Cartesia: Automated 3-point setup for metrology instruments in 3D CAD space

CAD-driven metrology applications using laser guns, scanners or cameras require situating the instruments in CAD coordinates, both positionally and rotationally. The new Cartesia instrument setup technique overcomes the requirement for surveying skill. The CAD coordinate system is pinned to the site by emplacing point emitters or retroreflectors at 3 CAD-specified reference points. Then, instruments may be set out at unknown locations and orientations. No leveling is required. An instrument interacts directionally with each reference point, acquiring raw, instrument-based polar angles. The Cartesia algorithm processes these observations to solve for the instrument's 3D position and rotational attitude. These data enable the instrument to think and work in CAD coordinates for data acquisition and point shooting. Correlation of data from multiple instruments may be solved elegantly at the outset, by setting up on a common reference pointset. This work uses recent advances in algorithmic geometry(1). The Cartesia system shifts the role of surveying expertise toward one-time emplacement of optical reference points, and away from daily instrument operation. The major benefit is that future automated metrology instruments can be designed for less technically skilled workers, lowering daily operational costs, and serving a broader base of users and applications.