Research On Small Unmanned Surface Vehicle Sailing State Obtaining System

With the continuous development of China economy, the inland shipping has arapid development. Building the smooth, efficient, safe, modern inland shippingsystem has been raised to national level strategy. The existing equipment can’t becarried out the cruise rescue boats or emergency response in high-risk environments,which restrict the development of maritime services, since the maritime agencystaffing, limited equipment, high safety supervision cruise costs, and small coverage.Research conducted unmanned surface vehicle (USV) helps to improve the capacityand efficiency of maritime search and cruise rescue and makes an importantcontribution to the "safer navigation and cleaner Ocean".It is the foundation for intelligent USV sailing to get the navigational stateinformation of USV. The effectiveness to control USV sailing largely depends on theprecise navigational state information. The main work is as follows:In this paper, an USV sailing state awareness system is proposed based on therequirements of controlling USV sailing. The system uses a high-precision inertialnavigation sensor, the three-axis orthogonal accelerometers and optical fibergyroscopes are induced x-axis, y-axis, z-axis acceleration and angular velocity. It canalso be used to dynamically calculate the velocity and position. The power supplysystem is designed and implemented. And the related sensors are install layout. Thecontinuous measurement of three axial accelerations and pitch angle, roll angle,heading angle to USV are realized in the system.MEMS Gyroscope random noise greatly affect the calibration precision of theUSV sailing state awareness system. As MEMS Gyroscope signal is a non-stationaryrandom signal with large random noise, the traditional de-noising method can’t reachthe intended effect. Wavelet transform threshold de-noising method is used inprocessing Gyroscope data. Allan variance method is used to compare test data withthe de-noising data.The interface module, function of the USV sailing state awareness system aredesigned in this paper. From the frame that software is divided into CANcommunication module, receive and display module, data analysis and display module, and data storage module. The CAN communication, the status informationreal-time display, data storage and other information recording tasks are realizedthrough these modules.Due to installation error, the inertial navigation sensor digital coordinates and theUSV vector coordinates do not coincide after the system is built. The registrationerror of the two coordinate systems is identified through USV standing for some timein the water. The digital coordinates in three-axis attitude angles are converted to theattitude angles of USV. And the initial position of the vessel is calibrated. In thispaper, a number of real ship carrying experiments are carried out and the test data areprocessed, verify the effectiveness of the system.