Abstract:
Disclosed is phased array inspection system with automatically generated PAUT scan plan based on a set of configurable probe operation parameters and a combination of preferred code requirement and rules given by PAUT expertise. The complex code requirements and PAUT expertise are pre-assembled into a plurality of templates applicable to categories of inspection tasks by PAUT experts. Requirements and optimization scoring schemes are then used to automatically score each of specifically proposed scan plan setup, including the selection of probe operation parameters against the corresponding template for a specific task. This allows less skilled field inspector to operate with the correct interpretation of the complex code and accurate evaluation of the scan plan.

Description:
FIELD OF THE INVENTION 
       [0001]    The present disclosure generally relates to a method and a system for conducting non-destructive testing/inspection (later as NDT/NDI), and more particularly to a system and method of automatically generating scan plans for assisting phased array ultrasonic inspections. 
       BACKGROUND OF THE INVENTION 
       [0002]    Phased array ultrasonic testing (PAUT) is an advanced method of ultrasonic testing (UT) that has applications in industrial non-destructive testing (NDT). Common applications are to find flaws in manufactured materials such as welds. 
         [0003]    Single-element (non-phased array) probes, known technically as monolithic probes, emit a beam in a fixed direction. To test a large volume of material, a conventional probe must be physically moved or turned to sweep the scan beam through the area of interest. 
         [0004]    In contrast, the beam from a PAUT probe can be moved electronically, without moving the probe, and can be swept through a wide volume of material at high speed. The beam is controllable because a PAUT probe is made up of multiple small elements, each of which can be pulsed individually at a computer-calculated timing, forming incidence angles. The term phased refers to the timing, and the term array refers to the multiple elements. The element that contributes to a beam formation is defined as the aperture of the beam; the aperture can include a portion or all of the elements of the PAUT probe. 
         [0005]    During typical inspections of welds, multiple ultrasound beams are generated from a single or multiple apertures at various incidence angles. These generate an image showing reflections (or diffractions) of the ultrasonic waves that are associated to defects within the scanned area in the test object. For weld inspection, the interest area, or the scanned area is usually the weld and its surrounding area. For cases where the aperture is fixed and only the angles are changed, the images are called a sectorial scan or S-scan. For cases where the angle is fixed and only the aperture is moved, the images are called a linear scan or E-scan. 
         [0006]    In order to have an appropriate coverage of the weld area, it is almost always required to combine inspections from both sides of a weld and it may also be required to do multiple passes on a given side of the weld if a single probe coverage proves insufficient. For defining an inspection plan, standards and normalized practice are the major factors composing the guidelines or codes for defining the probe and beam configurations, an example being Section V of ASME Boiler and Pressure Code—Nondestructive Examination. Such practices are referenced herein as code requirements. For weld inspection, the phased array configuration typically involves the use of a wedge, which defines a first mechanical incidence angle to generate an S-scan with shear waves in the 40 to 70 degree range of the refraction angle. The inspection of a complete weld area also involves a mechanical scan of the weld by moving the probe arrangement parallel to the weld axis. 
         [0007]    According to an international code “2010 ASME Boiler &amp; Pressure Vessel Code, 2010 Edition, Section V—Nondestructive Examination” (Herein after as “codes”), the definition of the inspection scan plan associated to weld inspection is as follows. This The scan plan is herein defined as the combination of,
       a, instrumentation configuration including probe, wedge, and acquisition unit;   b, acoustic setting, including, aperture size and position, focalization setting, beams angle, gating parameters and,   c, probe manipulation guideline, including probe to weld distance, maximum inspection speed.       
 
         [0011]    A recurring problem associated to weld inspection using phased array ultrasonic scans is that the combination gets extremely complicated when all the variables, each could have vast range of selections are into play. It is extremely difficult to have an individual trained in such a broad range of expertise as in phased array systems, phased array probes and wedges and in weld structure and flaws. 
         [0012]    As can be seen how stiff the challenge is to configure the right scan plan with ranges of parameters for all the factors listed above. A first approach being used in existing practice to address this problem is the use of modeling tools to visualize beams generated by the PAUT probe in the test object. Examples using this approach are “ESBeamTool” from Eclipse Scientific or “SetupBuilder” from Olympus. Whereas this approach to some degrees simplifies certain tasks such as weld coverage and probe placement, it does little to reduce the needs for high-level inspector expertise since a lot of knowledge is still required to bridge the gap between the codes requirement and the instrument selection, configuration and manipulation. More specifically, this approach does not automatically provide templates or models regarding the above listed aspects of a) and b) of a scan plan, and it does not automatically evaluate the above listed aspect c) for probe manipulation either. 
