8.5 Digital velocity control of DC motors

Motors!velocity control ofIn this section, the angular velocity control of permanent magnet brushed DC (PMDC) motors is considered. We take a general approach that will apply to many systems, but we will narrow the scope to the target system in Section 8.6. The two linear models described in Section 5.1 for modeling an electromechanical system with a PMDC motor—one for a voltage source and the other for a current source—are considered, in turn, as the model of the plant in a digital control system. As in Section 8.4, we take a digital emulation design approach, designing a continuous controller and then digitizing it using Tustin's method.

For both models, we use the block diagram of Figure 8.14. The amplifierAmplifiers!analogAmplifiers!currentAmplifiers!voltage is modeled as a simple gain \(K_a\); for the voltage-source model, its units will …