A SIX DEGREES OF FREEDOM END EFFECTOR PLACES 8000 LB. ROBOTIC CANISTERS IN THE NATIONAL IGNITION FACILITY

摘要

The National Ignition Facility (NIF), currently under design and construction at Lawrence Livermore National Laboratory, will be the world's largest laser when complete. The NIF will use about 8,000 large optics of 26 different types to focus up to 192 laser beams on a dime-size target. A system of auto-guided robotic vehicles transports opto-mechanical packages, called line replaceable units (LRUs), for installation and maintenance operations. Most LRUs are transported inside a portable clean room, or canister, containing robotic mechanisms that insert each LRU into its respective location in the laser. Together the LRU and canister can weigh up to 8000 lb. Due to precision-alignment requirements of the LRU and because the canister internal mechanisms operate in the canister reference frame, the canisters themselves must be precisely located relative to the laser support structure. In many instances precise location is obtained with the aid of precision canister locating points, called docking points, some of which are on the laser bay ceiling at 19 feet off the floor. The robotic vehicle transporting the LRU and canister is tasked with positioning these 8000 lb. canisters at 19-foot elevation with less than one inch offset error. The final positioning of the canister in six degrees of freedom is accomplished with an actively controlled three degree of freedom end effector coupled to a passive three degrees of freedom canister lift system.