Department of Electrical Engineering

&ldquo;IIT Jodhpur is committed to impart quality education to facilitate the creation of qualified, competent and responsible human resources to meet the emerging technological challenges of the world. It is working towards creating an equitable learning platform that is positive, accessible and effective in the face of the modern societal and scientific advancements.

Flexibility in curriculum, in all its academic programs, encompassing elements of teaching, research, creativity, innovation and entrepreneurship is the most unique feature of IIT Jodhpur. The Department of Science and Technology (DST), under the National Mission on Cyber Physical Systems, has identified IIT Jodhpur as a Technology &amp; Innovation Hub in the area of Augmented Reality and Virtual Reality. The institute has also been nominated as the coordinator for the Jodhpur City and Knowledge Cluster by the Office of Principal Scientific Adviser, Government of India.

The sprawling 852-acre IIT Jodhpur campus is a majestic tribute to the deep-rooted diverse cultural heritage of the region. The campus is an architectural masterpiece, which is slated to become an international exemplar of sustainability with net-zero energy, and advanced water and waste management strategies.&rdquo;

IIT Jodhpur

The present paper describes an integrated approach for design, fabrication and encapsulation of RF MEMS switches in view of the optimal performance subsequent to packaging. ‘Top and bottom contact’ fabrication approaches are explored using different RF MEMS switch topologies. In the ‘bottom contact package (BCP)’ the packaging cap alignment is less critical as compared to the top contact packaging (TCP) approach where contact via is an integral part of the cap. In this case, the connection layout through silicon via holes is independent of the cavity geometry. For the devices under consideration, bulk etched silicon cavity height has been optimized to 50 μm for optimal RF performance, e.g., isolation and insertion loss. Parasitic effects of top silicon cap are reduced by altering CPW impedance. Mechanical parameter damping is simulated for different cavity heights and found to be independent from cavity height after 20 μm onwards. © 2014, Electromagnetics Academy. All rights reserved.

World University root node

Progress In Electromagnetics Research M

Comparison of packaging technologies for RF MEMS switch

The main objective of this paper is to study and analyze the power supply stage of a series-series (SS) fixed-frequency inductive power transfer (IPT) system, in order to suggest effective soft switching techniques to improve its performance. Because of the characteristics of the system, zero voltage switching (ZVS) operation was used and three control strategies were compared: phase-shift (PS) control, asymmetrical duty cycle (ADC) control and optimal asymmetrical voltage cancellation (o AVC) control. The o AVC control is found to be more efficient for this application. Additionally, this paper presents an inductive power transfer transformer (IPTT) prototype that was built in the laboratory, which helped validate the theoretical analysis and simulation results with practical tests. The plots and circuit simulations were obtained from MATLAB and SIMULINK respectively. © 2014 IEEE.

IECON Proceedings (Industrial Electronics Conference)

Asymmetrical voltage-cancellation control for a series-series fixed-frequency inductive power transfer system

This paper presents a top-down design methodology for the design of EBG structures meeting design targets identified in terms of S/Z parameters. The design of EBG structures are based on multiple design considerations of central cell structures as well as cell to cell interconnect structures. Possible iterations of cell structures and cell to cell interconnects are captured in libraries for design trade-offs. The RLGC first order based approach followed by precise s-parameter models extraction (2.5D/3D) is proposed in this paper. RLC libraries created are generic and reusable for top-down design methodology. This methodology is generic and has high value add in terms of systematic EBG design, cost consideration and design trade-offs. Further library augmentation, flow automation can be applied and this flow can be offered as a design tool. Methodology validation is carried out by one real design case wherein fabricated structure results (S11, Z11) are correlated with the mentioned design flow. The real design case EBG structure is having stop-band from 750 MHz to 5.10 GHz with isolation better than -30 dB and target impedance of around 0.5 ohm up- To 200 MHz. A close correlation is achieved with s-parameter using the top-down design methodology and measured results.

DesignCon 2014: Where the Chip Meets the Board

Top-down design methodology for enhanced electromagnetic band-gap structures

This letter establishes the computational complexity savings that a properly positioned single bit of feedback can provide in the computationally intense setting of quasi-static MIMO communications. Specifically, this letter identifies novel practically constructed feedback schemes and explicit and non-random multiple-input multiple-output (MIMO) encoding-decoding schemes that, in the presence of a single bit of feedback, jointly guarantee the optimal diversity-multiplexing tradeoff (DMT) with a polynomial time complexity. Going one step further, this letter also presents an opportunistic communication scheme that, at all rates including rates close to the maximum multiplexing gain, can provide near-ergodic reliability at just polynomial time computational complexity costs. This is the best known computational complexity that suffices to achieve near-ergodic reliability in the quasi-static MIMO settings.

