基于干扰观测器的动力陀螺式导引头干扰力矩补偿

Disturbance Torque Compensation of Gyro-stabilized Seeker Based on Disturbance Observer

干扰力矩对导引头跟踪测量精度及导弹的制导精度有直接影响。为分析干扰力矩对动力陀螺式导引头跟踪精度的影响,建立了动力陀螺式导引头及框架摩擦干扰力矩和导线干扰力矩模型。为减小干扰力矩对导引头测量精度的影响,设计了实用的干扰观测器来对干扰力矩进行补偿。考虑了实际中导引头系统本身及干扰观测器采样保持时间不同的多速率采样问题。提出基于奈奎斯特稳定性理论的离散干扰观测器设计方法,消除了小增益定理设计方法的保守性。通过综合权衡系统稳定性、干扰力矩补偿及传感器噪声抑制能力,确定了干扰观测器采样保持时间及干扰观测器滤波时间常数。结合弹上及导引头量测信息,设计了干扰观测器所需信息的提取方式。数学仿真结果表明所设计的干扰观测器能有效地提高导引头的跟踪测量精度。

Disturbance torque directly affects the tracking and measuring accuracies of seeker and the guidance precision. To analyze the degradation of gyro-stabilized seeker tracking accuracy due to disturb- ance torque, the dynamics models of seeker, seeker gimbal friction and seeker cable disturbance torques are established. To reduce the influence of disturbance torque on seeker tracking accuracy, a practical disturbance observer （DOB） is designed to compensate the disturbance torques. Multi-rate sampling problem due to the difference between sampling and hold times of seeker system and DOB is considered. A discrete DOB design method is proposed based on Nyquist stability theory, so the conservation of small gain design method can be removed. Sampling, hold and filter time constants of DOB are specified by balancing system stability, disturbance torque compensation and sensor noise reduction. An extracting method of information which is required by DOB is proposed by integrating the measurement information of missile and seeker. The mathematical simulation results show that the designed DOB can improve the seeker tracking accuracy efficiently.