Evaluation of Robotic Open Loop Mechanisms using Dynamic Characteristic Charts.

摘要

Previously, dynamic characteristic charts were presented as the evaluation method of dynamic characteristics of the robotic parallel crank mechanisms. The dynamic characteristic charts reveal the change in dynamic torque which applied to each driving shaft of robots as they move the whole working space. The dynamic equations of the parallel crank mechanisms do not involve effects due to Coriolis' force so that the dynamic characteristic charts can be made easily. On the contrary, it is difficult to make the same charts for open loop mechanisms since their dynamic equations involve effects due to Coriolis' force. However, open loop mechanisms are the most commonly used so that an appropriate dynamic characteristic evaluation method is particularly needed for them. Therefore, we propose use of the dynamic characteristic charts for open loop mechanisms by transforming the dynamic equation. Furthermore, this paper describes a simple measurement method for dynamic torque applied to driving shafts of robotic mechanisms. Using the method, changes in the dynamic driving torque of robotic open loop mechanisms are measured practically, and the utility of the dynamic characteristic charts is confirmed based on those results.