图像信息反馈的目标航天器跟踪控制方法

Target Spacecraft Tracking Control Based on Image Information

定义目标航天器图像形心与像平面中心为跟踪误差,并将该像平面误差直接引入跟踪控制闭环,提出一种增益切换的目标航天器跟踪PD控制律,在由推力器开关控制特性定义开关函数的基础上,给出PD控制器增益切换策略。由于直接使用目标航天器在像平面中的视觉特征误差量,避免了视觉相机内参数标定和目标航天器位姿信息求解等过程,简化了服务航天器的系统配置,同时控制器增益切换实现对测量误差、推力器偏差、转动惯量偏差以及干扰力矩等多种不确定性因素进行补偿,提高了跟踪控制系统稳定性及抗干扰性能。最后,基于Lyapunov稳定性理论给出控制器参数估算方法,并理论分析了增益切换PD控制律的收敛性,数学仿真表明该控制律能够对复杂机动目标以及考虑多种不确定性因素等情况进行快速跟踪,校验了视觉跟踪控制策略的有效性及对多类型不确定性的鲁棒性。

The gain-switching PD control law for target tracking is proposed with the introduction of the image plane error, defined as the deviation between the target image centroid and the center of the image plane, into the close-loop of tracking control. The switching function is designed for switching of PD gain in order to compensate the effects of measurement error, thruster deviation, inertia uncertainty and disturbing moment, thus improving the system stability and anti-jamming performance. Using the visual characteristics error in the image plane directly avoids calibration of camera intrinsic parameters and solution for target attitude, which simplify the servicing spacecraft configuration. The method for estimation of control parameters is put forward and the stability is analyzed based on Lyapunov theory. Numerical simulations indicate that the system works well for tracking the complex maneuvering target while considering typical uncertainty factors. The resuhs demonstrate the effectiveness of visual tracking control strategy and robustness to multiple types of uncertainty.