Zhejiang University

Huifang Chen

Lei Xie

Wen Xu

Feng Liu

Chenglei Lv

Hongda Duan

Some embodiments of the disclosure provide a cooperative positioning system and method for an unmanned underwater vehicle (UUV) cluster based on ranging and information interaction. In some examples, the cooperative positioning system includes one master UUV, multiple slave UUVs, and a cooperative positioning apparatus. In some examples, the cooperative positioning method includes following steps. A master UUV and a slave UUV perform internal clock disciplining. The master UUV periodically packages a location of the master UUV and a covariance matrix of location estimation into a cooperative positioning data packet and broadcasts the cooperative positioning data packet to slave UUVs of a cluster. The slave UUV receives the cooperative positioning data packet. A cooperative positioning apparatus of the salve UUV constructs a state and a measurement equation according to data. The cooperative positioning apparatus calculates and obtains a cooperative positioning result by using an extended Kalman filter (EKF).

Cooperative positioning system and method for unmanned underwater vehicle (UUV) cluster based on ranging and information interaction

A method for positioning an underwater glider based on a virtual TDOA of a single beacon is provided. In the method, a positioning beacon periodically sends positioning messages, where the positioning message includes longitude, latitude and depth information of the positioning beacon; the underwater glider receives the positioning messages and records TOAs at which the positioning messages arrive at an acoustic positioning signal receiving module; and the underwater glider parses the positioning messages and stores positioning message data, creates virtual beacons based on beacon information and attitude information of the underwater glider, corrects the TOAs, and calculates a position of the underwater glider according to a TDOA algorithm. According to the method, the underwater glider passively listens to and receives the positioning messages without sending a positioning request to the positioning beacon, making the entire positioning process energy-saving with a certain degree of concealment.

Method for positioning underwater glider based on virtual time difference of arrival of single beacon

The present disclosure provides a method for optimizing a protograph-based LDPC code over an underwater acoustic (UAW) channel. The traditional protograph-based LDPC code over an UAW channel does not consider performance in an error floor region. The method first determines parameters such as a protograph-based LDPC code length, a basic protograph, a target decoding threshold, a threshold adjustment factor, and an ACE check parameter. The protograph is optimized, and the method constructs a parity check matrix by using a UAW channel-based PEG/ACE hybrid algorithm, performs ACE check on the parity check matrix, and calculates a decoding threshold for the matrix passing the check. If the decoding threshold is within a range of an iterative decoding threshold, the parity check matrix is a final optimized matrix. Otherwise, the method continues to optimize the protograph until a parity check matrix passing the check is obtained.

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Hangzhou, China

Huifang Chen