Research On Motion Constrainted Adaptive Algorithm For Single-axis Rotary Inertial Navigation System Of Submersible

The single-axis rotary modulation technology can improve the positioning accuracy of the strapdown inertial navigation system(SINS),but it is still an integral system in essence.In order to reduce the accumulation speed of the positioning error and achieve the high-precision navigation of the submersible,a motion constrained inertial navigation method is proposed.The method utilizes the inherent characteristics of velocity during the motion of the carrier to improve the navigation precision of the strapdown inertial navigation system without increasing the sensor and changing the concealment of the system.The paper focuses on improving the performance of a single-axis rotary navigation system under motion constraints:(1)The basic principle of the single-axis rotary SINS is studied.The attitude,velocity and position error equations of the single-axis rotary SINS are given.The modulation mechanism of single-axis rotary SINS for constant error,scale factor and installation error of gyros and accelerometers are analyzed.(2)Velocity constraints of vehicle in motion are studied,and the filtering model of motion constraints algorithm is established.The velocity information provided by motion constraints is fused with inertial navigation velocity information by the simplified Sage-Husa filtering.The navigation performance of no motion constraints algorithm,Kalman motion constraints algorithm and Sage-Husa motion constraints algorithm under different speed noise conditions is simulated.The Sage-Husa motion constraints algorithm achieves relatively optimal positioning accuracy in simulation.(3)Aiming at the problem that H_?filtering performance is limited by the selection of filtering parameters?,an adaptive H_?filtering method based on sliding window innovation is proposed.This method can adaptively adjust the filtering parameters?,balance the robustness and precision of the filter.The proposed adaptive H_?filtering method is used to perform motion constrained navigation,and the simulation analysis is carried out.The adaptive H_?filtering motion constraints algorithm can adjust the filtering parameters according to different noise conditions.Overall,the positioning accuracy is comparable or better than the Sage-Husa motion constraints algorithm.(4)The prototype of single-axis rotary SINS is used to perform the motion constrained navigation experiments under different environments and trajectories.The positioning accuracy of adaptive H_?filtering motion constrained navigation method is the best under the quasi-linear vehicle experiment,"8"shape vehicle experiment and lake experiment.It's better than that of the pure inertial navigation method by 23.7%~81%,which verifies the effectiveness of the adaptive algorithm in the actual system...