Design And Implementation Of Navigation System For Deep Sea Unmanned Underwater Vehicle

With the development of modern science and technology,deep-sea unmanned vehicles play an important role in military and civilian fields as an important tool for underwater resource exploration,target search and identification.In order to realize the design of a deep-sea unmanned vehicle navigation system with "cruising" and "gliding" dual-function modes,this paper designs the applicable applications based on the working characteristics of underwater unmanned vehicles and the complex and varied deep-sea environment.Inertial Measurement Unit(IMU)navigation system for high-and low-precision,high-and low-power switching in deep-sea environments.The hybrid IMU navigation system integrates low-power Micro Electro Mechanical System(MEMS)IMU and high precision fiber optic IMU,as well as geomagnetic navigation module and satellite navigation module.The data fusion algorithm is used to solve the carrier attitude,velocity and position information.When the underwater vehicle is in the cruise mode,the high precision fiber IMU and the satellite navigation module are used as navigation devices to provide high precision navigation information for the carrier;when the underwater vehicle is in the long-haul gliding mode,the low-power MEMS IMU With the geomagnetic navigation module as the navigation device,the navigation parameters are slightly lower in accuracy and the low power consumption performance of the system is guaranteed.This paper combines engineering design and algorithm optimization to improve the accuracy of deep sea navigation and reduce the system power consumption.The main work of the thesis are as follows:(1)Establish the inertial navigation parameter solving model from the carrier coordinate system to the navigation coordinate system,introduce the inertial navigation principle and analyze its error propagation equation.The Kalman Filter(KF)algorithm is used to fuse the combined navigation data of high-precision fiber optic IMU and satellite,and the optimal error of the inertial navigation system is estimated.The result is compensated to the inertial navigation system,and the inertial navigation output parameters are corrected in real time to obtain high precision.The navigation data ensures high-precision navigation and positioning under the underwater submersible cruise mode.The complementary filtering algorithm is used to fuse the data of the low-power MEMS IMU and the geomagnetic navigation module.When the navigation parameters are correct,the power consumption of the system when the submersible is in the gliding mode is reduced as much as possible.In addition,in order to balance the relationship between navigation accuracy and system power consumption in the underwater submersible cruise mode,an adaptive modal switching hybrid IMU combined navigation method is proposed.This method automatically switches the working state of high and low precision IMU by sensing the system motion state.To make the system achieve the balance of navigation accuracy and power in cruise mode.(2)Analyze and establish the error model of MEMS inertial sensor and magnetometer,and calibrate the error of the sensor by static and rate turntable experiments,and obtain the sensor error source parameters.(3)Designing the underwater underwater integrated navigation and positioning system based on TMS320C6748,the system is highly integrated,rich in interface,powerful in computing performance and low in power consumption,which is very suitable for navigation and positioning tasks of this system..In order to optimize system design,the "producerconsumer" multi-threaded concurrent software model and EDMA3 technology are used to improve data storage efficiency;to improve board stability,the hardware design fully considers signal integrity design.(4)Through the vehicle and AHRS experiment,the integrated navigation positioning accuracy of the navigation system in cruise and gliding mode and the power consumption problem in gliding mode are tested.After testing,the power consumption is limited within 0.42 W in crusie mode,which has meet the requirement(0.5W).In addition,the error accuracy of attitude is less than 0.7 deg.In gliding mode,the error accuracy of attitude is less than 1 deg,when GPS outages.The error accuracy of positioning and velocity are less than 3m and 0.2m/s,respectively.Finally,the summary and prospect of the system design are given.