         [0013]    Another solution to the problem of defining scan plans is the full integration of all the code requirements in the modeling software as disclosed in US Patent No. US20130218490. Even though this solution has certain success when integrated for the automated inspection of girth weld, when using a dedicated scanner it does have several drawbacks for the PAUT inspection of welds in general. Firstly, a significant amount of codes is needed for PAUT weld inspection in general because each group of codes represents the specific requirements associated to the specific weld usage (piping welds, boiler tubes, pressure vessels, etc.). Secondly, since code interpretation is complicated process and often without a straightforward answer, the code interpretation solely decided by a modeling tool does involve some potential responsibility and acceptance issues. 
         [0014]    It would thus be desirable to have a computer aided tool that more easily generates a PAUT scan plan, yet still provides the desired flexibility to allow code requirement interpretation by duly qualified end-users. 
       SUMMARY OF THE INVENTION 
       [0015]    A general object of the present disclosure is to provide a system and method that automatically generate scan plans for assisting phased array ultrasonic inspections based on a set of guidelines and expertise in the groups of instrument configuration, acoustic setting and probe manipulations. 
         [0016]    Another object of the present disclosure is to provide an automatic scan generation method for PAUT that first provides a template based on the NDT expertise knowledge in interpreting the codes for a category of inspection tasks. Then the scan generation method further uses a quantitative evaluation method to evaluate specific probe manipulation plan based on the templates and the test object geometry definition. 
         [0017]    More specifically, the method of generating a scan plan as presently disclosed involves firstly interpreting the codes with NDT expertise related to aspects of above a) and b) of a scan plan, and generating sets of templates readily available for varies categories of inspection tasks. The templates are stored and made readily available in the phased array system. Then secondly, with a specific inspection task and test object geometry defined, a corresponding template is chosen. Then the presently disclosed method involves employing quantitative evaluation of aspect c) of the above mention scan plan definition, benchmarked by the corresponding template. 
         [0018]    Code requirements and PAUT expertise are expressed in quantitative values in the invention, which makes it possible to automatically generate suitable instrument configuration, acoustic setting and probe manipulation guidelines. So, knowledge concerning best practices of PAUT weld inspection can be combined with the various codes that affect these inspections though the use of templates. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a schematic overview the automated scan plan generation process of the present disclosure. 
           [0020]      FIG. 2  is a schematic overview of the applicative guidelines that can be applied to the automatically generated scan plan. 
           [0021]      FIG. 3 a    is a detailed representation of the applicative guideline of a required heat affected zone. 
           [0022]      FIG. 3 b    is a detailed representation of the applicative guideline of tolerances on beam perpendicularity relative to a weld surface. 
           [0023]      FIG. 3 c    is a detailed representation of the applicative guideline of beam overlap. 
           [0024]      FIG. 3 d    is a detailed representation of the applicative guideline of overlap between successive scans for configuration. 
           [0025]      FIG. 4  is a schematic overview of the PAUT NDT expertise that is applied to the automatically generated scan plan. 
           [0026]      FIG. 5 a    is a detailed representation of PAUT NDT expertise to provide a uniform focalization depth for all beams traveling in the test object. 
           [0027]      FIG. 5 b    is a detailed representation of PAUT NDT expertise to provide focalization on a vertical axis. 
           [0028]      FIG. 5 c    is a detailed representation of PAUT NDT expertise to provide focalization after a given depth distance within the inspected material. 
           [0029]      FIG. 5 d    is a detailed representation of PAUT NDT expertise to provide focalization on a weld bevel. 
           [0030]      FIG. 5 e    is a detailed representation of PAUT NDT expertise that illustrates an H-scan. 
           [0031]      FIG. 5 f    is a detailed representation of PAUT NDT expertise that illustrates a multiple scan configuration performed with the configurable parameters of the present disclosure. 
           [0032]      FIG. 6  is a schematic overview of the automated optimization process of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    Referring to  FIG. 1 , the present disclosure, herein referred to as an automatic scan plan generator  100 , is comprised of: applicative guidelines  110 , a PAUT NDT technical expertise  115 , a template  120 , and an automated optimization process  130 . Applicate guidelines  110  and expertise  115  together form a template generating module  20 . 
