モータの軸受部の弾性とトルクリップルを考慮した水平2関節形ダイレクトドライブロボットの振動解析

抄録

In a direct-drive robot, motors are directly coupled to the links without reduction gears, and high-grade control performance can be achieved. However, transient vibrations may frequently be generated owing to little friction and torque ripple of motors. In this report, the transient vibration characteristics of a horizontal two-link direct-drive robot are investigated theoretically. In the analysis, the torque characteristics are modeled in consideration of the torque ripple and the torque saturation characteristics of direct-drive motors, and the nonlinear state equation of the direct-drive robot is derived in consideration of the bearing elasticity of motors. Numerical simulation is carried out, and the effects of the torque ripple, the torque saturation characteristics and the bearing elasticity of direct-drive motors on the transient vibration characteristics of the direct-drive robot are demonstrated.