Abstract
In this paper, a feedforward proportional-integral-derivative (PID) controller is developed to effectively control the clad height in laser solid freeform fabrication (LSFF). The scanning velocity is selected as the input control variable and the clad height is chosen as the output. A novel knowledge-based Hammerstein model, including a linear dynamic and a nonlinear memoryless block, is developed, and its parameters are identified offline using experimental data. The architecture of the controller consists of a PID and a feedforward module, which is the inverse of the identified model. The advantage of adding a feedforward path to the PID controller is evaluated experimentally, in which the results show a lower overshoot and faster response times. Also, the performance of the controller is verified in the presence of geometrical disturbances, as well as in the fabrication of a nonplanar part.
Similar content being viewed by others
References
Vilar R (1999) Laser cladding. J Laser Appl 11(2):64–79
Jeng JY, Lin MC (2001) Mold fabrication and modification using hybrid processes of selective laser cladding and milling. J Mater Process Technol 110(1):98–103
Hu D, Kovacevic R (2003) Sensing, modeling and control for laser-based additive manufacturing. Int J Mach Tools Manuf 43(1):51–60
Mazumder J, Schifferer A, Choi J (1999) Direct materials deposition: designed macro and microstructure. Mater Res Innov 3(3):118–131
Liu J, Li L (2004) In-time motion adjustment in laser cladding manufacturing process for improving dimensional accuracy and surface finish of the formed part. Opt Laser Technol 36(6):477–483
Hua Y, Choi J (2005) Adaptive direct metal/material deposition process using a fuzzy logic-based controller. J Laser Appl 17(4):200–210
Toyserkani E, Khajepour A, Corbin SF (2002) Application of experimental-based modeling to laser cladding. J Laser Appl 14(3):165–173
Römer GRBE, Aarts RGKM, Meijer J (1999) Dynamic models of laser surface alloying. Lasers Eng 8(4):251–266
Nelles O (2000) Nonlinear system identification. Springer, Berlin Heidelberg New York, ISBN 3-540-67369-5
Frenk A, Vandyoussefi M, Wagniere JD, Zryd A, Kurz, W (1997) Analysis of the laser-cladding process for stellite on steel. Metall Mater Trans B—Proc Metall Mater Proc Sci 28(3):501–508
Toyserkani E, Khajepour A, Corbin SF (2003) Vision-based feedback control of laser powder deposition. In: Billingsley J (ed) Mechatronics and machine vision 2003 (M2VIP2003): future trends, RSP Press, Great Britain, ISBN 0-8638-0290-7
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Fathi, A., Khajepour, A., Toyserkani, E. et al. Clad height control in laser solid freeform fabrication using a feedforward PID controller. Int J Adv Manuf Technol 35, 280–292 (2007). https://doi.org/10.1007/s00170-006-0721-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00170-006-0721-1