         [0034]    The objective of automatic scan plan generator  100  is to allow an inspector, who might have limited knowledge of PAUT NDT technical expertise  115  and/or code requirements  5 , to generate a scan plan  50  and further a suitable instrumentation setup that corresponds to inspecting a test object with component geometry  12  according to code requirements  5 . This is achieved by integrating PAUT NDT technical expertise  115  and the decomposition of code requirements  5  into a set of applicative guidelines  110 , which encompass the typical aspects covered for the vast majority of inspections. Alternatively, special case inspections that go beyond the scope defined by applicative guidelines  110  can still be addressed through a direct instrument configuration  54  that corresponds to existing practice which necessitates direct involvement of the experienced NDT engineer for the scan plan generation. 
         [0035]    Herein all components of the scan plan generator  100  are types of electronic memories and/or processing device, which can be discrete components or part of an integral device. 
         [0036]    Automatic scan plan generator  100  makes it possible for template generator module  20  to generate template  120  that integrates the interpretation of code requirements  5  by the NDT engineer through the settings of applicative guidelines  110 , PAUT NDT technical expertise  115 , and pre-existing default settings that include some of PAUT NDT technical expertise  115  and ‘best practices’ from applicative guidelines  110 . Automated optimization process  130  collaborates with (or is integrated into) a PAUT modeling tool  14  to find a suitable solution for the application of template  120  on component geometry  12  to be specifically inspected. 
         [0037]    Referring to  FIG. 2 , a novel aspect of automatic scan plan generator  100  is the decomposition of code requirements  5  into applicative guidelines  110  that are specific and quantitative. The preferred embodiment of the present disclosure has applicative guidelines for a weld to be inspected with a pulse echo PAUT: a required Heat Affected Zone (HAZ) applicative guideline  110   a , a beam perpendicularity tolerances applicative guideline  110   b , a beam overlap requirement applicative guideline  110   c , and a probe overlap between successive scans applicative guideline  110   d . Other possible embodiments include advanced acquisition methods for ultrasonic information, such as full matrix capture acquisition. It should be noted that other ultrasonic inspection techniques, such as time of flight diffraction (TOFD) and tandem inspection, fall under the scope of the present disclosure. 
         [0038]      FIGS. 3 a   ˜ 3   d  are representations of prior art practices showing exemplary applicative guidelines from code requirement  5 .  FIGS. 2, 3   a ˜ 3   d  together show the process of decomposition of code requirement  5  specifically for weld inspection, which is one of the novel aspects of the present disclosure. 
         [0039]    Referring to  FIG. 2  and  FIG. 3 a   , required Heat Affected Zone (HAZ) applicative guideline  110   a  on a test object  200  is illustrated in greater detail, and deals with the size of a HAZ area  220  and a HAZ area  222 , in addition to a weld bead  210 , that must be inspected by the pulse echo PAUT. Required Heat Affected Zone (HAZ) applicative guideline  110   a  can be further implemented by a few exemplary subcategory guidelines, such as  110   a   1  and  110   a   2  (described below). 
         [0040]    The HAZ coverage is managed for a first probe  204  by setting a first beam  250   a  on a top surface at the limit of HAZ area  220 , and by setting a last beam  250   i  on a bottom surface at the limit of HAZ area  222 . For a second probe  202 , the same logic applies: use a beam  260   a  for the top surface at the limit of HAZ area  222 , and a beam  260   i  for the bottom surface of HAZ area  220 . The inspection area is thus defined by the full thickness of part thickness, and is defined laterally by the limits of a HAZ coverage  224  and of a HAZ coverage  226 . 
         [0041]    A subcategory HAZ applicative guideline  110   a   1  can be used to calculate the HAZ as a corresponding fraction of the weld geometry, such as thickness, top surface, and bottom surface. In the case of using a top surface, HAZ applicative guideline  110   a   1  can have a recommended value representing size of HAZ area  220  as a fraction of area of the weld bead. In case of length on the top surface of the weld, this is the value of length of  220  on top surface divided by the length of weld bead  210  on top surface. This can apply correspondingly to HAZ weld thickness and HAZ bottom surfaces. 
         [0042]    Alternatively, a subcategory HAZ fixed value applicative guideline  110   a   2  can be defined by the NDT engineer according to the weld being inspected, along with notes and guidelines. In this case, an arbitrary value, instead of a fraction of the size of the test object, is given by the NDT engineer based on the engineer&#39;s experience. 
