BCI (Brain-Computer Interface) is a technology which goal is to create and manage a connection between the human brain and a computer with the help of EEG signals. In the last decade consumer-grade BCI devices became available thus giving opportunity to develop BCI applications outside of clinical settings. In this paper we use a device called NeuroSky MindWave Mobile. We investigate what type of information can be deducted from the data acquired from this device, and we evaluate whether it can help us in BCI applications. Our methods of processing the data involves feature extraction methods, and neural networks. Specifically, we make experiments with finding patterns in the data by binary and multiclass classification. With these methods we could detect sharp changes in the signal such as blinking patterns, but we could not extract more complex information successfully.
The purpose of the work described in this paper is to compare more configurations belonging to portables real-time operating systems for embedded devices based on Raspberry Pi board. The developed application in this work can monitor the status in a greenhouse: irrigation, heating, ventilation, humidification, closing/opening panels etc. following weather conditions. Our target is to choose an efficient, minimal operating system optimized for the desired application. Other targets are high flexibility, optimal modularity, high readability and maintainability of the source code.
The need for high capacity and bandwidth in broadband communication systems increased rapidly in a few past years. Optical fiber is now the major transmission medium for fast and reliable communication replacing the old copper-based connections. However, with the deployment of optical networks, number of problems arise. The main problem of optical networks is the amplification in the long-distance transmission. Erbium doped fiber amplifier (EDFA) is the leading technology in the field of optical amplifiers. It uses erbium doped fiber to amplify optical signal. The importance of amplification in optical domain is relevant in long-haul and high-speed transmission systems. In this paper the study of the EDFA is presented. Based on an analytical study, the simulation model of the EDFA is created. The main aim is to determine the optimal parameters of the EDFA for a long-haul 16-channel DWDM (Dense Wavelength Division Multiplexing) system. The performance of the proposed DWDM system is mathematically analyzed using BER (Bit Error Rate) and Q factor.
The purpose of this paper was to present a method for the estimation of the rotor speed and position of brushless DC (BLDC) motor. The BLDC motor state equations were developed, and the model was discretised. Extended Kalman filter has been designed to observe specific states from the state vector, needed for the sensorless control (rotor position) and to determine the speed, which may be useful to use as a feedback for the controller. A test was carried out to determine the noise covariance matrices in a simulation manner.
The purpose of the article was to present the idea of space vector pulse width modulation (SVPWM) and implementation in Nios II softcore processor. The SVPWM module was described in a classical method in hardware description language both as an independent structure and as an additional component to softcore processor. The available methods were compared, and the experiment was carried out in the laboratory to test implemented SVPWM algorithm using high-speed induction motor.
Alexandru Lodin, Lacrimioara Grama and Corneliu Rusu
Recently have been reported methods to deliver a digital filter from an analog active filter, described only by its circuits diagram. The proposed approaches have been implemented in MATLAB and Python, and they were based on state-space conversion from analog to digital domain. Based on the Python approach, we show in this paper how to compute the transfer function of a large order analog active filter. The analog filter is described only by its circuits diagram. Finally, the analog filter is converted to the corresponding digital filter, having similar frequency gain and phase characteristics.
In the paper, the concept of universal speed and flux estimator with additional parameters estimators is presented. Proposed solution is based on the Model Reference Adaptive System (MRAS) type flux and speed estimator and can be used in different industrial systems (especially in the automotive applications). Induction Motor (IM) parameters are estimated using the systems based only on simple simulators and adaptive systems (voltage model and current model). Proposed system was tested in the sensorless induction motor drive with the Direct Field Oriented Control (DFOC) algorithm. Simulation and experimental results are presented in the paper.
Honoriu Valean, Cola Cristian, Andrei Wegroszta and Cristinel Costea
This paper discusses mobile notifications in the context of health monitoring system that measure and store vital signs of the patient that are included in this program. The values measured are temperature and cardiac rhythm. This has two Android application, one is used by the patient to monitor his vital signs and the other is used by the physician to be able to see and receive push notifications of each individual patient. The sensors are connected to a Raspberry Pi and these devices send information to the Android smartphone via Bluetooth. The physician can monitor patient data in real time. All the information that is gathered by the smartphone from the sensors are sent to the cloud, can project a history and can detect some anomalies, for example, if the cardiac pulse is not within the limits of an accepted interval.
Permanent magnet motor drive is a widely used technology, offering many advantages, such as exceptional speed, torque control and greater flexibility. Improvement of reliability and efficiency has become a great research interest. Towards this direction and taking into account the major developments in permanent machine technology over the recent years, the use of energy recovery converters has been introduced in various industrial applications. In this paper, the effects of harmonics on a three-phase motor controlled by a drive are analysed, and the behaviours of the filter topology after adopting regenerative drives are studied. The main contribution of this study is a methodology to foresee the standards that can be achieved with the use of an active front end system topology with filters. Moreover, the use of an optimum filter that eases the power system distortion is presented. The analysis presented in this paper is validated experimentally.
Youssef Agrebi Zorgani, Mabrouk Jouili, Yassine Koubaa and Mohamed Boussak
A sensorless indirect stator-flux-oriented control (ISFOC) induction motor drive at very low frequencies is presented herein. The model reference adaptive system (MRAS) scheme is used to estimate the speed and the rotor resistance simultaneously. However, the error between the reference and the adjustable models, which are developed in the stationary stator reference frame, is used to drive a suitable adaptation mechanism that generates the estimates of speed and the rotor resistance from the stator voltage and the machine current measurements. The stator flux components in the stationary reference frame are estimated through a pure integration of the back electro-motive force (EMF) of the machine. When the machine is operated at low speed, the pure integration of the back EMF introduces an error in flux estimation which affects the performance torque and speed control. To overcome this problem, pure integration is replaced with a programmable cascaded low-pass filter (PCLPF). The stability analysis method of the MRAS estimator is verified in order to show the robustness of the rotor resistance variations. Experimental results are presented to prove the effectiveness and validity of the proposed scheme of sensorless ISFOC induction motor drive.