LPV系统的混合H_(2)/H_(∞)指标区间观测器设计

Interval observer design of LPV system with mixed H_(2)/H_(∞) performance

受模型偏差和系统扰动等影响,复杂系统难以获得准确的状态估计,往往仅能确定状态的区间,即设计区间观测器.通常,考虑单一性能指标的区间观测器难以获得较好的观测效果.对此,研究一种H_(2)/H_(∞)混合性能指标的线性参数变化系统区间观测器设计方法,基于真实值、估计值和误差三者关系,通过区间壳(interval hull)计算求取误差区间,以一般观测器和误差上下限的组合表示状态估计区间.引入混合H_(2)/H_(∞)范数约束,提高观测器的抗干扰性和鲁棒性,并提出基于H_(2)/H_(∞)混合性能指标的区间观测器设计方法.实例仿真表明,所提出的H_(2)/H_(∞)区间观测器设计方法对连续搅拌反应器(continuous stirred tank reactor,CSTR)系统能够获得更窄的状态上下界估计,有利于后续故障诊断、控制的设计与实施.

Due to the influence of model deviation and system disturbance,it is difficult to obtain accurate state estimation for complex systems,and generally only the interval of the state can be determined.That is,the interval observer can be designed.However,it is difficult to obtain good estimation results by considering a single performance interval observer.An interval observer approach with H_(2)/H_(∞) performance is designed.Based on the obvious relationship among real states,estimated states and estimated errors,the interval hull of errors is calculated and the interval estimation of real states is represented by the combination of estimated states and the upper and lower bounds of errors.Then,anti-interference and robustness of observer are efficiently improved by introducing the smallest mixed H_(2)/H_(∞) normconstraint.Finally,an example is presented to demonstrate the effectiveness of the proposed method.The result shows that the proposed H_(2)/H_(∞) interval estimation method has better estimation performance for the continuous stirred tank reactor and is convenient to design and implement the following control strategies.