S115011 スロットレスDDモータを用いた冗長駆動DELTA型パラレルロボットの開発([S115-01]機械システムにおける機構の設計と要素技術(1))

Abstract

A novel redundantly actuated DELTA parallel robot for mold polishing has been prototyped. Slotless direct drive motors, which have minimal cogging torque, are implemented in the prototype. Instead of using conventional spherical sliding bearings, ball bearings with appropriate preload are implemented in the rolling pairs of the prototype. These mechanical parts enable fine force control for mold polishing applications. The rated force along the mold surface of the prototype is 20 N with a tangential force of 5 N, which enable the robot to execute most polishing tasks as well as skilled workers. In addition, the polishing velocity along the tangential direction is 60 m/min, which exceeds skilled workers' velocity of 10 m/min. High speed feed contributes to reducing the polishing force and improving the quality of the surface of the mold. The kinetostatics of redundantly actuated DELTA robots is also discussed in this paper. The manipulating force ellipsoid demonstrates that the prototype has no singularity in its workspace. The transposed Jacobian matrix's orthogonal complement space, which relates internal forces of the redundantly actuated parallel robot, has been symbolically derived. These equations have been verified by numerical simulations.