Research And Implementation Of Positioning And Navigation Technology For Underwater Vehicle Based On Dual INS

Underwater robot has been widely used in many fields,which can replace human to complete the detection and maintenance task.It is an important tool for ocean exploration,river water conservancy project maintenance and danger disposal,which not only ensures the life safety of relevant personnel,but also expands the depth and breadth of the task.High precision positioning and navigation system is an important prerequisite for underwater vehicles to complete related tasks.At present,some small and medium-sized robots use the navigation mode of combining GPS Buoy and inertial navigation,but in some cases with poor GPS signal,the inertial navigation system needs to work independently for a short time and a short distance.How to improve the navigation accuracy of inertial navigation system is the research focus.In this paper,based on the existing underwater vehicle platform which is used in water quality investigation and underwater building inspection,two sets of MEMS inertial sensors are used to carry out the research of positioning and navigation technology of underwater vehicle based on dual inertial navigation,including the electronic hardware design of dual inertial navigation positioning and navigation system,the research of dual inertial navigation information fusion algorithm and the software development of positioning and navigation system.Firstly,the basic principle of strapdown inertial navigation technology is introduced,and the appropriate carrie r coordinate system is selected according to the navigation coordinate system adopted in this paper.The error sources of SINS are analyzed emphatically,and the error model of SINS is established as the theoretical basis of information fusion modeling of dual INS.According to the overall hardware architecture of underwater vehicle and the design requirements of dual INS positioning and navigation system,the selection and performance analysis of inertial devices are carried out.The dual INS sensor module is developed,including the design of hardware circuit and software program.Because MEMS gyroscope can't sense the rotation speed of the earth,the traditional initial alignment method of gyroscope combined with accelerometer can't be uesd.The coarse alignment method of inertial navigation system assisted by magnetometer and accelerometer is adopted in this paper.In order to improve the positioning and navigation accuracy ofAUV,the data fusion method of dual INS based on Kalman filter is introduced.According to the error model of strapdown inertial navigation system,the state space model suitable for dual inertial navigation system is selected,and the state equation and measurement equation of the system are designed respectively.The feedback correction process of Kalman filter is explained in detail.Finally,the rationality and correctness of the system model design are proved by land dynamic experiments.Corresponding to the overall hardware architecture of the robot,the software design scheme of the underwater vehicle is proposed.The positioning and navigation node design of the dual inertial navigation underwater vehicle based on ROS is adopted.The serial port node and positioning and navigation node program of the dual inertial navigation system are added and the human-computer interaction node program design is improved.In order to facilitate the use of underwater vehicle software and improve its future functions,a multi node startup file is configured.The operator monitoring interface is optimized,and the navigation information is connected to the monitoring interface and displayed.The platform of AUV with dual inertial navigation system is built,and the pool experiment is completed.The results show that the dual inertial navigation system is beter than the single inertial navigation system in the actual path deviation and various errors.The positioning and navigation system based on dual inertial navigation system basically meets the requirements of local positioning of AUV.