The paper introduces a new design of a platform mechanism with 6 DOF. The platform is supported on three active legs, each equipped with two rotating drives. The mechanism can be used in active vibration control systems. The values of drive angular velocities are precisely controlled, so that the transmission of the base vibrations onto the platform could be minimal. The values of drive torques to be generated are determined. The mechanism was modelled using the Working Model® 30. The effects of active vibration control are also presented.

The author suggests that a mobile counterweight mechanism could be introduced to the excavator structure for coupling the hydraulic system with the excavating equipment. It is shown that the mobile counterweight mechanism reduces power demand, at the same time improving stability of the excavator.