A manufacturing system for microscale robotic deposition

This paper presents initial results in the development of a fabrication system capable of producing prototype parts with feature sizes on both the meso- and micro-scale using a technique known as robocasting. A dual-stage design is proposed, but the work presented here focuses on individual control of the first or coarse stage. This stage suffers from several known position-dependent disturbances, and a technique for identifying and compensating for them through an inverse-mapping is presented. A loop-shaped feedback controller and iterative learning feedforward controller are designed. Experimental results show the controller to be extremely effective in tracking repeated trajectories. In many cases contour error is on the order of the feedback resolution.