laser cladding
TRANSCRIPT
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Feedback Control of Melt PoolTemperature During Laser Cladding
Process
Presented byVISAKH.V
M2 AEI,ROLL NO:12
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Overview
1 Introduction
2 Laser Cladding System
3 Experimental Setup
4 Melt Pool Temperature Dynamic
5 Predictive Control
6 Tracking Melt Pool Temperature
7 Simulations
8 Conclusions
9 References
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Introduction
Laser Cladding
Advantages
Rapid heating and coolingWell confined laser beamMinimal distortion
Disadvantage
Complex multi-parameter process
Nonintrusive sensors
CCD CamerasPhotodiodesPyrometers
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Laser Cladding System
MIMO
High power laser
Dual-colour pyrometer
Identify state-space model
Real time controller
GPC algorithm with input constraints
Reference temperature tracking
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Experimental Setup
Figure: Experimental setup of DMD process with a closed looptemperature controller
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
5-D adjustable CNC system
Pyrometer connected to collecting lens
Pyrometer monitors the melt pool temperature
View of pyrometer to match laser beam on substrate
H13 tool steel powder is used
Real-time controller
samples melt pool temperature from pyrometercontrols laser power through analog interface
Implements GPC algorithm with input constraints and samplinginterval= 10 ms
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Melt Pool Temperature Dynamic
Analog modulation of pulse duration and laser power
P = 1.5603V − 0.8849
4th order state-space model
x(k + 1) = Ax(k) + Bu(k) + Ke(k)
y(k) = Cx(k) + Du(k) + e(k)
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Figure: Input output signals for model identificationFeedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Predictive Control
Generalised predictive algorithm with input constraints,
x(k + N) = ANx(k) + AN−1Bu(k) + ....... + Bu(k + N − 1)
y(k + N) = CANx(k) + CAN−1Bu(k) + ..... + CBu(k + N − 1)
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Augmented State-Space Matrix
[x(k + 1)u(k)
]=
[A B0 I
]x(k) +
[BI
]∆u(k)
y(k)=[c D
] [ x(k)u(k − 1)
]+D ∆u(k)
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
For Offset free tracking,-Cost function to be minimised,
Jk =N∑
j=N0+1
{(y(k+ j)−w(k+ j))T×QTy Qy (y(k+ j)−w(k+ j))}
×Nu∑j=1
{∆uTk+j−1Q
Tu Qu∆uk+j−1}
Model is valid for a certain input rangeumin
umin
.
.
.umin
≤
u(k)u(k + 1)
.
.
.u(k + Nu − 1)
≤umax
umax
.
.
.umax
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
T-filter approach
T-filter is used in generalised predictive control.
Hf =1− β
1− βq−1
State Space Estimation
x(k+1, k) = Ax(k , k−1)+AK (k)(y(k)−Cx(k , k−1))+Bu(k)
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Tracking Melt Pool Temperature
Tuning GPC for better performance
Noise is used to tune the controller and the parameters weretuned
Tracking a sinusoidal and square temperature profile
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Tracking Temperature Profile
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Compensating Lack of Deposition
Lack of deposition and overbuilt
Lower melt pool temperature
Mismatch of temperature indicates Lack of deposition
Closed loop controller increases laser power tom increasedeposition
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Simulations
Figure: Deposition geometry
Figure: Detection of melt pool temperature for an uneven surfaceFeedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Figure: Melt pool temperature and laser action at 2nd and 3rd layer
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Figure: Melt pool temperature and laser action at 26th and 27th layer
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Figure: Melt pool temperature and laser action at 37th and 38th layer
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Figure: Pictures of deposition at (a) 10th layer (b) 20th layer(c) 30thlayer and (d) 40th layer
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Figure: Deposition heights on and off the step at every tenth layer withand without GPC Controller
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Figure: Melt pool temperatures and laser actions at the second layer withand without controller
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Figure: Melt pool temperatures and laser actions at the second layer withand without controller
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
Conclusions
Melt pool temperature measured using pyrometer
State-space model identified experimentally
GPC algorithm implemented in real time
Closed loop process tracked the melt pool temperature
GPC compensated lack of deposition
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
References
1. Lijun. Song, and Jyoti. Mazumder., Feedback Control of MeltPool Temperature During Laser Cladding Process ,IEEETransactions on Control Systems Techonology, Volume 19, No.6, Nov, 2011.
2. M. Asselin et al., Development of trinocular CCD-based opticaldetector for real-time monitoring of laser cladding , inProceedings of IEEE International Conference on Mechatronicsand Automation, volume 14, paper 11901196.
3. J. Koch and J. Mazumder, Apparatus and methods formonitoring and controlling multi-layer laser cladding, U.S.Patent 6 122 564, September 19, 2000.
4. E. Toyserkani and A. Khajepour, A mechatronics approach tolaser powder deposition process, Mechatronics, volume 16,paper. 631641, December2006.
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum
Introduction Laser Cladding System Experimental Setup Melt Pool Temperature Dynamic Predictive Control Tracking Melt Pool Temperature Simulations Conclusions References
5. M. J. D. Powell, On the quadratic-programming algorithm ofGoldfarb and Idnani, Math. Program. Study, volume 25, paper.4661, October. 1985.
6. D. Goldfarb and A. Idnani, A numerically stable dual method forsolving strictly convex quadratic programs, Math. Program.,volume. 27, paper. 133, 1983.
Feedback Control of Melt Pool Temperature During Laser Cladding Process College of Engineering, Trivandrum