In traditional through transmission ultrasonic detection for curved components with variable thickness, the amplitude of receiving pressure was unsteady and the signal to noise ratio was always low. In order to solve this problem, an acoustic modeling method, called multi-Gaussian beam superposition technique was introduced into the curved component ultrasonic detection system. A receiving pressure model was established to analyze the effect on receiving pressure under different parameters. Analysis and the experiment results showed that the receiving pressure is very sensitive to the probe position and orientation. The angle existed between ultrasonic beam propagating path and probe position and orientation planning by conventional path generation method shouldn ' t be ignored. Taking bi-cubic B-spline surface workpiece for example, a new probe position and orientation planning method was proposed based on tracking ultrasonic beam propagation. The triggering probe position and orientation was planned firstly by regular method, then the receiving probe position and orientation was decided by tracking beam propagation form the trigger probe. Compared with the conventional method, practical application showed that the receiving signal is better and the detection results are more accurate by thernproposed method.%针对传统变厚度曲面工件穿透法自动超声检测时各检测点声压变化大、信噪比低等问题,将多元高斯声束叠加声场建模方法引入曲面工件超声检测系统,建立接收声场数学模型,分析了检测参数对接收声压的影响,仿真与试验表明接收声压对探头姿态十分敏感,常规方法中探头位姿与声束路径间存在的小角度不可忽略,提出了基于声束追踪的探头位姿规划方法.针对双三次B样条曲面工件,先以常规方法确定发射探头位姿,然后从发射探头开始,追踪系统中声束,确定接收探头位姿.实际应用表明,与常规方法相比,基于声束追踪的探头位姿接收到的信号强、信噪比高,检测更精确.
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