Integrated navigation algorithms under the grid frame have been proposed based on the Kalman filter (KF) to solve the problem of navigation in some special regions. However, in the existing study of grid strapdown inertial navigation system (SINS)/Doppler velocity log (DVL) integrated navigation algorithms, the Earth models of the filter dynamic model and the SINS mechanization are not unified. Besides, traditional integrated systems with the KF based correction scheme are susceptible to measurement errors, which would decrease the accuracy and robustness of the system. In this paper, an adaptive robust Kalman filter (ARKF) based hybrid-correction grid SINS/DVL integrated navigation algorithm is designed with the unified reference ellipsoid Earth model to improve the navigation accuracy in middle-high latitude regions for marine application. Firstly, to unify the Earth models, the mechanization of grid SINS is introduced and the error equations are derived based on the same reference ellipsoid Earth model. Then, a more accurate grid SINS/DVL filter model is designed according to the new error equations. Finally, a hybrid-correction scheme based on the ARKF is proposed to resist the effect of measurement errors. Simulation and experiment results show that, compared with the traditional algorithms, the proposed navigation algorithm can effectively improve the navigation performance in middle-high latitude regions by the unified Earth models and the ARKF based hybrid-correction scheme.

Global path planning of mobile robot aims to provide a safe and smooth path for mobile robot navigation. Traditional A * algorithm is planning the path of more turns, and not smooth. Moreover, for the u-shaped terrain, the path stick to the obstacles. Aiming at the shortcomings of A* algorithm, cosine distance is selected as the heuristic function, and direction information is added and normalized. The 36-order neighborhood search matrix is selected to solve the problem of fitting u-bend. In addition, a post-processing method based on Bessel curve is proposed. Make the planned path curvature change continuously. Simulation results show the effectiveness of the improved algorithm.

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