Thermal Manufacturing Process Control by Lumped Mimo and Distributed-Parameter Methods

1995 ◽  
Vol 117 (4) ◽  
pp. 625-632 ◽  
Author(s):  
C. C. Doumanidis
Keyword(s):  
Real Time ◽  
Power Distribution ◽  
Thermal Characteristics ◽  
Thermal Control ◽  
Distributed Parameter ◽  
Material Structure ◽  
Manufacturing Process Control ◽  
Part Surface ◽  
Regulation Strategies ◽  
Continuous Power

A variety of geometric, material structure, and stress/distortion attributes are needed to characterize the quality of thermally manufactured products. Because of in-process sensing difficulties and transportation lags, these features must be regulated in real time through appropriate thermal outputs, measured by non-contact infrared pyrometry. In thermal processes with a localized, sequentially moving heat source, the necessary heat input distribution on the part surface is supplied by an innovative timeshared or scanned torch modulation, in a raster or vector pattern. A unified lumped multivariable and a distributed-parameter quasilinear modeling formulation provide a design methodology and real-time reference for the development of finite- or infinite-state adaptive thermal control systems. These controllers modulate the power and motion of a single torch, supplying distinct concentrated heat inputs or a continuous power distribution on the part surface, so as to obtain the specified thermal characteristics or the entire temperature field. These regulation strategies are computationally tested and implemented experimentally in arc welding, but their applicability can be extended to a variety of thermal manufacturing processes.

Distributed-Parameter Control of the Heat Source Trajectory in Thermal Materials Processing

1996 ◽  
Vol 118 (4) ◽  
pp. 571-578 ◽  
Author(s):  
C. Doumanidis ◽  
N. Fourligkas
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
Real Time ◽  
Welding Process ◽  
Thermal Control ◽  
Distributed Parameter ◽  
Material Structure ◽  
Parameter Control ◽  
Real Time Control ◽  
Distributed Parameter Control

In thermal manufacturing processes performed by a localized, sequentially moving heat source, simultaneous regulation of multiple thermal quality characteristics requires real-time control of the temperature field developed through the distributed heat input on the part surface. Such control of the thermal field to a desired distribution employs infrared sensing and feedback of the surface temperature hill, to modulate the torch power and motion in-process. The torch trajectory is guided in real time by an efficient optimization algorithm based on the concept of moving complexes. This distributed-parameter control strategy is developed using a numerical simulation model of thermal processing, and its performance is evaluated experimentally in heat treatment of thin stainless steel plates. The thermal controller is applied to the new scan welding process, in which it drives the torch in a reciprocating motion along the weld, yielding a uniform and smooth temperature field, and thus a favorable material structure and mechanical properties. Application of such thermal control to various other material processing methods is also investigated.

scholarly journals A Conceptual Framework for Intelligent Power Distribution Transformers

2020 ◽  
Vol 9 (4S2) ◽  
pp. 97-99
Keyword(s):  
Conceptual Framework ◽  
Real Time ◽  
Health Monitoring ◽  
Power Supply ◽  
Power Distribution ◽  
Smart Cities ◽  
Distribution Transformers ◽  
Iot Devices ◽  
Reliable Power Supply ◽  
Continuous Power

With the agenda of developing smart cities there is huge demand for continuous power supply. Power distribution transformers play avital role in providing a reliable power supply. Failure of a transformer will lead to interruptions in power supply. Many parameters lead to transformer failures. Health monitoring of transformer using IoT technology may help take proactive maintenance steps instead of reactive maintenance. When we combine IoT with AI it will more effective and IoT devices will take decision on their own. This paper presents a conceptual framework of this concept which makes the IoT devices in the transformers to make real-time decisions with the use of AI.

Scan Welding: Thermal Modeling and Control of Material Processing

1999 ◽  
Vol 121 (3) ◽  
pp. 417-424 ◽  
Author(s):  
G. Korizis ◽  
C. Doumanidis
Keyword(s):  
Real Time ◽  
Thermal Control ◽  
Joint Surface ◽  
Material Structure ◽  
Real Time Control ◽  
Welding Temperature ◽  
Modeling And Control ◽  
Gas Tungsten Arc ◽  
Time Control ◽  
And Control

This article provides a thermal analysis of scan welding, as a redesign of classical joining methods, employing computer technology to ensure the composite morphologic, material and mechanical integrity of the joint. This is obtained by real-time control of the welding temperature field by a proper dynamic heat input distribution on the weld surface. This distribution is implemented in scan welding by a single torch, sweeping the joint surface by a controlled reciprocating motion, and power adjusted by feedback of infrared temperature measurements in-process. An off-line numerical simulation of the thermal field in scan welding is established, as well as a linearized multivariable model with real-time parameter identification. An adaptive thermal control scheme is thus implemented and validated both computationally and experimentally on a robotic Gas-Tungsten Arc Welding setup. The resulting productivity and quality features of scan welding are comparatively analyzed in terms of material structure and properties of the joint.

