基于干扰观测器的挠性卫星姿态滑模变结构控制

Attitude Control of Flexible Satellites via Disturbance-Observer-Based Sliding Mode Controller

为抑制各种内外干扰因素对挠性卫星姿态控制性能的影响,设计基于干扰观测器的滑模变结构控制器.该控制器采用干扰观测器对系统中存在的内外干扰进行估计,并对估计值加以前馈补偿.在此基础上,采用滑模变结构控制器对未补偿的干扰进一步抑制,实现卫星姿态与姿态角速度的渐近收敛.与单纯的滑模变结构控制器相比,本文的控制器已根据干扰估计值对干扰进行了前馈补偿,采用较小的切换增益即可抑制剩余干扰,颤振现象减弱.仿真结果表明,本文设计的控制器是可行的.

To mitigate the effect of diverse internal and external disturbances of flexible spacecraft on attitude control performance, a composite control scheme is proposed by combining disturbance-observer （D0） and sliding mode control （SMC）. The disturbance observer can observe the disturbances and out- put the estimation, which can be compensated through feedforward. Then, SMC is used to suppress the uncompensated disturbances, so that the attitude and rate of the spacecraft are asymptotically converged. Compared with conventional SMC, the proposed DO ＋ SMC approach just need a smaller switching gain to restrain the remaining disturbances that the DO does not compensate, and the chattering is attenuated effectively. Simulation results demonstrate the feasibility of the designed controller.