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Full-Text Articles in Electrical and Computer Engineering

A Practical Approach To Disturbance Decoupling Control, Qing Zheng, Zhongzhou Chen, Zhiqiang Gao Sep 2009

A Practical Approach To Disturbance Decoupling Control, Qing Zheng, Zhongzhou Chen, Zhiqiang Gao

Electrical and Computer Engineering Faculty Publications

In this paper, a unique dynamic disturbance decoupling control (DDC) strategy, based on the active disturbance rejection control (ADRC) framework, is proposed for square multivariable systems. With the proposed method, it is shown that a largely unknown square multivariable system is readily decoupled by actively estimating and rejecting the effects of both the internal plant dynamics and external disturbances. By requiring as little information on plant model as possible, the intention is to make the new method practical. The stability analysis shows that both the estimation error and the closed-loop tracking error are bounded and the error upper bounds …


A New Control Method For Input-Output Harmonic Elimination Of The Pwm Boost-Type Rectifier Under Extreme Unbalanced Operating Conditions, Ana Vladan Stankovic, Ke Chen Jul 2009

A New Control Method For Input-Output Harmonic Elimination Of The Pwm Boost-Type Rectifier Under Extreme Unbalanced Operating Conditions, Ana Vladan Stankovic, Ke Chen

Electrical and Computer Engineering Faculty Publications

Under severe fault conditions in the distribution system, not only input voltages but also input impedances must be considered as unbalanced. This paper presents a new control method for input-output harmonic elimination of the pulsewidth-modulation (PWM) boost-type rectifier under conditions of both unbalanced input voltages and unbalanced input impedances. The range of imbalance in both input voltages and input impedances, for which the proposed method is valid, is analyzed in detail. An analytical approach for complete harmonic elimination shows that PWM boost-type rectifier can operate at unity power factor under extremely unbalanced operating conditions resulting in a smooth (constant) power …


Drive-Mode Control For Vibrational Mems Gyroscopes, Lili Dong, David Avanesian Apr 2009

Drive-Mode Control For Vibrational Mems Gyroscopes, Lili Dong, David Avanesian

Electrical and Computer Engineering Faculty Publications

This paper presents a novel design methodology and hardware implementation for the drive-mode control of vibrational micro-electro-mechanical systems gyroscopes. Assuming that the sense mode (axis) of the gyroscope is operating under open loop, the drive-mode controller compensates an undesirable mechanical spring-coupling term between the two vibrating modes, attenuates the effect of mechanical-thermal noise, and most importantly, forces the output of the drive mode to oscillate along a desired trajectory. The stability and robustness of the control system are successfully justified through frequency-domain analysis. The tracking error between the real output and the reference signal for the drive mode is proved …


A Novel Discrete Dimming Ballast For Linear Fluorescent Lamps, Haiyan Wang, Ana Vladan Stankovic, Louis Nerone, David Kachmarik Mar 2009

A Novel Discrete Dimming Ballast For Linear Fluorescent Lamps, Haiyan Wang, Ana Vladan Stankovic, Louis Nerone, David Kachmarik

Electrical and Computer Engineering Faculty Publications

A novel discrete dimming ballast for linear fluorescent lamps is proposed in this paper. A proposed dimming control circuit is combined with a ballast module for multiple lamps to realize control of three discrete lighting levels. Compared with conventional step dimming or ON-OFF control methods, the proposed discrete dimming method has the following advantages: 1) digital signal is generated by the dimming control circuit to control the lamps' turn- ON and -OFF, which makes the system more reliable and integrated; 2) the proposed discrete dimming system replaces relays, which are necessary in conventional lamp ON-OFF control, and therefore decreases the …


Scheduling Architectures For Diffserv Networks With Input Queuing Switches, Mei Yang, Henry Selvaraj, Enyue Lu, Jianping Wang, S. Q. Zheng, Yingtao Jiang Jan 2009

Scheduling Architectures For Diffserv Networks With Input Queuing Switches, Mei Yang, Henry Selvaraj, Enyue Lu, Jianping Wang, S. Q. Zheng, Yingtao Jiang

Electrical & Computer Engineering Faculty Research

ue to its simplicity and scalability, the differentiated services (DiffServ) model is expected to be widely deployed across wired and wireless networks. Though supporting DiffServ scheduling algorithms for output-queuing (OQ) switches have been widely studied, there are few DiffServ scheduling algorithms for input-queuing (IQ) switches in the literaure. In this paper, we propose two algorithms for scheduling DiffServ DiffServ networks with IQ switches: the dynamic DiffServ scheduling (DDS) algorithm and the hierarchical DiffServ scheduling (HDS) algorithm. The basic idea of DDS and HDS is to schedule EF and AF traffic According to Their minimum service rates with the reserved bandwidth …


Free Regions Of Sensor Nodes, Laxmi P. Gewali, Navin Rongatana, Henry Selvaraj, Jan B. Pedersen Jan 2009

Free Regions Of Sensor Nodes, Laxmi P. Gewali, Navin Rongatana, Henry Selvaraj, Jan B. Pedersen

Electrical & Computer Engineering Faculty Research

We introduce the notion of free region of a node in a sensor network. Intuitively, a free region of a node is the connected set of points R in its neighborhood such that the connectivity of the network remains the same when the node is moved to any point in R. We characterize several properties of free regions and develop an efficient algorithm for computing them. We capture free region in terms of related notions called in-free region and out-free region. We present an O(n2) algorithm for constructing the free region of a node, where n is the number of …