多星发射上面级的姿态解耦控制

Decoupling attitude control of upper stage

针对具有非线性和惯量积耦合的多星发射上面级姿态控制系统,提出了两种控制器综合方法。首先,基于奇异摄动理论,把姿态动力学分解成姿态角和姿态角速度跟踪内外两回路;将非线性动力学模型伪线性化,在每个跟踪回路用State-Dependent-Riccati Equation(SDRE)获得自适应非线性控制律,通过SDRE局部渐近稳定的特点保证系统闭环稳定。其次,基于分段仿射切换理论对原始非线性模型建模,设计了简单的分段仿射控制器,具有明确的航天物理意义,便于工程应用;最后,对两种控制方案进行了仿真验证和对比,结果两种方法都满足控制要求,其中分段仿射控制器便于工程应用。

Two feedback controller synthesis for attitude control of upper stage with nonlinear dynamic and inertia coupling are presented in the paper. First, the attitude dynamics is separated into fast and slow loops as angular velocity and attitude angular in terms of singular perturbation theory ; the nonlinear attitude dynamic equations are pseudo-linearly modeled based on state dependent coefficient. Every loop gets the dynamic control laws with solving State-Dependent-Riccati Equation （SDRE） optimal. The SDRE theory guarantees closed-loop systems stability. Second, piecewise affine （PWA） systems are powerful models for describing non-linear of the upper stage dynamics, the piecewise-affine state feedback input signal is parameterized by constant coefficient. Simulation results demonstrate the effectiveness of two methods.