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Pneumatic motors have several advantages and have many robotics and automation applications. The importance of the study is that it is a cheap and possible way to apply it to the fixed displacement pneumatic motors with simple directional control valve used. The purpose of the addition to any traditional pneumatic motors is to change the fixed displacement pneumatic motor to be variable speed and torque compared to the expensive systems such as the proportional control valve in many industrial applications. The study also included validated simulations using the Automation Studio program to control the pneumatic motor's speed and torque. In addition, the results showed remarkable success in controlling the pneumatic motor outputs depending on the frequency of the compressed air-source pulses and pressure. The pulsating air frequencies of 1.5, 3, and 4.5 Hz were considered at different inlet source pressure changes from 1.72, 3.45, and 5.17 bar. As the pulsating flow frequency of compressed air decreased from 4.5, 3, and 1.5 Hz, the motor pressure and torque decreased. Furthermore, empirical correlations related to frequency and pressure effect have been developed. The error is 6.3–9.5% in predicting the motor speed and torque outputs. The limitation of the proposed method in real-life applications is about a maximum of 7.5 bar. On the other hand, the frequency is limited to 9 Hz using a mechanical solenoid. [ABSTRACT FROM AUTHOR]

In this article, the wire electrical discharge machining of different heights of die steel workpieces has been carried out for different control strategies, i.e. proportional control mode, constant speed mode, constant voltage mode, and constant area feeding mode. It is very crucial to understand the thermo-mechanical aspect of the machining gap during machining of changing job height. For the efficient machining of variable thickness of jobs, these observations are extremely essential. Here, it is observed how job height influences cutting speed, surface roughness, kerf width, gap voltage, gap current, input power, and specific energy consumption under these control strategies. So far, very little research work has been reported in this area. Thus, it is quite imperative to carry out an intensive research study of wire electrical discharge machining (WEDM) during machining of different job thickness under those control strategies. An attempt has been made to understand the nature of variation of these important response parameters. The average and variance of some of the most influential parameters, i.e., cutting speed, surface finish, and kerf width were also calculated. Along with this, to predict the different important response parameters, i.e., cutting speed, surface finish, and kerf width for any given height job under any specified control strategy, regression analysis was carried out. [ABSTRACT FROM AUTHOR]

This work is dedicated to the synthesis of a new fault detection and identification scheme for the actuator and/or sensor faults modeled as unknown inputs of the system. The novelty of this scheme consists in the synthesis of a new structure of proportional-integral observer (PIO) reformulated from the new linear ARX-Laguerre representation with filters on system input and output in order to estimate the unknown inputs presented as faults. The designed observer exploits the input/output measurements to reconstruct the Laguerre filter outputs where the stability and the convergence properties are ensured by using Linear Matrix Inequality. However, a significant reduction of this model is subject to an optimal choice of both Laguerre poles which is achieved by a new proposed identification approach based on a genetic algorithm. The performances of the proposed identification approach and the resulting PIO are tested on numerical simulation and validated on a 2 order electrical linear system. [ABSTRACT FROM AUTHOR]

Recent research is recognizing that multiple criteria analysis should take account of the concepts of uncertainty and risk. In some cases, precise determination of the exact value of alternatives and weights of criteria is difficult. Consequently, to deal with these potential problems, their values are regarded as fuzzy and intervals. This paper proposes an interval-valued fuzzy multiple criteria complex proportional assessment (IVF-COPRAS) method that can reflect both a subjective judgment and objective information in real-life situations. In this method, the performance rating values versus selected criteria as well as the weights of conflicting criteria are linguistic variables represented by interval-valued triangular fuzzy numbers. Moreover, performances of alternatives against subjective criteria are described via linguistic variables and then transformed into interval-valued triangular fuzzy numbers. Finally, an application example for the robot selection problem is given in this paper to show this decision-making steps and the effectiveness of the proposed method in manufacturing companies. [ABSTRACT FROM AUTHOR]