Finite-time control for soft landing on an asteroid based on line-of-sight angle

Finite-time super-twisting sliding mode control for Mars entry trajectory tracking

“…Note that, finite-time control strategy not only has the property of finite-time convergence of tracking error and fast dynamical response, but also has a strong robustness against disturbances [16][17][18][19]. As such, the tracking controller with finite-time convergence property is more attractive for Mars entry trajectory tracking.…”

Finite-time guidance laws for landing process of a spacecraft subjected to disturbances

“…In general, the rendezvous problem of a space vehicle with a celestial target contains three stages as transfer to the neighborhood of the astronomical target, approach, and soft landing on the astronomical object [2]. The latest stage is deeply affected by many challenges including complicated dynamics, parameter uncertainties, combinatorial impacts of gravity and air drag, solar radiations, non-spherical astronomical body, environmental disturbances, and so on [2]. By considering the aforementioned motivation, numerous guidance strategies [1][2][3][4][5][6] have been introduced to study the discussed landing process.…”

“…The latest stage is deeply affected by many challenges including complicated dynamics, parameter uncertainties, combinatorial impacts of gravity and air drag, solar radiations, non-spherical astronomical body, environmental disturbances, and so on [2]. By considering the aforementioned motivation, numerous guidance strategies [1][2][3][4][5][6] have been introduced to study the discussed landing process. Most of these strategies suffer from various deficiencies reviewed in the following paragraph briefly.…”

“…As the second shortcoming, some researches [1-3, 5, 6] have neglected the influences of atmospheric drag and gravity. Finally, as the third disadvantage, many researches [1][2][3][4][5][6] have not considered the environmental disturbances and uncertainties in the model of the landing process.…”

“…Focusing on related works, one could find two basic approaches for finite-time stabilizing of nonlinear systems including explicit direct Lyapunov method [2,[7][8][9][10][11] and terminal sliding mode control (TSMC) [9,[12][13][14].…”