         [0043]    Referring to  FIGS. 1 and 3   a , it is another novel object of the present disclosure, with the size of HAZ coverages  224  and  226  determined by the above process, to automatically set a detection gate in instrument setup that includes only signals originating from the inspection area, such as HAZ coverages  224  and  226 . Setting tolerances on the gate position with respect to the inspection area can be performed as an additional applicative guideline (not included in further discussion for simplicity). 
         [0044]    Referring to  FIGS. 2 and 3   b , beam perpendicularity tolerances applicative guideline  110   b  is illustrated in greater detail, which pertains to perpendicularity to weld bevels. A weld bevel  215  is defined here as the surface made on the welded component in preparation to the welding process. Only probe  204  is illustrated on  FIG. 3 b    for clarity, but it will be noted that everything mentioned in further discussion also applies to the probe on the opposite side of the weld and potentially to any supplemental probes that may be required for a given inspection, and falls under the scope of the present disclosure. 
         [0045]    Beam perpendicularity tolerances are illustrated as an “alpha” variable. Ideally, all beams should hit a weld bevel with a perpendicular angle such as illustrated for a beam  250   h  (defined by the component geometry). However this solution is not practical, as it would greatly restrict the coverage of a PAUT probe. Code requirements  5  as a result have been established to allow a given tolerance “alpha” on beam perpendicularity. For a simple bevel configuration, such as the “V” shaped bevel illustrated on  FIG. 3 b   , only a first  250   b  beam and a last  250   h  beam hitting the bevel need to be controlled for perpendicularity. Welds involving a curved bevel, such as a “J” shaped bevel, require separate validation for each of the beams. 
         [0046]    Referring to  FIG. 2  and  FIG. 3 c   , beam overlap (BO) requirement applicative guideline  110   c  is illustrated in greater detail. Only a beam overlap between a beam  250   c  and a beam  250   d , which is generated by probe  204 , is provided for simplicity. (An actual requirement would be to have adequate beam overlap for each successive beam that is generated by the probe over the whole inspection area. For simplicity, multiple reflections are illustrated through mirror images of the bevel on  FIG. 3 c   , which is a common practice in PAUT NDT.) 
         [0047]    In order to address the beam overlap requirement, the NDT engineer must first define the beam width BW in function of the depth of the inspected material for each beam. The convention for PAUT NDT is to define the width limits of beam  250   c  as a position  250   c ′ and a position  250   c ″ and the width limits of beam  250   d  as a position  250   d ′ and a position  250   d ″ where a defect is to be detected at −6 decibels relative to the same defect at maximum amplitude (i.e. on the centerline of beam  250   c ). The actual beam width limit can be determined using simulation tools (example: CIVA), mathematic tools, or by using a database of pre-calculated values for each beam to be used for the inspection. Such tools are integrated in automated optimization process  130 . 
         [0048]    Beam overlap is then defined as the fraction of Beam Overlap/Beam Width (BO/BW), typically expressed as a percentage of beam overlap, where the beam width is the minimum of beam width BW 1  and beam width BW 2 . Beam overlap, or the areas shared by BW 1  and BW 2 , can be defined in a parameter as a required percentage. For a given beam overlap, automatic scan plan generator  100  must define a beam configuration that always meets or exceeds the overlap within a depth range D defined by HAZ coverage  224  and HAZ coverage  226  for each consecutive beam (in this example, beam  250   c  and beam  250   d ), which the NDT engineer defines as beam overlap applicative guideline  110   c . It is another novel object of the present disclosure to automatically define the number and angular position of each of the beams that define scan plan  50  and instrumentation setup  52 , in order to systematically meet or exceed beam overlap requirements set by the NDT engineer over the full inspection area. 
         [0049]    Referring to  FIG. 2  and  FIG. 3 d   , probe overlap between successive scans applicative guideline  110   d  is illustrated in greater detail, where it is not possible to cover the whole inspection area (including HAZ coverage requirements) from a unique probe position with a given probe. In this case, a probe overlap is evaluated between a last beam  272  corresponding to a probe  280  at a first position closer to the weld and a first beam  274  corresponding to a probe  282  at a second position farther from the weld. Probes  280  and  282  can be the same probe at different positions, or different probes at different position. 
