超声相控阵可控强度发射系统相关技术的研究
摘要
超声相控阵无损检测技术通过对超声阵列换能器中各阵元进行相位控制,获得灵活可控的合成波束,从而实现高速、全方位和多角度地对机械结构及零部件进行损伤检测。它具有能够进行动态聚焦、可进行成像检测、可以检测复杂形状物体、能提高检测灵敏度、分辨力和信噪比的多项优点,近年来已成为国际无损检测界的研究热点。国内工业领域超声相控阵检测技术尚处在起步阶段,本课题以超声相控阵探伤理论为基础,进行了针对超声相控阵探伤系统中超声相控发射相关技术研究。
本文在概述了超声相控阵的发展历史和发展现状后,说明了相控阵超声检测的研究意义以及超声相控阵探伤理论的相关知识,并详细阐述了超声相控阵系统中动态聚焦、相控延时等技术的原理和实现方法。
超声波在介质中传播的时候,由于材料阻尼效应的存在,超声波的能量随着传播距离的增加将逐渐衰减,这将严重影响工件的损伤检出率。对此本文提出了利用缺陷的回波信息调整后续驱动器激励信号强度,从而达到缺陷处等强度效果的可控强度激发技术。设计了基于正交异性压电复合材料(OrthotropicPiezoelectric Composite Materials,OPCM)超声相控阵换能器的超声相控阵可控强度驱动系统,包括数字化超声发射波束形成、低噪声的程控放大和信号的高频功放,并对系统进行了初步的实验验证。
对各阵元的发射相位延时进行精确控制是形成超声相控阵发射波束的关键环节,在相控发射中,需要精确控制相位延时,从而实现动态聚焦、偏转、声束形成等各种相控效果。理论分析显示,只有尽力提高相位延时的精度、分辨率和稳定性才能显著地抑制旁瓣。
本文研究了基于现场可编程门阵列(Field Programmable Gate Array,FPGA)的超声相控延时算法和相位延时技术。分析了超声相控阵系统中线性阵列换能器相控偏转、相控聚焦延时算法,并利用DSP技术完成了相控算法的设计并通过仿真实验进行了验证。相控延时部分包括相控发射粗延时和相控发射细延时:相控发射粗延时通常基于系统时钟频率,在66MHz的系统时钟频率下,延时分辨率可达15ns;相控发射细延时利用直接数字合成技术(DDS)的数字化波形发射方式,采用数字波形相位差的方法来实现相位的细调,本系统中相位分辨率为0.35°,对应250kHz发射信号下3.75ns的相位延时。
Ultrasonic phased array technique can help to achieve high-speed, all-round and multi-angle Nondestructive Testing by the flexible and controllable synthesized ultrasound beam, which is achieved by exciting each element of an ultrasonic array transducer with independent phase delay. Phased array ultrasonic testing can accomplish dynamic focusing, obtain visual image, inspect component of complex geometry. Also it can improve detection sensitivity, resolution and SNR, so it has recently been highly recognized in NDT research domain. This thesis studies several key technologies about ultrasonic phased array testing system based on the theory of ultrasonic phased array.
In this thesis, firstly the history and current situation of ultrasonic testing is outlined. After that the merit of phased array ultrasonic testing are discussed, then the principles and realizations of several key technologies of phased array testing system such as phase delay and dynamic focus are explicated in details.
The material damping effect prevents the transmission of the ultrasound. As the transmission distance increased, the ultrasound energy is gradually weakened. And it will seriously cut down the detection rate of the damage. The technology which can control the transducer's driving strength according to the message of Echo is proposed in this paper. And the driving system based on OPCM transducer array is designed, including digital beam forming, low noise programmable amplification and the high frequency power amplifier.
High precision ultrasonic transmission phased delay is the key technology in phased array ultrasonic beams. The basic link to achieve ultrasound phased array is phase delay. To achieve dynamic focus, deflection, beam forming, and other phased results need precise control of phase delay. Theoretical analysis showed that only to improve the precision, resolution and stability of phase delay. It can significantly inhibit side lobe.
In the following chapter, the algorithm of the phase delay and the phase delay technique are discussed. Firstly, the time delay algorithm of linear array ultrasonic transducers was analyzed, which was described and validated with DSP Builder. The phased ultrasonic transmission circuit designed uses the waveform excitation method. With the waveform excitation, the system clock is combined with DDS (direct digital synthesis) to obtain a high-precision transmissions phase delay. The coarse transmission phase delay based on the system clock is 15ns. The fine phase delay based on the DDS can achieve 0.35°phase resolution, which equals 3.75 ns time resolution at a 250 kHz transmission frequency.
