Improving dynamic operability in mimo systems with time delays

Time delays often dominate the process dynamics and limit the dynamic operability of the plant. The assessment of their effect has been investigated and has been quantified by upper bounds (unachievable) and lower bounds (achievable). Since existing delay compensators can perform only to the limits imposed by these measures, the problem of identifying the effects of time delays and developing strategies for reducing their impact on the control system performance has become very important. A rigorous approach for the study of these issues is introduced. Within the framework of mixed-integer linear programming, the suggested methodology provides the position of the delays that should be increased, as well as their new magnitude necessary to accomplish improved closed-loop performance. The optimum lower bounds when dynamic decoupling is required are identified. As a result of the modified process, the performance of existing multi-delay compensators can be improved and driven to the optimum lower bound for dynamic decoupling of the system.