Project #1 (In Progress)
Towards Feedforward Robot Control: Nonlinear Feedforward Control of Open-Loop Delta 3D Printer using Filtered B-Splines.
The Delta robot is a parallel-axis manipulator, invented by Reymond Clavel at EPFL, historically used for pick-and-place applications. The Delta robot is famous for reducing the mass at the end-effector through its use of stationary motors. It was recently adapted to a 3D printer by individuals like Johann Rocholl and is becoming an increasingly popular choice for 3D printer configurations. The objective of this project is to implement feedforward control on a Delta-type a 3D printer to minimize quality defects on printed parts, which are created from motion errors. The Delta 3D printer is faster than traditional serial-stack gantry 3D printers due to the light mass at the nozzle, but it suffers from poor contour tracking performance created by the myriad nonlinearities in the system, such as a spherical build area which limits the build volume, more complex kinematic and dynamic computation, and a nonlinear coupled dynamic model with kinematic chains. The control system is, thus, difficult to design due to its multivariable nature, in the presence of nonlinear elements and high interaction between robot links.
Coming soon.
A major hindrance to reaching the promise of 3D printing in industrial applications is its low speed and lack of repeatability in quality. My work broadly works to address these issues. The Delta 3D printer is one of few printers on the market with the potential to reach remarkably high accelerations and speeds. Augmenting its improved mechanical design with an advanced controller has the potential to be a significant step toward high-speed and high-quality 3D printing.
