1,721,051 research outputs found
Global modeling and simulation for analysis and design of a railway vehicle
No full textIn this paper the equivalent global dynamic model of a railway vehicle is presented. The dynamic model is based on the following fundamental submodels: inverter, asynchronous motor, train, brake, controller. These submodels, even if interacting, are developed such that they can be modified independently. Moreover, they are characterized by a minimum number of parameters and by a relatively simple mathematical structure, in order to properly describe the corresponding system, to be identified by relatively simple dynamical tests and be used by a single specialist. It is also proposed a sufficiently robust minimum energy controller. Finally several simulation results are reported that demonstrate the validity and the usefulness of the proposed dynamic model and the controller efficiency
DIRECT SYNTHESIS OF RELAY CONTROL SYSTEMS
No full textRelay control systems are widely employed in industry
because of their realization simplicity and of their high
work efficiency. Nevertheless, there are numerous
related theoretical and practical issues that need to be
further investigated. In particular, while the stability and
the limit cycle analyses can be considered sufficiently
assessed, the synthesis problem of relay controllers has
not been considered systematically.
In this paper a method for the direct design of relay
control systems is provided that makes use of graphs and
tables. Such graphs and tables are obtained by an
analytical/numerical technique optimised with respect to
the number of parameters that characterise both the
plant and the relay controller.
The effectiveness of the method is illustrated by the
solution of a practical engineering problem
NEW CONDITIONS FOR ROBUST STABILITY OF LINEAR SYSTEMS SUBJECT TO A BOUNDED RATE PARAMETER
No full textNEW RESULTS ON ROBOT MODELING AND SIMULATION
No full textIn this paper the possibility of simulating the robot forward dynamics by making use of the inertia matrix and of the kinetic energy gradient only is demonstrated. Such method is shown to be simpler and numerically more efficient than the classical approaches.
In the case of planar robots with revolute joints and link centers of mass belonging to the plane containing the rotating axes of the joints, theorems are formulated and demonstrated providing a relatively fast and simple method of calculation for both the inertia matrix and the gradient of the kinetic energy. This allows obtaining a simple and efficient tool to simulate practical robots with rigid links and can also be particularly useful for studying robots with flexible links.
By using the proposed approach, the model of a practical planar robot, designed by the CAD software package CATIATM, is easily developed and implemented. The simulation results when the gradient of the kinetic energy is computed analytically versus numerically are compared to illustrate that the computational costs are relatively low and the accuracy is high
ROBUST STABILITY ANALYSIS VIA A STATISTICAL APPROACH OF UNCERTAIN LINEAR SYSTEMS SUBJECT TO BOUNDED RATE PARAMETERS
No full textSVILUPPO DI UN SIMULATORE DINAMICO E REALIZZAZIONE HARDWARE/SOFTWARE DI UN SISTEMA PROTOTIPALE PER LA STABILIZZAZIONE A ROLLIO DI UNA NAVE
No full textSVILUPPO DI UN SIMULATORE DINAMICO DEL SISTEMA NAVE-MARE-SENSORI-ATTUATORI-PINNE-CONTROLLORE. REALIZZAZIONE CON MICROCONTROLLORI DI UN SISTEMA PROTOTIPALE (INTERFACCIA UOMO-MACCHINA, CONDIZIONAMENTO DEI SEGNALI I/O, CONTROLLORE) PER LA STABILIZZAZIONE A ROLLIO DI UNA NAV
LOW COST CONTROL OF AN OFFSHORE OIL LOADING SYSTEM
No full textShip tankers, used as floating oil storage and export units, are very sensitive to environmental conditions, and their position keeping during a loading operation may be a critical point.
For relatively deep wells and harsh environments, the ship is moored at an Articulated Loading Column with a single point mooring system. Nevertheless, for assuring a better positioning and/or uninterrupted loading operations, tankers with additional dynamic positioning capability are employed.
In this paper a hybrid control strategy for the ship dynamic positioning is proposed. The control aim is to reduce the plant capital and running costs, trying to pursue a tradeoff between the maximization of a safety index and the minimization of the control effort. For limiting the power peaks and the total energy spent during each loading operation, it is also planned to utilize the main propulsion system to counteract too severe weather conditions.
Starting from almost realistic data for the tanker, the mooring, the flexible articulated loading column and the thrusters, and from a statistical characterization of the disturbances and the uncertain dynamics, some simulation results are produced to prove the energy efficiency and show the good performance of the designed controller
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