FPGA based angular stabilization of a quadcopter

This paper presents an FPGA based method for stabilization of a quadcopter around the principal axes pitch, roll, and yaw using IMU sensors for angular estimation and the PID algorithm for control. The goal was to solve the problem in hardware level providing a fast method for stabilization. Using an FPGA circuit parallel with a microprocessor the control of the quadcopter becomes simpler the microprocessor can handle other tasks like area mapping or path calculation parallel with the stabilization hardware implemented on the FPGA. Sensor configuration and calibration was implemented on the FPGA along with the PID controller. The implemented circuit was tested in real time on the quadcopter.

Computing Algorithm for the Gear Tooth Space Points Cloud Envelope Generated by the Mixed Cad Method

The task of the mixed pure CAD generating method developed by the authors consists in finding only the points situated on the gear tooth surface. The use of the mixed CAD gear generating method results in a very large and particular type of Points Cloud: This contains points situated both in the tooth space, and on the tooth surface. The existing filtering programs and methods, as it was presented in previous papers, cannot deal with these particular point sets. The development of the named particular generating method claims an algorithm and a computer software which can find the envelope of the Points Cloud. This papers presents an Alpha Shape algorithm based filtering algorithm, adapted and developed to be used together with the mixed CAD generating software.

Evaluation and Comparison of Low FPGA Footprint, Embedded Soft-Core Processors

The paper presents three embedded soft-core processor architectures, developed by the authors to be easily implementable while yielding low digital resource usage. These architectures will be compared and contrasted between each-other by introducing a special testing method, based on control algorithm implementations. For reference, the same testing and comparison has been implemented on a well established architecture, too, on the Xilinx PicoBlaze processor. Measurement results and application suggestion are given in the concluding section.

Web Application for Romanian Language Phonetic Transcription

This paper presents a Romanian language phonetic transcription web service and application built using Java technologies, on the top of the Phonetisaurus G2P, a Word Finite State Transducer (WFST)-driven Grapheme-to-Phoneme Conversion toolkit.We used NaviRO Romanian language pronunciation dictionary for WFST model training, and MIT Language Modeling (MITLM) toolkit to estimate the needed joint sequence n-gram language model.Dictionary evaluation tests are also included in the paper.The service can be accessed for educational, research and other non-commercial usage at http://users.utcluj.ro/~jdomokos/naviro/.

DMA tests for 3D printed polymer specimens of fatigue test examination

Alongside the using of „technical materials’, the direct 3D printed different plastic also speeded up lately. Accordingly to this, it is often designed parts, which have to sustain extreme stress. The proper definition of material qualities is expensive; despite in every phase of designing, we need it to be done perfectly. In every industrial section, it is important to work with exact material characteristics, especially in fields where strict safety rules have to be kept (in connection with the lifespan) the design of fatigue tests of 3D printed polymer specimens. We planned the examinations on the way to avoid the critical temperature range shown by the DMA examinations’ results in the bending point of the inner friction coming up in the local range. This information could be important for the Military to change the busted parts quickly and sound. That is the reason why we designed these examinations in this way, so, it could help for designers in the field of military, in development of security technology and improvement of recovery.

Comparative FEM Analysis of Gears Modeled With Analytical, Solid Subtracting and Mixed CAD Generating Method

The paper proposes a comparative FEM analysis of gears solid model bodies, obtained with three different methods. The analytical method is based on the mathematical equations of the tooth flanks. It supposed to be the most accurate and precise solid modeling process. However, it reveals it’s limits by handling of surfaces that are not deduced mathematically, or in case of tooth geometries which needs to be modified in order to perform a quick test regarding the probably effects of the mentioned modifications. The solid subtraction- and the newly developed, mixed CAD method are pure CAD generating methods. As any discrete generating method, their precision is influenced by the fineness of the iteration steps. In case of the mixed CAD solution the precision is influenced by the filtering algorithm applied to the generated Points Cloud. The visual comparison of the three mentioned methods, was presented in previously published papers. The present paper validates the novel mixed CAD method comparing the FEA analysis of the generated solid models.

Bimodal RMS distributions for the objective detection of theta (θ) and gamma (γ) brain oscillations during long-term continuous LFP recordings in mice

In the rodent’s brain the theta (5-12 Hz) and gamma (30-120 Hz) oscillations can be readily detected in local field potential (LFP) recordings, but there is no universal consensus about an objective threshold for their detection.We FIR-filtered the long-term local field potential (LFP) recordings for theta and gamma oscillations. The RMS (root mean square) values of 8 s epochs in 0.5-4 s steps (using corresponding overlaps) were obtained from the filtered recordings. For both theta and gamma oscillations, the histograms showed a bimodal distribution well fitted by two Gaussians. The point of intersection between the two distributions proved to be the most reliable for separating the RMS values belonging to the two Gaussians.

Finger or Stylus: Their Impact on the Performance of On-line Signature Verification Systems

The widespread use of smartphones and the ability of these devices to digitize signatures have made it possible to sign electronic documents in this way. In this paper we compared two on-line signature databases in terms of verification performance: the MCYT containing signatures drawn by stylus pen, and MOBISIG containing finger drawn signatures. Performance evaluations were performed using both local and global systems. In the case of global systems, we evaluated the performance of a novel information theory features set. Little improvement was achieved by this feature set. There were large differences between the two databases in terms of performance. Finger drawn signatures collected by mobile device were proved inferior to signatures collected by digitizing tablet and its stylus.

Theoretical study of the Nonlinear Quadratic Optimal Control implementation

In this brief, I study the finite and infinite nonlinear discrete time optimal control. The quadratic control problem for nonlinear case can be solved with different methods such as: linearization of the system model around each operation point or some different methods, where should be used an on-line parameter identification algorithm. In this paper, I study some properties of these algorithms in order to improve the control efficiency of the nonlinear process control. In this paper, I supposed the all states are accessible, so there is not necessary any state estimation algorithm for the implementation of the proposed optimal control (LQR - Linear Quadratic Regulators) methods.

Hybrid modeling and model based control of the four tank process

Hybrid systems contain both continuous dynamics and discrete elements, where discrete transitions happen between different continuous operating modes as a consequence of certain events. The notion of modeling these types of systems is discussed in regard to the four tank process, which has hybrid and nonlinear characteristics. This paper describes the modeling of this system in Simscape software and a hybrid model is created as well, with a hybrid controller being built around it that includes finite-state automata and PI controller. Simulations implemented in Matlab Simulink software prove the viability and correctitude of the method presented.