本文在概述了超声相控阵的发展历史和发展现状后,说明了相控阵超声检测的研究意义以及超声相控阵探伤理论的相关知识,并详细阐述了超声相控阵系统中动态聚焦、相控延时等技术的原理和实现方法。
超声波在介质中传播的时候,由于材料阻尼效应的存在,超声波的能量随着传播距离的增加将逐渐衰减,这将严重影响工件的损伤检出率。对此本文提出了利用缺陷的回波信息调整后续驱动器激励信号强度,从而达到缺陷处等强度效果的可控强度激发技术。设计了基于正交异性压电复合材料(OrthotropicPiezoelectric Composite Materials,OPCM)超声相控阵换能器的超声相控阵可控强度驱动系统,包括数字化超声发射波束形成、低噪声的程控放大和信号的高频功放,并对系统进行了初步的实验验证。
对各阵元的发射相位延时进行精确控制是形成超声相控阵发射波束的关键环节,在相控发射中,需要精确控制相位延时,从而实现动态聚焦、偏转、声束形成等各种相控效果。理论分析显示,只有尽力提高相位延时的精度、分辨率和稳定性才能显著地抑制旁瓣。
本文研究了基于现场可编程门阵列(Field Programmable Gate Array,FPGA)的超声相控延时算法和相位延时技术。分析了超声相控阵系统中线性阵列换能器相控偏转、相控聚焦延时算法,并利用DSP技术完成了相控算法的设计并通过仿真实验进行了验证。相控延时部分包括相控发射粗延时和相控发射细延时:相控发射粗延时通常基于系统时钟频率,在66MHz的系统时钟频率下,延时分辨率可达15ns;相控发射细延时利用直接数字合成技术(DDS)的数字化波形发射方式,采用数字波形相位差的方法来实现相位的细调,本系统中相位分辨率为0.35°,对应250kHz发射信号下3.75ns的相位延时。
Ultrasonic phased array technique can help to achieve high-speed, all-round and multi-angle Nondestructive Testing by the flexible and controllable synthesized ultrasound beam, which is achieved by exciting each element of an ultrasonic array transducer with independent phase delay. Phased array ultrasonic testing can accomplish dynamic focusing, obtain visual image, inspect component of complex geometry. Also it can improve detection sensitivity, resolution and SNR, so it has recently been highly recognized in NDT research domain. This thesis studies several key technologies about ultrasonic phased array testing system based on the theory of ultrasonic phased array.
In this thesis, firstly the history and current situation of ultrasonic testing is outlined. After that the merit of phased array ultrasonic testing are discussed, then the principles and realizations of several key technologies of phased array testing system such as phase delay and dynamic focus are explicated in details.
The material damping effect prevents the transmission of the ultrasound. As the transmission distance increased, the ultrasound energy is gradually weakened. And it will seriously cut down the detection rate of the damage. The technology which can control the transducer's driving strength according to the message of Echo is proposed in this paper. And the driving system based on OPCM transducer array is designed, including digital beam forming, low noise programmable amplification and the high frequency power amplifier.
High precision ultrasonic transmission phased delay is the key technology in phased array ultrasonic beams. The basic link to achieve ultrasound phased array is phase delay. To achieve dynamic focus, deflection, beam forming, and other phased results need precise control of phase delay. Theoretical analysis showed that only to improve the precision, resolution and stability of phase delay. It can significantly inhibit side lobe.
In the following chapter, the algorithm of the phase delay and the phase delay technique are discussed. Firstly, the time delay algorithm of linear array ultrasonic transducers was analyzed, which was described and validated with DSP Builder. The phased ultrasonic transmission circuit designed uses the waveform excitation method. With the waveform excitation, the system clock is combined with DDS (direct digital synthesis) to obtain a high-precision transmissions phase delay. The coarse transmission phase delay based on the system clock is 15ns. The fine phase delay based on the DDS can achieve 0.35°phase resolution, which equals 3.75 ns time resolution at a 250 kHz transmission frequency.
引文
[1]R.C.P.Eng.Advances in NDE techniques for delayed coke drums[C].3rd MENDT-Middle East Nondestructive Testing Conference & Exhibition.2005,9:27-30
[2]J.Li,X.L.Zhan.S.J.Jin.Research on ultrasonic phased array system for automatic defect detection of pipeline girth welds[C].Proceedings of 9th International Conference on Electronic Measurement and Instruments.2009:903-907.