         [0050]    A probe overlap PO is measured, at a depth  290  corresponding to the intersection between HAZ coverage  224  and first beam  274 , as the horizontal distance between last beam  272  of probe  280  and first beam  274  of probe  282  at this depth. Probe overlap for the purposes of configuration can be further implemented by a few exemplary subcategory guidelines, such as  110   d   1  and  110   d   2  (described below). 
         [0051]    A probe overlap value as a fraction of the beam width BW can be used, and defined as a parameter by the NDT engineer as a fraction of probe overlap applicative guideline  110   d   1 . In this example, the probe overlap ratio is defined as a fraction of Probe Overlap/Beam Width (PO/BW), where BW is the maximum between the width of beam  274  at depth  290  and the width of beam  272  at depth  290 . Alternatively, a fraction of a full probe width PW at depth  290  can also be used as a ratio value of Probe Overlap/Probe Width (PO/PW), where PW is the maximum of a probe width PW 1  and a probe width PW 2 , and defined by the NDT engineer as a beam width applicative guideline  110   d   2 . 
         [0052]      FIGS. 2, 3   a ,  3   b ,  3   c , and  3   d  encompass most aspects of the code requirements that directly affect the scan plan generation for pulse echo PAUT manual weld inspection, which define the content of applicative guidelines  110  and the interfaces with the NDT engineer. Other applicative guidelines exist for other types of inspections, and fall under the scope of the present disclosure. 
         [0053]    Referring now to  FIGS. 1 and 4 , exemplary aspects of PAUT NDT technical expertise  115  that are set by the NDT engineer in template  120  for generating scan plan  50  further include: a beam focalization technical expertise  115   a , a beam aperture technical expertise  115   b , a probe and wedge selection technical expertise  115   c , a preferred scanning method technical expertise  115   d , a range of refraction angles technical expertise  115   e , and an optimization rules and levels of priority technical expertise  115   f.    
         [0054]    Referring to  FIGS. 4 and 5   a - 5   d , beam focalization technical expertise  115   a  is the strategy to adapt the focalization from probe  204  to the part geometry. Each beam, such as beam  250   c , is to be focalized at a certain position, such as a position  310  in  FIG. 5 a   . It is well known to those skilled in the art that various strategies, or schemes, can be adopted to properly perform a given inspection task. Examples of focalization schemes include a uniform focalization depth to all beams, a focalization on a vertical axis, a focalization after a given through depth distance within the inspected material, and a focalization on the weld bevel. Alternative beam focusing rules can be envisioned by NDT technical expertise, and remain within the scope of the present disclosure. 
         [0055]    Referring to  FIGS. 4 and 5   a , the preferred embodiment of the invention provides a uniform focalization depth to all beams using a focalization scheme  302 , and can be set by the NDT engineer as a fraction of the part wall thickness (WT) according to a focal spot  310 . An example of a default parameter is the focalization depth (labeled VP) to be 1.5 times the part wall thickness WT. 
         [0056]    Referring to  FIGS. 4 and 5   b , focalization on a vertical axis, according to a focalization scheme  304 , can be set by the NDT engineer from a focal spot  310 ′ as a fraction of the total inspected width (IW). An example of a default parameter is the focalization position (labeled HP) be at 0.25 times the inspected width IW. 
         [0057]    Referring to  FIGS. 4 and 5   c , focalization within the inspected material, according to a focalization scheme  306 , can be set by the NDT engineer from a focal spot  310 ″ as a fraction of total penetration depth (labeled TP) of the part wall thickness (WT). An example of a default parameter is the focalization of the total material penetration depth TP be at 2 times the part wall thickness WT. 
         [0058]    Referring to  FIGS. 4 and 5   d , focalization on the weld bevel, according to a focalization scheme  308 , can be set by the NDT engineer from the bevel shape directly at focal spot  310 ′″ of a part&#39;s upper surface for beams not crossing the bevel. 
         [0059]    Referring back to  FIG. 4 , another exemplary aspect defining the NDT technical expertise is beam aperture technical expertise  115   b , which is the number of active elements used to generate a PAUT beam. Beam aperture can be defined as a function of the wall thickness (WT) for specific ranges. Examples include using a beam aperture of 8 up to 0.25 inch WT, then a beam aperture of 16 up to 1 inch WT, and then a beam aperture of 32. Such ranges, including the selection of the number of element and the “up to” WT value, are defined by the NDT engineer. 
