Abstract: A fastener locating tool equipped with a sensor head having one or more probes and a method for operating such a tool for precisely locating a fastener that is hidden or buried under a thick coating applied on a surface of a structure. The fastener locating tool may be manually or automatically operated. The fastener locating tool includes a platform having a central opening, means for temporarily attaching the platform to a coated surface, and a sensor head that may be easily mechanically coupled to and then later decoupled from the platform. Optionally, the fastener locating tool also includes a multi-stage positioning system with X and Y stages which may be used to adjust the position of the sensor head. The sensor head includes at least one probe which generates electrical signals indicating the presence of a fastener beneath a coating when the probe is within a detection range.

Abstract: An aircraft lifecycle in which digital data for an aircraft part is automatically collected, retained, and utilized to individualize aircraft inspection and maintenance is described. Several types of data, including non-destructive evaluation and measurement data and structural health monitoring data, are used in a feedback loop having various phases which may automatically receive data in digital format from other phases. In this manner the part being designed, fabricated, tested, and maintained for the aircraft is optimized and processes involved in the lifecycle of the part is made more efficient.

Abstract: An end effector, for adhesively attaching a first part to a second part, comprises a support and a first nozzle, coupled to the support and movable relative to the support, and a second nozzle, coupled to the support and movable relative to the support. The first nozzle comprises a first-nozzle body, comprising a first-nozzle-body outlet port and a first-nozzle separator plate, extending from the first-nozzle body. The second nozzle comprises a second-nozzle body, comprising a second-nozzle-body inlet port and a second-nozzle separator plate, extending from the second-nozzle body. The end effector further comprises a roller, coupled to the support, rotatable relative to the support about a roller axis, and located between the first nozzle and the second nozzle.

Abstract: A motorized rolling maintenance cart that utilizes the angled trailing edge geometry of an airfoil-shaped body (such as a wind turbine blade or rotor blade) to traverse the length of the airfoil-shaped body. The trailing edge-following maintenance cart may be used to carry personnel doing maintenance activities on the blades, such as local repairs or re-painting. In accordance with one aspect, the maintenance cart carries non-destructive inspection sensor units or other maintenance hardware over the surface of the airfoil-shaped body (e.g., in a spanwise direction). In accordance with another aspect, the trailing edge-following maintenance cart is configured to also provide fall protection to one or more independently movable crawler vehicles by means of cables. Alternative embodiments may include only one of the two aspects.

Abstract: In an example, a method is described. The method comprises placing a repair patch over a repair area of a structure, the repair patch comprising a repair-patch hole. The method also comprises sealing the repair patch and repair area with a vacuum bag having a seal ring around a periphery of the vacuum bag. The method also comprises evacuating, via an adhesive injection apparatus attached to the repair-patch hole and the seal ring of the vacuum bag, the repair area and an injection channel of the adhesive injection apparatus. The method also comprises forcing adhesive through the evacuated injection channel and into the evacuated repair area.

Abstract: Methods and apparatus for performing repair operations using an unmanned aerial vehicle (UAV). The methods are enabled by equipping the UAV with tools for rapidly repairing a large structure or object (e.g., an aircraft or a wind turbine blade) that is not easily accessible to maintenance personnel. A plurality of tools are available for robotic selection and placement at the repair site. The tools are designed to perform respective repair operations in sequence in accordance with a specified repair plan, which plan may take into account the results of a previously performed UAV-enabled inspection.

Abstract: A system and method for detecting an anomaly of an optically transparent or translucent object are disclosed. The system and method include a light source configured to emit light, a light transmission element having a textured surface, and an optical couplant configured to be disposed between the light transmission element and the object. At least a portion of the light emitted by the light source is configured to pass into the light transmission element through the textured surface and pass into the object through the optical couplant. At least a portion of the light that passes into the object internally reflects within the object and impinges on the anomaly to provide an illumination that indicates the location of the anomaly.

Abstract: An example method of joining a first structure and a second structure is described that includes forming a bond cavity between a first structure and a second structure, placing a semi-permeable breather material at one or more exits of the bond cavity, placing a vacuum bag around the bond cavity and the semi-permeable breather material, evacuating the bond cavity via a vacuum port and forcing adhesive into the bond cavity via an adhesive port while the bond cavity is evacuated, and curing the adhesive via one or more heaters to bond the first structure to the second structure.

Abstract: A metamaterial-based substrate (meta-substrate) for piezoelectric energy harvesters. The design of the meta-substrate combines kirigami and auxetic topologies to create a high-performance platform including preferable mechanical properties of both metamaterial morphable structures. The creative design of the meta-substrate can improve strain-induced vibration applications in structural health monitoring, internet-of-things systems, micro-electromechanical systems, wireless sensor networks, vibration energy harvesters, and other applications whose efficiency is dependent on their deformation performance. The meta-substrate energy harvesting device includes a meta-material substrate comprising an auxetic frame having two kirigami cuts and a piezoelectric element adhered to the auxetic frame by means of a thin layer of elastic glue.

Abstract: Embodiments described herein utilize Non-Destructive Inspection (NDI) scan data obtained during a process performed on a surface of a structure to update a location of an NDI scanner on the surface. A subsurface feature within the structure is detected based on the NDI scan data, which are correlated with pre-defined position data for the subsurface feature. A measured location of the NDI scanner on the surface is corrected based on the pre-defined position data for the subsurface feature.

