Engineering Commons^™

Diagnosis Of Inter-Turn Short Circuit For A Polyphase Induction Motor In Closed-Loop Vector-Controlled Drives, Ahmed Sayed-Ahmed, Gennadi Y. Sizov, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

The main objective of this paper is to develop and experimentally verify a new technique to detect an inter-turn short circuit in one phase of a stator winding of an induction motor energized from a vector-controlled drive. This is in order to overcome the fault masking difficulties associated with the concept of depending on the actual magnetic field pendulous oscillation between the conventional voltage and current space vectors with respect to a reference that is unaltered by the compensation action of the drive. This technique is based on the flux pendulous oscillation phenomenon. This flux pendulous oscillation is also described …

A Light-Weight Event-Driven Protocol For Sensor Clustering In Wireless Camera Networks, Henry Medeiros, Johnny Park, Avinash Kak

Electrical and Computer Engineering Faculty Research and Publications

We propose a light-weight event-driven protocol for wireless camera networks to allow for formation and propagation of clusters of cameras for the purpose of collaborative processing during object tracking. Cluster formation is triggered by the detection of objects with specific features. Our protocol allows for simultaneous formation and propagation of multiple clusters. Cameras being directional devices, more than one cluster may track a single object since groups of cameras outside each others communication range may see the same object. Entry into a cluster and cluster membership maintenance require a sensor node to confirm the presence of features of the object …

Robust Minimum Variance Linear State Estimators For Multiple Sensors With Different Failure Rates, Franck O. Hounkpevi, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

Linear minimum variance unbiased state estimation is considered for systems with uncertain parameters in their state space models and sensor failures. The existing results are generalized to the case where each sensor may fail at any sample time independently of the others. For robust performance, stochastic parameter perturbations are included in the system matrix. Also, stochastic perturbations are allowed in the estimator gain to guarantee resilient operation. An illustrative example is included to demonstrate performance improvement over the Kalman filter which does not include sensor failures in its measurement model.

Speech Signal Enhancement Through Adaptive Wavelet Thresholding, Michael T. Johnson, Xiaolong Yuan, Yao Ren

Electrical and Computer Engineering Faculty Research and Publications

This paper demonstrates the application of the Bionic Wavelet Transform (BWT), an adaptive wavelet transform derived from a non-linear auditory model of the cochlea, to the task of speech signal enhancement. Results, measured objectively by Signal-to-Noise ratio (SNR) and Segmental SNR (SSNR) and subjectively by Mean Opinion Score (MOS), are given for additive white Gaussian noise as well as four different types of realistic noise environments. Enhancement is accomplished through the use of thresholding on the adapted BWT coefficients, and the results are compared to a variety of speech enhancement techniques, including Ephraim Malah filtering, iterative Wiener filtering, and spectral …

Potential Of A Suite Of Robot/Computer-Assisted Motivating Systems For Personalized, Home-Based, Stroke Rehabilitation, Michelle J. Johnson, Xin Feng, Laura M. Johnson, Jack M. Winters

Electrical and Computer Engineering Faculty Research and Publications

Background

There is a need to improve semi-autonomous stroke therapy in home environments often characterized by low supervision of clinical experts and low extrinsic motivation. Our distributed device approach to this problem consists of an integrated suite of low-cost robotic/computer-assistive technologies driven by a novel universal access software framework called UniTherapy. Our design strategy for personalizing the therapy, providing extrinsic motivation and outcome assessment is presented and evaluated.

Methods

Three studies were conducted to evaluate the potential of the suite. A conventional force-reflecting joystick, a modified joystick therapy platform (TheraJoy), and a steering wheel platform (TheraDrive) were tested separately with …