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Operational issues encountered by Apollo astronauts relating to lunar dust were catalogued, including material abrasion that resulted in scratches and wear on spacesuit components, ultimately impacting visibility, joint mobility and pressure retention. Standard methods are being developed to measure abrasive wear on candidate construction materials to be used for spacesuits, spacecraft, and robotics. Calibration tests were conducted using a standard diamond stylus scratch tip on the common spacecraft structure aluminum, Al 6061-T6. Custom tips were fabricated from terrestrial counterparts of lunar minerals for scratching Al 6061-T6 and comparing to standard diamond scratches. Considerations are offered for how to apply standards when selecting materials and developing dust mitigation strategies for lunar architecture elements.

The effectiveness of serial link articulated robots in aerospace drilling and fastening is largely limited by positional accuracy. Unguided production robotic systems are practically limited to +/-0.5mm, whereas the majority of aerospace applications call for tolerances in the +/-0.25mm range. The precision with which holes are placed on an aircraft structure is affected by two main criteria; the volumetric accuracy of the positioner, and how the system is affected when an external load is applied. Production use and testing of off-the-shelf robots has highlighted the major contributor to reduced stiffness and accuracy as being error ahead of the joint position feedback such as backlash and belt stretch. These factors affect the omni-directional repeatability, thus limiting accuracy, and also contribute to deflection of the tool point when process forces are applied.

This paper describes the principles of a new method to compensate for tool wear when drilling in complex materials such as Carbon Fibre Reinforced Plastics (CFRP), Carbon Fibre Reinforced Plastics / Titanium (CFRP/Ti) and Carbon Fibre Reinforced Plastics / Alloy (CFRP/AI) stacks. A reliable and repeatable hole quality is essential, especially in automatic drilling applications with robots or gantries. The method combines the unique feature to dynamically adjust the drilling diameter in very small steps in an Orbital drilling End-effector and a new type of software algorithm to predict and compensate for the tool wear in different materials. With this method a large number of holes can be drilled without changing the cutting tool, and a Cpk value of more than 2,5 can be achieved.

The MX-2 neutral buoyancy space suit analogue has been designed and developed at the University of Maryland to facilitate analysis of space suit components and assessment of the benefits of advanced space suit technologies, The MX-2 replicates the salient features of microgravity pressure suits, including the induced joint torques, visual, auditory and thermal environments, and microgravity through the use of neutral buoyancy simulation. In this paper, design upgrades and recent operations of the suit are outlined, including many experiments and tests of advanced space suit technologies, This paper focuses on the work done using the MX-2 to implement and investigate various advanced controls and displays within the suit, to enhance crewmember situational awareness and effectiveness, and enable human-robotic interaction.

Several space agencies have announced plans to return humans to the Moon in the near future. The objectives of these missions include using the Moon as a stepping-stone towards crewed missions to Mars, to test advanced technology, and to further exploration of the Moon for scientific research and in-situ resource utilization. To meet these objectives, it will be necessary to establish and operate a lunar base. As a result, a wide variety of tasks that may pose a number of crew health and safety risks will need to be performed on the surface of the Moon. Therefore, to ensure sustainable human presence on the Moon and beyond, it is essential to anticipate potential risks, assess the impact of each risk, and devise mitigation strategies. To address this, a nine-week intensive investigation was performed by an international, interdisciplinary and intercultural team on how to maximize crew safety on the lunar surface through a symbiotic relationship between astronauts and robots.

Dynamic and quasi-static axial cutting of circular AA6061-T6 extrusions with variable instantaneous wall thickness in the axial direction was completed to investigate the capability of controlling the load/displacement responses of the extrusions. Circular specimens considered for this research had an original nominal wall thickness of 3.175 mm, an external diameter of 50.8 mm, and a tube length of 300 mm. Variations of the wall thickness were completed by material removal of the extrusions using a CNC machine. Specially designed cutters having a block height of 20 mm, a blade tip width of 1.0 mm and a blade shoulder width of 3.0 mm were employed to generate the axial cutting deformation mode. Either one or two cutters were selected to initiate a single or dual cutting deformation. A curved deflector with a profile radius of 50.8 mm was used to flare the cut petalled sidewalk and facilitate the cutting system.

The general manufacturing objective during the fabrication of automotive components, particularly through machining, can be stated as the striving to achieve predefined product quality characteristics within equipment, cost and time constraints. The current state of the economy and the consequent market pressure has forced vehicle manufacturers to simultaneously reduce operating expenses along with further improving product quality. This paper examines the achievability of surface roughness specifications within efforts to reduce automotive component manufacture cycle time, particularly by changing cutting feeds. First, the background and attractiveness of aluminum as a lightweight automotive material is discussed. Following this, the methodologies employed for the prediction of surface roughness in machining are presented. The factors affecting surface roughness as well as practical techniques for its improvement through optimizing machining parameters are discussed next.

