Research On The Electrical Location Characteristic In Two-dimensional Space And The Positioning Algorithm Of Underwater Active Electrolocation System

Underwater vehicle has a great value in the tasks of marine resources exploration.With the development of further exploration, one of the key technologies the local environment underwater navigation is facing increasing challenges. Active electrolocation technology inspired by bionics receives more and more attention.Weakly electric fish locates and identifies the surrounding objects through generating a low-frequency electric field actively by EOD(Electric Organ Discharge) and sensing the change of the electric field due to existence of object, this ability is called active electrolocation.The main contents of this paper is the electrical location characteristic of the object in one-dimensional and two-dimensional space on the experimental platform of underwater active electrolocation system. After studying the influences of water environment conductivity and the amplitude and the frequency of the electric field excitation signal on the electrical location characteristic of the object in different sizes and different materials, we designed location and detection algorithms, then a lot of verification experiments were carried out on the experimental platform of underwater active electrolocation system. The main conclusions in this paper are as follows:1.The underwater distortion electric signal has the same frequency with the electric field excitation signal, analyze the underwater distortion electric signal in frequency domain by FFT and extract the amplitude corresponding to the frequency of the electric field excitation signal to characterize the electrical location characteristic of the object.2.The electrical location characteristic of the object is convex or concave, the former amplitude extracted at the position the object placed is maximum while the latter amplitude extracted at the position the object placed is minimum.3.The electrical location characteristic of the object is convex or concave is decided by the material of the object and the frequency of the electric field excitation signal(from 10 Hz to 1kHz). The electrical location characteristic of insulator is always convex no matter what the frequency is. For conductor, the electrical location characteristic is convex when the frequency is small and is concave when the frequency is greater than a certain value.4.Comparative experiments of the electrical location characteristic of the object inone-dimensional and two-dimensional space imply that the amplitude of the electric field excitation signal and water environment conductivity and the size of the object will influence the amplitude corresponding to the frequency of the electric field excitation signal but will not influence the basic laws and trends of the electrical location characteristic of the object.Location and detection algorithms were designed based on the electrical location characteristic and achieved the task of positioning the underwater object. Validation experiments imply that the conclusions about the electrical location characteristic are correct and the experimental platform of underwater active electrolocation system can be used to research the location and detection of underwater object.