Abstract: A bonded structure is described. The bonded structure includes an outer structure including a close tolerance hole associated with a first accuracy level. The bonded structure includes an interior structure comprising an oversized hole associated with a second accuracy level that is different from the first accuracy level. The bonded structure includes an elastomeric grommet disposed in the oversized hole. The bonded structure includes one or more spacers between the outer structure and the interior structure providing a space between the outer structure and the interior structure. The bonded structure includes a fastener positioned in the close tolerance hole and in the oversized hole. The bonded structure includes a bonding media disposed in the space between the outer structure and the interior structure via one or more channels of the fastener. The bonding media, elastomeric grommet, and oversized hole collectively position the interior structure relative to the outer structure.

Abstract: A piezoelectric sensor includes a substrate, a meta-membrane adhered to the substrate, and a piezoelectric element adhered to the meta-membrane. The substrate includes a support frame which laterally surrounds and partly defines a recess and a cover film which overlies and partly defines the recess. The support frame supports the cover film along an entire periphery of the cover film. The meta-membrane is adhered to the cover film of the substrate. In accordance with one embodiment, the meta-membrane has an auxetic bi-axial kirigami honeycomb structure. In accordance with another embodiment, the meta-membrane has an auxetic hexagonal honeycomb structure. The meta-membrane is adhered to the substrate and to the piezoelectric element using elastic glue. In one proposed implementation, the substrate and meta-membrane are made of polycarbonate and the piezoelectric element comprises a piezoelectric substrate made of polyvinylidene fluoride.

Abstract: Systems and methods for tracking the location of a non-destructive inspection (NDI) scanner using scan data converted into images of a target object. Scan images are formed by aggregating successive scan strips acquired using one or two one-dimensional sensor arrays. An image processor constructs and then compares successive partially overlapping scan images that include common features corresponding to respective structural features of the target object. The image processor is further configured to compute a change in location of the NDI scanner relative to a previous location based on the respective positions of those common features in the partially overlapping scan images. This relative physical distance is then added to the previous (old) absolute location estimate to obtain the current (new) absolute location of the NDI scanner.

Abstract: End effectors and systems may capture, release, and/or create a mating engagement between the end effector and a target object. Said end effectors are tolerant of positional and rotational misalignment of the target object, and include a plurality of roller wheels, one or more of which is arranged in a non-parallel plane with respect to one or more other roller wheels. A first roller wheel configured to rotate in a first plane, a second roller wheel configured to rotate in a second plane, and a third roller wheel configured to rotate in a third plane may be arranged such that the end effector is configured to engage a passive receptacle of the target object, to capture the target object. Rotating the roller wheels in the opposite direction may cause the target object to be released or launched, by urging the passive receptacle off of or away from the roller wheels.

Abstract: A reinforced sandwich panel, including two skin panels; a foam core disposed between the two skin panels; and an expandable framework disposed within the foam core.

Abstract: Methods for performing maintenance operations using unmanned aerial vehicles (UAVs). The methods are enabled by equipping a UAV with a maintenance tool capable of performing a desired maintenance operation (e.g., nondestructive inspection) on a limited-access surface of a large structure or object (e.g., a wind turbine blade). The UAV uses re-orientation of lifting means (e.g., vertical rotors) to move the maintenance tool continuously or intermittently across the surface of the structure while maintaining contact with the surface of the structure undergoing maintenance.

Abstract: Described herein is a system for determining structural characteristics of an object, the system including a first laser, a second laser, one or more processors, and a computer readable medium storing instructions that, when executed by the one or more processors, cause the system to perform functions. The functions include illuminating, by the first laser, a surface region of an object with an incident light pulse, thereby causing the object to exhibit vibrations; illuminating, by the second laser, the surface region with an incident light beam, thereby generating responsive light that is indicative of the vibrations; detecting the responsive light and determining a difference between a characteristic of the responsive light and a reference characteristic that corresponds to the surface region; determining a position of the surface region within a three-dimensional space; and displaying the surface region such that the difference is indicated at the position of the surface region.

Abstract: Systems and methods for tracking the location of a non-destructive inspection (NDI) scanner using images of a target object acquired by the NDI scanner. The system includes a frame, an NDI scanner supported by the frame, a system configured to enable motorized movement of the frame, and a computer system communicatively coupled to receive sensor data from the NDI scanner and track the location of the NDI scanner. The NDI scanner includes a two-dimensional (2-D) array of sensors. Subsurface depth sensor data is repeatedly (recurrently, continually) acquired by and output from the 2-D sensor array while at different locations on a surface of the target object. The resulting 2-D scan image sequence is fed into an image processing and feature point comparison module that is configured to track the location of the scanner relative to the target object using virtual features visible in the acquired scan images.

Abstract: Embodiments described herein utilize Non-Destructive Inspection (NDI) scan data obtained during a process performed on a surface of a structure to update a location of an NDI scanner on the surface. A subsurface feature within the structure is detected based on the NDI scan data, which are correlated with pre-defined position data for the subsurface feature. A measured location of the NDI scanner on the surface is corrected based on the pre-defined position data for the subsurface feature.

Abstract: Methods and apparatus for performing repair operations using an unmanned aerial vehicle (UAV). The methods are enabled by equipping the UAV with tools for rapidly repairing a large structure or object (e.g., an aircraft or a wind turbine blade) that is not easily accessible to maintenance personnel. A plurality of tools are available for robotic selection and placement at the repair site. The tools are designed to perform respective repair operations in sequence in accordance with a specified repair plan, which plan may take into account the results of a previously performed UAV-enabled inspection.