Portable X-ray back scattering imaging systems

Methods and systems for inspecting objects are disclosed. A portable X-ray backscatter imaging system includes a microfocus X-ray tube to emit X-rays at an object under inspection. A track system rasters the microfocus X-ray tube to inspect the object. A portable hood may enclose the microfocus X-ray tube and the track system against the object A rotation mechanism rotates the microfocus X-ray tube to angle the emitted X-rays at the object. A plurality of solid state detectors receive scattered X-rays to generate an image of the object.

TECHNICAL FIELD

The present disclosure pertains to inspecting objects, and more specifically, inspecting objects using portable X-ray Back Scattering imaging systems.

BACKGROUND

In some situations, various objects such as aircraft vehicles call for inspection at one or more generally known locations. For example, if a vehicle were to sustain an impact such as during a collision of two vehicles, it may be desirable to inspect one or both of the impacted vehicles at the impact location which generally can be determined by observing the impact or by a post-collision examination of the vehicles. At other times, statistical data may call for inspection of a group of objects at one or more generally known location. In situations where visual inspection cannot easily or adequately inspect the objects such as to determine whether or not there is internal structural damage after an impact, an alternative method of inspection is desirable.

Examples of vehicle objects that may call for inspection include aircraft, maritime vessels, automobiles, and other large investment assemblies. Examples of structure objects that may call for inspection include petrochemical facilities, power generation facilities, nuclear facilities, water treatment plants, etc. Effective inspection of such vehicle and structure objects may advantageously extend the operational lifespan of the objects.

One technique frequently used to inspect features or characteristics of an object at a generally known location includes disassembling the object in order to access interior elements. Although disassembly provides access to interior surfaces that are otherwise difficult to inspect, this technique is often time consuming and expensive.

Another technique for inspecting features or characteristics of an object includes using an application of ultrasonics. For example, pulse echo ultrasonics may be used to assess impact damage to the skin of various vehicles or structures; however, the ultrasonic method cannot assess impact damage to nearby stiffeners when the damage occurs further into the stiffener than can be interrogated with the pulse echo ultrasonics.

An alternative technique for inspecting features or characteristics of an object at a generally known location utilizes X-ray Back Scattering imaging. X-ray Back Scattering imaging involves generating images of the object using an X-ray imaging system. One advantage of X-ray Back Scattering imaging is that it reduces inspection time and costs since it may not require disassembly in order to inspect interior elements.

Traditional X-ray imaging and X-ray Back Scattering systems are often large cumbersome systems. For example, traditional X-ray imaging systems generally require large 160 kilovolt X-ray tubes hooked up to a large high voltage power supply. As a result of the large X-ray tube and power supply, such systems generally require cooling to prevent overheating. In general, it is not uncommon for such systems to weight up to 1000 pounds making them very cumbersome.

SUMMARY

Methods and systems to inspect objects using portable X-ray Back Scattering imaging systems are disclosed. In one embodiment, a portable X-ray backscatter imaging system may include a light weight low radiation microfocus X-ray tube to emit X-rays through a stationary aperture of the portable X-ray backscatter system. The stationary aperture of the portable X-ray backscatter system then directs the X-rays generally toward an object under inspection. A rotation mechanism may rotate the microfocus X-ray tube about a yaw axis to angle the emitted X-rays at the object. A plurality of solid state detectors may receive one or more scattered X-rays to generate an image of the object. The system may also include a track system to raster at least the microfocus X-ray tube. A portable hood may enclose the microfocus X-ray tube and the track system against the object.

In another embodiment, a method of inspecting a structure for internal damage includes attaching an X-ray Back Scattering imaging system to the structure at a potentially damaged area of the structure. A plurality of motors raster a microfocus X-ray tube of the X-ray Back Scattering imagining system to inspect the structure. Scattered X-rays are received from the structure to generate an image of the structure.

In a further embodiment, a system for performing vehicle inspection includes a portable X-ray backscatter imaging unit. A microfocus X-ray tube of the portable X-ray backscatter imaging unit emits X-rays at the vehicle and a track system rasters at least the microfocus X-ray tube. A portable hood may enclose the microfocus X-ray tube and the track system against the vehicle.

