■  View full text

AIAA Journal

JOURNAL OF GUIDANCE

Volume 38, Number 12December 2015

https://arc.aiaa.org/doi/abs/10.2514/1.G001060

■ Researchers

Namhoon Cho∗

Agency for Defense Development, Daejeon 34186, Republic of Korea

Youdan Kim†

Seoul National University, Seoul 08826, Republic of Korea

Sanghyuk Park

Department of Aerospace and Mechanical Engineering, Korea Aerospace University

■ Abstract

A three-dimensional nonlinear guidance law for path-following is proposed using differential geometry of space curves. The proposed guidance law makes a vehicle converge to and then follow a given desired path of general shape, which does not require strict restrictions on initial position and velocity. To take the advantages of the look-ahead effect for precise and robust path-following, the proposed guidance law takes the form of pure pursuit guidance, which is designed to align the velocity of the vehicle with the look-ahead vector. The look-ahead angle and the radially shifted distance are designed using differential geometry of the desired path. The proposed guidance law generates the normal acceleration command required for exact path-following and finally overcomes the limitations of previously developed look-ahead point-based methods in the case of general three-dimensional path-following. Stability analysis on the guidance law to follow constant-curvature planar paths is performed. The performance of the proposed guidance law is demonstrated by numerical simulations for various types of desired paths.