Thick Steel Tube Welding Speed Detection System Based On Ultrasonic

Narrow rectangular depth measurement is widely used in industry, common methods of measuring it are mechanical means and traditional ultrasonic ranging means.These ways are low in automation level and can not meet the demand of measurementing changed depth on real time. When depth is deep or seam is narrow, there is even no means to measure. Real-time detection of large-diameter thick steel pipe welding speed is the problem to be solved in this paper, according to this problem, ultrasound-based real-time depth measuring system of narrow rectangular was designed.Through the research on ultrasonic wave propagation characteristics and its beam spread, narrow rectangular depth measurement principle based on ultrasonic was proposed, that is, respectively recognize ultrasonic echoes from upper surface and lower surface of narrow rectangular, so as to measure the depth. Hardware circuit using MSP430 as the controlling core was designed.Commonly used 40 kHz transceiver-detached ultrasonic probes were selected to send and receive ultrasonic, pulse signals which mark arrival times of upper surface echo and lower surface echo were generated by signal conditioning circuit. In MCU software, timer B was used to capture identifying pulse. In order to improve measurement accuracy, temperature measuring circuit was designed to correct ultrasonic wave velocity. Visual C++ was used to develop real-time display interface of narrow rectangular depth and welding speed, welding speed alarm can also be set.Depth measurement experiments on narrow rectangular of different depth and width were done.Experimental results showed that time-varying narrow rectangular depth could be measured with measurement error less than 1 cm, and large-diameter thick steel pipe welding speed could be calculated, with non-contact, convenient, fast and low-cost features.