The features, functions, and advantages may be independently achievable in various embodiments of the present disclosure or combinable in yet other embodiments.

DETAILED DESCRIPTION

Overview

As discussed above, although X-ray Back Scattering imaging may advantageously enable nondestructive inspection of objects, further improvements are desirable. Techniques for further improving object inspection are disclosed herein. Some techniques include using a portable X-ray backscatter system consisting of a microfocus X-ray tube to inspect the object. Other techniques involve attaching the X-ray backscatter system to the object. In addition, a track system may enable X-Y rastering of the microfocus X-ray tube to generate an X-ray image of the object. The portable X-ray backscatter system may be yawed to a pre-selected angle to raster the microfocus X-ray tube at the pre-selected angle. A portable hood may surround the entire X-ray Back Scattering imaging system including the track system. As discussed herein, the techniques may be implemented on vehicles or structures, which includes without limitation, aircraft, maritime vessels, spacecraft, motor vehicles, mechanical devices, petrochemical facilities, power generation facilities, nuclear facilities, water treatment plants, and other structures of or machines that receive maintenance.

Illustrative System

FIG. 1is an isometric schematic diagram100of an illustrative portable X-ray Back Scattering imaging system102in an operational environment. In one embodiment, the portable X-ray imaging system102is an X-ray backscatter system. An X-ray backscatter system may be advantageous over transmission λ-ray systems since X-ray backscatter systems can inspect structures from one side since the means of X-ray generation and detection can be placed on the same side. Another advantage is that X-ray backscatter typically projects less radiation than a transmission λ-ray system and so requires a smaller exclusion area for radiation safety. As illustrated inFIG. 1, the portable X-ray Back Scattering imaging system102may include a small filament microfocus X-ray tube104. Since microfocus X-ray tubes are smaller in size than conventionally X-ray backscatter systems, the microfocus X-ray tube portable X-ray imaging system102does not require cooling during operation. In addition, microfocus X-ray tubes104are generally low in radiation leaking and have a small X-ray field of view108. The microfocus X-ray tubes104may be rastered110in the X-Y direction as illustrated inFIG. 1. A track system such as the track system described below with reference toFIG. 2advantageously allows rastering110of the microfocus X-ray tube104while eliminating the need to use a rotating aperture such as used in conventional X-ray backscatter systems.

The microfocus X-ray tube104inspects an object112by projecting an X-ray field of view108onto the object. As the microfocus X-ray tube104generates X-rays, the X-rays may pass through one or more stationary apertures (not shown) to generate the X-ray field of view108. The small filament of the microfocus X-ray tube104allows for generation of a more collimated X-ray field of view108than the conventional large kilovolt X-ray tubes. The portable X-ray Back Scattering imaging system102may move the X-ray field of view108about an inspection object112using a rotational mechanism as described further below with reference toFIG. 3. Any power source may supply power to the microfocus X-ray tube104via a power cord114. One or more solid state detectors106of the portable X-ray Back Scattering imaging system102may receive at least a portion of the X-rays as they are scattered from the object112to generate an image of the object.

The microfocus X-ray tube104may use any technique well known in the art to generate the X-rays. In one or more embodiments, the microfocus X-ray tube104is a vacuum tube and includes a cathode to emit electrons into the vacuum. An anode collects the electrons emitted from the cathode to establish an electrical current through the microfocus X-ray tube104. To generate the X-rays, electrons are boiled off the cathode and collide with the anode under a high energy electric field. If the colliding electrons have sufficient energy, they can knock an electron out of an inner shell of the target metal atoms. X-ray photons with precise energies are emitted when electrons from higher states drop down to fill the vacancy created when the electron is knocked out of the inner shell.

