针对高超声速飞行器再入过程中强耦合特性和干扰所带来的非匹配不确定控制问题,提出了一种新的含干扰观测补偿的滑模姿态控制设计方法.首先,基于高超声速飞行器姿态动力学模型,将系统内部摄动和未知扰动统一作为未知干扰,采用扩展干扰观测器进行干扰估计.其次,利用参考模型建立飞行器姿态控制的误差模型,设计了一种新的含干扰观测补偿的高超声速飞行器滑动姿态控制系统.该方法的特色在于相比基于传统滑模的高超声速飞行器姿态控制系统,对姿态动力学中的非匹配耦合不确定因素具有很强的鲁棒性,同时也避免了基于反演法的高超声速飞行器姿态控制系统中出现的"微分膨胀"问题.最后,仿真结果表明,在参数拉偏和未知扰动存在的情况下,姿态控制系统都能实现对姿态角的稳定跟踪,并提高了传统滑模控制系统中的跟踪精度,且具有良好的鲁棒性能.%A novel sliding mode control method is proposed for the reentry phase of hypersonic vehicle with mis?matched uncertainties composed of strong coupling and disturbances based on a nonlinear disturbance observer ( DOB) . Firstly, an extended DOB is established to estimate the disturbances including internal perturbation and unknown disturbance in the attitude dynamics model of hypersonic vehicle. Secondly, the error dynamic model is built by introducing reference model, and a new sliding mode surface with the uncertainties estimation is designed, the sliding mode control is derived from the erorr dynamic model. Comparing the traditional sliding mode control, the feature of the proposed method has the better performance in the robustness to the mismatched uncertainty. Meanwhile, the problem of differential expansion in the back?stepping method is avoided. Finally, simulation results show that the proposed attitude control could be stably tracked with expected commands in the case of there exists the parameters deviation and unknown disturbances, and the performance of tracking accuracy and robustness is better than the traditional sliding mode controller.
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