General-purpose Low-altitude Navigation Pod Terrain-following Algorithm And Implementation

The terrain following algorithm of the general low altitude navigation pod is researched in this paper. Considering to improve the flight performance of the system and to satisfy the requirement of the algorithm design's practicable application, the correcting method of flight path angle is adopted to design the algorithm of low altitude navigation pod in order to satisfy the requirement of modern war, and a corresponding mathematic model and system simulation platform are built in the paper.The principles of radar and radio altimeter are analyzed firstly, and the method of terrain data storing and updating between the lately two working phases of radar is interpreted in this design, then the terrain following algorithm is designed. Furthermore, the mathematic models of the plane, terrain, pilot and the terrain following algorithm are built with the SIMULINK toolbox, which build the simulation base to verify the terrain following algorithms.The data fusion algorithm based on Kalman federal filtering is adopted to accomplish the data fusion of the terrain following radar and radio altimeter because of the complexity of Multi-sensor Data Fusion, and the simulation result with filtering algorithm is obtained.The terrain following system simulation platform is designed in the MATLAB environment, which has verified the real time simulation of the system having been designed, and the mixed programming method in C/C++ and MATLAB is chosen to realize the access among various process according to the systematic module design mode.Finally, the terrain following system is simulated with a certain plane according to the terrain following and multi-sensor data fusion algorithm having been designed, and the key performance indexes in the different terrains (mainly including the single peak or the double peaks) and different flight states are analyzed. The simulation results show that the TF algorithm and the data fusion algorithm designed in this paper is feasible and valid, and the various error index of the simulation system designed is satisfactory.