A hood116may surround at least the microfocus X-ray tube104as illustrated inFIG. 1to form the portable X-ray Back Scattering imaging system102. In one embodiment, the portable X-ray Back Scattering imaging system102attaches to the object112such that the object is on one side of the microfocus X-ray tube104while the hood116surrounds the microfocus X-ray tube104on all the other sides. The portable X-ray Back Scattering imaging system102may utilize any attachment mechanism118to attach to the object112. For example, the portable X-ray Back Scattering imaging system102may use a suction mechanism such as vacuum assisted suction cups as illustrated inFIG. 1to attach to the object112. Alternatively, the attachment mechanism118may include clamps, bolts, tape, magnets, or screws to attach the portable X-ray Back Scattering imaging system102to the object112. Alternatively, the hood116including the portable X-ray Back Scattering imaging system102may be mounted on a stand or robotic arm (not shown).

As further illustrated inFIG. 1, a safety interlock120may ensure a proper attachment of the portable X-ray Back Scattering imaging system102to the object112. The safety interlock120links to the microfocus X-ray tube104such that the safety interlock is able to communicate with the microfocus X-ray tube. For example, the safety interlock120may communicate an attachment indication (whether or not the portable X-ray Back Scattering imaging system102is properly attached to the object112to the microfocus X-ray tube104. If the safety interlock120communicates an attachment failure communication (communication indicating that the portable X-ray Back Scattering imaging system102is not properly attached to the object112), the microfocus X-ray tube may be prevented from inspecting the object. In a further embodiment, the microfocus X-ray tube104may be prevented from generating the X-rays Back Scattering until the safety interlock120communicates an attachment pass communication (communication indicating that the portable X-ray Back Scattering imaging system102is properly attached to the object112). If the portable X-ray imaging system102becomes unattached from the object112while the microfocus X-ray tube104is operatively emitting X-rays, an attachment failure communication may automatically shut off the microfocus X-ray tube. If the portable X-ray imaging system102becomes properly attached to the object112, an attachment pass communication may automatically commence a generation of X-ray beams from the microfocus X-ray tube104.

The safety interlock120may be any mechanism that identifies an attachment of the portable X-ray Back Scattering imaging system102with the object112. For example, the safety interlock120may be a mechanical plunger switch, an optical interlock, a proximity sensor, and so forth.

AlthoughFIG. 1illustrates the hood116having a trapezoidal shape, the hood may be of any shape so long as it is open on one end and able to surround the microfocus X-ray tube104. For example, the hood116may be cone-shaped or cube-shaped. In one embodiment, the hood116is made of lead material such that it is non-transparent.

The hood116may include adjustable legs306(not shown) to adjust a distance of the hood relative to the object112. The adjustable legs306may be of any adjustable mechanism as well known in the art. For example, the adjustable legs306may be telescoping legs. Expanding the length of the adjustable legs306can alters a distance of the microfocus X-ray tube104to the object112. As illustrated inFIG. 1, the small size of the microfocus X-ray tube104allows the portable X-ray Back Scattering imaging system102to be positioned close to the object. Being close to the object112advantageously enables the portable X-ray imaging system102to capture low energy X-ray images of the object at equivalent resolution levels to the X-ray images captured by the high energy X-ray Back Scattering imaging systems. For example, the portable X-ray imaging system102may perform close-proximity nondestructive testing such as water detection in honeycombed structure or corrosion detection in subsurface of the aluminum skin and/or composites structures.

Illustrative Track System

FIG. 2is a top view schematic diagram of an illustrative track system200for a portable X-ray Back Scattering imaging system102. As mentioned above, the small filament of the microfocus X-ray tube104is advantageous for various reasons including enabling an X-Y rastering of the microfocus X-ray tube.

Any conceivable translational mechanism may enable the rastering of the microfocus X-ray tube104. In one embodiment, as illustrated inFIG. 2, a plurality of threaded rod elements enable the rastering of the microfocus X-ray tube104by moving the microfocus X-ray tube along an X-axis and a Y-axis of the track system200. As illustrated inFIG. 2, the microfocus X-ray tube104is attached to at least a first threaded rod element202. An X-direction motor204may rotate at least the first threaded rod element202such that as the first threaded rod element rotates, the microfocus X-ray tube104moves along an X-axis. The microfocus X-ray tube104may attach to at least a second threaded rod element206such that as a Y-direction motor208rotates the second threaded rod element206, the microfocus X-ray tube104moves along a Y-axis.

