Extraction And Analysis Of Underwater Core Wire Cutting Features Based On Ultrasonic Sensing

With the continuous development of marine resources,the application of underwater cutting technology has gradually been widely used.Among them,the advantages of underwater core cutting wire arc cutting technology,such as high efficiency and convenience,have been widely concerned by people and have broad application prospects.At present,there are insufficient monitoring in the process of underwater core cutting wire arc cutting,and it is impossible to accurately judge the cutting state of the workpiece.The ultrasonic sensor can realize accurate underwater distance measurement and has strong anti-interference ability,which is suitable for the complicated environment of underwater cutting.Therefore,the work of this thesis is to use the ultrasonic sensor to monitor the underwater cutting process and extract the cutting characteristic information.In addition,try to use acoustic sensors to obtain acoustic information and analyze the cutting process in combination with electrical signals.In order to use the ultrasonic sensor to obtain the information of the underwater cutting process,the parameters of the ultrasonic sensor were clarified and the ultrasonic sensing experiment system was constructed.First,in the non-arc state,the different workpiece cutting states are detected.As the width of the workpiece cut increases,the echo on the top surface of the workpiece decreases and the echo on the bottom surface of the cut increases.In the uncut state of the workpiece,there is an echo on the bottom surface of the cut.When the workpiece is cut through,the echo on the bottom of the cut disappears.When the tilt angle of the probe or the distance of the workpiece increases,the amplitude of the ultrasonic echo is significantly reduced.Secondly,when detecting the position of the kerf behind the arc during the cutting process,the echo characteristics are consistent with those in the non-arc state.Finally,according to the echo conditions in different cutting states,a workpiece cutting state judgment program based on ultrasonic echo was developed in the matlab environment,and the cross-correlation calculation and the workpiece upper surface echo amplitude detection method were used to determine the cutting depth and upper surface of the workpiece.The cut width is calculated.In order to further clarify the reliability of the algorithm program,a process comparison experiment was designed for the underwater workpiece to be completely cut through and incompletely cut through.The program was used to analyze the ultrasonic echo signal during the continuous cutting process and visualize the results.The test results were compared with The actual cutting situation is basically the same.The distance measurement accuracy based on cross-correlation is ±1mm,and the average error of the cutting width detection on the workpiece is 0.89 mm.The detection result is relatively accurate and suitable for the underwater cutting process.In addition,this article also tried to use the acoustic sensor to obtain the audible sound signal during the underwater cutting process.The experimental results show that the acoustic energy received by the acoustic sensor decreases during the cutting and drilling process,and the amplitude of the acoustic signal increases with the depth of the cutting hole.The increase gradually decreases,and the acoustic signal amplitude at the beginning of arc ignition is significantly greater than the perforated arc-extinguishing acoustic signal.In the continuous cutting process,the arc is always in the state of continuous arc ignition-arc ignition-arc extinguishing.The cutting electrical signal has a certain periodicity.The sound signal also changes with the periodic change of the arc during the cutting process.The current cycle process is matched.