MIMO Control

• For a multi DOF coupled system, the equation of motion is represented as a Matrix Equation of motion in the time domain.
• The entire analysis is carried out directly in the time domain for reducing real-time computational effort. This is also known as ‘State-Space Analysis'.
• The controller is also represented in matrix form and the system performance is predicted by analysing the open and closed-loop plant matrices.

Distributed Control

• The MIMO model could trigger problems of spillover as discussed earlier. This happens more in the case of control of flexible body system.
• One-way to avert such problem is to represent the governing equation of motion in the form of partial differential equation (without spatial and temporal decomposition). Thus, error due to model truncation is avoided.
• Again, for stability of such system, one would need continuous control force distributed over the entire system. The use of smart material based distributed actuator could resolve this problem.
• However, the difficulty arises while the controller is implemented in the real system. A continuously distributed controller is very difficult to achieve in real-time. An approximate discretely distributed controller is used in practice. Such systems indeed have limited applicability.