The X-direction motor204and the Y-direction motor208may be of any motor types. For example, the X-direction motor204and the Y-direction motor208may be computer-controlled smart motors. In some situations, the X-direction motor204and the Y-direction motor208move the microfocus X-ray tube104along both the X-axis and the Y-axis at the same time. In other situations, the X-direction motor204may only be used to move the microfocus X-ray tube104along just the X-axis. Similarly, the Y-direction motor208may be used to move the microfocus X-ray tube104along just the Y-axis.

As discusses above with respect toFIG. 1, one or more solid state detectors106may receive at least a portion of the X-rays as they are scattered from an object to generate an image of an object under inspection. In one embodiment, the track system200moves the solid state detectors106move along with the microfocus X-ray tube104regardless of the direction in which the microfocus X-ray tube is moving. Alternatively, the track system200may move the solid state detectors106along with the microfocus X-ray tube104only when the microfocus X-ray tube moves along the X-axis. In such an embodiment, if the track system200moves the microfocus X-ray tube104along the Y-axis, then the microfocus X-ray tube moves independently from the solid state detectors106while the solid state detectors remain stationary.

The track system200may raster the microfocus X-ray tube in an X-Y direction as noted above. In one embodiment, the track system200rasters the microfocus X-ray tube104while the solid state detectors106operatively receive at least a portion of the X-rays as they are scattered from an object. The images of the object may be generated at every point in time and for every position along the track system for each detector. These images can be overlayed to increase contrast without reducing the scan speed. If the detectors106are placed in different planes relative to each other, parallax between images can be produced in the reconstruction that can be used to provide depth information with simple measurements.

The track system may be attached to a hood (not shown) such that the hood surrounds at least the track system200and the microfocus X-ray tube104on all sides except for the side that the hood attaches to an object. Any mechanism may attach the track system200to a hood. For example, the hood may include a guide rail such that the track system200slides into the hood and clamps into place. Alternatively, the track system200may bolt to or screw into the hood.

Illustrative Rotation Mechanism

FIG. 3is a side view schematic diagram300of an illustrative rotational mechanism for a portable X-ray Back Scattering imaging system. As mentioned above, a rotational mechanism may move the X-ray field of view108about an inspection object112. The rotational mechanism may rotate the microfocus X-ray tube104about a yaw axis (not shown) to move the X-ray field of view108about an inspection object. Specifically, rotating the microfocus X-ray tube may alter the angle302at which the emitted X-rays impinge upon the object112.

The rotation mechanism may rotate one or more elements of the portable X-ray imaging system about the yaw axis to any angle within a 360 degree range. In one embodiment, the rotation mechanism rotates at least the microfocus X-ray tube104and the solid state detectors106about the yaw axis. Alternatively, the rotation mechanism rotates at just the microfocus X-ray tube104about the yaw axis.

In one embodiment, a motor may rotate the one or more elements of the portable X-ray imaging system about the yaw axis to any desired angular orientation within a 360 degree range. The motor may rotate the one or more elements of the portable X-ray Back Scattering imaging system while the X-ray imaging system is operatively imaging the object112such that a continuous image of the object is generated. In such an embodiment, a power source does not have to be disconnected from the X-ray imaging system in order to rotate the elements about the yaw axis.

The combination of the roll mechanism ofFIG. 3with the track system illustrated inFIG. 2advantageously allows the microfocus X-ray tube104to rotate continuously through a selected fan angle at each position along an X axis to scan X-rays across the object112to produce an image. Alternatively, the angle302may be a set to a specific pre-selected angle such that the track system performs rastering in the X-Y direction at the pre-selected yaw angle. Rastering the microfocus X-ray tube104in the X-Y direction at the pre-selected yaw angle advantageously allows the portable X-ray Back Scattering imaging system102to take advantage of the particular geometry of the inspection object in order to obtain an image of the structure that is most likely to show desired features or elements. For example, if the user of the portable X-ray Back Scattering imaging system102is inspecting the object112for specific features such as delamination damage in a hat stiffener304, it may be desirable to aim the microfocus X-ray tube104(and transmitted X-ray field of view108) at a specific angle that the portable X-ray imaging system102is sensitive to finding disbond damage. The track system may then perform rastering in the X-Y direction to inspect for delamination damage.

