end effectors in which the rivet is blown into the hole. The paper shows the technical components of the end effector in sequence: the pneumatic clamp, rivet insert and upset. The end effector will be used for riveting shear ties to frames on the IML of fuselage panels.

Airbus UK was interested in a high-speed riveting machine cell that could automatically rivet over 30 different wing panels for a wide range of aircraft to fit in a limited floor space. Electroimpact was approached and proposed a Flexible, High Speed, Riveting Machine (HSRM). The resulting flexible riveting cell is 170 feet long and contains two flexible fixtures located end to end. Two fixtures allow manual work on one fixture while the machine is riveting on the second fixture. Each fixture can be quickly reconfigured to accommodate a broad range of Airbus panels. The system went into production on January 12, 2003 and has been extremely effective, riveting the first wing panel, a lower panel 1 for the A330-300 in only 5 days. This was one of the largest panels the cell was sized to accommodate. Anticipated process improvements will reduce the riveting time to just three days per panel.

A new style of all electric riveting machine has been developed with saddle hoppers that does not require a track between the hoppers and the fingers. This enables feeding square rivets without difficulty. The upper ram has a bent knee which allows the rivet fingers to be brought up to the hopper and rotated 30 degrees rather than the rivet sliding down a track, which minimizes jamming that occurs with some fasteners in the track, and increases reliability. A mixture of fasteners can be loaded side by side in the hoppers, increasing flexibility. The rivet feeding is accomplished by bringing the rivet fingers to the hopper. The machine uses a power drawbar to change out different rivet fingers. A small industrial robot is incorporated into the machine to complete different sized coupons and also complete small assemblies. In larger machines larger robots or CNC positioners can be used to scale up the use of the machine.

Serial link articulated robots applied in aerospace assembly have largely been limited in scope by deficiencies in positional accuracy. The majority of aerospace applications require tolerances of +/−0.25mm or less which have historically been far beyond reach of the conventional off-the-shelf robot. The recent development of the accurate robot technology represents a paradigm shift for the use of articulated robotics in airframe assembly. With the addition of secondary feedback, high-order kinematic model, and a fully integrated conventional CNC control, robotic technology can now compete on a performance level with customized high precision motion platforms. As a result, the articulated arm can be applied to a much broader range of assembly applications that were once limited to custom machines, including one-up assembly, two-sided drilling and fastening, material removal, and automated fiber placement.

Interference bolts are widely used in aircraft assembly. Electroimpact has used its Low voltage Electromagnetic Riveter (LVER) technology to automatically swage collars on these bolts. The bolts are installed using two process tools, a percussive bolt inserter and the EMR. The bolt inserter inserts the bolt and the EMR swages the collar. This increased productivity over manual installation, but there was still production time to be saved. The Electromagnetic Bolt Inserter (EMB) was designed to increase production rate even more when installing bolts and swaging a collar onto the bolt. The EMB combines the great benefits of Electroimpact's Low Voltage Electromagnetic riveting technology with a bolt inserter.

The Electroimpact Automatic Fan Cowl Riveter exhibits new and unique design features and automated process capabilities that address and overcome three primary technical challenges. The first challenge is satisfying the customer-driven requirement to access the entire fastening area of the fan cowl doors. This necessitates a unique machine design which is capable of fitting ‘inside’ a fan cowl door radius. The second challenge is determining drill geometry and drill process parameters which can produce consistent and high-quality countersunk holes in varying mixed-metal stack-up combinations consisting of aluminum, titanium, and stainless steel. The third challenge is providing the capability of fully automatic wet installation of hollow-ended titanium rivets.