This paper proposes a rolling machine that forms fine corrugated section patterns for thin sheets. A prototype of the machine was made and the performance of the machine was tested. As compared with press forming, rolling has the advantages of the high forming limit, the low forming reaction force, the easy control of the thin sheet's curve and high productivity. We confirmed these four advantages by using finite element analyses and the prototype rolling machine. Stainless steel sheets and titanium sheets, which were one of the materials with a low forming limit, were used. Firstly, the rolling showed a 1.3-times higher forming limit than the press forming in the case that a fine corrugated section pattern was formed in a stainless steel sheet of 22-mm square sizes. Secondly, the forming reaction force of the rolling was about one-twentieth of the press forming without coining, and the experimental results agreed with the finite element simulation.

Quasi-static axial cutting of AA6061-T6 and T4 round extrusions were completed using a specially designed cutter with multiple blades. The round specimens had a length of 200 mm, a nominal outer diameter of 50.8 mm, and a wall thickness of 3.175 mm or 1.587 mm. Four different cutters, constructed from heat-treated 4140 steel, having 3, 4, 5 and 6 blades on each cutter with a nominal tip width of 1.0 mm were used to penetrate through the round extrusions. A clean cutting mode was observed for the AA6061-T6 and T4 extrusions with wall thickness of 3.175 mm with an almost constant steady state cutting force. A braided cutting mode was observed for extrusions with both tempers with wall thickness of 1.587 mm, which resulted in a slightly oscillating steady state cutting force. For all extrusions with a wall thickness of 3.175 mm, the steady state cutting force increased with an increase in the number of cutter blades.

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.

Once limited by insufficient accuracy, the off-the-shelf industrial robot has been enhanced via the integration of secondary encoders at the output of each of its axes. This in turn with a solid mechanical platform and enhanced kinematic model enable on-part accuracies of less than +/−0.25mm. Continued development of this enabling technology has been demonstrated on representative surfaces of an aircraft fuselage. Positional accuracy and process capability was validated in multiple orientations both in upper surface (spindle down) and lower surface (spindle up) configurations. A second opposing accurate robotic drilling system and full-scale fuselage mockup were integrated to simulate doubled throughput and to demonstrate the feasibility of maintaining high on-part accuracy with a dual spindle cell.

This paper presents a computational framework for the physics-based simulation of light vehicles operating on discrete terrain. The focus is on characterizing through simulation the mobility of vehicles that weigh 1000 pounds or less, such as a reconnaissance robot. The terrain is considered to be deformable and is represented as a collection of bodies of spherical shape. The modeling stage relies on a novel formulation of the frictional contact problem that requires at each time step of the numerical simulation the solution of an optimization problem. The proposed computational framework, when run on ubiquitous Graphics Processing Unit (GPU) cards, allows the simulation of systems in which the terrain is represented by more than 0.5 million bodies leading to problems with more than one million degrees of freedom.

Pre-collision systems (PCS) use forward-looking sensors to detect the location and motion of vehicles ahead and provide a sequence of actions to help the driver either avoid striking the rear-end of another vehicle or mitigate the severity of the crash. The actions include driver alerts, amplification of driver braking as distance decreases (dynamic brake support, DBS), and automatic braking if the driver has not acted or has not acted sufficiently (crash imminent braking, CIB). Recent efforts by various organizations have sought to define PCS objective test procedures and test equipment in support of consumer information programs and potential certification. This paper presents results and insights from conducting DBS and CIB tests on two production vehicles sold in the US. Eleven scenarios are used to assess the systems' performance. The two systems' performance shows that commercial systems can be quite different.

The 30 month COMET project aims to overcome the challenges facing European manufacturing industries by developing innovative machining systems that are flexible, reliable and predictable with an average of 30% cost efficiency savings in comparison to machine tools. From a conceptual point of view, industrial robot technology could provide an excellent base for machining being both flexible and cost efficient. However, industrial robots lack absolute positioning accuracy, are unable to reject disturbances in terms of process forces and lack reliable programming and simulation tools to ensure right first time machining, once production commences. These three critical limitations currently prevent the use of robots in typical machining applications. The COMET project is co-funded by the European Commission as part of the European Economic Recovery Plan (EERP) adopted in 2008.

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.

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.

The 30 month COMET project aims to overcome the challenges facing European manufacturing industries by developing innovative machining systems that are flexible, reliable and predictable with an average of 30% cost efficiency savings in comparison to machine tools. From a conceptual point of view, industrial robot technology could provide an excellent base for machining being both flexible and cost efficient. However, industrial robots lack absolute positioning accuracy, are unable to reject disturbances in terms of process forces and lack reliable programming and simulation tools to ensure right first time machining, once production commences. These three critical limitations currently prevent the use of robots in typical machining applications. The COMET project is co-funded by the European Commission as part of the European Economic Recovery Plan (EERP) adopted in 2008.

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.

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.

Path planning and re-planning for serial 6 degree of freedom (DOF) robotic systems is challenging due to complex kinematic structure and application conditions which affects the robot's tool frame position, orientation and singularity avoidance. These three characteristics represent the key elements for production planning and layout design of the automated manufacturing systems. The robot trajectory represents series of connected points in 3D space. Each point is defined with its position and orientation related to the robot's base frames or predefined user frame. The robot will move from point to point using the desired motion type (linear, arc, or joint). The trajectory planning requires first to check if robot can reach the selected part(s). This can be simply done by placing the part(s) inside the robot's work envelope. The robot's work envelope represents a set of all robots' reachable points without considering their orientation.