As further illustrated inFIG. 3, an attachment mechanism118may attach the portable X-ray Back Scattering imaging system102to the object112. For example, as illustrated inFIG. 3, a suction mechanism such as vacuum assisted suction cups may attach the portable X-ray Back Scattering imaging system102to the object. The portable X-ray Back Scattering imaging system102may include adjustable legs306to adjust a distance of the portable X-ray Back Scattering imaging system102to the object112. The adjustable legs306may be any adjustable mechanism such as telescoping legs.

Illustrative Implementation

As mentioned above with respect toFIG. 1, the combination of the roll mechanism with the track system advantageously allows the microfocus X-ray tube to perform rastering in the X-Y direction at the pre-selected yaw angle to take advantage of the particular geometry of the structure to be inspected.FIG. 4shows an illustrative image400generated by an illustrative portable X-ray Back Scattering imaging system. InFIG. 4, the portable X-ray Back Scattering imaging system inspected an aircraft fuselage hat stiffener402to search for substructural damage404after an impact. The image400shows hat stiffener impact damage406that cannot be seen from the skin side with traditional inspection methods. The portable X-ray imaging system advantageously inspected the structure without having to dissemble to aircraft.

FIG. 5is an illustrative operational embodiment500of a portable X-ray backscatter system. The operational embodiment500is illustrated as a collection of blocks in a logical flow graph, which represent a sequence of operations that can be implemented in hardware, software, or a combination thereof. In the context of software, the blocks represent computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures, and the like that perform particular functions or implement particular abstract data types. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described blocks can be combined in any order and/or in parallel to implement the process.

The process500may be performed, at least in part, by the portable X-ray imaging system ofFIG. 1. At502, the portable X-ray backscatter system attaches to an inspection object. Attaching the portable X-ray backscatter system to the object may include attaching a portable hooded X-ray imaging system including a track rack unit to the object. The portable X-ray backscatter system may attach to the object using a plurality of vacuum assisted suction cups as described above with reference toFIG. 3. The portable X-ray backscatter system preferably attaches to the object at a predetermined location such as at a location of a known hat stiffener to inspect structural features of the hat stiffener. The portable X-ray Back Scattering imaging system may automatically determine the predetermined location by examining the geometry of the object and sensing its location relative to the object. Alternatively, a user may input the predetermined location.

At504, a microfocus X-ray tube of the portable X-ray backscatter system is linearly and/or rotationally prepositioned. A translational mechanism such as the track system described above with reference toFIG. 2may linearly preposition the microfocus X-ray tube to a desired X and Y location. A rotation mechanism may preposition the microfocus X-ray tube to a desired angle based on known specific features of the object such that the portable X-ray backscatter system can perform optimum feature assessment of the object. In one embodiment, a user operates a mechanism, such as a remote control linked to the track system and the rotation mechanism, to translate the microfocus X-ray tube to the desired location on the track system and/or rotate the microfocus X-ray tube to the desired angle. Alternatively, as described further below with reference toFIGS. 6 and 7, the portable X-ray backscatter system may include a scanner alignment control system to translate the microfocus X-ray tube to an ideal location on the track system and/or rotate the microfocus X-ray tube to an ideal angle based on analyzing a digital model of the object.

At506the portable X-ray backscatter system operably performs rastering in an X-Y direction at the desired angle. A track system may move at least the microfocus X-ray tube in the X-Y direction using one or more motors. The motors may be remotely operable such that a user can initiate the rastering while the X-ray backscatter system remains enclosed by a hood. Alternatively, the X-ray backscatter system may sense its location relative to the object and automatically perform the rastering with minimal or no user interaction. In one embodiment, a safety mechanism may prevent the X-ray backscatter system from becoming operational if the X-ray backscatter system is not properly hooded. For example, the safety mechanism may use a safety interlock method as described above with reference toFIG. 1.

