Apparatus and method for ultrasonic testing

Abstract

An apparatus and a method for ultrasonic testing obtains high-resolution and high-S/N ratio testing results by driving a number of piezoelectric elements using fewer pulsers and receivers in comparison with the number of elements composing an array transducer. A sensor information setter sets a plurality of piezoelectric element groups used for transmission and a plurality of piezoelectric element groups used for reception among the plurality of piezoelectric elements composing an ultrasonic array transducer. A computer transmits an ultrasonic wave from the element cluster set for transmission, and stores an ultrasonic wave received by the element cluster set for reception. The procedure is repeated including different element cluster sets for transmission and reception to obtain first receive signals. The first receive signals are summed to obtain a second receive signal; and the second receive signal is displayed with reference to the sensor center position on a display unit.

1 . An ultrasonic testing apparatus for testing the inside of an object under test by transmitting an ultrasonic wave to the object under test and receiving reflected waves (echoes) from the surface or inside thereof by using an ultrasonic array transducer composed of a plurality of one- or two-dimensionally arranged piezoelectric elements, the ultrasonic testing apparatus comprising:
 sensor information setting means configured to set a plurality of element groups (element clusters) to be used for transmission and reception out of the plurality of piezoelectric elements composing the ultrasonic array transducer;   transmission selection means configured to select an element cluster used for transmission out of the set plurality of element clusters;   reception selection means configured to select an element cluster used for reception out of the set plurality of element clusters;   delay time control means configured to give a delay time to each of the piezoelectric elements used for transmission and piezoelectric elements used for reception with reference to a sensor center position serving as a reference for the delay time;   a computer configured to obtain a second receive signal by performing the steps of:
 transmitting an ultrasonic wave from the element cluster set for transmission, and storing an ultrasonic wave received by the element cluster set for reception as a first receive signal; 
 repeating a procedure for changing the element cluster set for transmission and the element cluster set for reception and storing another first receive signal; and 
 summing up the plurality of first receive signals obtained by repeating the same procedure; and 
   display means configured to display the second receive signal with reference to the sensor center position.   
     
     
         2 . The ultrasonic testing apparatus according to  claim 1 ,
 wherein the computer sets a virtual array transducer and uses a center position of the virtual array transducer as a sensor center position or a reference for a delay time.   
     
     
         3 . The ultrasonic testing apparatus according to  claim 1 ,
 wherein the computer selects a first or second set of element cluster combinations;   wherein the first set of element cluster combinations used for transmission and reception includes combinations in which an element cluster used for transmission is identical to an element cluster used for reception; and   wherein the second set of element cluster combinations used for transmission and reception includes combinations in which an element cluster used for transmission is different from an element cluster used for reception.   
     
     
         4 . An ultrasonic testing method for testing the inside of an object under test by transmitting an ultrasonic wave to the object under test and receiving reflected waves (echoes) from the surface or inside thereof by using an ultrasonic array transducer composed of a plurality of one- or two-dimensionally arranged piezoelectric elements, the ultrasonic testing method comprising the steps of:
 setting a plurality of element groups (element clusters) for transmission and reception out of a plurality of piezoelectric elements composing the ultrasonic array transducer;   selecting an element cluster used for transmission out of the set plurality of element clusters, and selecting an element cluster used for reception out of the set plurality of element clusters;   giving a delay time to each of the piezoelectric elements used for transmission and/or the piezoelectric elements used for reception with reference to a sensor center position serving as a reference for the delay time;   transmitting an ultrasonic wave from the element cluster set for transmission, and storing an ultrasonic wave received by the element cluster set for reception as a first receive signal;   repeating a procedure for changing the element cluster set for transmission and the element cluster set for reception and storing another first receive signal;   summing up the plurality of first receive signals obtained by repeating the same procedure to obtain a second receive signal; and   displaying the second receive signal with reference to the sensor center position.   
     
     
         5 . The ultrasonic testing method according to  claim 4 ,
 wherein the method sets a virtual array transducer and uses a center position of the virtual array transducer as a sensor center position or a reference for a delay time.   
     
     
         6 . The ultrasonic testing method according to  claim 4 ,
 wherein the method selects a first or second set of element cluster combinations;   wherein the first set of element cluster combinations used for transmission and reception includes combinations in which an element cluster used for transmission is identical to an element cluster used for reception; and   wherein the second set of element cluster combinations used for transmission and reception includes combinations in which an element cluster used for transmission is different from an element cluster used for reception.   
     
     
         7 . A method for three-dimensional ultrasonic imaging comprising the steps of:
 transmitting an ultrasonic wave from a two-dimensional array ultrasonic sensor to focus at a desired depth;   three-dimensionally scanning the inside of an object under test while varying the ultrasonic beam angle, and storing waveform data;   converting the obtained waveform data to three-dimensional testing data;   storing the three-dimensional testing data by sequentially changing the set position of the array ultrasonic sensor; and   combining the three-dimensional testing data obtained at each testing position while making a shift by the displacement of the array ultrasonic sensor to attain three-dimensional imaging.   
     
     
         8 . The three-dimensional ultrasonic imaging method according to  claim 7 , comprising the steps of:
 measuring a surface shape of the object under test, following the surface shape thereof, and storing three-dimensional testing data of the inside of the object under test while varying the ultrasonic beam angle;   sequentially moving the set position of the array ultrasonic sensor and testing the object under test; and   combining three-dimensional testing data obtained at each testing position while making a shift by a displacement and a rotation angle of the array ultrasonic sensor to attain three-dimensional imaging.   
     
