16 research outputs found
Konflikty współczesnego świata. 1
Ze wstępu: "Książka, którą oddajemy do rąk czytelników to rezultat kilkuletniej pracy pracowników
Instytutu Nauk Społecznych AGH zajmujących się między innymi prowadzeniem
wykładów i konwersatoriów z przedmiotów „Konflikty współczesnego świata”, „Wojny
i polityka”, „Filozofia przemocy, terror, terroryzm i ekstremizm”, „Pośrednie i bezpośrednie
formy agresji”. Stanowi ona I część serii wydawniczej poświęconej politycznym, społecznym
i kulturowym problemom współczesnego świata."(...
Uzależnienie od internetu wśród studentów Akademii Górniczo-Hutniczej w Krakowie
Tyt. z nagłówka.Bibliogr
Kinetic Energy-Based Indicators to Compare Different Load Models of a Mobile Crane
This paper presents a proposal for the use of energy indicators to evaluate the load modelling methods on the dynamics of a mobile crane. Three different variants of mathematical models of a load carried were examined and compared: as a lumped mass on one hook-sling, as a sphere on one hook-sling, and as a box on four hook-slings. The formalism of joint coordinates and homogeneous transformation matrices were applied to define the kinematics of the system. The equations of motion were derived using the Lagrange equations of the second kind. These equations were supplemented by the Lagrange multipliers and constraint equations formulated for the cut-joints and drives. The energy indicators were proposed to evaluate the behavior of the crane and the carried load. The authors proved that modeling a load in the form of a lumped mass is a great simplification in the analysis of crane dynamics
Kinetic Energy-Based Indicators to Compare Different Load Models of a Mobile Crane
This paper presents a proposal for the use of energy indicators to evaluate the load modelling methods on the dynamics of a mobile crane. Three different variants of mathematical models of a load carried were examined and compared: as a lumped mass on one hook-sling, as a sphere on one hook-sling, and as a box on four hook-slings. The formalism of joint coordinates and homogeneous transformation matrices were applied to define the kinematics of the system. The equations of motion were derived using the Lagrange equations of the second kind. These equations were supplemented by the Lagrange multipliers and constraint equations formulated for the cut-joints and drives. The energy indicators were proposed to evaluate the behavior of the crane and the carried load. The authors proved that modeling a load in the form of a lumped mass is a great simplification in the analysis of crane dynamics
Programmed task based motion analysis of robotic systems equipped with flexible links and supports
The automatic computational procedure to derivate dynamics equations of systems with programmed constraints modified to encompass compliant mechanical components in their structures is discussed in the paper. The dynamics analysis of the compliant manipulator model with a flexible link is presented as an example. The rigid finite element method is used in order to take into account the flexibility of the link. The formalism of joint coordinates and homogeneous transformations are used to describe the manipulator motion
Vibration of a crane system model equipped with flexible links in the presence of kinematic task-based constraints
The paper presents motion analysis of dynamic models of systems with flexible mechanical components and subjected to position and kinematic programmed constraints, which can be imposed as control goals, work or service task demands. The constrained dynamics is derived using an automated computational procedure dedicated to constrained systems. The procedure was successfully implemented to rigid models. A class of systems composed of flexible parts and subjected to programmed motions is considered in the paper. The novelty of the approach is in possibility of analyzing system motions, including vibration, in the presence of programmed constraints. The constrained motion is examined using a crane model equipped with a flexible link. The example delivers a realistic work situation, in which the crane carries loads and moves according to programmed constraints put on its trajectory and velocity
Dynamika układu tylnego zawieszenia pojazdu z silnikami elektrycznymi wbudowanymi w koła
The dynamics analysis of the rear suspension system of the Fiat Panda III with electric motors mounted in wheels is presented in the paper. The simplified model of this system modeled using the multibody system dynamics method and the MSC. Adams package is proposed. In order to validate the proposed numerical model, the road tests were carried out consisting on passing the vehicle without motors in wheels at constant speed through the obstacle. The vertical displacement of the center of the vehicle wheel was measured during the tests. During the validation, parameters of the wheel-to-road contact, stiffness coefficients of springs and shock absorber damping coefficients of the suspension of the simulation model were modified so that the numerical results were consistent with the experiment. Further, such a tuned model was used to simulate the motion of suspension with the motors mounted into the wheels. The obtained results were validated, obtaining the accepted compatibility. In the following, a series of calculations was carried out in order to analyze the influence of stiffness coefficients of springs and shock absorber damping coefficients on the dynamic response of the suspension.W artykule przedstawiono analizę dynamiki układu tylnego zawieszenia samochodu Fiata Panda III z silnikami elektrycznymi wbudowanymi w koła. Uproszczony model układu uzyskano przez zastosowanie metod dynamiki układów wieloczłonowych i ich implementacji programowej w postaci pakietu MSC.Adams. W celu walidacji zaproponowanego modelu symulacyjnego wykonano testy drogowe polegające na przejeździe pojazdu bez silników wbudowanych w koła przez przeszkodę ze stałą prędkością. Podczas badań mierzono pionowe przemieszczenia środków kół pojazdu. W procesie walidacji modyfikowano parametry kontaktu koła z nawierzchnią, współczynniki sztywności sprężyn zawieszenia oraz współczynniki tłumienia amortyzatorów, tak aby otrzymać akceptowalną zgodność wyników numerycznych z eksperymentem. Dostrojony model symulacyjny został dalej użyty do symulacji ruchu zawieszenia z silnikami wbudowanymi w koła. Otrzymane wyniki dalej porównano z badaniami uzyskując akceptowalną zgodność. W pracy wykonano również szereg symulacji mających na celu zbadanie wpływu współczynników sztywności sprężyn zawieszenia i współczynników tłumienia amortyzatorów na odpowiedź dynamiczną układ tylnego zawieszenia