| The digital signal processing which takes multitudinous discipline as the rationale and widely applies in many domains is a new high-tech technology. NDT and DSP technology are close connected. The importance of signal processing stage is not inferior to signal gain stage. According to corresponding programming processing, DSP can realize the convolution, the filter and Fourier transforms etc. The typical Harvard assembly line structure enables the majority instruction to complete in a cycle. Moreover, DSP is widely applied in NDT. It's characteristic is the high precision, big flexibility, high reliability and sharing.So this article took TMS320LF2407A as the hardware foundation, used a method of zero-phase and max-flat frequency pass-band to produce digital filter, took CCS as platform. We have realized the software design of digital filter and fast Fourier transforms, completed the system's simulation and debugging. In certain degree, it suppressed the influence produced by noise. We used this system to perform qualitative test for hardness of the 65Mn spring steel and 28MnCr5 gear semifinished materials. The result was satisfactory.The result indicated that applying DSP to realize digital filter which took digital signal as object can achieve the good filter goal. Replacing or simplifying the hardware by the software can conform to the development of the modern digitization NDT. But this application is at the start stage and some aspects are waiting for the further research. |
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