Closed-loop control of laser cladding process by powder injection

2003 ◽  
Author(s):  
E. Toyserkani ◽  
A. Khajepour ◽  
S. Corbin
Keyword(s):  
Laser Cladding ◽  
Closed Loop ◽  
Powder Injection ◽  
Closed Loop Control ◽  
Loop Control ◽  
Laser Cladding Process

Improving solid freeform fabrication by laser-based additive manufacturing

2002 ◽  
Vol 216 (9) ◽  
pp. 1253-1264 ◽  
Author(s):  
D Hu ◽  
H Mei ◽  
R Kovacevic
Keyword(s):  
Additive Manufacturing ◽  
Metal Powder ◽  
Laser Cladding ◽  
Closed Loop ◽  
Solid Freeform Fabrication ◽  
Three Dimensional ◽  
Closed Loop Control ◽  
Loop Control ◽  
Freeform Fabrication ◽  
Laser Cladding Process

Solid freeform fabrication (SFF) methods for metal part building, such as three-dimensional laser cladding, are generally less stable and less repeatable than other rapid prototyping methods. A large number of parameters govern the three-dimensional laser cladding process. These parameters are sensitive to the environmental variations, and they also influence each other. This paper introduces the research work in Research Center for Advanced Manufacturing (RCAM) to improve the performance of its developed three-dimensional laser cladding process: laser-based additive manufacturing (LBAM). Metal powder delivery real-time sensing is studied to achieve a further controllable powder delivery that is the key technology to build a composite material or alloy with a functionally gradient distribution. An opto-electronic sensor is designed to sense the powder delivery rate in real time. The experimental results show that the sensor's output voltage has a good linear relationship with the powder delivery rate. A closed-loop control system is also built for heat input control in the LBAM process, based on infrared image sensing. A camera with a high frame rate (up to 800frame/s) is installed coaxially to the top of the laser—nozzle set-up. A full view of the infrared images of the molten pool can be acquired with a short nozzle—substrate distance in different scanning directions, eliminating the image noise from the metal powder. The closed-loop control results show a great improvement in the geometrical accuracy of the built feature.

Laser Cladding Forming and Closed-Loop Control of Thickness-Variable Eccentric Ring Structure

2018 ◽  
Vol 45 (3) ◽  
pp. 0302007
Author(s):  
沈婷 Shen Ting ◽  
石拓 Shi Tuo ◽  
傅戈雁 Fu Geyan ◽  
张锐 Zhang Rui ◽  
胡晔 Hu Ye
Keyword(s):  
Laser Cladding ◽  
Closed Loop ◽  
Ring Structure ◽  
Closed Loop Control ◽  
Loop Control ◽  
Eccentric Ring ◽  
Thickness Variable

Dynamical Identification Model of Laser Cladding Width in Metal Parts Laser Shaping Process

2013 ◽  
Vol 820 ◽  
pp. 216-219
Author(s):  
Shu Juan Jiang ◽  
Fei Fei Yu ◽  
Mao Zheng Fu
Keyword(s):  
Laser Cladding ◽  
Closed Loop ◽  
Scanning Speed ◽  
Step Response ◽  
Closed Loop Control ◽  
Loop Control ◽  
Simulating Experiment ◽  
Metal Parts ◽  
Shaping Process

The dynamical model of laser cladding width is identified by the method of step response experiments. Mathematical models between the cladding width and the laser power, the scanning speed, or the powder flowrate are established respectively according to corresponding experimental results. Simulating experiment results verify the validity of these models. The dynamical identification lays foundation for the closed loop control in laser shaping process so as to improve the quality of the laser formed parts.

Heat Input Control in 3D Laser Cladding Based on Infrared Sensing

2001 ◽  
Author(s):  
Dongming Hu ◽  
Yunxin Wu ◽  
Radovan Kovacevic
Keyword(s):  
Laser Cladding ◽  
Heat Input ◽  
Molten Pool ◽  
Closed Loop ◽  
Solid Freeform Fabrication ◽  
Infrared Image ◽  
Frame Rate ◽  
Closed Loop Control ◽  
Loop Control ◽  
Infrared Sensing

Abstract Solid Freeform Fabrication (SFF) methods for building metallic part, such as 3D laser cladding, are generally less stable and less repeatable than other rapid prototyping methods. The infrared image of the molten pool is a promising sensing technique for the closed-loop control of the cladding process. In this paper, the closed-loop control of heat input based on infrared image sensing in 3D laser cladding is introduced. A high frame-rate (up to 800frame/s) camera is installed coaxially at the top of the laser-nozzle setup. A full view of the infrared images of the molten pool can be acquired with a short nozzle-substrate distance in different scanning directions, eliminating the noise from the metal powder. The features of the images show a clear relationship with the variation of the cladding process parameters. The closed-loop control results show a great improvement in the geometrical accuracy and microstructure of the built part.

The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

2012 ◽  
Vol 220 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Sandra Sülzenbrück
Keyword(s):  
Empirical Research ◽  
Visual Feedback ◽  
Closed Loop ◽  
Motor Planning ◽  
Visual Input ◽  
Closed Loop Control ◽  
Loop Control ◽  
Feedback Type ◽  
Effective Use ◽  
The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

118-LB: Glucose Variability throughout the Menstrual Cycle on Closed-Loop Control in Type 1 DM

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 118-LB
Author(s):  
CAROL J. LEVY ◽  
GRENYE OMALLEY ◽  
SUE A. BROWN ◽  
DAN RAGHINARU ◽  
YOGISH C. KUDVA ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Closed Loop ◽  
Glucose Variability ◽  
Closed Loop Control ◽  
Loop Control ◽  
Type 1 Dm

101-LB: Eighteen-Month Use of Closed-Loop Control (CLC): A Randomized, Controlled Trial

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 101-LB
Author(s):  
SUE A. BROWN ◽  
DAN RAGHINARU ◽  
BRUCE A. BUCKINGHAM ◽  
YOGISH C. KUDVA ◽  
LORI M. LAFFEL ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Closed Loop ◽  
Controlled Trial ◽  
Closed Loop Control ◽  
Loop Control ◽  
Randomized Controlled
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