A multirate fractional-order repetitive control for laser-based additive manufacturing. (August 2018)

• Record Type: Journal Article
• Authors: Wang, D.; Chen, X.
• Is Part Of: Control engineering practice. Volume 77(2018)
• Page Start: 41
• Page End: 51
• Publication Date: 2018-08
• Subjects: Selective laser sintering -- Laser scanning mechanism -- Numerical simulation -- Multirate sampled-data control; Automatic control -- Periodicals; 629.89
• DOI: 10.1016/j.conengprac.2018.05.001
• Languages: English
• ISSNs: 0967-0661

Abstract

Abstract: This paper discusses fractional-order repetitive control (RC) to advance the quality of periodic energy deposition in laser-based additive manufacturing (AM). It addresses an intrinsic RC limitation when the exogenous signal frequency cannot divide the sampling frequency of the sensor, e.g., in imaging-based control of fast laser-material interaction in AM. Three RC designs are proposed to address such fractional-order repetitive processes. In particular, a new multirate RC provides superior performance gains by generating high-gain control exactly at the fundamental and harmonic frequencies of exogenous signals. Experimentation on a galvo laser scanner in AM validates effectiveness of the designs. Highlights: A multirate control for precise rejection of fractional-order repetitive disturbances. A closed-loop analysis exhibiting full fractional disturbance-attenuation properties. High-frequency fractional-order disturbances challenge single-rate repetitive control. A multirate repetitive control attenuating both low and high-frequency disturbances.