Abstract—This paper presents the digital implementation of a
double-loop feedback controller for speed and current regulation
on a permanent-magnet direct current servo motor based on the
real-time microcontroller TMS320F28335. The topology of the
controller is based on a cascade control scheme; the speed
controller (external loop) sets the reference of the current
controller (internal loop). In this way, a high performance on the
servo drive can be obtained. A online tuned Proportional-
Integral controller regulates the speed reference, the armature
current is regulated using a hysteresis controller. In order to
make comparisons a single topology speed controller (one control
loop) and cascade topology speed and current controllers (double
control loop) are digitally implemented. Simulation results are
validated by practical experimentation. Electrical drive and
sensor platform were developed for the tests. Additionally a data
acquisition system is proposed.