1.3 BLOCK-DIAGRAM REPRESENTATION OF A GENERAL CONTROL SYSTEM

In state-variable formulation of a system, the state-variables are usually represented by x ₁( t), x ₂( t), x ₃( t) ; the inputs by u ₁( t), u ₂( t), u ₃( t), ; and the outputs by y ₁( t), y ₂( t) The state-space representation of a system that has m inputs, p outputs, and n-state variables may be visualized in block-diagram form as shown in Figure 1.1. For notational economy, the different variables may be represented by the input vector u( t), output vector y( t), and the state vector x( t), where