Hutao Cui

Spacecraft Attitude Maneuver Planning Based on Rapidly Exploring Random Tree and Sliding Mode Control

During the orbit time of a spacecraft, a great variety of attitude maneuver operations need to be accomplished according to the requirements of mission. How to satisfy the complicated pointing constraints is one of the problems need to be solved in the future space mission. An algorithm of constrained attitude path generation of spacecraft based on Rapidly Exploring Random Tree(RRT) and Sliding Mode Control(SMC) is proposed in this paper. Using RRT as a global planner, the uniformly distributed nodes in Quaternion Space of Attitude are randomly sampled, the expanded nodes of which are kept to check whether they are in obstacle zone. By this means the satisfaction of pointing constraints is guaranteed. In the meantime, under the condition of the inputs of control satisfying the saturation constraint, the SMC method is introduced to expand the local nodes in order to meet the satisfaction of the pointing and dynamic constraints respectively, also the maneuver path of Kino dynamics is generated. Finally, the simulation results and analysis validate the advantages of the proposed algorithm.

Indirect Trajectory Optimization for Mars Entry with Maximum Terminal Altitude

In this paper, a novel computational optimization framework is presented for the design of Mars entry trajectories with maximum terminal altitude. The second-order path constraints included in the ...

Constrained Attitude Maneuver Control Based on Command Filter and Backstepping Method

Aiming at solving the problem of attitude maneuver control of spacecraft with pointing constraints, this paper proposes an algorithm based on navigation function, command filter and back stepping method. The expected angular velocity of spacecraft is obtained through navigation function, then its amplitude is saturated by a saturation function. After that, the angular velocity is used as the input of reference system. Due to the limitation of amplitude, the angular velocity command maybe non-differentiable at some point, so a first-order filter is adopted to smooth the angular velocity command. Moreover, two auxiliary systems are designed, the inputs of which are the difference between the angular velocity command before and after filter, and the difference between control input before and after saturation element respectively. The back stepping control is used to ensure the stability of attitude system and auxiliary system, therefore the attitude of spacecraft is able to track the angular velocity and attitude of reference system, which also makes the safe arrival of spacecrafts target attitude possible. Finally a simulation of this algorithm is carried out, and the results of which are thoroughly analyzed.