一类含中立项的非线性系统的复合抗干扰控制方法

Combining H_∞ and disturbance-observer-based control for a class of uncertain nonlinear systems with neural term

针对一类含中立项的非线性系统,提出一种基于干扰观测器设计和H∞控制的复合抗干扰控制方法。将输入通道中的干扰信号表示为1个动态子系统,可以涵盖常值、谐波等信号。被控对象和干扰子系统都含有参数和结构不确定性。基于线性矩阵不等式,通过引入依赖于调节参数的Lyapunov函数,提出降阶干扰观测器设计方法。模型已知或部分信息已知的外部干扰可以通过干扰观测器被抵消,由参数不确定性部分引起的干扰通过H∞控制抑制。通过集成传统控制器,可使闭环系统在没有参数不确定性时渐近稳定,在有未建模动态以及参数和结构的不确定性时满足H∞控制性能指标。对高精度飞行控制系统的仿真结果表明该方法有效。

The disturbance rejection and attenuation problem is investigated for a class of uncertain nonlinear systems with neutral-term via the combined H∞ control and disturbance - observer - based control. The unknown external disturbances are supposed to include two parts. One is generated by an exogenous system with uncertainty, which can represent the harmonic signals with a perturbation. Another is the classical signals used in H∞ control. Parametric uncertainties exist both in concerned plant and in exogenous system. By integrating the disturbance observers with conventional control laws, the disturbances can be rejected and the desired dynamic performances can be guaranteed. For the uncertain disturbances, H∞ control is applied to attenuate the disturbances. Finally, a simulation for a flight control system is given to demonstrate the effectiveness of the results.