Direct metal deposition plays an important role in rapid manufacturing industry to fabricate geometrically complicated, dense, near-net-shape components. A large number of parameters are involved in the deposition process. Its present development stagnates in its control. A good understanding of the laser material processing and a well designed controlling system are essential for the system reliability. This paper addresses the development of a linear model based generalized predictive control system for direct metal deposition. The molten pool temperature during the direct metal deposition process was monitored by a two-colour pyrometer. A single-input single-output linear system that describes the dynamics between the molten pool temperature and the laser power was considered. The incremental generalized predictive control algorithm with Kalman filter estimation was used to control the molten pool temperature. The performance of the controller was compared with the on-off controller.

1.
Mazumder
J.
,
Dutta
D.
,
Kikuchi
N.
,
Ghosh
A.
, (
2000
)
Closed loop direct metal deposition: art to part
,
Optics and Laser Engineering
34
,
397
414
2.
Koch
J.
and
Mazumder
J.
, (September 19,
2000
) U.S. Patent #6,122,564,
Apparatus and methods for monitoring and controlling multi-layer laser cladding
3.
Ordis
,
A
,
Clarke
,
D.
, (
1993
)
A state-space description for GPC controllers
,
Int. J. Systems SCI.
,
24
,
1727
1744
4.
Hu
D.
,
Kovacevic
R.
(
2003
)
Sensing, modelling and control for laser based additive manufacturing
,
International Journal of Machine Tools & Manufacture
,
43
,
51
60
.
5.
Song
L
,
Mazumder
J.
(
2006
),
Sensing and experimental based modelling of direct metal deposition
,
25th International Congress on Applications of Lasers & Electro-Optics (ICALEO)
,
Scottsdale, AZ
6.
Hagan
M.
,
Demuth
H.
,
Jesus
O.
, (
2002
)
An Introduction to the use of neural networks in control systems
,
International Journal of Robust and Nonlinear Control
,
12
,
959
985
7.
Goldfarb
,
D.
and
Idnani
,
A
, (
1983
)
A Numerically Stable Dual Method for Solving Strictly Convex Quadratic Programs
,
Mathematical Programming
,
27
,
1
33
,
8.
Powell
M.J.D.
, (
1985
)
On the Quadratic Programming Algorithm of Goldfarb and Idnani
,
Mathematical Programming Study
,
25
,
46
61
.
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