Informatics Publishing Limited

A. Nandhini ¹, V. Kannan ², E. Logashanmugam ¹, B. Sheela Rani ¹, Raju Daniel ³

Affiliations
1 Sathyabama University, Sholinganallur, Chennai, Tamilnadu, IN
2 Jeppiaar Institute of Technology, Kunnam, Kanchipuram District, IN
3 Institute of Plasma Research, Bhat, Gujrat, IN

Abstract

A stable integrator of long duration up to 5s has been designed for Aditya tokamak. In tokamaks, the accurate knowledge about the plasma position has been required for maintaining the distance between plasma and in vessel component. Hence, the value of plasma current, magnetic field and magnetic flux are to be calculated by integrating signals from the magnetic pick up loops. High accuracy integrators are required for the accurate magnetic measurements for long duration signals. The proposed integrator design composed of microcontroller, DAC, integrator and ADC. This design provides a stable output for noisy and drift input signal level up to 5s. The microcontroller has been used to maintain the stability of the output signal and also eliminate the offset induced noise components.

Keywords

ADC, Drift, Integrator, Microcontroller, Plasma.

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P. Ragunathan ¹, E. Logashanmugam ¹

Affiliations
1 Sathyabama University, Jeppiar Nagar, Rajiv Gandhi Salai, Chennai - 600119, Tamil Nadu, IN

Abstract

Background/Objectives: Eddy current sensors are noncontact displacement sensors of high resolution providing measurement of the absolute position or change in position of any electrically conductive target. They are most suitable in dusty, smoky, dirty industrial environments where most other sensors would fail. This paper presents a design method and fabrication of a low cost eddy current sensor used in real time servo-control feed-back in Active magnetic Bearing. Method/Statistical Analysis: The primary functional piece of the eddy-current sensor is the sensing coil. This is a coil of wire near the end of the sensor probe. This piece of coil forms a part of an oscillator circuit there by carrying an alternating current through it which creates an alternating magnetic field. This field creates an eddy-current to flow on the target material whose distance is to be measured. This variation in field is used to sense the distance to the target. The coil is encapsulated in plastic and epoxy and housed in threaded stainless steel housing. Findings: The designed sensor has a measuring range of 0-3 mm and displacement resolution of 7 microns at a speed of 20 kHz sampling rate. This sensor was designed for the purpose of servo control feed-back in Active Magnetic Bearing System for position control. In this feedback control system we have employed a novel method of using time to digital conversion which converts the time period of the eddy current sensor’s square wave signal into digital counts using the 32bit timer counter of the enhanced capture module available in Texas Instruments C2000 controller. The digital counts give us the direct displacement value that can be used as feedback to generate the required error signal in the PID control loop. Application: The output frequency of the sensor is in the range of 700 kHz. We scale down this signal to 20 KHz by using the built-in divide by counter in the C2000 controller before feeding it to the capture module to capture the time period in a 32bit timer counter. This method of time period to digital count converter or displacement measurement helps reduce noise and errors in signal processing usually associated with ADC chips which converts analog voltage signal to digital counts.

Keywords

Active Magnetic Bearings, Eddy Current, Position Control, Servo Control.

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S. Velmurugan ¹, E. Logashanmugam ²

Affiliations
1 Department of Electronics and Communication Engineering, St. Peter’s University, Chennai - 600054, Tamil Nadu, IN
2 Department of Electronics and Communication Engineering, Sathyabama University, Chennai - 600119, Tamil Nadu, IN

Abstract

Objective: The objective of this scheme is to improve the quality of service in WSNs. Method: In this paper, we propose Detecting and Replacing Beacon Node Failure (DRBF) and Secure Communication in WSNs. DRBF focus on Beacon Node Failure and reliable data transmission in WSNs. Findings: The beacon node fails due to resource, hardware failure or some other reasons whereas the Base Station (BS) replaces that beacon node by mobile user. This mobile user acts as the beacon nodes and updates the location information to the sensor nodes. The cryptography key technique provides secure data transmission to the network. Improvement: The DRBF reduces both the packet loss rate and delay, which are shown in the simulation results.

Keywords

Beacon Node, Clustering, Key Management, Localization, Mobile User, Security.

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A. Senthil Kumar ¹, E. Logashanmugam ²

Affiliations
1 Department of Electronics and Communication Engineering, St. Peter’s University, Chennai - 600054, Tamil Nadu, IN
2 Department of Electronics and Communication Engineering, Sathyabama University, Chennai - 600119, Tamil Nadu, IN

Abstract

Security is a most significant challenge for generating a vigorous and consistent sensor networks, such as routing attacks have the capability to separate or isolate a sensor network from its Base Station (BS). Routing misbehavior in the network is that some malicious nodes will play in the route discovery and maintenance process but refuses to forward the data packets. In this paper, we propose Secure Acknowledgement (S-ACK) based Routing Misbehavior Detection in Wireless Sensor Networks (WSN). Objective: The objective of this scheme is to identify the node misbehavior and reduce the overhead in WSN. Methods/Statistical Analysis: This scheme consists of 3 phase such as Acknowledgement (ACK) phase, Secure Acknowledgement (S-ACK) phase and (Misbehavior Verification) MV phase. If the source does not get the acknowledgement from the destination during ACK phase, the source sent the S-ACK packet to the S-ACK phase. S-ACK phase generates the misbehavior report. The Misbehavior Verification phase verifies the misbehavior report is authenticated or not. Finding: The proposed misbehavior detection scheme is capable to attain high detection accuracy for routing attacks. Application/Improvements: The simulation result implies that the SACK provides better Packet Delivery Rate and reduces end-to-end delay.

Keywords

Acknowledgement, Misbehavior Detection, Misbehavior Verification, WSNs.

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D. Jayakumar ¹, E. Logashanmugam ²

Affiliations
1 Department of ECE, St. Peter’s University Chennai - 600054 , Tamil Nadu, IN
2 Department of ECE, Sathyabama University, Chennai - 600119, Tamil Nadu, IN

Abstract

Objectives: FFT algorithm is used for enhancing the performance of DFT.In the previous years, various types of FFT algorithms have been introduced. Particularly, the pipeline algorithms have been reputed as proper algorithms for processing high-speed data. Some pipeline FFT algorithms like split radix, radix-2 and the mixed radix have been developed. Methods: In the existing method of Radix-2 SDF FFT has more hardware utilization and also computational stages are increased. Findings: To conquer this problem, we developed a combined radix-2, 4 & 8 butterfly elements based Single path Delay Feedback (SDF) fast fourier transform method for reducing the computational stages in this paper. The developed method has the identical number of multipliers and the smaller number of stages and butterfly elements than the existing radix-2 FFT. Improvements: This architecture offers 62.47% reduction in LUTs, 58.78% reduction in slices, and 37.85% reduction in delay and 30.86% reduction in power consumption than the existing method.

Keywords

Discrete Fourier Transform (DFT), Fast Fourier Transform (FFT), Look Up Tables (LUTs), Single path Delay Feedback (SDF).

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