Vibration Control of Flexible Base Mobile Manipulators under Impedance Controller Using New Control Element on the End Effector

In this paper new method for vibration control of Flexible Base Mobile Manipulator (FBMM) under constrained motion control were proposed. When robotic manipulator with base flexibility contacts environment under impedance control, vibration occurs at transient and contact moments. Vibration causes position and force inaccuracy, instability and servicing requirements of equipment. Previous active vibration control is based on vibration control elements on the base of manipulator. As new method, control element on the manipulator’s End Effector was proposed for vibration control and vibration damping on the mechanism. This controller includes same or better response and lower control coefficients because of its performance on the End Effector instead of the base. Active Vibration Controller on the End Effector (AVEE) was simulated for two models. First model is a simple FBMM composed of a 2 DOFs planar manipulator and a single DOF moving base with flexibility in between. Second model is an advanced 10 DOF’s FBMM. Combined Impedance/AVEE controller provides desired position/force control with satisfactory damped vibration especially at the point of contact. Results show that control coefficients of active vibration controller on the Base (AVCB) are so bigger than these coefficients for AVEE. Index Terms — Mobile Manipulator, Vibration Control, Position/Force Control, Flexible base , End Effector