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Saravanakumar Devaraj

Bio: Saravanakumar Devaraj is an academic researcher from VIT University. The author has contributed to research in topics: Composite number & Heat exchanger. The author has an hindex of 1, co-authored 1 publications receiving 5 citations.

Papers
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Proceedings ArticleDOI
13 Nov 2015
TL;DR: In present research, a system comprising of two pneumatic cylinders attached to each other is used and a fuzzy based control system has been designed for servo position control of the system.
Abstract: Pneumatic systems exhibits many advantages including high speed and better efficiency. Servo pneumatic system enables the pneumatic system to be employed in varying position applications such as robots. There will be always a compromise between the speed and allowable overshoot in determining the parameters of the system based on the applications. In present research, a system comprising of two pneumatic cylinders attached to each other is used. A small cylinder which is used to for fine adjustments in accuracy is mounted on the rod end of the large cylinder which travels the coarse movement. This system reduces the overshoot of the system without much reduction in speed. Mathematical model of the system comprising of motion dynamics, pressure and temperature dynamics inside cylinder chambers and mass flow variation in the valves are derived from the physical laws and recent literature information. Based on the mathematical model, a simulation model of the system is created in the Matlab-Simulink software. A fuzzy based control system has been designed for servo position control of the system. The simulation model is validated using the experimental results. The energy efficiency of the system is computed from the overall power developed in the system and cumulative air power supplied to the system. The analysis of the dynamics of the system while tracking a sinusoidal signal is taken as a task for analyzing the energy efficiency of the system. The energy efficiency of the system has been analyzed for various sizes of cylinders, various supply pressure levels to both the cylinders in the system and various applied loads to the system. To reduce the number of experiments to be conducted, a Taguchi based design of experiments is carried out. A statistical analysis has been made for analyzing the variation of energy efficiency with the above parameters. From the study, external load affects the energy efficiency in a considerable way which has 54.39% of the overall contribution. The second dominant factor on influencing energy efficiency is supply pressure to cylinder A which has the contribution of 23.65%.Copyright © 2015 by ASME

5 citations

Journal ArticleDOI
TL;DR: In this paper , the authors used decision trees, random forests, naive Bayes, and Bayes net algorithms to diagnose the delamination in laminated composite structures using structural health monitoring techniques.
Abstract: Delamination in laminated structures is a concern in high-performance structural applications, which challenges the latest non-destructive testing techniques. This study assesses the delamination damage in the glass fiber-reinforced laminated composite structures using structural health monitoring techniques. Glass fiber-reinforced rectangular laminate composite plates with and without delamination were considered to obtain the forced vibration response using an in-house developed finite element model. The damage was diagnosed in the laminated composite using machine learning algorithms through statistical information extracted from the forced vibration response. Using an attribute evaluator, the features that made the greatest contribution were identified from the extracted features. The selected features were further classified using machine learning algorithms, such as decision tree, random forest, naive Bayes, and Bayes net algorithms, to diagnose the damage in the laminated structure. The decision tree method was found to be a computationally effective model in diagnosing the delamination of the composite structure. The effectiveness of the finite element model was further validated with the experimental results, obtained from modal analysis using fabricated laminated and delaminated composite plates. Our proposed model showed 98.5% accuracy in diagnosing the damage in the fabricated composite structure. Hence, this research work motivates the development of online prognostic and health monitoring modules for detecting early damage to prevent catastrophic failures of structures.

3 citations


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Journal ArticleDOI
TL;DR: A mode-switching sliding controller with the nonlinear gain generated by a fuzzy logic controller is put forward to enhance the tracking performance in an electro-pneumatic position control system which includes four solenoid ON–OFF valves and a double rod-end cylinder.
Abstract: In this paper, a mode-switching sliding controller with the nonlinear gain generated by a fuzzy logic controller is put forward to enhance the tracking performance in an electro-pneumatic position control system which includes four solenoid ON–OFF valves and a double rod-end cylinder. The proposed method is designed to increase the response speed and reduce the overshoots by utilizing the nonlinear gain which is determined by a fuzzy logic controller. In addition, several improvements are made in the mode-switching sliding controller originally from previous works. The mode-switching strategy is totally redesigned and a hysteresis control scheme is introduced to the new mode-switching sliding controller. Moreover, the improved controller is properly combined with the fuzzy nonlinear gain. Simulation and experiments with various kinds of input are carried out to verify the effectiveness of the proposed method. All the experiments are conducted on a field programmable gate array platform, and the experimental results validate the reliability of the novel scheme.

