Research On Array Ultrasonic Precise Detection Technology

Array ultrasonic is an effective method to measure dynamic liquid level,but in a narrow space,the accuracy of dynamic liquid level measurement is low.Aiming at the mutual coupling and non-uniform noise of transmit receive array,the efficient and stable direction of arrival(DOA)estimation method of MIMO array system is studied,and the array ultrasonic precise detection technology is studied.Firstly,the signal model of MIMO uniform linear ultrasonic array structure is studied from the basic theory.Based on this,the mechanism of mutual coupling error of ultrasonic array is studied.Then,under the condition of mutual coupling between transmit and receive arrays,the high-precision DOA estimation is realized in MIMO array.Aiming at the limitation of the ex isting mutual coupling correction algorithm under unknown mutual coupling condition,a block sparse weighting algorithm based on norm optimization constraint model is adopted.At the same time,the vector singular value method is used to decoherence the coherent signal,and the DOA estimation of MIMO ultrasonic array of coherent signal under unknown mutual coupling condition is obtained,The performance of the algorithm is analyzed and verified by simulation.Secondly,in order to solve the problem that there are multiple spectral peaks and the energy of spectral peaks is not concentrated,a joint approximate diagonalization algorithm based on blind source separation theory is adopted,and the denoising simulation of uniform linear MIMO array in non-uniform noise is studied based on this algorithm.Finally,the experimental verification of the algorithm is carried out.The results show that the ultrasonic array signal processed by mutual coupling error self-tuning algorithm and joint approximate diagonalizati on algorithm can effectively estimate the accurate echo direction.Finally,the target is located by liquid level scanning method,and the waveform of dynamic liquid level is estimated by simulation,so as to obtain the liquid level information of dynamic liquid level,which meets the needs of practical engineering.This method can also be applied to the real-time detection of liquid level in rainy and snowy weather,which has good practical significance.