State space analysis

State space analysis.

Drawbacks of transfer function analysis.

• Transfer function is defined under zero initial conditions.
• Transfer function approach can be applied only to linear time invariant systems.
• It does not give any idea about the internal state of the system.
• It cannot be applied to multiple input multiple output systems.
• It is comparatively difficult to perform transfer function analysis on computers.

Any way state variable analysis can be performed on any type systems and it is very easy to perform state variable analysis on computers. The most interesting feature of state space analysis is that the state variable we choose for describing the system need not be physical quantities related to the system. Variables that are not related to the physical quantities associated with the system can be also selected as the state variables. Even variables that are immeasurable or unobservable can be selected as state variables.

• It can be applied to non linear system.
• It can be applied to tile invariant systems.
• It can be applied to multiple input multiple output systems.
• Its gives idea about the internal state of the system.

State of a dynamic system.

Output variables = Y1(t), Y2(t), Y3(t)…………………………..Yb(t)

Input variables  = U1(t), U2(t), U3(t)……………………………Ua(t)

State space representation of a system