Accounting of DC-DC power converter dynamics in DC motor velocity adaptive control

This paper deals with the problem of velocity control of a DC motor taking account the dynamics of the DC-DC power converter, supposed here of Buck type. We will develop for the global system, constituted by combined DC-motor and Buck-converter, a model of fourth order. On the basis of this model a regulator is designed using the backstepping technique. The control purpose is, on one hand, asymptotic stability of the closed-loop system and, on the other hand, perfect tracking of the reference signal (the machine speed). Both non adaptive and adaptive versions are designed and shown to yield quite interesting performances. A theoretical analysis shows that both controllers meet their objectives. These results are confirmed by simulations which, besides, show that the adaptive version deals better with load torque changes.