Modeling and Control of Timeshared and Scanned Torch Welding

1994 ◽  
Vol 116 (3) ◽  
pp. 387-395 ◽  
Author(s):  
C. C. Doumanidis
Keyword(s):  
Thermal Characteristics ◽  
Distributed Parameter ◽  
Weld Quality ◽  
Modeling And Control ◽  
Quality Regulation ◽  
Pipe Welding ◽  
Part Surface ◽  
Decoupled Control ◽  
Process Disturbances ◽  
And Control

Optimization of the weld quality and productivity requires in-process identification and simultaneous regulation of several thermal characteristics of the joint. Since in traditional single-torch welding only a few process variables can be modulated in real-time, multiple source configurations are implemented by a rapidly reciprocated (timeshared) GTAW torch to obtain decoupled control of the weld geometry, structure and properties. Further, to widen the range of achievable weld features, a scanning motion of the torch on the entire part surface generates the necessary heat distribution for any specified thermal field in the weld, which is observed through surface temperature measurements. Analytical, numerical, and experimental thermal modeling techniques are employed for the design of multivariable adaptive and distributed-parameter controllers, applied to girth and flange welding simulations, and tested in seam pipe welding experiments, for rejection of process disturbances and for weld quality regulation performance.

Distributed Parameter-Dependent Modeling and Control of Flexible Structures

2004 ◽  
Vol 127 (2) ◽  
pp. 230-239 ◽  
Author(s):  
Fen Wu ◽  
Suat E. Yildizoglu
Keyword(s):  
Optimization Problems ◽  
Flexible Structures ◽  
Synthesis Condition ◽  
Distributed Model ◽  
Linear Matrix ◽  
Distributed Parameter ◽  
Modeling And Control ◽  
L2 Norm ◽  
And Control ◽  
Parameter Dependent

In this paper, distributed parameter-dependent modeling and control approaches are proposed for flexible structures. The distributed model is motivated from distributed control design, which is advantageous in reducing control implementation cost and increasing control system reliability. This modeling approach mainly relies on a central finite difference scheme to capture the distributed nature of the flexible system. Based on the proposed distributed model, a sufficient synthesis condition for the design of a distributed output-feedback controller is presented using induced L2 norm as the performance criterion. The controller synthesis condition is formulated as linear matrix inequalities, which are convex optimization problems and can be solved efficiently using interior-point algorithms. The distributed controller inherits the same structure as the plant, which results in a localized control architecture and a simple implementation scheme. These modeling and control approaches are demonstrated on a non-uniform cantilever beam problem through simulation studies.

scholarly journals Distributed Parameter Modeling and Control of Electromagnetic Molding Machine

2009 ◽  
Vol 45 (10) ◽  
pp. 502-511
Author(s):  
Takayuki ISHIZAKI ◽  
Kenji KASHIMA ◽  
Jun-ichi IMURA ◽  
Atushi KATOH ◽  
Hiroshi MORITA
Keyword(s):  
Distributed Parameter ◽  
Molding Machine ◽  
Modeling And Control ◽  
And Control ◽  
Distributed Parameter Modeling

Temperature Field Regulation in Thermal Cutting for Layered Manufacturing

1999 ◽  
Vol 121 (3) ◽  
pp. 440-447 ◽  
Author(s):  
N. Fourligkas ◽  
C. Doumanidis
Keyword(s):  
Temperature Field ◽  
Thermal Processing ◽  
Pole Placement ◽  
Time Variability ◽  
Material Structure ◽  
Source Power ◽  
Modeling And Control ◽  
Thermal Sensing ◽  
Process Disturbances ◽  
And Control

A general thermal modeling and control methodology for thermal processing of layered materials for rapid prototyping technologies is established in this article. An analytical multivariable model of lumped temperature outputs generated by heat inputs on a surface grid is developed, based on Green’s function and state-space descriptions. The few independent parameters needed in such a linearized formulation are experimentally identified, and their time-variability reflects the heat transfer nonlinearities and process disturbances. A robust controller with thermal feedback is designed by pole placement methods, to obtain a specified dynamic temperature field yielding the desired material structure and properties. The regulated thermal processing is optimized in real time by proper heat source power modulation and torch guidance through a simulated annealing strategy. Its performance is tested on both the computer model and a laboratory station, using robotically guided plasma-arc cutting and infrared thermal sensing, in regulating the sensitized zone during blanking of an elementary contour pattern on stainless steel.

scholarly journals Modeling and control of two five-phase induction machines connected in series powered by matrix converter

2021 ◽  
Vol 12 (2) ◽  
pp. 685
Author(s):  
Mohamed Nekkaz ◽  
Abdelkader Djahbar ◽  
Rachid Taleb
Keyword(s):  
Induction Machines ◽  
Matrix Converter ◽  
Drive System ◽  
Modeling And Control ◽  
Input Side ◽  
In Series ◽  
Decoupled Control ◽  
Simulation Results ◽  
Five Phases ◽  
And Control

The two five-phase Induction Motor (IM) drive system that is serially connected is available in literature. The power supply of such system is considered as a matrix converter (a direct AC to AC converter system) by three and five-phases outputs. The main benefit from the drive topology is the sinusoidal source as a side current with a controllable input side power factor. The decoupled control is achieved similarly to the inverter based drive system. In this paper; the decoupled control of two five-phase induction machines serially connected and powered by a five-phase matrix converter as well as analytical and simulation results are presented.

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