The mixed l1/H2 optimization problem for MIMO (multiple input-multiple output) discrete-time systems is considered. This problem is formulated as minimizing the l1-norm of a closed-loop transfer matrix while maintaini...The mixed l1/H2 optimization problem for MIMO (multiple input-multiple output) discrete-time systems is considered. This problem is formulated as minimizing the l1-norm of a closed-loop transfer matrix while maintaining the H2-norm of another closed-loop transfer matrix at prescribed level. The continuity property of the optimal value in respect to changes in the H2-norm constraint is studied. The existence of the optimal solutions of mixed l1/H2 problem is proved. Because the solution of the mixed l1/H2 problem is based on the scaled-Q method, it avoids the zero interpolation difficulties. The convergent upper and lower bounds can be obtained by solving a sequence of finite dimensional nonlinear programming for which many efficient numerical optimization algorithms exist.展开更多
A new approach is proposed for robust H2 problem of uncertain sampled-data systems. Through introducing a free variable, a new Lyapunov asymptotical stability criterion with less conservativeness is established. Based...A new approach is proposed for robust H2 problem of uncertain sampled-data systems. Through introducing a free variable, a new Lyapunov asymptotical stability criterion with less conservativeness is established. Based on this criterion, some sufficient conditions on two classes of robust H2 problems for uncertain sampled-data control systems axe presented through a set of coupled linear matrix inequalities. Finally, the less conservatism and potential of the developed results are illustrated via a numerical example.展开更多
In the design of IMC controller or other robust controller for robust performance in process control application, one of the necessary conditions is model (or process) uncertainty bound. The method of calculating mode...In the design of IMC controller or other robust controller for robust performance in process control application, one of the necessary conditions is model (or process) uncertainty bound. The method of calculating model (or process) uncertainty bound for the first order lag process with dead time (FOPDT) in the robust controller design is reported in literatures. Up to the now, however, no any analytical method of calculating model (or process) uncertainty bound can be used in the second order lag process with dead time (SOPDT). Therefore, the design of the IMC controller for robust performance used to SOPDT also can not be simply achieved.By using first order Pade approximation for the dead time,an analytical method of calculating model (or process) uncertainty bound for SOPDT in the robust controller design is given for the first time.By using this bound, IMC controller design for robust performance can be made satisfactorily.展开更多
基金This project was supported by the National Nature Science Foundation of China (60374009)Nature Science Foundation of Guangdong Province of China (990795).
文摘The mixed l1/H2 optimization problem for MIMO (multiple input-multiple output) discrete-time systems is considered. This problem is formulated as minimizing the l1-norm of a closed-loop transfer matrix while maintaining the H2-norm of another closed-loop transfer matrix at prescribed level. The continuity property of the optimal value in respect to changes in the H2-norm constraint is studied. The existence of the optimal solutions of mixed l1/H2 problem is proved. Because the solution of the mixed l1/H2 problem is based on the scaled-Q method, it avoids the zero interpolation difficulties. The convergent upper and lower bounds can be obtained by solving a sequence of finite dimensional nonlinear programming for which many efficient numerical optimization algorithms exist.
文摘A new approach is proposed for robust H2 problem of uncertain sampled-data systems. Through introducing a free variable, a new Lyapunov asymptotical stability criterion with less conservativeness is established. Based on this criterion, some sufficient conditions on two classes of robust H2 problems for uncertain sampled-data control systems axe presented through a set of coupled linear matrix inequalities. Finally, the less conservatism and potential of the developed results are illustrated via a numerical example.
文摘In the design of IMC controller or other robust controller for robust performance in process control application, one of the necessary conditions is model (or process) uncertainty bound. The method of calculating model (or process) uncertainty bound for the first order lag process with dead time (FOPDT) in the robust controller design is reported in literatures. Up to the now, however, no any analytical method of calculating model (or process) uncertainty bound can be used in the second order lag process with dead time (SOPDT). Therefore, the design of the IMC controller for robust performance used to SOPDT also can not be simply achieved.By using first order Pade approximation for the dead time,an analytical method of calculating model (or process) uncertainty bound for SOPDT in the robust controller design is given for the first time.By using this bound, IMC controller design for robust performance can be made satisfactorily.
