敏捷卫星的联合执行机构控制策略

 针对对地观测敏捷卫星大角度快速机动、高控制精度的任务需求,提出了联合推力器与飞轮作为执行机构的控制策略。该控制策略综合利用2种执行机构的优点:推力器以前馈的形式提供机动过程中所需的主要力矩以实现航天器大角度的快速机动,而飞轮以反馈的形式提供精准的控制力矩以提高机动过程中的姿态控制精度。为补偿由于初始状态偏差和推力器输出力矩不准确所带来的控制误差,采用变结构控制设计了2种姿态跟踪控制器,使航天器能够渐进地跟踪上参考轨迹。并对姿态机动控制过程中,飞轮力矩及转速可能出现的饱和问题作了相应的修正。仿真结果表明了所提控制策略及所设计控制算法的可行性和有效性。

Control Strategy of Hybrid Actuator for Agile Satellites

A control strategy integrating thrusters and flywheels as a hybrid actuator is presented for an earth observation agile satellite with large-angle rapid maneuver and high-precision control performance.This strategy seeks to take advantage of the strong points of each individual type of actuators: the thrusters will offer the primary reorientation maneuver torque in the form of feed-forward to make the spacecraft rotate rapidly,while the flywheels provide the fine control torque in the closed loop to evaluate the control precision.To compensate for the bias due to initial state mismatch and the coarse output torque of the thrusters,two attitude tracking controllers based on variable structure control are designed to enable the spacecraft to approach the reference trajectory asymptotically.The torque and speed saturation of the flywheels during maneuver is resolved accordingly.Simulation results show the feasibility and effectiveness of the proposed control strategy and the variable structure tracking control law.