Virtual prototyping of tilting and lifting mechanism in ITER tractor

ITER (international thermonuclear experimental reactor) tractor is an in-cask remote handling equipment, and its tilting and lifting mechanism is very important for the tractor to operate 45t plug in front of the ports of the hot cell and the VV (vacuum vessel) successfully. This paper was aimed at proposing a tilting and lifting mechanism to accurately grasp and operate the heavy-load plug in the ITER cask. The 3D virtual prototype of mechanism is presented and it is simplified as 7-linkage plane structure to reduce the complexity of analysis. The kinematics and dynamics characteristics of this mechanism were studied. To realize bidirectional solution of the movement, the motion parameters relationship between input and output was set up by the kinematics models. Based on Lagrange equation, the driving force of every joint for hydraulic cylinders was calculated. The results of dynamics simulation validated the correctness of calculation. The excellent hydraulic loop model was also built to guarantee the motion stability of system. All the above analytical models can provide intelligent control strategies for hydraulic cylinders of the mechanism to achieve the stable grasping and operation of heavy-load plug.