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This paper presents a vector current controller scheme, which operates according to grid virtual flux orientation for the three phase, 3-wire pulse-width modulated voltage source converter (VSC). The usage of voltage sensors to determine the grid voltage angle for synchronization and the grid voltage magnitude for the controller operation are avoided by applying a virtual flux concept in the proposed...
This Electromagnetic Core Imperfection Detection (ELCID) has been widely used on generators and large motors in detecting inter-laminar insulation failure in stator cores. Comparing to traditional detecting method, the requirements of ELCID are much more easier to obtain, so it is necessary to analyze the results of ELCID in engineering application. On the one hand, the validity of ELCID in detecting...
This paper developed the common transmissibility to a quaternion form. The quaternion transmissibility was calculated based on the time-domain sequences of spatial vibration signals by using technique of quaternion Fourier transforms (DQFT). The quaternion transmissibility is superior to the common one because it can be used to deal with the spatial vibrations that are composed from three directional...
The area of compressed sensing has developed a lot and is of high interest in the last few years because it provides a solid and promising method to exactly recover signals by sampling at very low rate compared to traditional rates. It has been proved that the topic can be applied to almost all signal processing area which deals with sparse signals. But most of the works done in compressed sensing...
This paper proposes a discrete-time sliding mode current observer (DSMCO) that relies only on the measure of the voltage between a distribution static compensator (DSTATCOM) and a self-excited induction generator (SEIG). Thus, the proposed observer reduces the overall cost of the voltage regulator system, however, the current sensor's cost is significant. The proposed algorithm is also adaptive, because...
This paper investigates a new approach to develop and implement a virtual flux oriented control (VFOC) for the front-end three phase bidirectional voltage source converter (VSC) by adapting the principle operations of voltage oriented control (VOC) and power estimation used in virtual flux direct power control (VFDPC). The proposed VFOC operates with minimal number of sensors by avoiding the used...
Now that Autonomous Underwater Vehicles (AUVs) are exploring more challenging terrain than ever, the need for an obstacle avoidance system has become apparent. Obstacle avoidance systems (OAS) in unmanned systems are far from new. However, adapting existing methodologies to AUVs presents a new set of challenges. Underwater obstacle sensing relies on limited and often noise prone acoustic range sensors,...
This paper addresses the computational complexity of the Dirichlet process mixture model (DPMM)-based Bayesian non-parametric classifier in cognitive radios (CR's). The DPMM is an ideal signal classification tool for wideband CR's (W-CR's) due to its non-parametric structure. However, it can incur a high computational complexity since it usually requires a large number of Gibbs sampling iterations...
Radar resource management (RRM) is an active research field that has a strong practical importance and attracts the attention of both the scientists and industry experts. A discussion of the various approaches to RRM became essentially a discussion on how to formulate the optimization problem. Although much work has been done on optimal performance-based RRM, the approaches that take mission objectives...
Channel estimation provides channel state information (CSI) for equalizing channel distortion and demodulating received signals. As a consequence, this technique takes an important part in modern wireless communications systems. Comparing with conventional pilot-aided channel estimators, compressive sensing based channel estimation methods can exploit the sparse property of the wireless channel and...
In this paper, a stagewise approach has been adopted in the Direction of Arrival (DOA) estimation procedure to improve the speed and efficiency of the whole estimation, i.e. a coarse estimation is firstly carried out by means of Minimum Variance Distortionless Response (MVDR) to provide a smaller searching angle for the secondary high precision estimator, which is realized by a modified Orthogonal...
D-S evidence theory has been widely used in various fields of information fusion due to its efficiency in dealing with uncertain information. Unfortunately, combination of conflicting evidences with the classical Dempster's rule may produce the counter-intuitive results. In this paper, Definitions of correlation coefficient and credibility are first presented, followed by the introduction of evidence...
The design of the robotic vehicle VILMA at UNICAMP is developed in-vehicle platform Fiat Punto. In addition to a set of sensors, actuators, mechanism and components (hardware and/or software), new technologies should be developed in support of Automation, Control, Perception, Localization and Navigation. This work presents the design and simulation of path tracking control using model predictive control...
The primary task of strap down inertial navigation system (SINS) algorithms is updating attitude timely and precisely. This paper presents an ARM based quad copter, using low-cost MEMS inertial sensors. In this paper we propose to use three methods, namely linear interpolation, gradient descent and complementary filter for attitude-updating. Meanwhile, an idea that the quaternion attitude could be...
A novel cooperative spectrum sensing approach is introduced based on a approximate model of the power spectral density (PSD) map in space and frequency domain. This scheme uses a model coefficients estimator based the theory of Variational Bayesian Inference. It reveals the unknown positions of transmitting CRs and the spectrum holes in authorized frequency bands, by capitalizing on the forms of sparsity...
The current paper presents a conceptual architecture of a distributed train localization solution based on GNSS(Global Navigation Satellite System) and inertial sensors. The requirements attached to this application are stringent, due to the fact that they need to prove safety of life. Additionally this solution proposes a cost efficient hardware and software configuration which allows deployment...
In recent years, the wireless sensors networks raise a great attention in the world. In this paper we proposed a method — multi-innovation coupled stochastic gradient (MICSG) algorithm for the global parameters estimation of the distributed sensors. This algorithm utilizes the identified result of the previous adjacent node and the local historical data to modify own estimated parameters. Then we...
This paper describes a method for score-level fusion in multi-cue two-class classification problems. Fusion based on the probability density function (PDF) of multiple scores given for each class is a promising approach because it guarantees optimality as long as the estimated PDFs are correct. Instead of lattice-type control points used in previous non-parametric density-based approaches, floating...
In this paper, we study the performance of sensing in mobile sensor networks with imperfect knowledge of neighborhood mobility. We examine the impact of exchanging incorrect mobility information on the cost of sensing and the required target coverage. The study is performed for two target coverage models: an independent coverage model and a Markovian one. We demonstrate via extensive simulations that...
Precise navigation of mobile robots in unknown areas is common problematic in many research. For the robot navigation in exterior is commonly used the Global Navigation Satellite System (GNSS). For better results in exteriors is also possible to use the Satellite Based Augmentation Systems (SBAS). In Europe is usually used the European Geostationary Navigation Overlay Service (EGNOS), in US Wide Area...
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