Table 5 and Figs. 101112–13 show detailed statistical results of the simulation. In Table 5, $P11\u223cP33$ denote nine models of different states; De, De1, and Dopen denote the variance of error signals with the $H\u221e$ control, integrator, and open-loop system, respectively; De/Dopen denotes the ratio of the variance of error signals with the $H\u221e$ control to the variance of open-loop error signals, De1/Dopen denotes the ratio of the variance of error signals with the integrator to the variance of open-loop error signals. The smaller the ratio value is, the better the controller performance will be. De1/De denotes the variance ratio of the closed-loop error signal of AO system with integrator and the one with $H\u221e$ controller. It shows the comparison between the integrator and $H\u221e$ control in terms of correction capability. upv and u1pv denote the peak value of control signals of $H\u221e$ controller and integrator, respectively. epv and e1pv denote the peak value of mean value of error signal of $H\u221e$ controller and integrator, respectively. Ee, Ee1, and Eopen denote the mean value of error signal of $H\u221e$ controller, integrator, and open-loop errors, respectively. Eu and Eu1 denote the mean value of control signal of $H\u221e$ controller and integrator, respectively. Du and Du1 denote the variance of control signal of $H\u221e$ controller and integrator, respectively.