Design and implementation of fast output sampling feedback control for shape memory alloy actuated structures

Dhanalakshmi, K.,Umapathy, M.,Ezhilarasi, D.,Bandyopadhyay, B. Techno-Press 2011 Smart Structures and Systems, An International Jou Vol.8 No.4

This paper presents the design and experimental evaluation of fast output sampling feedback controller to minimize structural vibration of a cantilever beam using Shape Memory Alloy (SMA) wires as control actuators and piezoceramics as sensor and disturbance actuator. Linear dynamic models of the smart cantilever beam are obtained using online recursive least square parameter estimation. A digital control system that consists of $Simulink^{TM}$ modeling software and dSPACE DS1104 controller board is used for identification and control. The effectiveness of the controller is shown through simulation and experimentation by exciting the structure at resonance.

Microcontroller based split mass resonant sensor for absolute and differential sensing

Uma, G.,Umapathy, M.,Kumar, K. Suneel,Suresh, K.,Josephine, A. Maria Techno-Press 2009 Smart Structures and Systems, An International Jou Vol.5 No.3

Two degrees of freedom resonant systems are employed to improve the resonant property of resonant sensor, as compared to a single degree of freedom resonant system. This paper presents design, development and testing of two degrees of freedom resonant sensor. To measure absolute mass, cantilever shaped two different masses (smaller/absorber mass and bigger/drive mass) with identical resonant frequency are mechanically linked to form 2 - Degree-of-Freedom (DOF) resonator which exhibits higher amplitude of displacement at the smaller mass. The same concept is extended for measuring differential quantity, by having two bigger mass and one smaller mass. The main features of this work are the 3 - DOF resonator for differential detection and the microcontroller based closed loop electronics for resonant sensor with piezoelectric sensing and excitation. The advantage of using microcontroller is that the method can be easily extended for any range of measurand.

Experimental evaluation of discrete sliding mode controller for piezo actuated structure with multisensor data fusion

Arunshankar, J.,Umapathy, M.,Bandhopadhyay, B. Techno-Press 2013 Smart Structures and Systems, An International Jou Vol.11 No.6

This paper evaluates the closed loop performance of the reaching law based discrete sliding mode controller with multisensor data fusion (MSDF) in real time, by controlling the first two vibrating modes of a piezo actuated structure. The vibration is measured using two homogeneous piezo sensors. The states estimated from sensors output are fused. Four fusion algorithms are considered, whose output is used to control the structural vibration. The controller is designed using a model identified through linear Recursive Least Square (RLS) method, based on ARX model. Improved vibration suppression is achieved with fused data as compared to single sensor. The experimental evaluation of the closed loop performance of sliding mode controller with data fusion applied to piezo actuated structure is the contribution in this work.

Design, analysis and experimental investigation of a rotational piezoelectric energy harvester with storage system

Raja V,Umapathy Mangalanathan,Uma Gandhi,Praveen kumar B,Premkumar S 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.11

Energy harvesting from rotational motion has drawn attention over the years to energise low-power wireless sensor networks in a rotating environment. The harvester works efficiently in a small frequency range which has to be similar to the driving frequency. Because of the constraints of size, precision, and the energy harvester’s weight, it is challenging to design it to suit micro applications. To deal with this problem, this paper proposes a rotational piezoelectric energy harvester (RPEH), which generates a voltage output from rotational motion. This design increases the gravitational force acting on the system by increasing the length of the beam, which in turn increases its vibration in a transverse direction. EulerBernoulli’s theory is utilized to derive the mathematical model of the RPEH under rotational motion, and harvester dynamic equations are derived using the electromechanical Lagrange equations. A prototype of RPEH is developed and the exactness of the proposed mathematical model is verified using experimental results and numerical simulation. Maximum power of 43.77 µW is produced at a rotating frequency of 21 Hz (1260 rpm) with an optimum load resistance of 1141.3 kΩ.

Measurement of Diesel Exhaust Fluid Concentration in Urea-SCR after-Treatment System

PalaniKumar Gurusamy,Uma Gandhi,Umapathy Mangalanathan,Karl Marx LR 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.8

In an effort to meet the established emission standards Selective Catalytic Reduction (SCR) is used to reduce NOx emissions with diesel exhaust fluid (DEF) as additive in the exhaust of diesel engines. ISO 22241-1:2006 specifies the quality characteristics of DEF in order to maintain efficiency and hence, it is essential that the concentration of urea in DEF is accurately monitored. In this paper, a measurement system is designed, developed and tested for measuring the concentration of urea in DEF. The design involves piezoelectric ultrasound transmitter and receiver with associated electronics operating at a frequency of 4 MHz. The concentration of urea in DEF is measured (i) by measuring the time of flight of ultrasound waves between transmitter and receiver (ii) by measuring the amplitude of received signal in terms of frequency using voltage-to-frequency converter. The measurement system is modeled using two-port network model for piezoelectric transmitter/receiver and transmission line model for DEF medium. The prototype of measurement system is fabricated with all associated electronics and tested for variation in concentration of urea in DEF. The results from prototype are in close agreement with the results obtained from analytical model. The measurement system is tested for repeatability and sensitivity to temperature.