[3]周正干,向上,魏东,高羿飞.复合材料的超声检测技术[J].航空制造技术,2009(8):70-73.
[4]钟德煌,郑攀忠.便携式相控探伤仪在焊缝超声检测技术中的应用[J].无损检测2009(33):233-235.
[5]夏欣,毕向东等.大口径管道对接环焊缝相控阵超声检测系统的研制[J].无损检测2005,(10):1-2.
[6]T.J.Johnson et al.Embedded sensitivity functions for characterizing structural damage[J].Smart Material Structure.2005,14:155-169.
[7]A.P.Jorge,R.Owen and T.Okam.Automatic ultrasonic testing for condition monitoring of coke drums[C].2003 ASME Pressure Vessels and Piping Conference.2003,468:209-216.
[8]Xiuli.C,Dechang.Z,Guixiong.L.Study on simulation and experiment of the magnetizer in magnetic flux leakage testing[C].2007 IEEE International Conference on Mechatronics and Automation.2007:3083-3087.
[9]王余刚,骆英;柳祖亭.全波形声发射技术用于混凝土材料损伤监测研究[J].岩石力学与工程学报.2005,24(5):803-807.
[10]R.C.P.Eng.Advances in NDE techniques for delayed coke drums[C].3rd MENDT-Middle East Nondestructive Testing Conference & Exhibition.2005,9:27-30.
[11]张光义.相控阵雷达的技术特点及关键技术[J].电子科技导报,1996,7:2-4.
[12]J.V.Hatfield,et al.An integrated multi-element array transducer for ultrasonic imaging[J].Sensors and Actuators.1994,V41-42:167-173.
[13]L.Satyarnarayan,J.Chandrasekaran,B.Maxfield and K.Balasubramaniam.Circumferential higher order guided wave modes for the detection and sizing of cracks and pinholes in pipe support regions[J].NDT & E International.2008,41:32-43.
[14]A.Erhard,G.Schenk.New applications using phased array techniques[J].Nuclear Engineering and Design.2001,206(6):325-336.
[15]B.Jonathan.Ultrasonic method for the accurate measurement of crack height in dissimilar metal welds using phased array[P].Patent,US2007000328A1,2007.1.4.
[16]T.J.Batzinger,B.Hills,et al.Phased array ultrasonic inspection method for industrial applications[P].United States Patent,US6789427B2,2004.9.14.
[17]P.JerEme.Special linear phased array probes used for ultrasonic examination of complex turbine components[C].8th European Congress on NDT.Barcelona,Spain,June,17-21,2002.
[18]A.Erhard,G.Schenk.Ultrasonic phased array technique for austenitic weld inspection[C].15th WCNDT[M/CD],Rome,2000.
[19]R/Dtech.Inc.Introduction to phased array ultrasonic technology application[A].2005:189-291.
[20]S.Mahaut.用动态自适应超声聚焦系统确定缺陷特性(译文)[J].无损检测.1998,20(8):236-238.
[21]J.Ritter.Universal phased array UT probe for nondestructive examinations using composite crystal technology[J].The Journal of Nondestructive Testing.2000,5(9):1-8.
[22]W.K Deutsch,K.Deutsch.Defect detection with Rayleigh and Lamb waves generated by a self-focusing phased array[J].The e-Journal of Nondestructive Testing.www.ndt.net.1998,3(12):1-6.
[23]周琦,刘方军,李志军等.超声相控阵成像技术与应用[J].兵器材料科学与工程.2002,25(3):34-37.
[24]李新育,刘宁等.超声相控阵波仪器及其检测方法[P].中国专利.01131936.4,2003.4.23.
[25]鲍晓宇,施克仁,陈以方,张伟.超声相控阵系统中相控发射与同步的实现[J].无损检测.2003,25(10):507-510.
[26]杨建华,周海鹏,刘文琦.Development of phased array ultrasonic transmission system based on CPLD[C].中国兵工学会第六届国际测试技术研讨会.2005:1-6.
[27]韩相勇.长输管线对接环焊缝自动相控阵超声波检测技术[J].无损检测.2006,28(5):237-241.
[28]杨斌,王召巴,金永.基于CPLD的超声相控阵相控发射与同步系统的实现[J].微计算机信息.2007,23(7-2):1-2.
