用圆弧样条计算地形跟随技术中的期望航迹

从地形外形的采样数据设计飞机贴地飞行的期望航迹,然后由相应的最优控制器使飞机按此航迹飞行,这一地形跟随技术中的最优控制算法,日益得到重视和发展,并应用在综合地形跟随/回避技术中。 本文提出了采用圆弧样条计算期望航迹的方法,在几十种地形情况下进行了对比研究,证明是可行的。明显地减少了期望航迹计算的工作量,增加了系统实时计算的可能性。

THE METHOD OF CALCULATING THE DESIRED FLIGHT PATH OF TERRAIN FOLLOWING TECHNIQUE WITH CIRCULAR ARC SPLINE

A new algorithm-optimal control algorithm of terrain following（TF）system was presented by Funk, J. E. and Kelly, R. T. in 1975.This algorithm is used to design the desired flight path（DFP）with cubic spline from the sampled data of terrain contour, then the aircraft is forced to fly along this path by corresponding optimal controller. Since then, increasing attention has been paid to it, furthermore, it has been applied to terrain following/terrain avoidance system.Because this algorthm uses cubic spline to design DFP, it is difficult to consider constraint conditions, such as the normal acceleration limit &; nd the flight trace angle limit of vehicle. Consequently, it needs long computation time, then can not satisfy the requirement of real tim e calculation.This paper presents a method of designing DFP with circular arc spline. Under forty terrain conditions, This method is compared with the DFP of cubic spline and proven to be feasible.This new method decreases needed computation time, thus making real time calculation possible.