LAUSR

In this paper, we rely on the equivalent dynamic approach to compensate external forces applied to the upper part of the robot. This study allows us to determine on-line the required movements and accelerations of the two arms in order to maintain the robot stability. We firstly develop the kinematics and dynamic equations of the robot under perturbations. Then, we use the SimMechanics platform to perform a simulation of ADAM robot during the external force compensation. The robot is composed of a rotating torso and two three-degrees-of-freedom arms. Each arm is equipped with three Brushless Direct Current motors which are controlled by IPOS 4808 drives. The 3D assembly of the robot is built on SolidWorks and exported to SimMechanics. Then, to achieve the best performance in terms of robot dynamic balance preservation, a Proportional and Derivative control is implemented in the dynamic model of the robot to modify the values of desired angular velocities of arms. The proposed method was confirmed in a second phase of study through experiments for two types of disturbances applied to the trunk. This study highlights the importance of arms in the robot stability.