IEEE Wireless Communications Letters

Achieving ergodicity in quasi-static MIMO with polynomial-time complexity and one bit of feedback

Robustness to unmatched parametric uncertainty is prime requirement of roll control algorithm, especially when it is modelled in discrete time domain and implemented through on-board processor. Sliding mode control is a well established nonlinear control technique, which ensures a robust performance in presence of matched uncertainties and disturbances. In case of the discrete version of sliding mode control, due to finite operational sampling frequency, the system trajectories cannot be forced to slide on the switching manifold. The trajectories remain confined to certain domain around the sliding surface and this is known as Quasi Sliding Mode (QSM) motion. The bound of QSM decides the accuracy and performance of the discrete version of sliding mode. By design, the discrete-time sliding modes are robust to the matched bounded perturbations, however, unmatched perturbations directly affect the boundary layer width and hence the performance of the system. In the present paper, discrete time Lyapunov inequality based sliding hyperplane is designed, which enables robustness to unmatched perturbations arising due to uncertain system matrix A. Further, the requirement of full state-vector for the design of control and sliding surface is met through the multi-rate output feedback (MROF). This control strategy is then demonstrated with application to roll position control of missile with a bandwidth limited actuator. © 2013 The Franklin Institute.

Journal of the Franklin Institute

Roll control using discrete-time robust sliding hyperplanes and fast output sampling

This paper addresses the flow control design of a connection-oriented communication network from the robust control theory perspective. Network is modelled as a n th order discrete system whose first order model is obtained using the two-time scale property associated with the process. The proposed scheme is characterised by an equivalent control based discrete sliding mode design for the first order model which is applied to n th order systems through aggregation. Besides its design simplicity, the proposed method exhibits finite time convergence property for the states while applied to the full order system emulating the characteristics of terminal sliding mode in a certain way. Simulation results via Matlab and ns-2 validate the efficacy of the proposed algorithm as an effective flow controller for connection-oriented networks. © 2014 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

Finite-time sliding mode flow control design via reduced model for a connection-oriented communication network

The paper presents a new method for higher order sliding mode control using control Lyapunov function for chain of integrator system with nonlinear uncertainties. The stability proof of the suggested scheme is analyzed in terms of two Lyapunov functions using appropriate switching function. Using these Lyapunov functions and switching scheme it is proved that, output and its higher order derivatives converge to origin in finite time. Simulation results illustrate the efficacy of the method. © 2014, World Scientific and Engineering Academy and Society. All rights reserved.

WSEAS Transactions on Systems and Control

Higher order sliding mode control: A control lyapunov function based approach

Implementation of the Super-Twisting Control (STC) requires the first time derivative of the sliding surface must be Lipschitz in time. It is shown that if we will use STC based on the absolutely continuous estimation of the surface, controller can not be implemented. In this paper two methodologies are proposed to avoid the above problem. For simplicity we are considering here only perturbed double integrator which can be generalized for an arbitrary order. Numerical simulations are also presented to show the effectiveness of the proposed method. © 2014 IEEE.

Proceedings of IEEE Workshop on Applications of Computer Vision

How to implement Super-Twisting Controller based on sliding mode observer?

Machine Learning (ML) is a powerful tool to support the development of objective visual quality assessment metrics, serving as a substitute model for the perceptual mechanisms acting in visual quality appreciation. Nevertheless, the reliability of ML-based techniques within objective quality assessment metrics is often questioned. In this study, the robustness of ML in supporting objective quality assessment is investigated, specifically when the feature set adopted for prediction is suboptimal. A Principal Component Regression based algorithm and a Feed Forward Neural Network are compared when pooling the Structural Similarity Index (SSIM) features perturbed with noise. The neural network adapts better with noise and intrinsically favours features according to their salient content. © 2014 EURASIP.

European Signal Processing Conference

Robustness and prediction accuracy of Machine Learning for objective visual quality assessment

Many saliency detection models for 2D images have been proposed for various multimedia processing applications during the past decades. Currently, the emerging applications of stereoscopic display require new saliency detection models for salient region extraction. Different from saliency detection for 2D images, the depth feature has to be taken into account in saliency detection for stereoscopic images. In this paper, we propose a novel stereoscopic saliency detection framework based on the feature contrast of color, luminance, texture, and depth. Four types of features, namely color, luminance, texture, and depth, are extracted from discrete cosine transform coefficients for feature contrast calculation. A Gaussian model of the spatial distance between image patches is adopted for consideration of local and global contrast calculation. Then, a new fusion method is designed to combine the feature maps to obtain the final saliency map for stereoscopic images. In addition, we adopt the center bias factor and human visual acuity, the important characteristics of the human visual system, to enhance the final saliency map for stereoscopic images. Experimental results on eye tracking databases show the superior performance of the proposed model over other existing methods. © 2014 IEEE.