At508, a determination is made as to whether the rastering performed at506generated the desired image of the object. A user may make the determination at508based on examination of a backscatter image generated from block506. Alternatively, the portable X-ray backscatter system may automatically make the determination at508by sensing a position of the portable X-ray backscatter system relative to the object. The portable X-ray backscatter system may use a stored schematic diagram of the object to aid in automatically making the decision at508.

If more areas of the object are to be inspected (i.e., the “Yes” branch from508), a determination is made at510whether the additional elements of the object can be inspected by yawing at least a portion of the portable X-ray backscatter system using the rotation mechanism described with reference to block504. If so (i.e., the “Yes” branch from510), the rotation mechanism yaws at least a portion of the portable X-ray backscatter system about a yaw axis at512. In one embodiment, the rotation mechanism yaws only the microfocus X-ray tube about the yaw axis at512. Alternatively, the rotation mechanism yaws the microfocus X-ray tube as well as one or more detectors about the yaw axis at512In one operational mode, the rotation mechanism rotates at least the microfocus X-ray while the portable X-ray backscatter system operatively images the object.

Regardless of whether yaw is used (i.e., from512) or is not used to capture other parts of the objects (i.e., the “No” branch from510), a determination is made whether a rastering of at least the microfocus X-ray tube in the X-Y direction along the track system enables additional inspection of the object. If so (i.e., the “Yes” branch from514), the portable X-ray backscatter system moves along the track system. In the described implementation above, an X-direction motor and a Y-direction motor rasters at least the microfocus X-ray tube along the track system using a plurality of threaded rod elements.

In one embodiment, the portable X-ray backscatter system simultaneously yaws at512and moves at516. In an alternative embodiment, the portable X-ray backscatter system independently yaws at512and independently moves at516.

At least a portion of the emitted X-ray beam scatters back off the object to generate an image of the object at518.

Illustrative Scanner Alignment Control System

FIGS. 6 and 7together illustrate an exemplary scanner alignment control system to position a microfocus X-ray tube.FIG. 6is a flow diagram600for an illustrative scanner alignment control system.FIG. 7is a combined hardware and flow diagram700for an illustrative scanner alignment control system.FIGS. 6 and 7are described together. The elements illustrated inFIGS. 6 and 7represent operations that may be implemented in hardware, software, or a combination thereof. In the context of software, the elements represent computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures, and the like that perform particular functions or implement particular abstract data types. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described elements can be combined in any order and/or in parallel to implement the process.

As mentioned above with respect toFIG. 5, the portable X-ray backscatter system may include a scanner alignment control system to translate the microfocus X-ray tube to an ideal location on the track system and/or rotate the microfocus X-ray tube to an ideal angle based on analyzing a digital model of the object. The ability to automatically translate and/or rotate the microfocus X-ray tube to the ideal position based on a digital model of the object advantageously aims the microfocus X-ray tube directly at a desired feature of the object without having to perform trial and error even if there is no direct line of sight between the microfocus X-ray tube and desired feature.

With reference toFIG. 6, a digital model602containing data relating to an object under inspection604is provided. The digital model602may include interior and exterior data, such as the mass that defines the interior and exterior surfaces. The data in the digital model602may be in a coordinate system specific to the object under inspection604. For example, if the object under inspection604is an aircraft, the data in the digital model may be in an aircraft coordinate system. A position monitoring system608may generate a virtual representation of a scanning system610, such as the illustrative portable X-ray Back Scattering imaging system102ofFIG. 1, such that the virtual representation of a scanning system is in the same coordinate system as the digital model of the object.