Toward Generic, Immersive, and Collaborative Solutions to the Data Interoperability Problem which Target End-Users

Sanchez-Ruiz, Arturo,Umapathy, Karthikeyan,Hayes, Pat Korean Institute of Information Scientists and Eng 2009 Journal of Computing Science and Engineering Vol.3 No.2

In this paper, we describe our vision of a "Just-in-time" initiative to solve the Data Interoperability Problem (a.k.a. INTEROP.) We provide an architectural overview of our initiative which draws upon existing technologies to develop an immersive and collaborative approach which aims at empowering data stakeholders (e.g., data producers and data consumers) with integrated tools to interact and collaborate with each other while directly manipulating visual representations of their data in an immersive environment (e.g., implemented via Second Life.) The semantics of these visual representations and the operations associated with the data are supported by ontologies defined using the Common Logic Framework (CL). Data operations gestured by the stakeholders, through their avatars, are translated to a variety of generated resources such as multi-language source code, visualizations, web pages, and web services. The generality of the approach is supported by a plug-in architecture which allows expert users to customize tasks such as data admission, data manipulation in the immersive world, and automatic generation of resources. This approach is designed with a mindset aimed at enabling stakeholders from diverse domains to exchange data and generate new knowledge.

Microcontroller based split mass resonant sensor for absolute and differential sensing

G. Uma,M. Umapathy,K. Suneel Kumar,K. Suresh,A. Maria Josephine 국제구조공학회 2009 Smart Structures and Systems, An International Jou Vol.5 No.3

Two degrees of freedom resonant systems are employed to improve the resonant property of resonant sensor, as compared to a single degree of freedom resonant system. This paper presents design, development and testing of two degrees of freedom resonant sensor. To measure absolute mass, cantilever shaped two different masses (smaller/absorber mass and bigger/drive mass) with identical resonant frequency are mechanically linked to form 2 - Degree-of-Freedom (DOF) resonator which exhibits higher amplitude of displacement at the smaller mass. The same concept is extended for measuring differential quantity, by having two bigger mass and one smaller mass. The main features of this work are the 3 - DOF resonator for differential detection and the microcontroller based closed loop electronics for resonant sensor with piezoelectric sensing and excitation. The advantage of using microcontroller is that the method can be easily extended for any range of measurand.

Design and implementation of fast output sampling feedback control for shape memory alloy actuated structures

K. Dhanalakshmi,M. Umapathy,D. Ezhilarasi,B. Bandyopadhyay 국제구조공학회 2011 Smart Structures and Systems, An International Jou Vol.8 No.4

This paper presents the design and experimental evaluation of fast output sampling feedback controller to minimize structural vibration of a cantilever beam using Shape Memory Alloy (SMA) wires as control actuators and piezoceramics as sensor and disturbance actuator. Linear dynamic models of the smart cantilever beam are obtained using online recursive least square parameter estimation. A digital control system that consists of Simulink modeling software and dSPACE DS1104 controller board is used for identification and control. The effectiveness of the controller is shown through simulation and experimentation by exciting the structure at resonance.

Experimental evaluation of discrete sliding mode controller for piezo actuated structure with multisensor data fusion

J. Arunshankar,M. Umapathy,B. Bandhopadhyay 국제구조공학회 2013 Smart Structures and Systems, An International Jou Vol.11 No.6

This paper evaluates the closed loop performance of the reaching law based discrete sliding mode controller with multisensor data fusion (MSDF) in real time, by controlling the first two vibrating modes of a piezo actuated structure. The vibration is measured using two homogeneous piezo sensors. The states estimated from sensors output are fused. Four fusion algorithms are considered, whose output is used to control the structural vibration. The controller is designed using a model identified through linear Recursive Least Square (RLS) method, based on ARX model. Improved vibration suppression is achieved with fused data as compared to single sensor. The experimental evaluation of the closed loop performance of sliding mode controller with data fusion applied to piezo actuated structure is the contribution in this work.

Modelling and experimental investigations on stepped beam with cavity for energy harvesting

A. Rami Reddy,M. Umapathy,D. Ezhilarasi,G. Uma 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.16 No.4

This paper presents techniques to harvest higher voltage from piezoelectric cantilever energy harvester by structural alteration. Three different energy harvesting structures are considered namely, stepped cantilever beam, stepped cantilever beam with rectangular and trapezoidal cavity. The analytical model of three energy harvesting structures are developed using Euler-Bernoulli beam theory. The thickness, position of the rectangular cavity and the taper angle of the trapezoidal cavity is found to shift the neutral axis away from the surface of the piezoelectric element which in turn increases the generated voltage. The performance of the energy harvesters is evaluated experimentally and is compared with regular piezoelectric cantilever energy harvester. The analytical and experimental investigations reveal that, the proposed energy harvesting structures generate higher output voltage as compared to the regular piezoelectric cantilever energy harvesting structure. This work suggests that through simple structural modifications higher energy can be harvested from the widely reported piezoelectric cantilever energy harvester.