考虑安装偏差的联合执行机构自适应控制算法

An adaptive control algorithm for hybrid actuator with installation deviation

为满足卫星机动过程中成像的需求,采用联合控制力矩陀螺和飞轮作为执行机构提供大且精确的控制力矩,但其安装的偏差会降低卫星姿态控制精度,基于设计自适应控制律处理这一问题.在携带变速控制力矩陀螺卫星通用模型的基础上,建立考虑安装偏差的联合执行机构控制模型.基于修正罗德里格参数描述的姿态运动学,设计多输入多输出自适应跟踪控制律估计执行机构的安装偏差与卫星转动惯量,并进行控制补偿以提高姿态控制精度.采用平滑映射避免控制律出现奇异现象而导致的无法执行,并基于Lyapunov原理分析了控制系统稳定性.数学对比仿真结果表明,该控制方法能够有效的实现卫星快速机动过程中的高精度控制,可提高2个数量级的跟踪控制精度.

To meet the requirement of satellite imaging during maneuver,the mixed control moment gyroscopes and flywheel are used as the actuator to provide large and precise control torque. Due to the fact that the installation deviation of these actuators will reduce the attitude control accuracy of satellite,an adaptive control law is designed to deal with this issue. Based on the dynamic model of a satellite with a cluster of single-gimbal variable-speed control moment gyros,the control model with the consideration of installation deviation is derived. Based on the kinematic equation described by modified Rodrigues parameters,a multi-input multi-output adaptive tracking control law is designed to estimate the installation deviation of the actuators and the inertia of satellite,and the corresponding control compensation is adopted to improve the control accuracy. The singularity phenomenon of the tracking control law is avoided by using smooth projector principle,and the stability of the controlled system is analyzed via Lyapunov theory. Simulation results show that the proposed adaptive controller enables the satellite fast maneuver with high control accuracy,and the accuracy of the tracking control can be improved by two orders of magnitude.