         [0060]    Yet another exemplary aspect defining the NDT technical expertise is probe and wedge selection technical expertise  115   c . Probe and wedge selection is affected by the part&#39;s external diameter (OD), the wall thickness WT, and by the weld orientation and geometry relative to the pipe. Typically, separate templates  120  would be correspondingly used for fundamentally different weld geometries by the NDT engineer, as they follow different element of code requirements  5 . For example, a first geometry can be a girth weld between two pipes (typically defined in the art as an AOD inspection), a second geometry can be a longitudinal weld along the pipe axis (defined in the art as an COD inspection), a third geometry can be a complex weld at the junction of two pipes (defined in the art as a nozzle, and/or a TKY inspection). For a given template  120 , the NDT engineer can maintain a table describing probe and wedge selection as a function of wall thicknesses WT and external diameters OD, along with default values corresponding to the recommended practice for most applications, edited special cases, preferences, and limited probe or wedge availability. 
         [0061]    Another aspect defining the NDT technical expertise is preferred scanning method technical expertise  115   d . Well known scanning methods include the sectorial scan, or S-scan (defined by a preferred S-scanning method technical expertise  115   d   1 ), where the aperture is kept at a fixed position and the refraction angle is swept through a range of angles. Another well-known scanning method is the linear scan, or E-scan (defined by a preferred E-scanning method technical expertise  115   d   2 ), where the beam refraction angle is kept fixed and scanning is made by lateral movement of the selected probe aperture. 
         [0062]    Referring to  FIGS. 4 and 5   e , another novel object of the present disclosure another aspect of technical expertise in choosing scanning method is the usage of an H-scan, which is a hybrid scanning method that combines lateral and angular movement. In this method, the angular sweep is done from a single virtual apex external to the probe, and apertures corresponding to the virtual beam position at the probe/wedge interface are selected to generate the beam. This method increases the probe coverage, and is well adapted to an optimized scan plan, as the additional degrees of liberties offer added value to automated optimization process  130 . 
         [0063]    Referring to  FIGS. 4, 5   e , and  5   f , an S-scan and E-scan can be considered as a particular case of an H-scan configuration (defined by a preferred H-scanning method technical expertise  115   d   3 ). The E-scan is an H-scan with an apex very far (infinite) from the probe and the S-scan is an H-scan with the apex at the probe surface (at the very center of the active aperture). Any scanning definition can be described with the following variables (focalization schemes, beam aperture definition and wedge/probe selection are separate, fixed parameters): first beam angle “B 0 ”, last beam angle “Bn”, first aperture position “A 0 ”, last aperture position “An” and the number of beams “n”. From these variables the apex (x′,y′) position can be automatically calculated and an intermediate beam  450  can be defined. Intermediate beams are rounded to the closest discrete aperture position. The (x′,y′) reference coordinate is defined here as being aligned with the probe surface and referenced to the probe (i.e. when the probe move so does the x′,y′ system). For the S-scan, the apex position is set along the (x,o) line. For the E-scan, the apex is set far away on  FIG. 5 f    along an (x,INF) line, where “INF” stands for a very large number. 
         [0064]    Returning to  FIG. 4 , another aspect defining the NDT technical expertise is range of refraction angles technical expertise  115   e . This aspect defines the allowed range for the refraction angles knowing that typically low (&lt;40 degrees) and high (&gt;65 degrees) angles are not as reliable as intermediate angles. Since these limits are linked to the probe and wedge selection, the allowed range definition can alternatively be linked to the probe/wedge selection table (or set as range of refraction angles technical expertise  115   e ). 
         [0065]    Yet another aspect defining the NDT technical expertise is optimization rules and levels of priority technical expertise  115   f . Levels of priority between optimization rules deal with interferences between these rules. More specifically, for weld inspection with pulse echo PAUT, there are typically four different optimization rules. The first optimization rule, named as technical expertise  115   f   1 , is to reduce the number of separate probe passes that are required to cover an inspection area. The second optimization rule, named as probe technical expertise  115   f   2 , is to reduce the angular range be generated by the PAUT probe. The third optimization rule, named as technical expertise  115   f   3 , is to minimize the distance between the probe and the weld (ideally down to the minimum distance not leading to mechanical interferences, information that should be found in the definition of component geometry  12 ). The fourth optimization rule, named as technical expertise  115   f   4 , is to reduce the total number of beams that maximizes scan productivity. 
         [0066]    One of the novel aspects of the present disclosure is let NDT engineer to assign priority among the optimization rules as described above. More specifically, for the preferred embodiment, the engineer or inspector is asked for a priority score from 0 [not important] to 10 [very important] for each of those optimization rules. 
