Surface mapping feedback for robot-assisted rapid prototyping

A fundamental problem with many solid freeform fabrication systems is the production of large dimensional errors, due to the freeform construction process. The subject of this paper is surface mapping feedback (SMF), a closed-loop technique for minimizing the dimensional errors produced by rapid prototyping systems. The main steps of the technique are presented, namely part measurement, control implementation, and deposition adjustment. A test platform, the Cobra 600 rapid freeze prototyping system, is used to validate SMF. A helical gear part is constructed first with open-loop control and then with SMF control; system performance and part quality are compared for the two cases.