     
         9 . The three-dimensional ultrasonic imaging method according to  claim 7 ,
 wherein the method changes the beam angle of the ultrasonic wave transmitted from the two-dimensional array ultrasonic sensor to select rotation scanning, swing scanning, or wedged swing scanning as an ultrasonic scanning process for three-dimensional testing of the inside of the object under test.   
     
     
         10 . The three-dimensional ultrasonic imaging method according to  claim 7 ,
 wherein the method combines three-dimensional testing data by summing up (or averaging) three-dimensional testing data to attain imaging.   
     
     
         11 . A three-dimensional ultrasonic imaging apparatus comprising:
 a two-dimensional array ultrasonic sensor composed of a plurality of piezoelectric elements;   pulsers configured to transmit a transmit signal to each piezoelectric element of the array ultrasonic sensor;   receivers configured to receive a receive signal;   delay control means configured to perform time control for the transmit and receive signals by varying a delay time for each piezoelectric element;   data storage means configured to store ultrasonic waveforms transmitted and received by the array ultrasonic sensor;   sensor moving means configured to feed the array ultrasonic sensor, and scanning control means configured to control the sensor moving means;   displacement detection means configured to measure the displacement of the array ultrasonic sensor;   a computer configured to convert the stored waveform data to three-dimensional testing data, and combine the plurality of pieces of three-dimensional testing data while making a shift by the displacement of the array ultrasonic sensor measured by the displacement detection means; and   display means configured to display the combined testing data.   
     
     
         12 . The three-dimensional ultrasonic imaging apparatus according to  claim 11 , further comprising:
 sensor moving means which moves the sensor following a surface shape of the object under test, a scanning controller, and displacement detection means; and   a computer which combines three-dimensional testing data while making a shift by the displacement and angle of the array ultrasonic sensor based on the detected displacement of the array ultrasonic sensor and measurement value or design value of the surface shape of the object under test.   
     
     
         13 . The three-dimensional ultrasonic imaging apparatus according to  claim 11 ,
 wherein the display means includes data processing switching means configured to switch between testing data obtained by ordinary testing and testing data obtained by combining processing;   wherein, in ordinary testing, a maximum value out of testing data sequentially obtained by moving the array ultrasonic sensor is handled as testing data.   
     
     
         14 . A three-dimensional ultrasonic testing apparatus comprising:
 an ultrasonic sensor composed of a plurality of piezoelectric elements;   pulsers configured to supply a transmit signal to each piezoelectric element of the ultrasonic sensor;   receivers configured to input a receive signal from each piezoelectric element of the ultrasonic sensor;   data storage means configured to store ultrasonic waveforms received by the ultrasonic sensor;   a computer for image processing configured to generate three-dimensional testing data from the waveforms stored in the data storage means; and   three-dimensional display means configured to display the three-dimensional testing data generated by the computer,   wherein the computer outputs the distance between the two points specified on the three-dimensional display means.   
     
     
         15 . The three-dimensional ultrasonic testing apparatus according to  claim 14 ,
 wherein the computer displays three-dimensional shape data superimposed with three-dimensional testing data on the three-dimensional display means.   
     
     
         16 . The three-dimensional ultrasonic testing apparatus according to  claim 14 ,
 the two points specified on the three-dimensional display means constitute an echo caused by a reflected ultrasonic wave signal on the three-dimensional testing data.   
     
     
         17 . The three-dimensional ultrasonic testing apparatus according to  claim 16 ,
 wherein the points composing the echo caused by the reflected ultrasonic wave signal is contained in a three-dimensional region specified on the three-dimensional display means, a signal value of the echo being maximized at the point.   
     
     
         18 . The three-dimensional ultrasonic testing apparatus according to  claim 14 ,
 wherein one of the two points specified on the three-dimensional display means is an ultrasonic incidence point or the point constituting three-dimensional shape data.   
     
     
         19 . The three-dimensional ultrasonic testing apparatus according to  claim 14 ,
 wherein the computer displays on the three-dimensional display means a distance between the two points specified on the three-dimensional display means   
     
     
         20 . The three-dimensional ultrasonic testing apparatus according to  claim 14 ,
 wherein the computer displays on the three-dimensional display means a straight line connecting the two points specified on the three-dimensional display means.   
     
     
         21 . The three-dimensional ultrasonic testing apparatus according to  claim 14 ,
 wherein the computer outputs a relative position of the points specified on the three-dimensional display means relative to an ultrasonic incidence point using an angle and a distance.   
     
     
         22 . A three-dimensional ultrasonic testing method for testing the inside of an object under test by transmitting an ultrasonic wave to the object under test and receiving reflected waves therefrom by using an ultrasonic sensor composed of a plurality of piezoelectric elements,
 wherein the method measures a distance between two echoes caused by a reflected ultrasonic wave signal based on a distance between the two points specified on the three-dimensional display means.   
     
     
         23 . A three-dimensional ultrasonic testing method according to  claim 22 ,
 wherein, based on the points specified on the three-dimensional display means, the method outputs a relative position of the echoes caused by a reflected ultrasonic wave signal relative to an ultrasonic incidence point using an angle and a distance.