         [0067]    Referring back to  FIG. 1 , most aspects comprised in applicative guidelines  110  and/or PAUT NDT technical expertise  115  can be transferred from the NDT engineer to the inspector with written notes and guidelines, making it possible to account for special situations where one of the automated template settings is not adapted for a specific situation. It is also possible for the NDT engineer to define which aspect of direct instrument configuration  54  is accessible to the inspector. For example, an inspector can be provided with manual control over a beam aperture along with the following note: “Test 8 and 16 element apertures and use the one that gives you the best signal to noise ratio on the reference defect.” 
         [0068]    Referring to  FIG. 6 , the novelty of generating scan plans as introduced above from applicative guidelines  110  and PAUT NDT technical expertise  115  also further includes an optimization process with scoring mechanism as elaborated in  FIG. 6 . Each scan plan is comprised of two parts of operation specification. One is the fixed specification represented by template setting module  120  and component geometry module  12 . Fixed operation specifications deals with preferences guided by the corresponding applicative guideline  110  and the technical expertise  115  that is not related to specific probe setup and number of runs. The other is the “transient operation specifications” represented by variable input module  540 , with two distinct sets of variables: a variable output for one probe setup  540   a , and a variable output for two probe setup  540   b . For this exemplary case for weld design, the variables of probe setup include those variables above introduced in association with scanning method in  FIG. 5 f   . Probe setup  540   a  relates to variables of probe setup when one probe is used. Probe setup  540   b  relates to variables of probe setup when two probes are used. 
         [0069]    In  FIG. 6 , automated optimization process  130  is preferably based on a quantitative scoring system, which comprises two scoring tracks, one called requirement scoring and the other optimization scoring. In the requirement scoring track, the process comprises a requirement scoring guideline  510 , a requirement score calculator  515  and a requirement score checker  550 . In the optimization scoring track, the process comprises an optimization scoring guideline  520 , an optimization score calculator  525 . Variable setup module  540  preferably provides probe variable combinations for both  540   a  and  540   b  which subsequently feed the variable setup for one-probe and two-probe scenarios to requirement score calculator  515 . The input from template setting module  120 , component geometry  12 , raw variable output for one probe setup  540   a , and raw variable output for two probe setup  540   b  are all provided to the optimization process. A variable output selector  570  selects the better optimized score from either variable output for one-probe setup  540   a  or variable output for two-probe setup  540   b  in order to be used with PAUT modeling tool  14   
         [0070]    More specifically, requirement scoring module  510  is obtained by evaluating the input from component geometry module  12  with the settings of template  120 . Settings of template module  120  are obtained from applicative guidelines  110  based on decomposition of relevant code requirement  5  and NDT expertise  115 . Requirement scores on a set of input variables from variable input module  540  are computed against requirements in scoring module  510  and stored in requirement score calculator  515 . 
         [0071]    Requirement scoring module  510  has guidelines correspond to aspects that must be met in order for template generator module  20  to design and automatically generate scan plan  50 . Typically aspects of guidelines included in requirement scoring module  510  are applicative guidelines  110 . In the preferred embodiment, the score system is designed to provide a value of 1 for each of the applicative guidelines  110  that are met, and a value of less than 1 for those that are not. For example, perpendicularity relative to the weld bevel can be expressed as (score=1-excessive_perpendicularity/allowed_perpendicularity), area coverage can be expressed as the fraction of the area covered, and beam and pass overlap (BO) can be expressed as the fraction of the target overlap covered (i.e. if BO&lt;BOtarget, then the score is BO/BOtarget; if BO&gt;=BOtarget, then the score is 1). Other scoring systems can also be used as long as the score system provides a fixed target value, and has a gradual slope that makes it possible to improve toward the fixed target value. 
         [0072]    When template  120  is applied to component geometry  12 , a set of variables from variable output for one probe setup  540   a  is sent to requirement score calculator  515  in comparison to applicable guidelines requirement scoring guideline  510 . Requirement score checker  550  determines if the current variable stored in requirement score calculator  515  meets requirement score scoring guideline  510 . 
