Search results for "Simulation."
showing 10 items of 4779 documents
Analysis of Offshore Knuckle Boom Crane - Part One: Modeling and Parameter Identification
2013
This paper presents an extensive model of a knuckle boom crane used for pipe handling on offshore drilling rigs. The mechanical system is modeled as a multi-body system and includes the structural flexibility and damping. The motion control system model includes the main components of the crane's electro-hydraulic actuation system. For this a novel black-box model for counterbalance valves is presented, which uses two different pressure ratios to compute the flow through the valve. Experimental data and parameter identification, based on both numerical optimization and manual tuning, are used to verify the crane model. The demonstrated modeling and parameter identification techniques target…
A standard-compliant prototype for PV module curve detection
2014
In this paper, a prototype for PV module curve detection which features low cost and size and ensures high accuracy is proposed. The proposed architecture is based on a buck-boost converter in open-loop configuration. The proposed architecture is fully compliant with actual standard IEC60904. The duty-cycle control algorithm and its own effects on system performances are accurately investigated. The comparison of different duty-cycle patterns is carried out and performance evaluation is performed. Simulation results are shown to perform a valuable comparison of control algorithms. Preliminary experimental results on a laboratory prototype are presented.
Time-Optimal Synthesis for Three Relevant Problems: The Brockett Integrator, the Grushin Plane and the Martinet Distribution
2015
We construct the time-optimal synthesis for 3 problems that are linear in the control and with polytopic constraints in the controls. Namely, the Brockett integrator, the Grushin plane, and the Martinet distribution. The main purpose is to illustrate the steps in solving an optimal control problem and in particular the use of second order conditions. The Grushin and the Martinet case are particularly important: the first is the prototype of a rank-varying distribution, the second of a non-equiregular structure.
Composite nonlinear feedback control for path following of four-wheel independently actuated autonomous ground vehicles
2015
This paper studies the path following control problem for four-wheel independently actuated (FWIA) autonomous ground vehicles (AGVs) through integrated control of active front-wheel steering (AFS) and direct yaw-moment control (DYC). A modified composite nonlinear feedback (CNF) strategy is proposed to improve the transient performance and eliminate the steady-state errors in the path following control considering the tire force saturations, in the presence of the time-varying road curvature for the desired path. The path following is achieved through vehicle lateral and yaw control, i.e., the lateral velocity and yaw rate are simultaneously controlled to track their respective desired valu…
Scalable and Privacy-Preserving Admission Control for Smart Grids
2015
International audience; Energy demand and production need to be constantly matched in the power grid. The traditional paradigm to continuously adapt the production to the demand is challenged by the increasing penetration of more variable and less predictable energy sources, like solar photovoltaics and wind power. An alternative approach is the so called direct control of some inherently flexible electric loads to shape the demand. Direct control of deferrable loads presents analogies with flow admission control in telecommunication networks: a request for network resources (bandwidth or energy) can be delayed on the basis of the current network status in order to guarantee some performanc…
A Simple Multibody Dynamic Model of Cross-Country Ski-Skating
2013
The purpose of this paper is to present the development of a simple multibody dynamic model matching the observed movements of the center of mass of a skier performing the skating technique in cross-country skiing. The formulation of the equation of motion was made using the Euler–Lagrange equations applied to a multibody tree-type system in three dimensions. The description of the lower limb of the skier and the ski was completed by employing three bodies, one representing the ski, and two representing the natural movements of the leg of the skier. This simple model is able to show an approximation of the movement of the center of mass of the skier and its velocity behavior allowing to stu…
Dynamic characterization for the dielectric electroactive polymer fundamental sheet
2012
Published version of an article published in the journal: International Journal of Advanced Manufacturing Technology. Also available from the publisher at: http://dx.doi.org/10.1007/s00170-012-4423-6 A study into the appropriateness of characterizing the dynamics of the dielectric electroactive polymer (DEAP) fundamental sheet has been performed. Whereby a model describing the dynamics of the DEAP fundamental sheet is developed, parameters of the models are determined using experimental/simulation results, and verification has been conducted to determine the precision of the dynamic model. The precision for the DEAP sheet-obtained dynamic model could not be verified unless some parameters c…
Uncertainty Management in the measurements performed by means of virtual instruments
2008
The uncertainty management is the discipline of optimising the cost of a measurement versus the uncertainty target. In particular, the paper deals with the measurements performed by using a generic virtual instrument. The task is achieved by using the PUMA (procedure for uncertainty management) method that is an iterative technique originally conceived for geometrical and mechanical measurements. The approach is completely based on the "guide to the expression of uncertainty in measurement" rules, but provides a more engineering methodology, since it allows to optimize the cost of the measurements versus the uncertainty target, avoiding the use of inadequate or, on the contrary, too expensi…
Data gathering and mathematical modelling for pitch stabilisation of a high speed catamaran
2011
This paper deals with the data gathering phase for a 21-foot long planing catamaran. The boat experiences a take-off phenomenon at high speed which needs to be countered. An overview of stability problems in high speed hydroplanes is described with possible solutions recommended. A subsequent gathering of data using laser scanning and computational fluid dynamics (CFD) analysis of the boat are described. The paper ends with a look at the initial developments of stabilising systems for the boat.
Machining Economics in FMS by a Fuzzy Approach
1995
Abstract In a conventional manufacturing system, cutting parameters have to be fixed in order to pursue the economical and productive target related to each cutting operation. In a Flexible Manufacturing System (FMS), as a consequence of the unbalanced workload due to the mutual interaction among the shared resources, the optimization of each operation does not allow the optimum of the global production system to be reached. A fuzzy programming model is developed in this paper in order to select cutting speeds of the operations in the production plan as a satisfying compromise solution between single operation and the integrated system targets.