Rohrs benchmark problem revisited by adaptive control with closed loop reference model

In this paper, a benchmark problem of adaptive control Rohrs example has been revisited with recently developed model reference adaptive control (MRAC) with closed-loop reference model (CRM). The paper incorporates an overview of CRM architecture with state feedback, which is appropriate for the control of such system. We also explore through qualitative considerations the fundamental difference between the conventional MRAC referred as open loop reference model ORM and CRM.