Audrius Senulis

Multibody dynamic simulation and transient analysis of quay crane spreader and lifting mechanism

Nowadays, container shipment in the intermodal terminals is overloaded. The quay crane and its control system have to be properly prepared for rapid cargo reloading. The advanced control system may increase container loading efficiency due to the reduced transportation time. However, faster transportation demands higher safety. In this article, the authors performed multibody dynamics simulation of the container spreader and lifting mechanism by analyzing more advanced mathematical model of the quay crane. Trolley motion and cargo swing angle transient responses of the dynamic system were acquired and analyzed during model simulation. The main target of this research is to determine the system behavior during transients. The simulation results showed that the transients induced by startup of the vertical spreader travel affect the whole crane system in all the investigated cases. In addition, the influence of flexible cable causes additional oscillations of cargo and reciprocating trolley displacement. The simulation of the container spreader and lifting mechanism will help detect motion deviations of the quay crane in real time.

Intelligent Containers Network Concept

In this paper, a novel approach is presented to increase the security of shipping containers transportation and storage in container yards. This approach includes wireless sensors networks with programmable modules to increase the effectiveness of the decision support functionality for operators’ onsite. This approach is closely related to the Container Security Initiative and is intended to deepen knowledge in the intelligent transportation research area. This paper examines an urgent challenge secure of cargo transportation in containers, i.e., how quickly it is possible to detect dangerous goods in shipping containers without changing their tightness and hence rationally implements international security regulations all around the world. This paper contributes to the development of new approaches of shipping containers handling and monitoring in terms of smart cities and smart ports (for the development of the Smart Port initiative) for ports that have higher levels of security violations. This contribution is addressed as an informative measure to the general public working in the Information and Communications Technologies (ICT) research area.

A study on the electromagnetic fields in wind mills farm area

This study presents the mathematical model of electromagnetic waveforms parameters which can be used for determination of the electromagnetic pollution level in windmills farm. The electromagnetic field parameters such as electric field intensity and magnetic field density were measured by EMF detectors on different frequencies ranges. The measured values for the waveform reconstruction in time domain were processed using Inverse Discrete Fourier Transform (IDFT). Obtained wave shape of electric field strength as well as magnetic flux density allowed defining the general of electromagnetic radiation level in chosen measurement point of windmills farms which includes all electromagnetic radiation values from all possible nearby sources. Also analysis of electromagnetic radiation impact for environment was considered. The measurement parameters were compared with the limit values.

System of power supply and oscillating pulse current synchronous drive in power network

There are a number of electrical drives with oscillatory driven mechanisms. As a result it is possible to use oscillating movement electrical drives there. These drives create ineligible reactive power, therefore it is required to provide conductors with the bigger cross-section, to design reactive energy storage devices. Reactive power is objectionable in electrical power network. Thus, in order to ensure the best work of oscillating drive the necessity for searching of reactive power reduction or its use methods occurs. The aim of the research is to examine pulsed power supply and oscillating movement pulse current synchronous drive system, in order to minimize the reactive power usage from power supply network and increase drive efficiency. To achieve this purpose pulse power supply and oscillating movement drive system mathematical model was designed, the influence of selected pulsed power supply to oscillating movement, drive performance indicators was determined as well.

Statistical and Continuous Wavelet Analysis of wind speed data in Mardin-Turkey

In this paper, wind speed measurements are considered for Mardin region in Turkey. Mardin city is situated in East part of Turkey. Mardin is a mountainous area suitable for wind. And also, its wind energy potential is at an acceptable level. Wind speed data in this study, is obtained from the national meteorology station. This real-time measured data is suitable to international criteria. This annual data is related to the measurements of 2011, from January 1, 2011 to December 31, 2011. There are two important aspects of the study. First one is related to calculation of the statistical parameters for wind speed data. Here four parameters of a statistical distribution are calculated. These are mean value, standard deviation, skewness and kurtosis. Last two parameters are used to determine the non-Gaussian (or Gaussian) characteristics. In this study, the skewness and kurtosis parameters are are calculated and compared. Parameters indicate asymmetrical and non-Gaussian characteristics. Hence the wind speed distribution is defined by Weibull distribution and its probability density function is shown for shape parameter and average speed of the wind. Thus the histogram and Weibull probability density function are calculated as well as the statistical findings. As a second aspect of the study, data is accepted as non-stationary. So its Continuous Wavelet Transform is used for the determination of the seasonal transitions and determined the time-frequency content. Thanks to the continuous wavelet transform, low and high frequency regions of wind speed data are distinguished. Continuous wavelet transform findings are quite satisfactory.

The Microwave Energy Harvesting by Absorbent Structures Based on Composite Materials

—This study presents two types of Salesbary Screen models which can be used for the microwave EMR harvesting in the occupational areas for the prevention case of the EMF impact for human health. The proposal structures operate on the 618GHz frequency electromagnetic radiation and allow collecting heating energy of the defined range. There are two types of fillers of 3% MWCNTs and 3% CNFs where considered in meaning of well electromagnetic radiation absorbency properties. The special attention had been paid for the outer, spacer and back layers thickness evaluation. The specific power as well as the total power in the proposal structures were calculated

Control Efficiency Analysis of Linear Oscillating Mechatronic Device

This paper deals with the control efficiency analysis of the linear oscillating mechatronic device (linear oscillating synchronous motor–compressor). These mechatronic devices can be controlled by using thyristor control [1, 4], square-wave voltage [2, 3], ect. There is analyzed the case, when square-wave voltage pulses’ frequency is changed and so the piston stroke duration time is reduced. The control of piston stroke changes the energetic parameters of the mechatronic device. This type of controlling has one disadvantage – it needs a DC voltage source. The pulsating voltage control is based on thyristor control system and does not have the previously mentioned disadvantage, because uses the AC voltage source, but both control ways have influence to the energetic parameters due to higher harmonics. The analysis of the chosen mechatronic device (open-loop tests) is based on comparing the modeling and experimental results with respect to power losses, simplicity of the control, power factor and disturbances to the supply system. These results are important for the optimal design of the drive with oscillating synchronous pulsating current motors and the selection of control type for the different type of load.