Prof. Balakumar Balachandran Profile

Prof. Balakumar Balachandran

at Univ of Maryland, College Park

SPIE Involvement:

Author

Publications (30)

Proceedings Article | 17 April 2013 Paper

Error analysis of the extended Kalman filter applied to the simultaneous localization and mapping problem

R. Jaai, N. Chopra, B. Balachandran, H. Karki

Proceedings Volume 8695, 86950M (2013) https://doi.org/10.1117/12.2009924

KEYWORDS: Error analysis, Complex systems, Sensors, Matrices, Process modeling, Radon, Motion models, Astatine, Mobile robots, Filtering (signal processing)

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Proceedings Article | 3 April 2012 Paper

Simultaneous localization and mapping with consideration of robot system dynamics

R. Jaai, N. Chopra, B. Balachandran, H. Karki

Proceedings Volume 8345, 83451F (2012) https://doi.org/10.1117/12.914982

KEYWORDS: Motion models, Error analysis, Sensors, Robotic systems, Kinematics, Robotics, Feature extraction, Motion estimation, Environmental sensing, Time metrology

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Proceedings Article | 14 April 2011 Paper

Decentralized multi-robot simultaneous localization and mapping

R. Jaai, N. Chopra, B. Balachandran, H. Karki

Proceedings Volume 7981, 798126 (2011) https://doi.org/10.1117/12.880516

KEYWORDS: Sensors, Telecommunications, Systems modeling, Data communications, Mechanical engineering, Surveillance, Robotic systems, Environmental sensing, Environmental monitoring, Pollution control

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Proceedings Article | 1 April 2010 Paper

Noise effects on localization of mobile sensor platforms

Nikhil Chopra, Balakumar Balachandran, Hamad Karki

Proceedings Volume 7647, 76471N (2010) https://doi.org/10.1117/12.847605

KEYWORDS: Sensors, Error analysis, Distance measurement, Mechanical engineering, Numerical simulations, Inspection, Dynamical systems, Environmental monitoring, Environmental sensing, Analytical research

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Proceedings Article | 31 March 2008 Paper

Pre- and post-machining and release residual stresses in microelectromechanical systems (MEMS)

Mary Vechery, Andrew Dick, B. Balachandran, Madan Dubey

Proceedings Volume 6931, 69310B (2008) https://doi.org/10.1117/12.776262

KEYWORDS: Resonators, Thin films, Microelectromechanical systems, Semiconducting wafers, Microresonators, Data modeling, Ferroelectric materials, Remote sensing, Platinum, Thin film devices

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A major concern in the development of microelectromechanical systems (MEMS) is the presence of residual stress. This stress, which is produced during the fabrication of multi-layer thin-film structures, can significantly affect the performance of micro-scale devices. Though experimental measurement techniques are accurate, actual stress measurements can vary dramatically from run to run and wafer to wafer. For this reason, the modeling of this stress can be a challenging task. Past work has often focused on experimental, static techniques for determining residual-stress levels in single-layer and bi-layer structures. In addition, in prior studies, the focus has primarily been on residual-stress measurements in thin films as they are being deposited and prior to the release of a particular device. In this effort, residual stresses in MEMS resonators are characterized pre- and post-micro-machining and release of the structures. This is accomplished by applying three residual-stress identification techniques. The first technique, which is based on wafer-bow measurements and Stoney's formula, is suited for determining the residual stresses in thin film layers as they are being deposited and before the occurrence of a micro-machining or release process. In the second technique, a static parametric identification technique, device deflection data is made use of to approximate individual device residual stress immediately after release of a structure. The third technique, a dynamic parametric identification technique, which can be based on linear or nonlinear frequency response data can be used to estimate device residual stress immediately after release and after the device has been polarized. The results obtained by using these techniques are used to develop an understanding of how geometry, fabrication, release and polarization of resonators affect the stress state in a piezoelectric device. The results, which show that the stress levels can be quite different after a device has been released and poled, point to the importance of considering parameter identification schemes such as those described in this effort for identifying residual stresses in multi-layer, micro-structures.

Proceedings Article | 18 April 2007 Paper

Adaptive control of vibration transmission in a strut system

C-M. Liao, D. Roy Mahapatra, B. Balachandran

Proceedings Volume 6523, 65230Q (2007) https://doi.org/10.1117/12.715972

KEYWORDS: Actuators, Digital filtering, Filtering (signal processing), Adaptive control, Mechanics, Control systems, Optical filters, Electronic filtering, Computing systems, Aluminum

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Proceedings Article | 11 April 2007 Paper

Comparison of techniques for measurement of residual stresses in multilayered micro-electro-mechanical devices

Mary Vechery, A. Dick, B. Balachandran, M. Dubey

Proceedings Volume 6528, 65280D (2007) https://doi.org/10.1117/12.715692

KEYWORDS: Resonators, Semiconducting wafers, Thin films, Microelectromechanical systems, Composites, Ferroelectric materials, Measurement devices, Platinum, Microresonators, Thin film devices

