磁力矩器的刚度控制技术及应用

Stiffness control technology and application in magnetic rods

使用磁力矩器控制俯仰轴带有偏置动量的卫星的姿态时,沿地磁场方向的控制力矩无法保证.刚度控制策略利用磁力矩器产生控制力矩,加速动量矩矢量绕轨道法线方向的旋转速度,使进动控制方向更快的与地磁场方向分离,进入进动控制的有利位置.针对运行在太阳同步轨道的偏置动量卫星,推导了加入刚度控制项后,其俯仰轴磁矩的表达式.利用蚁群算法ACA(Ant Colony Algorithm)对磁力矩器控制策略中进动反馈系数,章动反馈系数,刚度反馈系数3个反馈系数及相关的3个系数进行了寻优,利用优化的结果进行仿真实验.通过比较刚度控制策略和经典控制策略的仿真试验结果,证明在长期外部干扰力矩下,采用刚度控制可以改善进动控制效率,提高姿态控制精度.

Control torque along geomagnetic vector could not be generated by magnetic rods when they are employed in momentum bias satellites with a pitch dipole moment. Stiffness control policy was developed to provide control torque by using magnetic rods to accelerate the motion of angular momentum vector along orbital normal. It made precession control vector move away from geomagnetic vector and move into location in favor of precession control. The expression of pitch dipole moment for stiffness control policy was developed by adding a stiffness term to classical control policy for momentum bias satellites on sun-synchronous orbit. Precession, nutation, stiffness feedback coefficient and their corresponding ratios were optimized and obtained via ant colony algorithm （ACA） and applied to numerical simulation. The comparison with the performance of the controllers with and without stiffness feedback coefficient indicates that stiffness control policy can improve precession control efficiency and increase pointing accuracy under persistent external disturbances.