Critical review on complete dynamic balancing of mechanisms

When mechanisms and parallel manipulators move, due to the fact that the center of mass is not fixed and angular momentum is not constant, they often produce vibrations in the base. Shaking force and shaking moment balancing can be achieved by making the linear momentum and angular momentum constant. There are generally two main ways for the shaking force and shaking moment balancing, i.e. "balancing before kinematic synthesis" and "balancing at the end of the design process". Under the category of balancing at the end of design process, add counterweights & counter-rotations, add ADBU and add auxiliary links are mostly used principles; here a new method is proposed, i.e. balancing through reconfiguration, which can reduce the addition of mass and inertia. Fischer's method belongs to the method of balancing before kinematic synthesis. In this paper, we will discuss the advances and problems on dynamic balancing of mechanisms in detail under the above two main categories. Two main contributions of the paper can be concluded as follows: new reactionless parallel manipulators are derived and dynamic balancing through reconfiguration concept is proposed in first time.