Novel augmented proportional navigation guidance law for mid-range autonomous rendezvous

Abstract

In this paper, a novel augmented proportional navigation (APN) guidance law is proposed for the mid-range autonomous rendezvous. The line-of-sight (LOS) rotation coordinate system is used, which can decouple the three-dimensional relative motion between the chaser and target into the relative motion in the engagement plane and the rotation of this plane. The APN guidance law is consisted of two parts. The first one is a novel nonsingular terminal sliding mode control (NTSMC) along LOS to drive the relative distance and approaching speed to the desired values in finite time. The second one is the modified true proportional navigation (TPN) guidance law perpendicular to LOS to control the LOS rate in a certain range. It has been proven that, even when there are disturbances and uncertainties along and perpendicular to LOS, the proposed APN can guarantee the finite time convergence of the relative distance and approaching speed and limit the LOS rate within a certain acceptable range. Hence, the mid-range autonomous rendezvous can be perfectly realized. The new theoretical findings are demonstrated by numerical simulation results.