The modeling and analysis for the natural frequency adjustments of Vehicle Manipulator for the ITER Blanket Remote Handling System

This paper describes a method to adjust the natural frequency of the Vehicle Manipulator of the ITER Blanket Remote Handling System (BRHS). The natural frequency was adjusted to avoid the seismic resonance by using the redundancy of degree of freedom of the Vehicle Manipulator. The Vehicle Manipulator was modeled and analyzed with lumped mass model with joint stiffness. The analysis has shown that the natural frequencies of the Vehicle Manipulator can be changed from 0.5 Hz to 12 Hz in the gripping posture of the First Wall in the vacuum vessel, suggesting that the dominant seismic frequency around 7Hz-9 Hz can be avoided.