The Research Of The Algorithms For GFSINS In High Dynamic Environment

Gyroscope free strap-down inertial navigation system (GFSINS) is a kind of SINS with only accelerometers. Because the accelerometers are directly mounted to the vehicle, the vehicle's high-frequency motions will affect the accuracy of the GFSINS. When the vehicle has angular and linear vibrations, the coining error and sculling error will occur. To reduce these errors perfect algoritlims must be designed. Thus, it is a key point to study the high precision algorithms for GFSINS in highly dynamic environments.In the thesis, the fundamental theory of the GFSINS is introduced first, including the specific force equations at the vehicle's non-centroid, the configuration method of accelerometers and the calculation of the angular velocity. Through the study of the coining error and sculling error, attitude and velocity updating algorithms are provided. The following investigations have been done:1. Firstly, it is analyzed that how the coining motion affected the attitude updating in GFSINS. According to the characteristic of GFSINS, it is analyzed that the coining error's spread form during the calculation of angular velocity. So the rotation vector algorithm is used to compensate the coining error. The simulation results show that the rotation vector algorithm can improve the precision of the attitude calculation effectively.2. The sculling error in the velocity calculation is described and sculling optimal compensation algorithms are derived. The simulation results show that the sculling compensation term in the velocity integration algorithms can not be neglected for the high accuracy GFSINS in highly dynamic environments.