Helicopter forward-looking warning method based on image matching for urban low-altitude flight

Abstract

Aiming at the unique geographical characteristics of urban environment, combined with image matching aided navigation and forward-looking warning technology, the helicopter forward-looking warning method based on image matching is studied. Based on precise navigation and positioning, dangerous obstacles are predicted and warnings are generated. Firstly, the image matching algorithm applied to helicopter forward-looking warning is studied, and a normalized cross-correlation matching algorithm based on variable step-size second-order difference fast search strategy is proposed. Then, the principle and algorithm of helicopter forward-looking warning algorithm are given, and the warning boundary is determined based on helicopter escape trajectory. A test example is built to verify the algorithm. The simulation results show that compared with the conventional warning method, the ground proximity warning algorithm based on image matching can effectively correct the navigation error and improve the success rate of the warning, especially suitable for low-altitude anti-collision warning in urban environment. The proposed fast search strategy of variable step-size second-order difference method can effectively improve the speed of the algorithm.