Process variable

About: Process variable is a research topic. Over the lifetime, 3983 publications have been published within this topic receiving 43130 citations. The topic is also known as: process parameter.

Automatic process control device

Abstract: Automatic Process Control Device having input transistors to receive process and set point signals; a subtractive amplifier to compare the process and set point signals and produce one of two amplified deviation signals which are limited to maximum values by zener diodes; capacitors to receive, time-integrate and store the amplified and limited deviation signals, and produce a neutral output if the time-integration of the amplified and limited deviation signals is in balance, and one of two trigger signals if the time-integration of the amplified and limited deviation signals is positive or negative; and relay switches connected to discharging circuits and in series with zener diodes to receive the trigger signals and operate a controlling device upon the process to urge the process toward its desired set point, and simultaneously produce a corresponding tripping signal which urges the capacitors toward a status to produce the neutral output, such that as the controlling device is operating upon the process the Automatic Control Device is simultaneously being urged toward its neutral position, and the response of the controlling device is time-integrated to the accumulative deviation of the process. In use, the disclosed Automatic Control Device virtually eliminates "hunting", and it can also accomodate and control extreme and sudden changes ("bumping") in either the process variable or the set point without damage to the Automatic Process Control Device or its operation.

Selective optical proximity layout design data correction

Abstract: After layout design data has been modified using an OPC process, a repair flow is initiated. This repair flow includes analyzing the modified data to identify any remaining or new potential print errors in the layout data. Regions then are formed around the identified potential print errors, and a subsequent OPC process is performed only on the data within these regions using a different set of process parameters from the process parameters employed by the initial OPC process. This repair flow is iteratively repeated, where a different set of process parameter values for the subsequent OPC process is used during each iteration.

Optimization of GMAW Protocols and Parameters for Improving Weld Strength Quality Applying the Taguchi Method

Abstract: The strength value most desired in any welding process is an excellent Ultimate Tensile Strength (UTS) of the weld, compared with the parent metal. Process parameters applied during the welding process ought to be subjected to continuous scrutiny and assessment because of the ever increasing demand for structural and industrial materials with weld joints possessing higher strength values. This study is intended to investigate the inadequacies of existing GMAW welding process parameters utilized by the investigated industrial firm in its signature welding protocol, by suggesting alternative, uniquely crafted, and improved process parameters to replace its existing signature welding protocol, thereby improving the weld results by attaining higher UTS. These suggested process parameters were thereafter subjected to reported literature, following which optimization was achieved by employing the Taguchi Method. From the analysis conducted by applying the Taguchi Method, an optimum process parameter of A3 B3 C1 D1, which consists of welding current of 240A, welding time of 2.0 mins, welding speed of 0.0062 m/s, and welding voltage of 33V, was suggested. These optimum parameters were found to have an improvement of 2.32dB of the S/N ratio, and 1.11 times over the UTS of the existing process parameters. This study elucidates a step by step approach for applying the Taguchi Method. The study also shows that the use of the Taguchi Method has successfully improved on the existing process parameters, giving the industrial firm a more efficient signature welding protocol.

Analysis and Multi-objective Optimisation of Surface Modification Phenomenon by EDM Process with Copper-Tungsten Semi-sintered P/M Composite Electrodes

Abstract: In the present experimentation work, attempts have been made to model, analyse and optimise the surface modification phenomenon in electrical discharge machining process using response surface methodology. The central composite second order rotatable design has been chosen for designing the experiments and response surface methodology was applied for developing the mathematical models. Efforts has been made to correlate the four input process parameters; peak discharge current, pulse-on time, pulse-off time and tool electrode powder compaction pressure with two output responses; surface deposition rate and surface roughness. Results obtained were presented in the form of three dimensional surface plots. Analysis of variance had been performed to check the adequacy of the developed mathematical models as well as significance of each term comprising the models. Statistical software was used to construct the plots to analyse the influence of individual input process parameter on output responses. Composite desirability function approach was used for multi-objective optimisation of the developed models. Optimal parameter combinations for achieving maximum surface deposition rate and minimum surface roughness have been observed and presented in the form of contour plots. The optimal predicted results were experimentally verified, matched well with the predicted results.