Dinamička simulacija mehaničkih opterećenja – pristup zasnovan na svojstvima industrijskih elektromotornih pogona

Dynamic emulation of mechanical loads presents a modern and interesting approach for testing and validating performance of electrical drives without a real mechanical load included in the test rig. The paper presents an approach to dynamic emulation of mechanical loads when the load torque and inertia mass of emulated load can be significantly greater than that of laboratory test rig. Closed-loop control of load torque and feedforward compensation of inertia and friction torques are used in a test rig. The approach is focused on the use with standard industrial converters. The described method can be used for design and validation of speed control algorithms in mechatronic applications. Experimental results with the emulation of linear loads are presented in end of the paper.Dinamička simulacija mehaničkih opterećenja predstavlja moderan i zanimljiv pristup testiranju i validaciji ponašanja elektromotornih pogona bez uključenog stvarnog mehaničkog opterećenja u eksperimentalni postav. U radu je predstavljen pristup s dinamičkom simulacijom mehaničkih opterećenja za slučaj kada moment tereta ili moment tromosti simuliranog tereta mogu biti daleko veći od onih dostupnih u eksperimentalnom postavu. U postavu se koristi upravljanje momentom tereta u zatvorenoj petlji uz unaprijednu petlju kompenzacije momenta tromosti i momenata trenja. Pristup je usmjeren na upotrebu standardnih industrijskih pretvarača. Opisana metoda može se koristiti za sintezu i validaciju algoritama za upravljanje po brzini u mehatroničkim primjenama. U radu su predstavljeni eksperimentalni rezultati za slučaj simulacije linearnih tereta

Automatic Near-Real-Time Image Processing Chain for Very High Resolution Optical Satellite Data

In response to the increasing need for automatic and fast satellite image processing SPACE-SI has developed and implemented a fully automatic image processing chain STORM that performs all processing steps from sensor-corrected optical images (level 1) to web-delivered map-ready images and products without operator's intervention. Initial development was tailored to high resolution RapidEye images, and all crucial and most challenging parts of the planned full processing chain were developed: module for automatic image orthorectification based on a physical sensor model and supported by the algorithm for automatic detection of ground control points (GCPs); atmospheric correction module, topographic corrections module that combines physical approach with Minnaert method and utilizing anisotropic illumination model; and modules for high level products generation. Various parts of the chain were implemented also for WorldView-2, THEOS, Pleiades, SPOT 6, Landsat 5-8, and PROBA-V. Support of full-frame sensor currently in development by SPACE-SI is in plan. The proposed paper focuses on the adaptation of the STORM processing chain to very high resolution multispectral images. The development concentrated on the sub-module for automatic detection of GCPs. The initially implemented two-step algorithm that worked only with rasterized vector roads and delivered GCPs with sub-pixel accuracy for the RapidEye images, was improved with the introduction of a third step: super-fine positioning of each GCP based on a reference raster chip. The added step exploits the high spatial resolution of the reference raster to improve the final matching results and to achieve pixel accuracy also on very high resolution optical satellite data

Influence of Zn and Mg Alloying on the Corrosion Resistance Properties of Al Coating Applied by Arc Thermal Spray Process in Simulated Weather Solution

In this study, Al–Zn and Al–Mg coatings were deposited on steel substrates by an arc thermal spray process. X-ray diffraction and scanning electr on microscopy were used to characterize the deposited coatings and corrosion products. Open circuit potential (OCP), electrochemical impedance spectroscopy, and potentiodynamic studies were used to assess the corrosion characteristics of these coatings after exposure according to the Society of Automotive Engineers (SAE) J2334 solution of varying durations. This solution simulates an industrial environment and contains chloride and carbonate ions that induce corrosion of the deposited coatings. However, the Al–Mg alloy coating maintained an OCP of approximately - 0.911 V versus Ag/AgCl in the SAE J2334 solution even after 792 h of exposure. This indicates that it protects the steel sacrificially, whereas the Al–Zn coating provides only barrier-type protection through the deposition of corrosion products. The Al–Mg coating acts as a self-healing coating and provides protection by forming Mg 6 Al 2 (OH) 16 CO 3 (Al–Mg layered double hydroxides). Mg 6 Al 2 (OH) 16 CO 3 has interlocking characteristics with a morphology of plate-like nanostructures and an ion-exchange ability that can improve the corrosion resistance properties of the coating. The presence of Zn in the corrosion products of the Al–Zn coating allows dissolution, but, at the same time, Zn 5 (OH) 6 (CO 3 ) 2 and Zn 6 Al 2 (OH) 16 CO 3 are formed and act to reduce the corrosion rate