This paper presents the identification of fractional Wiener nonlinear systems. Such systems, consist of a linear dynamic block followed by a static non-linear subsystem. In this work, Polynomial Non Linear State Space(PNLSS) models are used to describe them. A non linear optimization algorithm in occurence Levenberg-Marquardt algorithm is developped for the fractional wiener non linear system. Numericul simulations test the efficiency of the method for various signal to noise ratios.
Compressive sensing (CS) is a rapidly evolving field in biomedical signal processing. Our objective is to design low-cost photoacoustic system, which can be used to reconstruct Photoacoustic images of good quality. In this work, photoacoustic simulations and compressive sensing are used to reconstruct Photoacoustic images based on different number of sensors, different sensor locations and simulation durations. Simulation results show that Photoacoustic images of better quality around the tumor can be reconstructed using non-uniform sensor distribution based on CS framework compared with equal number of symmetrically distributed sensors around the tumor.
Electrocardiography (ECG) represents the hearts electrical activity and has features such as QRS complex, P-wave and T-wave that provide critical clinical information for detection and prediction of cardiac diseases. This paper presents an ECG processing architecture for extracting ECG features. These features are utilized to define intervals in order to detect or predict a heart failure. The architecture is optimized for ultra-low power applications. The architecture is based on Curve Length Transform (CLT) for the detection of QRS complex and Discrete Wavelet Transform (DWT) for the delineation of TP waves. Moreover ultra-low power design techniques such as clock gating and voltage scaling are implemented so as to minimize the overall power consumption. The architecture is implemented on chip and has a power consumption of only 4.2uW when operated from a supply voltage of 1V.
High temperature compression samples were manufactured by 3-D printing and tested to investigate on the high temperature deformation behavior of Inconel 718 manufactured by 3-D printing in a laser powder bed system.
Hybrid UAVs combine the advantages of fixed-wing and VTOL UAVs where they have the ability of vertical takeoff and landing as well as high cruising speed and enhanced endurance. In this paper, a comprehensive high-fidelity model that considers rotor and propeller aerodynamics as well as coaxial effects is constructed using firstprinciples approach for hovering mode. The overall model validity is examined by practical flight experiment.
This report relates to the pulse Doppler weather Radar digital signal processing field and especially about the estimation of the spectral moments of weather Doppler echoes in severe meteorological situations such as wind shears, tornadoes, We will analyze in first place the most known algorithms in the literature such as pulse pair, and Fourier algorithm. We will develop an algorithm based on the Principal Components Analysis which is a data reduction method. This PCA method will be paired with one of spectral estimation algorithms. pulse pair in this report.
Innovative aerodynamic technologies will play a key role in improving the nextgeneration aircraft's performance. Active flow control using the Sweeping Jet (SWJ) actuators is one of the most promising technologies to solve critical problems of aerospace industry such as drag and weight reduction, flow separation, and noise. The performance of SWJ actuator depends upon many parameters such as, flow rate, size, geometry of feedback channels, design of Coanda surfaces, exit nozzle angle, etc. The main objective of this paper is to understand internal flow physics, jet oscillation process, and pressure drop mechanism using Two-Dimensional-Unsteady Reynolds- Averaged-Navier-Stokes simulations. This understanding will help to the development of design methodologies for the sweeping jet with minimum pressure losses, controllable sweeping frequency, and a more efficient flow control actuator for required conditions.
As the gap between robots and humans comes closer it is of utmost necessity to have efficient human-robot control interfaces. The challenge is to build the bridge between observation and execution, the mapping between human motions and motor programs. In this project, electromyographic (EMG) signals from muscles of the human upper limb are used as the control interface between the user and robotic platform which consists of the Mitsubishi arm and Barrett hand. The root mean square (RMS) method is used to classify and analyze the object's hand gesture into either an open or closed grasp based upon EMG signals. While the motion capture system is used to capture arm position which is then decoded into robot motion. Those techniques are then mapped to the two platforms enabling the robot with dexterous and intelligent manipulation skills through the continuous generalizations of human demonstrations.
One of the challenges in robotics is the optimization of a controller to achieve a given task. With improvements in simulation technology it has become possible to test behaviors virtually and rapidly before attempting them on hardware. A method for automatically learning desired behaviors is presented through a process that mimics biological evolution. The system was able to automatically discover a variety of viable strategies that optimize a given fitness function. The system was also able to accept preexisting strategies and improve them through this process.
In this paper we present the mathematical model of a novel passive variable stiffness joint, the Khalifa University Robotics Institute Passive Variable Stiffness Joint (KURIPVSJ). The main feature of PSVJ is its capability of varying the stiffness from zero (transparent to the user) to infinity (rigid for the user) condition with a simple mechanical system. More than that, the joint can rotate freely at the zero stiffness case without any limitation. The stiffness varying mechanism consists of two torsional springs, mounted with an offset from the PSVJ rotation center, and coupled the joint shaft with an idle roller. The variation of the resulting output stiffness is obtained by changing the distance of the roller-springs contact point from the joint rotation center (effective arm).
