Clad height control in laser solid freeform fabrication using a feedforward PID controller
- 581 Downloads
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.
KeywordsLaser solid freeform fabrication Feedforward control Feedback control Clad height control Rapid prototyping
Unable to display preview. Download preview PDF.
- 1.Vilar R (1999) Laser cladding. J Laser Appl 11(2):64–79Google Scholar
- 8.Römer GRBE, Aarts RGKM, Meijer J (1999) Dynamic models of laser surface alloying. Lasers Eng 8(4):251–266Google Scholar
- 9.Nelles O (2000) Nonlinear system identification. Springer, Berlin Heidelberg New York, ISBN 3-540-67369-5Google Scholar
- 11.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 0-8638-0290-7Google Scholar