【作者】 王成；

【导师】 苏龙滨；

【作者基本信息】 哈尔滨工程大学 ， 信号与信息处理， 2011， 硕士

【摘要】 超声检测作为应用最为广泛的无损检测方法之一在我国的工业现代化进程中起着越来越重要的作用,随着电子技术和计算机技术的快速发展,超声检测正在朝着数字化、自动化、智能化和图像化方向发展。超声波衍射时差检测法是基于接收回波信号之间的时间差进行缺陷高度和位置的测量,而非传统的超声检测采用回波信号强度进行测量,因而在缺陷的定性定量方面更加的准确可靠。但TOFD必须结合B扫描才能对缺陷进行精确的定位,本论文采用的是基于TOFD和双椭圆定位技术相结合的定位测量方法TOFD-LWE (Time of Flight Diffraction and Locating with Ellipse),实现了无需B扫描就可以获得缺陷二、三维几何特征参数。本论文首先在理论上对TOFD和TOFD-LWE技术做了阐述,指出TOFD-LWE技术的优势和TOFD-LWE检测系统的构成。重点介绍了检测系统中的实时信号处理平台,本处理平台采用两片TI公司的TMS320C6747作为核心处理器构成的并行信号处理机,对其硬件结构的设计做了详细的介绍,包括与ARM和FPGA之间的接口电路设计。其中该处理平台的拓扑结构是本设计中的重点和难点,可以根据不同的管材进行不同的信号处理算法而灵活的改变数据流的分配,增强了超声检测系统的灵活性和精确性。此外该处理平台还可以作为通用信号处理平台应用于其它的场合,具有良好的扩展性,增加了本系统的实用性。论文最后介绍了该实时处理平台的软件设计,包括EDMA方式的数据传输,McASP数据接收以及HPI引导程序设计。处理平台采用由主机ARM通过HPI接口对核心处理器进行引导,避免了外扩存储器,节约了成本。更多还原

【Abstract】 Ultrasonic testing as a widely used NDT methods is playing a more and more important role in the process of the industrial modernization in China,with the rapid development of electronics and computer technology,ultrasonic testing is moving for digitization, automation, intelligent and visualization direction.TOFD is based on the time difference of the received echo signal to carry on the survey to the flaw, instead of the traditional ultrasonic testing method to use the echo signal’s intensity, so this method is more accurate and reliable in the aspect of the defect’s qualitative and quantitative. But TOFD must combine with B scanning to get the accurate position, what the present paper uses is TOFD-LWE which unifies TOFD and the double ellipses measurement’s technology that can obtain two, three-dimensional geometrical characteristic parameters without B scanning.This paper firstly introduces the TOFD and TOFD-LWE technology in theory and points out the technical superiority and the detection system formation of TOFD-LWE. This paper mainly introduces the testing system of real-time signal processing platform. This processing platform uses two chips of TI company’s TMS320C6747 as the core processor to constitute a parallel signal processor. The hardware’s structure is described in detail, included with the ARM and FPGA’s interface circuit design. The processing platform’s topological structure is the key and difficult point, which can change the distribution of the data flexiblely accord to the different signal processing algorithm for different pipes, and enhance the ultrasound detection system’s flexibility and accuracy. Besides, this processing platform can act as a universal signal processing platform to be used in other occasions, which has good expansibility and increases the practicability of this system.Finally, this essay introduces the real-time processing platform’s software design, including the EDMA data transfer mode, McASP data reception and HPI boot design.This processing platform uses the external host ARM for HPI bootload to avoid expanding the memory and save the cost.更多还原