A polar flight guidance method based on polar-plane rhumb route

基于极平面等角航线的极区飞行引导方法

¹ School of Automation, Northwestern Polytechnical University, Xi'an 710072, China
² AVIC the First Aircraft Institute, Xi'an 710089, China

Received: 27 May 2025

Abstract

When civil aircraft flies along a great circle route, the route is usually approximated by multiple rhumb routes segments in order to guide easily. However, traditional guidance methods become inadequate for the flight in polar regions since great circle routes exhibit non-constant azimuth, while rhumb routes converge into high-curvature spirals. To solve these problems, a polar guidance method based on the polar-plane rhumb route was proposed in this paper. Firstly, the polar plane was defined and a polar-plane parameter projection algorithm was derived, therefore overcoming the limitations of traditional mechanization schemes that only work within specific ranges and require complex coordinate system switching calculation based on navigation area. Then, according to the projection characteristics of great circle routes on the polar plane, the polar-plane rhumb route was defined and its route equations were deduced. The proposed polar-plane rhumb route maintains constant polar-plane azimuth while possessing the route length comparable to that of the great circle route, thus being more suitable as a reference route in polar regions. Finally, a flight guidance algorithm based on polar-plane rhumb route was derived and relative polar flight simulation was conducted based on a transport aircraft model. The simulation results demonstrate that the aircraft guided based on polar-plane rhumb route can fly with high precision in polar regions.

摘要

民航客机在执行大圆航线飞行时, 为便于飞行, 通常将大圆航线近似为多段等角航线。但在极区飞行时, 大圆航线航向通常不是常值、等角航线收敛为螺旋线, 因此传统飞行引导方式不能适应极区飞行环境。为解决此问题, 提出了一种基于极平面等角航线的极区飞行引导方法。定义了极平面并提出了极平面参数投影转换算法, 克服了传统力学编排方案只在一定范围内适用, 且需要根据导航范围进行复杂的坐标系切换的问题。在分析大圆航线极平面投影特性的基础上, 给出了极平面等角航线定义, 并推导了极平面等角航线航程方程; 极平面等角航线在保证其极平面航向角不变的同时拥有与大圆航线相近的航程, 便于极区飞行引导。在定义极平面等角航线后, 提出了基于极平面等角航线的飞行引导算法, 并以某型运输机为例进行了极区仿真飞行测试, 仿真结果表明, 该引导方法能够在极区实现高精度飞行引导。