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Proceedings Article | 27 March 2006 Paper

Nonlinear vibration modes in micro-resonator arrays

Andrew Dick, Balakumar Balachandran, C. Daniel Mote

Proceedings Volume 6166, 61660N (2006) https://doi.org/10.1117/12.650113

KEYWORDS: Oscillators, Resonators, Microresonators, Complex systems, Microelectromechanical systems, Solids, Solid state physics, Signal processing, Silicon, Ferroelectric materials

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Proceedings Article | 27 March 2006 Paper

Active control of dispersive waves: coupling finite-dimensional control system using isospectra

D. Roy Mahapatra, B. Balachandran

Proceedings Volume 6166, 61661L (2006) https://doi.org/10.1117/12.658892

KEYWORDS: Control systems, Control systems design, Wave propagation, Feedback control, Signal attenuation, Sensors, Actuators, Waveguides, Systems modeling, Composites

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Proceedings Article | 19 May 2005 Paper

Computational multi-field mechanics model of piezoelectric micro-resonators

Sergio Preidikman, Balakumar Balachandran

Proceedings Volume 5757, (2005) https://doi.org/10.1117/12.599146

KEYWORDS: Resonators, Microresonators, Electrodes, Microelectromechanical systems, Composites, Finite element methods, Sensors, Mechanics, Connectors, Systems modeling

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Proceedings Article | 19 May 2005 Paper

Nonlinear analysis of sensor diaphragm under initial tension

Miao Yu, B. Balachandran, X.-H. Long

Proceedings Volume 5757, (2005) https://doi.org/10.1117/12.599945

KEYWORDS: Sensors, Protactinium, Fiber optics sensors, Mechanical engineering, Mechanics, Bessel functions, Nonlinear response, Fiber optic components, Silicon, Piezoresistive sensors

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Proceedings Article | 19 May 2005 Paper

Nonlinear forced oscillations of piezoelectric resonators

H. Li, S. Preidikman, B. Balachandran

Proceedings Volume 5757, (2005) https://doi.org/10.1117/12.597950

KEYWORDS: Resonators, Composites, Microelectromechanical systems, Laser resonators, Microresonators, Electrodes, Complex systems, Platinum, Ferroelectric materials, Beam shaping

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Proceedings Article | 1 August 2003 Paper

Relaxed zero spillover controller for active structural acoustic control systems

Moustafa Al-Bassyiouni, Balakumar Balachandran

Proceedings Volume 5049, (2003) https://doi.org/10.1117/12.482724

KEYWORDS: Actuators, Sensors, Acoustics, Control systems, Signal attenuation, Interference (communication), Ferroelectric polymers, Linear filtering, Amplifiers, Ferroelectric materials

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Proceedings Article | 15 July 2002 Paper

Experimental study of model-based feedforward control of longitudinal wave transmission through hollow cylinders

Ion Pelinescu, Balakumar Balachandran

Proceedings Volume 4701, (2002) https://doi.org/10.1117/12.474677

KEYWORDS: Actuators, Sensors, Control systems, Digital signal processing, Signal attenuation, Finite element methods, Model-based design, Modal analysis, Interfaces, Chemical elements

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Proceedings Article | 10 July 2002 Paper

Fiber optic sensors for active acoustics control

Moustafa Al-Bassyiouni, Miao Yu, Balakumar Balachandran, Jae-Eung Oh

Proceedings Volume 4693, (2002) https://doi.org/10.1117/12.475236

KEYWORDS: Sensors, Acoustics, Fiber optics sensors, Modulators, Fabry–Perot interferometers, Particles, Prototyping, Velocity measurements, Demodulation, Fiber optics

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Proceedings Article | 21 August 2001 Paper

Zero-spillover control of enclosed sound fields

Moustafa Al-Bassyiouni, Balakumar Balachandran

Proceedings Volume 4326, (2001) https://doi.org/10.1117/12.436515

KEYWORDS: Actuators, Sensors, Scanning probe lithography, Control systems, Interference (communication), Ferroelectric polymers, Ferroelectric materials, Acoustics, Device simulation, Systems modeling

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Proceedings Article | 16 August 2001 Paper

Experimental study of active control of wave transmission through hollow cylindrical struts

Ion Pelinescu, Balakumar Balachandran

Proceedings Volume 4327, (2001) https://doi.org/10.1117/12.436517

KEYWORDS: Actuators, Feedback control, Control systems, Algorithm development, Sensors, Systems modeling, Vibration control, Direct methods, Double positive medium, Mechanics

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Proceedings Article | 22 June 2000 Paper

Analytical and experimental investigations into active control of wave transmission through gearbox struts

Ion Pelinescu, Balakumar Balachandran

Proceedings Volume 3985, (2000) https://doi.org/10.1117/12.388866

KEYWORDS: Actuators, Sensors, Finite element methods, Modal analysis, Control systems, Systems modeling, Vibration control, Interfaces, Ions, Ferroelectric polymers

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Proceedings Article | 19 June 2000 Paper

