Automatic transducer operating parameter selection

Abstract

Operating parameters are selected for inspecting a structure. Selecting the operating parameters includes exciting broadband ultrasonic guided waves in a multilayered structure, acquiring data corresponding to the sensed broadband ultrasonic guided waves in the multilayered structure, selecting one or more narrow frequency bands based on the acquired data, and inspecting the multilayered structure using ultrasonic guided waves in the one or more narrow frequency bands. In some examples, the data is acquired by an inspection tool capable of sensing the broadband ultrasonic guided waves in the multilayered structure.

1 - 5 . (canceled) 
     
     
         2 . A inline inspection (ILI) system for inspecting a metallic structure using guided waves, the system comprising:
 an electromagnetic acoustic transducer (EMAT) ultrasonic transmitter configured to excite broadband ultrasonic guided waves in the metallic structure, wherein the metallic structure is a multilayered structure comprising a load carrying metal layer and a non-load carrying coating, wherein the guided waves travel along peripheral surfaces of the multilayered structure, and wherein the guided waves are bounded by the peripheral surfaces of the multilayered structure;   an electromagnetic acoustic transducer (EMAT) ultrasonic receiver that is longitudinally or circumferentially offset from the EMAT ultrasonic transmitter, the EMAT ultrasonic receiver configured to:
 sense the broadband ultrasonic guided waves in the multilayered structure and to generate data corresponding to the sensed broadband ultrasonic guided waves in the multilayered structure, and 
 generate data corresponding to the sensed broadband ultrasonic guided waves in the multilayered structure; and 
   a controller configured to:
 select, based on the acquired data by the EMAT ultrasonic receiver, one or more narrow frequency bands of the ultrasonic guided waves, and 
 dynamically change operating frequencies of the EMAT ultrasonic transmitter, wherein the guided waves that are generated at the operating frequencies are operating points within the one or more narrow frequency bands for use in a subsequent inspection of the multilayered structure, 
   wherein the inline inspection (ILI) tool is in contact with the load carrying metal layer structure.   
     
     
         3 . (canceled) 
     
     
         4 . The system of  claim 6 , wherein the EMAT ultrasonic transmitter is configured to excite the broadband ultrasonic guided waves in one of a plurality of layers of the multilayered structure, and wherein the ultrasonic receiver is configured to sense the broadband ultrasonic guided waves in the at least one of the plurality of layers. 
     
     
         5 . The system of  claim 6 , wherein the EMAT ultrasonic receiver is configured to traverse the structure while sensing the broadband ultrasonic guided waves in the coated structure. 
     
     
         6 . The system of  claim 6 , wherein the EMAT ultrasonic receiver comprises a guided wave phased transducer array installed on the coated structure. 
     
     
         7 . The system of  claim 10 , wherein the guided wave phased transducer array comprises one or more additional receivers configured to sense the broadband ultrasonic guided waves in a load carrying portion of the structure. 
     
     
         8 . (canceled) 
     
     
         9 . The system of  claim 6 , wherein the EMAT ultrasonic transmitter is configured to traverse the structure while transmitting the broadband ultrasonic guided waves in the multilayered structure. 
     
     
         10 . The system of  claim 6 , wherein the EMAT ultrasonic transmitter and the EMAT ultrasonic receiver have physical access only to the outermost metal layer of the multilayered structure. 
     
     
         11 - 20 . (Canceled) 
     
     
         21 . The system of  claim 6 , wherein the controller is further configured to:
 determine a first average thickness of the load carrying metal layer based on a frequency separation between the narrow frequency bands in the sensed broadband ultrasonic guided waves; and   determine a second average thickness of the non-load carrying coating based on a location of troughs in the sensed broadband ultrasonic waves.