A Laser Metal Deposition (LMD) height controller design methodology is presented in this paper. The height controller utilizes the Particle Swarm Optimization (PSO) algorithm to estimate model parameters between layers using measured temperature and track height profiles. The process model parameters for the next layer are then predicted using Exponentially Weighted Moving Average (EWMA). Using the predicted model, the powder flow rate reference profile, which will produce the desired layer height reference, is then generated using Iterative Learning Control (ILC). The model parameter estimation capability is tested using a four-layer deposition. The results demonstrate the simulation based upon estimated process parameters matches the experimental results quite well. Simulation study also shows that the methodology described above works well in producing the reference layer height.

Meeting Name

19th Annual International Solid Freeform Fabrication Symposium (2008: Aug. 4-6, Austin, TX)


Mechanical and Aerospace Engineering

Research Center/Lab(s)

Intelligent Systems Center


This research was supported by the Intelligent Systems Center at Missouri S&T.

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type




Publication Date

06 Aug 2008

Included in

Manufacturing Commons