         [0073]    Continuing with the requirement scoring track in  FIG. 6 , if the set of variables stored in requirement score calculator  515  meets a target score in target score check  550 , it is sent to optimization score calculator  525  for further evaluation. If the set of variables does not meet requirement scoring guideline  510 , optimal probe variable selector  530  selects another set of variables from variable output for one probe setup  540   a  and  540   b , sends it to requirement score calculator  515  again, wherein the previous set of variables is dynamically stored. The process continues until the set of variables from variable output for one probe setup  540   a  and  540   b  in requirement score calculator  515  meets requirement scoring guideline  510 . It should be understood that optimization score calculator  525  does not start to work until a requirement score is fully met at requirement score checker  550  or until an optimal is found without meeting target score (in this case there is not solution possible for this probe configuration on the component geometry with the template setting). 
         [0074]    Referring to  FIGS. 4 and 6 , optimization scoring module  520  is based on PAUT NDT technical expertise  115 , particularly from optimization rules and levels of priority technical expertise  115   f  in  FIG. 4 . Optimization scoring module  520  also uses the input from component geometry module  12  with the settings of template  120 . At optimization score calculator  525 , specific variable output from  540   a  and  540   b  with good requirement scores are calculated against optimization scoring system given in the scoring module  520 . 
         [0075]    For example, an optimization priority can be set from 0 to 10 by the NDT engineer for defining the priority factor in each of the aspects of PAUT NDT technical expertise  115  that are subject to optimization. The priority factor can then be used as a multiplicative factor over the base score for each of these aspects. Aspects that can gradually change through the optimization are provided a base score that also gradually changes. Base scores must be balanced to accurately reflect the NDT engineer preference, and also to reflect the underlying physics that motivate the optimization rule. 
         [0076]    For an exemplary case of weld inspection, in the reduction of the angular range, it is well known to those skilled in the art that the generation of extreme angles, such as a 75 degree shear wave, is not desirable. The optimization scoring system therefore provides a more important scoring benefit to reduce the angular range from 75 to 70 degrees, than from 65 to 60 degrees. Such an optimization receives values in optimization score calculator  525  for the scan plan solution. 
         [0077]    Optimal probe variable selector  530  in itself or retrieves from a system memory all the data regarding all previously scored prove variables. The parameters of prove variables and their associated requirement scores and optimization score seeking optimization scores are the basis for selector  530  to conduct a process of mathematical deduction seeking a next optimal set of probe operation parameters. The mathematical deduction process used by selector  530  can use known optimization algorithms such as a gradient descent optimization, a Newton optimization, and an A* search algorithm, to automatically find a next most suitable probe variables, whether it&#39;s using one probe or two probes. All variations of implementing the optimization scheme  530  for selecting a more optimal set of probe variables is within the scope of the present disclosure. 
         [0078]    After probe variable selector  530  has processed all the variables from  540   a  and  540   b , one of three results can occur. First, if optimal scores have been found for both variable output for one probe setup  540   a  and variable output for two probe setup  540   b , then the outputs are sent to variable output selector  570 . Variable output selector  570  selects the variable output with the better optimization score ( 540   a  or  540   b ) to be used with PAUT modeling tool  14 . Second, if an optimal score is found for either variable output for one probe setup  540   a  or variable output for two probe setup  540   b , then variable output selector  570  selects the variable output that has the optimal score by default, and uses it with PAUT modeling tool  14 . Third, if probe variable selector  530  does not yield variables from variable output for one probe setup  540   a  or variable output for two probe setup  540   b  that meet requirement scoring guideline  510 , then no suitable scan plan solution can be found for template  120 . 
         [0079]    It should be noted that the steps of the method herein disclosed can be implemented by using executive software or firmware codes residing in different types of processors not explicitly shown in the present disclosure. Computer memories of varies type are also needed to implement the steps of the herein disclosed method. These processors and memory can be part of already existing PAUT system, modified with the spirit of the present disclosure, or it can be newly designed processors and memories implementing the steps of herein disclosed method. However the usage of such industrially readily available processors and memories are all within the scope of the present disclosure. 
         [0080]    It should further be noted that the steps of the methods herein disclosed can also be implemented in form of executable software that is independent of any particular phased array apparatus. The software can reside in any stand-alone electronic media and ready to be imported to any phased array apparatus. Such variation is also within the scope of the present disclosure. 
         [0081]    It yet should further be noted that the steps of the methods or the functional modules carrying out the method as herein disclosed can be combined together or spitted into separate sub-steps or units in any fashion, all of which are within the scope of the present disclosure. 
         [0082]    The present disclosure is not limited to the use of a weld inspection, which is herein used as an exemplary embodiment. Other types of probes and test objects may be suited for using the method and apparatus as disclosed.