A New Approach To Dynamic Balancing Of Robotic Mechanisms

Dynamic balancing of machines refers to balancing of shaking force, shaking moment and driving torque. Mechatronics mechanisms refer to mechanisms that are driven by servomotors. With the advancement of servomotor technology, robotic mechanisms become more and more popular in high speed machine tools. The effective balancing for robotic mechanisms has not been achieved very well; in particular there is not an approach that is good to any kind of robotic mechanisms.In this thesis, a new approach to balancing of robotic mechanism is proposed. The new approach is based on a couple of ideas. First, a concurrent integrated approach to robotic mechanisms design may not be always a best choice. A decoupled integrated design process, which is also proposed in this thesis, is the best to suit robot mechanisms design. Second, servomotor has a residual capability available, which can be utilized to contribute to dynamic balancing. This thesis takes four-bar and five-bar robotic mechanisms as examples to illustrate the proposed approach. The validation of theoretical developments is made through a well-proven simulation technique.This thesis concludes:(1) it is indeed true that the concurrent integrated approach to designing robotic mechanisms may degrade the fulfillment of main function requirements; (2) the new approach in combination of the decoupled design process and redundancy servomotor concept is promising in terms of fulfillment of the main function requirement and improvement of dynamic performance; (3) the new approach allows for a full cancellation of shaking moments at a number of positions under the condition that the shaking force is fully balanced by a counterweight method.The contribution of this thesis to the field of mechanisms and design theory and methodology includes:(1) the finding that a concurrent integrated approach to design of robotic mechanism is not the best choice, as opposed to the popular doctrine that concurrent design is the best, and (2) the new approach named redundancy servomotor approach, as opposed to the existing approach to use servomotors for integrated design and dynamic balancing and to use servomotors to balancing of deflections for flexible mechanisms.