| With the increase of conventional projectile guidance requirements,low-cost navigation systems have been difficult to meet it due to the limitations of their accuracy.In view of the problems of low self-alignment accuracy and error accumulation in inertial navigation system,this paper proposes an initial alignment method based on geomagnetic vectors,and optimizes the attitude update algorithm of strapdown inertial navigation system,a satellite-inertial integrated navigation algorithm based on geomagnetic assistance has been designed,and the numerical simulation and semi-physical simulation test have been carried out.The main research content is as follows:1、According to the conventional low-rotating projectile,the coordinate transformation relationship in the navigation process is derived.The mechanics arrange of the strapdown inertial navigation system and the update algorithm of the navigation parameters are analyzed.The attitude optimization algorithm based on angular rate input is proposed and the simulation of the attitude update algorithm is completed.2、The application of geomagnetic exploration technology in projectile roll angle identification system is studied.Mathematical models for calculating the roll angle of geomagnetic vectors in different dimensions were established;an initial coarse alignment method based on geomagnetism and accelerometer was proposed,an initial precision alignment algorithm based on the geomagnetic assistance is designed,the accuracy and convergence speed of it are simulated and analyzed.3、The geomagnetic satellite/inertial integrated navigation algorithm based on Kalman filter is designed,the state equation and measurement equation of the integrated navigation system are established.The projectile trajectory is used as the simulation conditions to complete simulation and comparative analysis of the pure inertial navigation algorithm and geomagnetic/inertial combination navigation algorithm,satellite/inertial integrated navigation algorithm and geomagnetic satellite/inertial integrated navigation algorithm.The results show that the precision of the navigation system can improve the precision of the navigation system effectively.4、According to the requirements of the integrated navigation algorithm proposed in this paper,the design of the integrated navigation hardware system is completed,and the relevant hardware-in-the-loop simulation tests are performed on the dual-axis turntable to verify the stability of the navigation system and the feasibility of the integrated navigation algorithm.Numerical simulation and hardware-in-the-loop simulation experiments show,the accuracy of the geomagnetic-assisted satellite/inertial integrated navigation system has been greatly improved,the research results have good applicability in the control of low-spin conventional projectile. |
