This paper investigates a practical impedance control system design that utilizes a DC servomotor actuator and a shaft encoder feedback sensor. Based on a state filter for velocity and acceleration information and the dominate-pole principle, a partial model-matching design, based on the direct torque control scheme is proposed for ease of impedance control. An analysis of stability robustness is given due to the plant‘s parametric perturbations and controller parameters variations, and a stability bound is also derived to characterize possible perturbations.