5.2 Open-loop control and the step response

Open-loop control Control systems!open-loop

In this chapter, we use open-loop control, which depends entirely on predictions about what will happen if a certain input is applied to the system. Measurements of actual system responses can inform these predictions, but not in real time. Our open-loop controller will take a user's commanded angular velocity of the motor and must decide the voltage \(V_S(t)\) or current \(I_S(t)\) to be applied to the motor. One approach to designing an open-loop controller is to choose a step input voltage or current that corresponds to the desired steady-state angular velocity in model predictions.

5.2.1 With a voltage source

For the voltage-source electromechanical system model, the step input is \[ u(t) = V_S(t) = m\, u_s\!(t), \] where \(m\) is a real constant and \(u_s\) is the unit step function.

The step …