17 citations

Journal ArticleDOI
TL;DR: In this novel hybrid control scheme, an original approach named Time Interlaced Modulation is developed to replace the traditional Pulse Width Modulation (PWM) approach and a new switching method which is referred as seven possible control modes is designed to ensure the proper switching states of the valves.
Abstract: In this paper, a novel hybrid control scheme is proposed to improve the control performance in a real-time pressure tracking system using fast on-off solenoid valves. In this novel hybrid control s...

11 citations

Journal ArticleDOI
22 Oct 2019-Energies
TL;DR: In this paper, a fuzzy logic based volume flow control method is proposed to precisely control the force of a pneumatic actuator in an electro-pneumatic system including four on-off valves.
Abstract: In this paper, a fuzzy logic based volume flow control method is proposed to precisely control the force of a pneumatic actuator in an electro-pneumatic system including four on-off valves. The volume flow feature, which is the relationship between the duty cycle of the pulse width modulation (PWM) period, pressure difference, and volume flow of an on-off valve, is based on the experimental data measured by a high-precision volume flow meter. Through experimental data analysis, the maximum and minimum duty cycles are acquired. A new volume flow control method is introduced for the pneumatic system. In this method, the raw measured data are innovatively processed by a segmented, polynomial fitting method, and a newly designed procedure for calculating the duty cycle is adopted. This procedure makes it possible to combine the original data with fuzzy logic control (FLC). Additionally, the method allows us to accurately control the minimum and maximum opening pulse width of the valve. Several experiments are performed based on the experimental data, instead of the traditional theoretical models. Only 0.141 N (1.41%) overshoot and 0.03 N (0.03%) steady-state error are observed in the step response experiment, and 0.123 N average error is found while tracking the sine wave reference.

10 citations

Journal ArticleDOI
TL;DR: A fuzzy based position control system for the interconnected pneumatic cylinders system has been developed and implemented and the disturbance avoidance and trajectory tracking characteristics of the system have been studied.
Abstract: Pneumatic systems are widely used in industries as they possess many advantages such as high speed and better efficiency. The main problem in the pneumatic servo drives is large overshoots due to its high speed. In the design of such pneumatic servo drives, a trade-off between speed and accuracy is common. To overcome this issue, a new design of a positioning system using interconnection of two pneumatic cylinders is presented in this paper. The interconnected system using two pneumatic cylinders for fast and accurate positioning has been design and implemented. A fuzzy based position control system for the interconnected pneumatic cylinders system has been developed and implemented. The disturbance avoidance and trajectory tracking characteristics of the system has been studied. The performance of the positioning ability of the proposed system with interconnected pneumatic cylinders is compared with the conventional servo pneumatic system with single cylinder. The step response characteristics shows that interconnected pneumatic cylinders system exhibits 13.8% more rise time but the overshoot is reduced 28.8% compared to conventional single cylinder servo pneumatic system with supply pressure 0.6 MPa. The sinusoidal responses shows that band width of the interconnected pneumatic cylinder remains almost near the conventional single cylinder servo pneumatic system with supply pressure 0.6 MPa.

8 citations

Journal ArticleDOI
TL;DR: An intelligent phase-change PWM strategy for a position tracking system which includes four solenoid on–off valves and a double-acting double-rod-end cylinder is presented to minimize the tracking errors and improve the position tracking performance.
Abstract: This paper presents an intelligent phase-change PWM strategy for a position tracking system which includes four solenoid on–off valves and a double-acting double-rod-end cylinder. The proposed technique is designed to minimize the tracking errors and improve the position tracking performance. For an electro-pneumatic system with four valves, only seven switching modes are considered valid. We initially set two switching modes in a pulse width modulation (PWM) period, and this method can also be regarded as a PWM method with changeable phases. In the complete strategy, the operating mode of the system will be selected according to the pressure state and the sliding function. All the switching modes are applied properly in the strategy. A sliding mode controller is designed to utilize the phase-change PWM strategy, and stability of the system is proved. The performance of the proposed strategy is experimentally verified on a field programmable gate array platform. All simulations and experiments verify the effectiveness of the proposed scheme.

5 citations