A kind of ultrasound excitation method for ultrasound tomography systemTechnical field
The invention belongs to field of non destructive testing, and in particular to a kind of ultrasonic action side for ultrasound tomography systemMethod.
Background technique
Ultrasound tomography (Ultrasound Computerized Tomography, UCT) technology be process chromatography atAs one of the hot spot of technology (Process Tomography, PT) research, it is concentrated mainly on using the technology measurement process parametersMedical treatment detection, multiphase flow parameter detecting and non-destructive testing.The energisation mode of UCT sensor is that the important of UCT system optimization is groundStudy carefully content.
The energisation mode of UCT system sensor is usually a sharp more receipts, cycle motivation.Single sensor inspires ultrasonic letterNumber amplitude it is smaller, simultaneously because tube wall and internal each phase constituent acoustic impedance difference are larger in UCT system, sound wave is situated between in multiphaseReflection, scattering can occur when propagating in matter and by reasons such as Interface Absorptions, keep sound wave attenuation amplitude when propagating big.With propagationThe increase of distance, acoustic attenuation is even more serious, and receiving sensor can only receive faint signal, extracts useful less than apparentInformation leads to poor imaging results.
Summary of the invention
The technical problem to be solved by the present invention is to improve the amplitude of pumping signal in ultrasound tomography system, improvingImage quality and resolution ratio, the present invention provide a kind of ultrasound excitation method for ultrasound tomography system.
To solve the above problems, the present invention adopts the following technical scheme that:
A kind of ultrasound excitation method for ultrasound tomography system, the ultrasound tomography system (UCT system)Comprising a pipeline, the ultrasound excitation method the following steps are included:
Step S1, ultrasonic sensor group is set
The ultrasonic sensor group include the 1st ultrasonic sensor, the 2nd ultrasonic sensor ..., the 16th ultrasonic sensor,It is made of 16 standalone ultrasound sensors, each ultrasonic sensor can excite and receive Wideband Fan ideophone beam, 16 sensorsIt is distributed at equal intervals on pipeline outer wall counterclockwise, the surface of each ultrasonic sensor is flat with pipe surface alwaysRow；
Step S2, the excitation and reception of ultrasonic signal
The 2nd ultrasonic sensor is controlled first and the 16th ultrasonic sensor emits the width with identical frequency and field angle simultaneouslyThe fan-shaped ultrasonic signal A of band1And B1, couple the main lobe of two fan-shaped acoustic beams in the water of pipeline, synthesize a branch of ultrasonic signalC1, it is defined as the ultrasonic composite signal of two sensors, successively controls the 3rd ultrasonic sensor and the 15th ultrasonic sensor, the 4thSonic transducer and the 14th ultrasonic sensor emit ultrasonic wave A2And B2、A3And B3, can be obtained the respective ultrasound of two sensors and closeAt signal C2、C3；Excitation arbitrary neighborhood or separately two sensor emission ultrasonic waves, every two sensor are circuited sequentially in this wayThe ultrasound synthesis of sending is a ultrasonic signal, and remaining ultrasonic sensor receives ultrasound synthesis letter in subsequent sensor groupNumber, while time-domain analysis is carried out to ultrasonic composite signal.
Preferably, each ultrasonic sensor is fixed on pipeline outer wall by couplant.
Compared with prior art, beneficial effects of the present invention are as follows:
1, it by the dual sensor energisation mode in sensor group, realizes signal coupling, increases the width of synthesis ultrasonic signalValue can receive receiving sensor and relatively detect signal by force, more completely can extract and identify the acoustics of bubble in pipelineInformation.
2, increase system detection data volume, improve image quality and resolution ratio.
Detailed description of the invention
Basic device figure Fig. 1 of the invention；
Basic principle schematic Fig. 2 of the invention；
The ultrasonic signal of any dual sensor group of Fig. 3 cycle motivation synthesizes schematic diagram；
The sound pressure amplitude schematic diagram of Fig. 4 dual sensor group ultrasonic signal synthesis front and back.