Modeling the Melting and Dissolution Stages During Thermal Processing of Intermetallic Coatings from Layered Precursors

2005 ◽  
Vol 127 (1) ◽  
pp. 148-156 ◽  
Author(s):  
Marios Alaeddine ◽  
Rajesh Ranganathan ◽  
Teiichi Ando ◽  
Charalabos C. Doumanidis
Keyword(s):  
Real Time ◽  
Power Distribution ◽  
Thermal Processing ◽  
Nickel Aluminide ◽  
Composite Coatings ◽  
Thermal Control ◽  
Metallographic Analysis ◽  
Plasma Arc ◽  
Aluminide Coatings ◽  
Time Basis

This paper presents a simple analytical model of the temperature and concentration dynamic distributions during thermal processing of intermetallic and metal-matrix composite coatings, such as nickel aluminide coatings on steel substrates, by melting, e.g., preplated aluminum/nickel layers using a moving heat source such as a plasma arc. Such a source of Gaussian power distribution scans the surface of the coating, giving rise to the temperature evolution and component dissolution during the thermal melting and reaction process. The model is based on a system of lumped energy and mass balances, and convolution expressions of distributed temperature and concentration Green’s fields (accounting for the orientation of their gradient and decomposing heat and mass transfer across the coating from substrate conduction), and is solved numerically in real-time. The simulation results are validated on Ni–Al coatings processed using a robotic plasma arc laboratory station, through in-process infrared thermal sensing and off-line metallographic analysis. It is shown that the predicted temperature and dissolution penetration values compare well with the experimentally obtained results, therefore supporting the model as a real-time basis for design and/or adaptation of a thermal control system for the coating process.

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.

scholarly journals Power Hardware-in-the-Loop: Response of Power Components in Real-Time Grid Simulation Environment

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 593
Author(s):  
Moiz Muhammad ◽  
Holger Behrends ◽  
Stefan Geißendörfer ◽  
Karsten von Maydell ◽  
Carsten Agert
Keyword(s):  
Real Time ◽  
Power Distribution ◽  
Control Strategies ◽  
Power Grid ◽  
Energy System ◽  
Hardware In The Loop ◽  
Distribution Grid ◽  
Compensation Strategy ◽  
Software Environment ◽  
The Real

With increasing changes in the contemporary energy system, it becomes essential to test the autonomous control strategies for distributed energy resources in a controlled environment to investigate power grid stability. Power hardware-in-the-loop (PHIL) concept is an efficient approach for such evaluations in which a virtually simulated power grid is interfaced to a real hardware device. This strongly coupled software-hardware system introduces obstacles that need attention for smooth operation of the laboratory setup to validate robust control algorithms for decentralized grids. This paper presents a novel methodology and its implementation to develop a test-bench for a real-time PHIL simulation of a typical power distribution grid to study the dynamic behavior of the real power components in connection with the simulated grid. The application of hybrid simulation in a single software environment is realized to model the power grid which obviates the need to simulate the complete grid with a lower discretized sample-time. As an outcome, an environment is established interconnecting the virtual model to the real-world devices. The inaccuracies linked to the power components are examined at length and consequently a suitable compensation strategy is devised to improve the performance of the hardware under test (HUT). Finally, the compensation strategy is also validated through a simulation scenario.

Dynamic Temperature Testing and Modeling for an Automatic Transmission Clutch

2001 ◽  
Author(s):  
Thomas DeMurry ◽  
Yanying Wang
Keyword(s):  
Experimental Data ◽  
Real Time ◽  
Automatic Transmission ◽  
Thermal Characteristics ◽  
Torque Converter ◽  
Telemetry System ◽  
Temperature Model ◽  
And Control ◽  
Good Agreement ◽  
Dynamometer Test

Abstract The primary objectives of this study are (1) to validate the hardware design and control methodologies for preserving the thermo-mechanical integrity of a launch clutch emulating a torque converter and (2) to develop a simple, control oriented clutch-temperature model that may act as a virtual thermocouple in the processor of an automobile for real-time clutch-temperature predictions. In a dynamometer test cell, a Ford CD4E transaxle is instrumented with a thermocouple-based telemetry system to investigate clutch thermal characteristics during engagements, neutral idle, single and repeated launching, torsional isolation, and hill holding. A nonlinear, SIMULINK™-based model for estimating temperature is developed. The results from the simulations are in good agreement with the experimental data.

scholarly journals Neural Spike Digital Detector on FPGA

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 392 ◽  
Author(s):  
Elia Vallicelli ◽  
Marco Reato ◽  
Marta Maschietto ◽  
Stefano Vassanelli ◽  
Daniele Guarrera ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Real Time ◽  
Power Distribution ◽  
Electrode Array ◽  
Sorting Algorithm ◽  
Noise Power ◽  
Neural Spikes ◽  
Low Snr ◽  
Analog Electronics ◽  
Digital Detector

This paper presents a multidisciplinary experiment where a population of neurons, dissociated from rat hippocampi, has been cultivated over a CMOS-based micro-electrode array (MEA) and its electrical activity has been detected and mapped by an advanced spike-sorting algorithm implemented on FPGA. MEAs are characterized by low signal-to-noise ratios caused by both the contactless sensing of weak extracellular voltages and the high noise power coming from cells and analog electronics signal processing. This low SNR forces to utilize advanced noise rejection algorithms to separate relevant neural activity from noise, which are usually implemented via software/off-line. However, off-line detection of neural spikes cannot be obviously used for real-time electrical stimulation. In this scenario, this paper presents a proper FPGA-based system capable to detect in real-time neural spikes from background noise. The output signals of the proposed system provide real-time spatial and temporal information about the culture electrical activity and the noise power distribution with a minimum latency of 165 ns. The output bit-stream can be further utilized to detect synchronous activity within the neural network.

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