This paper presents the use of angular position control approaches for a flexible robot manipulator with disturbances effect in the dynamic system. Delayed Feedback Signal (DFS) and ProportionalDerivative (PD) controller are the techniques proposed in this investigation to actively control the vibrations of flexible structure. A constrained planar single-link flexible manipulator is considered and the dynamic model of the system is derived using the assume mode method. A complete analysis of simulation results for each technique is presented in time domain and frequency domain respectively. Performances of the controller are examined in terms of vibration suppression and disturbances cancellation. Finally, a comparative assessment of the impact of each controller on the system performance is presented and discussed.