A Guidance Approach Based on Line-of-sight Angle in Planar Guidance Problem

In the guidance algorithms based on the line-of-sight (LOS) rate, the lateral acceleration commands are computed in such a way that the LOS rate is nullified. So, keeping constant the LOS angle, the condition in which the vehicle speed is greater than the target speed, the vehicle reaches the target position asymptotically. In this paper, a new guidance algorithm, based on the LOS angle, is presented for a typical guidance system. To this aim, considering the governed guidance equations and using the corresponding trigonometric relations, the proposed guidance law is transformed into an algebraic equation. Although the utilized guidance procedure is independent of the rate of LOS angle, the rate of LOS angle would equal zero instantly via applying the proposed method. Then, to illustrate the effectiveness of the idea, the derived mechanism is evaluated in a two-dimensional guidance problem. The advantages of the approach are shown in comparison with similar methods.