Specific embodiment
The embodiment of the present invention provides a kind of ultrasound excitation method for ultrasound tomography system, the ultrasonic ct atPicture system (UCT system) includes a pipeline, and the pipeline is the steel pipe (round tube) with certain wall thickness, fills liquid in pipeline,Liquid contains bubble, the ultrasound excitation method the following steps are included:
Step S1, ultrasonic sensor group is set
The ultrasonic sensor group is made of 16 standalone ultrasound sensors, 16 ultrasonic sensor properties having the same(such as resonant frequency, field angle), the ultrasonic sensor can excite/receive Wideband Fan ideophone beam, and 16 sensors are from firstUltrasonic sensor starts to be distributed at equal intervals on pipeline outer wall counterclockwise, the surface of ultrasonic sensor always with pipelineSurface is parallel, and each ultrasonic sensor is fixed on pipeline outer wall by couplant.As shown in Figure 1, number 1-16 represents 16Ultrasonic sensor, i.e. the 1st ultrasonic sensor 1, the 2nd ultrasonic sensor 2 ..., the 16th ultrasonic sensor 16, outer ring great circle 17 isPipeline, the eccentric roundlet 18 in great circle 17 are bubble, and 19 in great circle 17 represent the liquid in pipeline.
Step S2, the excitation and reception of ultrasonic signal
The field angle of ultrasonic sensor generally refers to main beam directivity function and drops to primary maximum in principal maximum two sidesValue 0.707 angle, for make ultrasonic sensor issue ultrasonic wave received by most receiving sensor, therefore motivate andReceiving sensor selects the biggish ultrasonic sensor of field angle.As shown in Figure 2,3, first with the 2nd ultrasound of controller controlSensor 2 and the 16th transmitting simultaneously of ultrasonic sensor 16 have the broadband sector ultrasonic signal A of identical frequency and field angle1And B1,The field angle of two sensors is θ, couples the main lobe of two fan-shaped acoustic beams in the water of pipeline, synthesizes a branch of ultrasound letterNumber C1, it is defined as the ultrasonic composite signal of two sensors, the field angle of the ultrasound composite signal is also θ.Successively control the 3rdUltrasonic sensor 3 and the 15th ultrasonic sensor 15, the 4th sonic transducer 4 and the 14th ultrasonic sensor 14 emit ultrasonic wave A2And B2、A3And B3, can be obtained the respective ultrasonic composite signal C of two sensors2、C3.Excitation arbitrary neighborhood or phase are circuited sequentially in this wayTwo sensor emission ultrasonic waves are spaced, the ultrasound synthesis that every two sensor issues is a ultrasonic signal, is then sensedRemaining ultrasonic sensor receives ultrasonic composite signal in device group, while carrying out time-domain analysis to ultrasonic composite signal, after synthesisThe amplitude of ultrasonic signal significantly increases.
As shown in figure 4, the present invention emits broadband sector ultrasonic signal by the dual sensor energisation mode in sensor group,2nd ultrasonic sensor 2 and the 16th transmitting simultaneously of ultrasonic sensor 16 have the fan-shaped ultrasound letter in the broadband of identical frequency and field angleNumber, A is formed in water1And B1Two fan-shaped acoustic beams, sound pressure amplitude is respectively p1And p2, two fan-shaped acoustic beam A1And B1Propagate oneAfter the fixed time, main lobe couples in the water of pipeline, synthesizes a branch of ultrasonic signal C1, the sound pressure signal amplitude after synthesis isp.Then successively control the 3rd ultrasonic sensor 3 and the 15th ultrasonic sensor 15, the 4th sonic transducer 4 and the 14th ultrasonic sensor 14Emit ultrasonic wave A2And B2、A3And B3Deng can be obtained the respective ultrasonic composite signal C of two sensors2、C3Deng.So successivelyCycle motivation arbitrary neighborhood or separately two sensor emission ultrasonic wave AiAnd Bi, sound pressure amplitude is respectively p '1And p '2, oftenThe ultrasonic wave A that two sensors issueiAnd BiAfter propagating the regular hour, main lobe couples in the water of pipeline, synthesizes oneUltrasonic signal Ci, the sound pressure signal amplitude after synthesis is p ', and remaining ultrasonic sensor receives ultrasound and closes in subsequent sensor groupAt signal.It is learnt using the means of time-domain analysis, the sound pressure signal amplitude after synthesis significantly improves.By in control sensor groupThe position (interval) for emitting two sensors of ultrasonic wave, can be obtained different ultrasonic composite signals, with different fingersTropism, check frequency and signal strength.It can receive unlike signal amplitude by remaining ultrasonic sensor in sensor group,Convenient for the extraction and identification of signal, while the ultrasound detection signal with high-resolution and high-penetration is obtained.It can be completeerSite preparation extracts the acoustic information of bubble in pipeline, is suitable for ultrasound tomography system to strong heteropical multiphase flowDetection.