Actuator nonlinearities in interior acoustics control

Balakumar Balachandran, M. Zhao

Proceedings Volume 3984, (2000) https://doi.org/10.1117/12.388755

KEYWORDS: Actuators, Ferroelectric materials, Acoustics, Complex systems, Data modeling, Interfaces, Curium, Control systems, Dielectrics, Shape analysis

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Proceedings Article | 9 June 1999 Paper

Control of flexural wave transmission through struts

Douglas Ortel, Balakumar Balachandran

Proceedings Volume 3668, (1999) https://doi.org/10.1117/12.350734

KEYWORDS: Actuators, Wave propagation, Signal attenuation, Control systems, Systems modeling, Mechanics, Matrices, Feedback control, Smart structures, System integration

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Proceedings Article | 9 June 1999 Paper

Control of wave transmission through struts

Ion Pelinescu, Balakumar Balachandran

Proceedings Volume 3668, (1999) https://doi.org/10.1117/12.350761

KEYWORDS: Actuators, Magnetism, Mechanics, Phase shifts, Numerical simulations, Vibration control, Wave propagation, Magnetostrictive materials, Signal attenuation, Adaptive control

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Proceedings Article | 4 June 1999 Paper

Nonlinear oscillations of a plate with piezoceramic patches

Balakumar Balachandran, M. Zhao

Proceedings Volume 3667, (1999) https://doi.org/10.1117/12.350113

KEYWORDS: Actuators, Ferroelectric materials, Complex systems, Acoustics, Control systems, Interfaces, Curium, Dielectrics, Shape analysis, Mechanical engineering

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Proceedings Article | 31 May 1999 Paper

Bragg-grating-based Fabry-Perot sensor system for acoustic measurements

Christopher Baldwin, Miao Yu, Craig Miller, James Sirkis, Steve Chen, Balakumar Balachandran

Proceedings Volume 3670, (1999) https://doi.org/10.1117/12.349745

KEYWORDS: Sensors, Acoustics, Fiber Bragg gratings, Fabry–Perot interferometers, Control systems, Multiplexing, Optical sensors, Demodulation, Modulation, Interferometers

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Proceedings Article | 27 July 1998 Paper

Active control of multiple tones transmitted into an enclosure

Chang Ahn, Balakumar Balachandran

Proceedings Volume 3329, (1998) https://doi.org/10.1117/12.316897

KEYWORDS: Actuators, Sensors, Optical filters, Ferroelectric materials, Control systems, Denoising, Filtering (signal processing), Electronic filtering, Acoustics, Adaptive control

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Proceedings Article | 27 July 1998 Paper

Active control of vibration transmission through struts

Ion Pelinescu, Balakumar Balachandran

Proceedings Volume 3329, (1998) https://doi.org/10.1117/12.316929

KEYWORDS: Actuators, Mechanics, Chemical elements, Vibration control, Phase shifts, Wave propagation, Numerical simulations, Electrodes, Control systems, Motion models

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Proceedings Article | 16 April 1998 Paper

Active acoustics control

Balakumar Balachandran, Arun Sampath

Proceedings Volume 3321, (1998) https://doi.org/10.1117/12.305572

KEYWORDS: Sensors, Actuators, Acoustics, Scanning probe lithography, Ferroelectric polymers, Denoising, Control systems, Ferroelectric materials, Optical filters, Filtering (signal processing)

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Proceedings Article | 6 June 1997 Paper

Active interior acoustics control of bandlimited disturbances

Arun Sampath, Balakumar Balachandran

Proceedings Volume 3041, (1997) https://doi.org/10.1117/12.275641

KEYWORDS: Sensors, Actuators, Acoustics, Ferroelectric materials, Ferroelectric polymers, Electronic filtering, Numerical simulations, Denoising, Scanning probe lithography, Aluminum

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Proceedings Article | 1 May 1996 Paper

Active structural acoustic control of band-limited disturbances

Arun Sampath, Balakumar Balachandran

Proceedings Volume 2717, (1996) https://doi.org/10.1117/12.239045

KEYWORDS: Actuators, Sensors, Control systems, Ferroelectric materials, Scanning probe lithography, Acoustics, Denoising, Electronic filtering, Digital signal processing, Digital filtering

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Proceedings Article | 1 May 1996 Paper

Structural intensity calculations for active control of plate vibrations

Mei Jin, Balakumar Balachandran

Proceedings Volume 2717, (1996) https://doi.org/10.1117/12.239043

KEYWORDS: Ferroelectric materials, Actuators, Vibration control, Active vibration control, Aluminum, Sensors, Dielectrics, Protactinium, Smart materials, Mechanical engineering

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Proceedings Article | 8 May 1995 Paper

Feedforward active interior noise control

Balakumar Balachandran, Arun Sampath, John Park

Proceedings Volume 2443, (1995) https://doi.org/10.1117/12.208304

KEYWORDS: Ferroelectric materials, Acoustics, Sensors, Aluminum, Actuators, Analog electronics, Amplifiers, Control systems, Dielectrics, Phase shifts

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