[29]应崇福.超声学[M].北京:科学出版社,1990.
[30]中国机械工程学会无损检测分会.超声波检测[M].北京:机械工业出版社,2000.
[31]超声波探伤.中国锅炉压力容器安全杂志社,1995.
[32]P.A.Meyer,J.W.Anderson.Ultrasonic Testing Using Phased Arrays.In:Proceedings of 15th World Conference on NDT[C].Rome,Italy:2000.
[33]冯若.超声诊断设备原理与设计[M].北京:中国医药科技出版社,1993.
[34]鲍晓宇.相控阵超声检测系统及其关键技术的研究[D].北京:清华大学,2005.
[35]庞勇.超声成像方法综述.华北工学院测试技术学报[J].2001,15(4):280-283.
[36]高上凯,程克正,宋松.医学超声诊断设备中的若干新技术[J].现代科学仪器,1995,1:11-13.
[37]张舜臣.全数字化超声成像系统[J].医疗设备信息,1996,3:23-25.
[38]何正权,邹平.数字化超声成像设备中的几项关键技术[J].中国超声医学杂志,1995,11(3):211-212.
[39]J.H.Kim,T.K.Song,S.B.Park.Pipeline sampled delay focusing in ultrasound imaging systems[J].Ultrasonic Imaging,1987,9:75-91.
[40]A.H.Quzai.An overview on time delay estimation in active and passive systems for target localizations[C].In:Proc.of IEEE,70(8):527-533.
[41]何正权,刘志宏,袁勤.数字多声束形成技术的研究及意义[J].中国超声医学杂志,1997,13(8):14-16.
[42]沈毅,裴文江,骆英.OPCM动态传感特性AE数值模拟与实验研究[J].压电与声光,2008(30):649-654.
[43]潘松.黄继业等 现代DSP技术[M].西安:西安电子科技大学出版社,2003.
[44]潘松.黄继业.EDA技术与VHDL[M].北京:清华大学出版社.2007.
[45]朱明程.现场可编程逻辑门阵列器件FPGA原理及应用设计[M].北京:电子工业出版社,1994.
[46]冯若主编.超声手册[M].南京:南京大学出版社,1999.
[2]J.Li,X.L.Zhan.S.J.Jin.Research on ultrasonic phased array system for automatic defect detection of pipeline girth welds[C].Proceedings of 9th International Conference on Electronic Measurement and Instruments.2009:903-907.
[3]周正干,向上,魏东,高羿飞.复合材料的超声检测技术[J].航空制造技术,2009(8):70-73.
[4]钟德煌,郑攀忠.便携式相控探伤仪在焊缝超声检测技术中的应用[J].无损检测2009(33):233-235.
[5]夏欣,毕向东等.大口径管道对接环焊缝相控阵超声检测系统的研制[J].无损检测2005,(10):1-2.
[6]T.J.Johnson et al.Embedded sensitivity functions for characterizing structural damage[J].Smart Material Structure.2005,14:155-169.
[7]A.P.Jorge,R.Owen and T.Okam.Automatic ultrasonic testing for condition monitoring of coke drums[C].2003 ASME Pressure Vessels and Piping Conference.2003,468:209-216.
[8]Xiuli.C,Dechang.Z,Guixiong.L.Study on simulation and experiment of the magnetizer in magnetic flux leakage testing[C].2007 IEEE International Conference on Mechatronics and Automation.2007:3083-3087.
[9]王余刚,骆英;柳祖亭.全波形声发射技术用于混凝土材料损伤监测研究[J].岩石力学与工程学报.2005,24(5):803-807.
[10]R.C.P.Eng.Advances in NDE techniques for delayed coke drums[C].3rd MENDT-Middle East Nondestructive Testing Conference & Exhibition.2005,9:27-30.
[11]张光义.相控阵雷达的技术特点及关键技术[J].电子科技导报,1996,7:2-4.
[12]J.V.Hatfield,et al.An integrated multi-element array transducer for ultrasonic imaging[J].Sensors and Actuators.1994,V41-42:167-173.
[13]L.Satyarnarayan,J.Chandrasekaran,B.Maxfield and K.Balasubramaniam.Circumferential higher order guided wave modes for the detection and sizing of cracks and pinholes in pipe support regions[J].NDT & E International.2008,41:32-43.
[14]A.Erhard,G.Schenk.New applications using phased array techniques[J].Nuclear Engineering and Design.2001,206(6):325-336.
