Design Of Rock Bolt Nondestructive Testing Instrument Based On ARM

Rock bolt technology has been widely used in the slope and underground engineering. However, the evaluation of the quality of the rock bolt is still a difficult task. Coring method and pull-out test are the traditional pull-destructive testing methods, with drawbacks as complex operations, huge cost etc. Stress wave reflection method used in the anchorage quality nondestructive testing, has shown its good effects and has been widely used in engineering. At the same time, with the rapid development of electronic technology, ARM embedded technology has been widely used too. Based on the stress wave reflection method and ARM technology, the paper completes the following research:(1)Study the operating characteristics of the rock bolt system, and the basic principles of stress wave reflection detection method. Analyse one-dimensional characteristics of the Longitudinal Vibration and stress wave propagation characteristics under ideal conditions.(2)Selecting the S3C6410(ARM11 cores) chip as the core processor, hardware circuit of rock bolt nondestructive testing instrument is to be designed. Design a data acquisition module constituting the IEPE acceleration sensor, the constant current source circuit, a booster circuit, a signal conditioning circuit and A/D converter circuit.Complete Flash memory circuit, LCD display circuit, the system power supply circuit,crystal oscillator circuit, reset circuit and USB expansion interface circuit.(3)According to requirements of the hardware platform, cut ARM embedded operating system, customize Win CE6.0 embedded operating system, which is successfully ported to the hardware platform.(4)Using the object-oriented programming methods, choose programming frame MFC based on the C++ to develop application of the bolt nondestructive testing instrument. The applications of nondestructive testing instrument have features being full-featured, simple interface, easy to operate, etc. The main achievement is the signal acquisition function, signal display, signal storage and signal processingfunctions. The acquisition signal can more accurately reflect the characteristics of the original signal, the processed signal can more accurately show the signal characteristics, able to meet the engineering requirements.(5)Apply the wavelet transform, HHT and data fusion in the instrument,achieving a good result. Using HHT and wavelet transform to filter noise of the original signal, respectively, both of which can be more effective to reduce the detection error and improve the accuracy of the test results of bolt length. The data fusion can also reduce error. Select 5.5m long bare anchor produced by rebar and 2m anchor as test object, and build platform to test the system. The results show the designed features have been achieved.