Research On Techniques Of Underwater Target Electro-Location Based On Optimization Theory

Underwater target locating technology plays an important role in areas such as autonomous underwater vehicl locating,diver and deep ocean exploitation.The underwater electro-locating system could provide better locating performance in area such as the seabed with complicated geomorphology,no light illuminates,turbidity water and large obstacles.The underwater electro-locating system could not be easily affected by Doppler and multipath effect,and the channel model is easily to be constructed with less parameters.Moreover,the cost of underwater electro-locating system are much lower than sonar and optical positioning sensors.Thus,the underwater electro-locating technology is studied in details in this dissertation.The research of our work can be summarized as follows:1.The electro-locating based on the optimal theory is realized,by estimating the position of the target with the measured voltages from the array system.The forward models describing the field distribution underwater are constructed.In this paper,the field distribution forward models are constructed based on imaging principle and boundary element method for single source target in subsurface or shallow ocean area.The field distribution forward models are also proposed based on boundary element method for single metallic and insulator target in deep ocean area.The array manifolds are given when spatial is linearly scaled.2.The determinant based fast locating algorithm determinant multiple signal classification is proposed.The unbiased estimation model of the underwater target electro-locating is established,and the error covariance matrix Cramer-Rao bound is proposed to analyze the accuracy of the algorithm.The calculating speed is also studied in detials and the results show that Det-MUSIC algorithm can significantly reduce the computing time without reducing accuracy.3.The distributed electrode array for underwater target passive electro-locating is designed because of the bad locating performance of a series of arrays such as canonical uniformed circular array and uniformed linear array for underwater electro-locating.In this thesis,a novel electrode array is also designed with which the primary excitation signal can be reduced for underwater target active electro-locating.Experiments are setup and proved the proposed electro-locating method.The experiments show that the location error can be 2.2 cm when the target is 0.5 meter from the electrodes array.4.The covariance matrix adaptive evolution strategy and matrix adaptive evolution strategy are studied.The improved MA-ES method is proposed to overcome the problem that coefficient mismatch in the MA-ES can lead to degrade of searching optimum solution performance.The learning rate for the cumulation for the step-size control and learning rate for cumulation for the rank-one update of the covariance matrix can be the same by calculating the surviving individual weight by the use of power series.The convergence speed and output resolution are mainly studied by comparing with CMA-ES,MA-ES,point-by-point scan method and Monte-Calo method.The analysis indicates that the proposed improved MA-ES has much higher convergence speed,which is 59.7% higher than that of the MA-ES.