Vibration compensation of delta 3D printer with position-varying dynamics using filtered B-splines

The delta robot can reach higher speeds than traditional serial-axis machines used in fused filament fabrication 3D printing. However, like serial machines, printers suffer from undesirable vibration at high which degrades the quality of fabricated parts. This has been suppressed using linear model-inversion feedforward control methods filtered B-splines (FBS) approach. techniques FBS approach are computationally challenging to implement on because their coupled, position-dependent dynamics. In this paper, we propose a methodology address computational bottlenecks by (1) parameterizing portions dynamics offline enable efficient computation model online, (2) computing models sampled points (instead every point) along given trajectory, and (3) employing QR factorization reduce number floating-point arithmetic operations associated with matrix inversion. simulations, report time reduction up 23× proposed method when compared expensive exact LPV model—all while maintaining tracking accuracy. Accordingly, demonstrate significant improvements parts printed various positions commercial printer our controller baseline alternative, uses an LTI one position. Acceleration measurements during printing show that improvement print is due reductions 39% controller.