基于SMDO-TLC的高超声速飞行器姿态控制

针对高超声速飞行器快时变、强耦合以及存在参数不确定和外部干扰情况下的姿态控制问题,同时考虑到执行机构动态和输入受限,提出了基于滑模干扰观测器-轨迹线性化(SMDO-TLC,Sliding-Mode Disturbance Observer-Trajectory Linearization Control)的高超声速姿态控制方法.首先,引入二阶线性微分器(SOLD,Second-Order Linear Differentiator)的概念,通过理论分析指出了当前TLC中采用一阶惯性+伪微分器求取输入指令的微分信号时会存在与SOLD类似的峰值现象,随后利用韩式跟踪微分器求取姿态标称指令及其微分信号,可有效解决过渡过程中执行机构饱和问题;接着,分别在姿态和角速率回路设计二阶滑模干扰观测器,利用符号函数积分来重构内外回路的复合干扰,在此基础上设计补偿控制律,以实现姿态控制器设计.仿真结果表明,所提出的方法能够克服时变干扰及气动参数大范围摄动的影响,同时兼具良好的动态特性与静态品质,能够满足高超声速飞行器的快时变、高精度以及强鲁棒的控制需求.

Attitude control for hypersonic vehicle based on SMDO-TLC

In consideration of actuator input constraints, a novel attitude control method driven by sliding-mode disturbance observer was presented for supersonic vehicle which is fast time-varying, strong coupling combining with parameter non-deterministic. Firstly, via introducing the concept of second-order linear differentiator (SOLD), it was indicated that peaking phenomenon caused by a combination of first-order lag and pseudo differentiator, which is similar with SOLD, would emerge during the transient profile of differentiation of the nominal command in the existing trajectory linearization control (TLC). Nonlinear tracking differentiator (TD) was used to produce the nominal command and its derivative, saturation of actuator during transition time was solved. Secondly, second order sliding-mode disturbance observer (SOSMDO) based on integration of sign function was designed to reconstruct compound disturbances in the loops of attitude and angular rate respectively, and then compensation control law was proposed to realize attitude control. Simulation results show that the technique proposed can overcome the impact of large-scale perturbations of interference and aerodynamics parameters, meanwhile good dynamic character and steady quality was achieved, the hypersonic vehicle control demand of fast time-varying, high precision and strong robustness can be satisfied.