Homing guidance laws based on speed control for anti-ballistic missiles

Abstract

In this paper, a new guidance law for intercepting ballistic missiles at high altitude is proposed. The proposed guidance method, called velocity control guidance (VCG), unlike the conventional guidance method which controls the collision triangle by adjusting the flight-path angle, achieves a collision triangle by controlling the intercept speed. In the proposed method, a new impact point (or collision triangle) is first determined that automatically nullifies a given initial heading angle error without changing the flight-path angle. Speed control is maintained until a particular time in order to reach the new impact point. In this paper, the control effectiveness and the fuel consumption of the proposed method are analyzed to provide better insights into the proposed method. It turns out that compared to existing methods the proposed method can save control energy when intercepting a high-speed target. Numerical simulations confirm the performance of the proposed method.

The concept of VCG was applied in three-dimensional geometry conditions. For 3D application, axial control based on speed control and lateral control were simultaneously performed. The CPA method is used to find point closest points when the target and the KV are moving in the direction of the speed, and the KV is guided to the point on the target. Numerical simulations were conducted to demonstrate the characteristics of the proposed method and verify feasibility of the proposed method.

From the equation of motion of the heading error, general guidance law that makes heading error zero was derived. This generalized guidance law includes the conventional lateral guidance, the proposed guidance (VCG), and the guidance mixed with normal and axial accelerations.

Characteristics of the three guidance methods are compared by nonlinear simulations. The results show that it is possible to overcome the disadvantages of using the axial guidance law alone. As shown in some simulation results of GCCCG, it can be seen that the fuel efficiency is further increased for the fast target. Through the distribution of normal and axial accelerations, fuel effective guidance laws for large engagement areas could be generated.