To apply a spinning hemisphere as a mobile robot drive is an unconventional idea. Equipping a mobile robot with two such hemispheres brings to life a device with absolutely novel properties. In this paper we derive kinematics models of a mobile robot with two driving hemispheres, analyse shortly their properties, and adopt a control algorithm designed to follow a path. There are two kinematics models presented: the full model of the original system, and the model of the simplified system, equivalent to the original one. The second model is expressed in two different coordinate systems – the later allowing for the application of known control algorithms to drive the robot. The performance of the analysed algorithm is illustrated by computer simulations
Jednym z oryginalnych pomysłów napędu robotów mobilnych jest wykorzystanie do tego wirującej półsfery. Zastosowanie w napędzie robota dwóch takich półsfer daje obiekt o niezwykle ciekawych własnościach. W referacie przedstawiamy model kinematyki takiego układu, analizujemy jego zachowanie, proponujemy uproszczoną postać modelu i dyskutujemy cechy tego uproszczenia. Dla ilustracji właściwości wyprowadzonych modeli prezentujemy zestaw wyników symulacji wskazujących na podobieństwa i różnice w ich zachowaniu.
EN
The paper presents analysis of a two HOG wheel mobile robot. Capabilities of this drive are presented and discussed. Nonholonomic constraints and kinematics models are derived. Simplified model is proposed and its features are analysed. In addition, to present properties of the models, series of simulation arc performed. In result similarites and differences are shown.
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The best known and the the most important of Neanderthal sites in Slovakia is the travertine mound of Ganovce-Hradok (49°01' N 20° 19' E) with the sedimentary record from the Saalian termination up to the Holocene. A scientific research at the site was realized since 1880s, but the complex systematic research was realized only during 1955-1960, conditioned by the famous record of Neanderthal braincase in 1926. The research results have been published in the final report and within a monograph. The basic analysis of palaeontological findings of mammals was realized by Fejfar, who divided them into 6-7 groups, providing together with fossil molluscs (V. Lożek) and plants (V. Kneblova) a basic picture on both the climate and the palaeoenvironment in the vicinity of Ganovce during the formation of the travertine mound. Apart from remains of mammals, birds, and reptiles, the most important record at the site is represented by fossils of Neanderthal Man. The age of the place, where Neanderthal fossils have been found, was determined as 105,000 BP. The environment of Neanderthals was distinctly changed during the Late Pleistocene in the whole area of their occurrence because of severe climatic changes. Differences found in the composition of fossil assemblages reflect those in the terrestrial environment. Based on the definition of the taxonomical diversity of extinct organisms, the palaeoenvironmental reconstruction, and the exact age determination of the fossil record, a definition of individual events is possible from the evolutionary-phylogenetic and the climatic-environmental viewpoints.
Knowledge of the current tectonic regime plays an essential role in natural hazard assessment, especially in the risk assessment of fault activity. Structural analysis of brittle deformations (using in version techniques) was used to determine the stress field state occurring within Pliocene and Quaternary deposits in the western part of the Central Western Carpathians. The deformation pattern of the reduced stress tensor showed that all structural measurements could be separated into two groups. An older, Late Pliocene fault population was activated un der NNW-SSE oriented extension. A younger, Quaternary fault population reflected origin in a NE–SW extensional tectonic regime and it distinctly showed a change the orientation of the S3 of about 70. The change in tectonic activity, as well as in the stress field orientation, is dated to the Pliocene-Pleis to cene boundary. The Quaternary stress field developed dur ing the post-collisional stage of the orogen. Our study shows that the West ern Carpathian internal units document NE-SW to NNE-SSW extension in the broader region around of the north ern Danube Basin.
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