[15]B.Jonathan.Ultrasonic method for the accurate measurement of crack height in dissimilar metal welds using phased array[P].Patent,US2007000328A1,2007.1.4.
[16]T.J.Batzinger,B.Hills,et al.Phased array ultrasonic inspection method for industrial applications[P].United States Patent,US6789427B2,2004.9.14.
[17]P.JerEme.Special linear phased array probes used for ultrasonic examination of complex turbine components[C].8th European Congress on NDT.Barcelona,Spain,June,17-21,2002.
[18]A.Erhard,G.Schenk.Ultrasonic phased array technique for austenitic weld inspection[C].15th WCNDT[M/CD],Rome,2000.
[19]R/Dtech.Inc.Introduction to phased array ultrasonic technology application[A].2005:189-291.
[20]S.Mahaut.用动态自适应超声聚焦系统确定缺陷特性(译文)[J].无损检测.1998,20(8):236-238.
[21]J.Ritter.Universal phased array UT probe for nondestructive examinations using composite crystal technology[J].The Journal of Nondestructive Testing.2000,5(9):1-8.
[22]W.K Deutsch,K.Deutsch.Defect detection with Rayleigh and Lamb waves generated by a self-focusing phased array[J].The e-Journal of Nondestructive Testing.www.ndt.net.1998,3(12):1-6.
[23]周琦,刘方军,李志军等.超声相控阵成像技术与应用[J].兵器材料科学与工程.2002,25(3):34-37.
[24]李新育,刘宁等.超声相控阵波仪器及其检测方法[P].中国专利.01131936.4,2003.4.23.
[25]鲍晓宇,施克仁,陈以方,张伟.超声相控阵系统中相控发射与同步的实现[J].无损检测.2003,25(10):507-510.
[26]杨建华,周海鹏,刘文琦.Development of phased array ultrasonic transmission system based on CPLD[C].中国兵工学会第六届国际测试技术研讨会.2005:1-6.
[27]韩相勇.长输管线对接环焊缝自动相控阵超声波检测技术[J].无损检测.2006,28(5):237-241.
[28]杨斌,王召巴,金永.基于CPLD的超声相控阵相控发射与同步系统的实现[J].微计算机信息.2007,23(7-2):1-2.
[29]应崇福.超声学[M].北京:科学出版社,1990.
[30]中国机械工程学会无损检测分会.超声波检测[M].北京:机械工业出版社,2000.
[31]超声波探伤.中国锅炉压力容器安全杂志社,1995.
[32]P.A.Meyer,J.W.Anderson.Ultrasonic Testing Using Phased Arrays.In:Proceedings of 15th World Conference on NDT[C].Rome,Italy:2000.
[33]冯若.超声诊断设备原理与设计[M].北京:中国医药科技出版社,1993.
[34]鲍晓宇.相控阵超声检测系统及其关键技术的研究[D].北京:清华大学,2005.
[35]庞勇.超声成像方法综述.华北工学院测试技术学报[J].2001,15(4):280-283.
[36]高上凯,程克正,宋松.医学超声诊断设备中的若干新技术[J].现代科学仪器,1995,1:11-13.
[37]张舜臣.全数字化超声成像系统[J].医疗设备信息,1996,3:23-25.
[38]何正权,邹平.数字化超声成像设备中的几项关键技术[J].中国超声医学杂志,1995,11(3):211-212.
[39]J.H.Kim,T.K.Song,S.B.Park.Pipeline sampled delay focusing in ultrasound imaging systems[J].Ultrasonic Imaging,1987,9:75-91.
[40]A.H.Quzai.An overview on time delay estimation in active and passive systems for target localizations[C].In:Proc.of IEEE,70(8):527-533.
[41]何正权,刘志宏,袁勤.数字多声束形成技术的研究及意义[J].中国超声医学杂志,1997,13(8):14-16.
[42]沈毅,裴文江,骆英.OPCM动态传感特性AE数值模拟与实验研究[J].压电与声光,2008(30):649-654.
[43]潘松.黄继业等 现代DSP技术[M].西安:西安电子科技大学出版社,2003.
[44]潘松.黄继业.EDA技术与VHDL[M].北京:清华大学出版社.2007.
[45]朱明程.现场可编程逻辑门阵列器件FPGA原理及应用设计[M].北京:电子工业出版社,1994.
[46]冯若主编.超声手册[M].南京:南京大学出版社,1999.