The position monitoring system608may use object reference features612measurements, scanner reference features614measurements, and known locations of the object reference features (provided via the digital model602) to set the scanning system and the object to a common reference coordinate system. For example, element702ofFIG. 7illustrates the position monitoring system using various object reference features612as well as various scanner reference features614to generate the virtual representation of the scanning system610. AlthoughFIG. 7only illustrates three object reference features612and three scanner reference features614, it is appreciate that many more reference features may be used to generate a comprehensive virtual representation of the scanning system610. Element704ofFIG. 7illustrates that the position monitoring system608is also provided with known locations of the object reference features612. In one embodiment, the object under inspection604is an aircraft and the object reference features612are golden rivets located throughout the aircraft and identified in the structural repair manual.

The position monitoring system608may perform a best fit analysis of the scanner reference features614to the object reference features612to generate the virtual representation of the scanning system610. The position monitoring system608may export the virtual representation of the scanning system610, illustrated by line706ofFIG. 7, to a scanner alignment control system616. The scanner alignment control system616may then combine the virtual representation of the scanning system610with the digital model602of the object under inspection604. It is appreciated that without the best fit analysis of the position monitoring system608, a digital representation of the scanning system610would render the scanning system floating out in space since there would be no common reference to link the scanning system with the object.

As Illustrated inFIG. 7, the scanner alignment control system may display the virtual representation of the scanning system610together with the digital model602of the object under inspection604on an interactive display device708. An operator of the interactive display device may then select a hidden feature618of the object to inspect (i.e. element620ofFIG. 6). Since the operator is selecting the desired location using a digital model of the object, it is appreciated that the operator may easily select any feature of the object including features which are not visible from the exterior surface of the object such as virtually represented hidden feature710ofFIG. 7. For example, an operator may employ common tools available for interacting with digital models such as zooming, panning, etc. . . . to locate the hidden feature on the display device and then the operator could select the hidden feature on the display device by clicking on it. In response to the user input, the scanner alignment control system616may send a command (line712inFIG. 7) to a motion system622of the scanning system610instructing the scanning system to aim a microfocus X-ray tube624of the scanning system610at the hidden feature618. In a situation where the scanner reference features614are located on a track system of the scanning system610and not on the microfocus X-ray tube itself, such as illustrated inFIG. 7, the scanning system may still accurately aim the microfocus X-ray tube at the hidden feature618by taking into account any differences between the location scanner reference features with respect to the location of the microfocus X-ray tube.

AlthoughFIGS. 6 and 7illustrate the position monitoring system608and the scanner alignment control system616being separate elements, it should be appreciated that one element may perform both the features of the position monitoring system and the scanner alignment control system. Alternatively, the scanning system itself may contain the software and hardware elements necessary to perform the operations of the position monitoring system608and the scanner alignment control system616.

Illustrative Inspection Object

FIG. 8is a side elevational view of an illustrative aircraft800, which may experience inspection using the techniques disclosed herein. One may appreciate that the aircraft800may include various known and unknown parts, particularly if the aircraft has been in-service for many years, such as an aircraft assembled for large-scale war service (e.g., circa1945, etc.) Thus, the X-ray Back Scattering imaging system may generate an X-ray image to inspect for heel cracks or other sub-surface structural damage.

In this embodiment, the aircraft800includes a fuselage802including wing assemblies804, a tail assembly806, and a landing assembly808. The aircraft800further includes one or more propulsion units810, a control system812, and a host of other systems and subsystems that enable proper operation of the aircraft800. One should appreciate that many parts included in an aircraft may be imaged using the X-ray imaging system techniques disclosed herein.

Although the aircraft800shown inFIG. 8is generally representative of a commercial passenger aircraft; the teachings of the present disclosure may be applied to the maintenance, manufacture, and assembly of other structures including passenger aircraft, fighter aircraft, cargo aircraft, rotary aircraft, other types of manned or unmanned aircraft, ground vehicles, ships, petrochemical facilities, power generation facilities, nuclear facilities, water treatment plants, etc. . . .

Conclusion

While embodiments of the disclosure have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the disclosure. Accordingly, the scope of the disclosure is not limited by the disclosure of these embodiments. Instead, the disclosure should be determined entirely by reference to the claims that follow.