This paper addresses the problem of grasped object weight compensation in the one-handed manipulation of impedance controlled robots. In an exemplary identification procedure, the weight of an object and its centre of mass together with gripper kinematic configuration are identified. The procedure is based on the measurements from a 6-axis force/torque sensor mounted near the gripper. The proposed method reduces trajectory tracking errors coming from the model imprecision without compromising the main advantages of impedance control. The whole approach is applied according to the embodied agent paradigm and verified on the two-arm service robot both in simulation and on hardware. Due to the general description that follows system engineering standards, the method can be easily modified or applied to similar systems.