Integrated Guidance and Attitude Control for Asteroid Proximity Operations using Higher Order Sliding Modes

Abstract

An integrated guidance and attitude control scheme for asteroid proximity operations is presented. The development of this algorithm is motivated by the desire to implement robust and integrated spacecraft GNC schemes for asteroid close proximity operations. Autonomous maneuvering about small bodies is particularly challenging because of the uncertain, low-gravity environment. Based on Higher Order Sliding Mode (HOSM) control theory, the integrated Multiple Sliding Surface Guidance and Control (MSSGC) law has been designed to drive the system to the selected sliding surface in a finite time. The MSSGC scheme integrates the spacecraft's guidance and attitude control into a common framework that guides the 6-DOF spacecraft to a desired position about the asteroid with the desired orientation, all without the need for a pre-computed reference trajectory. A Lyapunov-based stability analysis shows that the system is globally stable against unmodeled dynamics and perturbations typically expected in small body environments. Results demonstrate that the algorithm is successful in driving the system to the desired target point (either landing on the surface or hovering above a desired location) with zero velocity and with the desired attitude and zero rotational rates.

Orbit-Attitude Predictive Control in the Vicinity of Asteroids with In Situ Gravity Estimation

“…The optical and laser devices have to point to the asteroid surface for close-proximity navigation [31,32]. As a consequence, the spacecraft attitude must be accounted for in order to ensure navigation.…”

Deep reinforcement learning for six degree-of-freedom planetary landing

“…This essentially assumes decoupling of translational and rotational motion; consequently, the system does not map observations directly to commanded thrust for the lander's individual engines, and a separate controller would be required to do so. Wibben and Furfaro use a multiple sliding surface approach to develop an IGC system for lunar landing [22]. However, the system was not truly integrated, as the 3-DOF thrust vector is first computed and mapped to the body frame, where the algorithm then works out the required attitude and the required torque to target that attitude.…”

Attitude-Orbit Cooperative Control for Small-Scale Spacecraft with Chemical Propulsion: Adaptive Sliding Mode Control Based on Neural Network

“…More researchers have focused on controller design schemes of small-scale spacecraft systems. Common control methods include sliding mode control (Xu et al 2005;Zhai et al 2017;Wibben and Furfaro 2012), optimal control (Jadhav and Gomathi 2018;Li et al 2010a), adaptive control (Wang et al 2014;Wang and Wei 2015), robust control (Sun and Huo 2015), compound control (Sun et al 2011a) and others. A method of orbit-tracking control was proposed based on an adaptive super-twisting algorithm for soft landings of spacecraft on asteroids (Zhang et al 2016a).…”