Approach Guidance with Double-Line-of-Sight Measuring Navigation Constraint for Autonomous Rendezvous

Based on double-line-of-sight measuring relative navigation method, an approach guidance law with the triangle-measuring constraint is presented for autonomous rendezvous. The observability of double-line-of-sight measuring relative navigation system is analyzed using the state estimation error covariance matrix. The triangle-measuring navigation constraint is described as a keep-out cone. The approach guidance law is designed via artificial potential function method. It is ensured that there is a high region of potential in the keep-out cone and the potential still has a unique minimum at the goal position. Numerical simulations are undertaken to verify the guidance method proposed. The results indicate that the control impulses of the potential function guidance ensure convergence of the chase spacecraft to reach the goal position without violating the navigation keep-out zone.