Search results for "Simulation."
showing 10 items of 4779 documents
Cost Analysis of FMS Throughput
1988
Abstract The need for an effective cost planning and control system is stressed in today highly competitive manufacturing environment. The conventional approaches of machining economics to cost analysis are no more able to cope with the new structure of the production costs in the highly automated - highly integrated manufacturing systems. Suitable cost analysis procedures should provide a strong integration between process planning data and overall system performances. The here proposed procedure for the estimate of the unit manufacturing cost in FMSs achieves this integration by using performance evaluation techniques like discrete event simulation or queueing network models.
A Geometrical Simple Approach for Power Silicon Devices Fault Detection and Fault-Tolerant Operation of a Voltage Source Inverter
2012
Fault-tolerant converters have been widely investigated for years and nowadays an extensive technical literature on this field exists. This paper presents a novel fault detection algorithm based on a simple geometrical approach. In the algorithm analysis both the case of faults in single device and the lose of an entire inverter leg have been considered. False positive detections are avoided by considering a proper number of current samples. The proposed fault detection algorithm is characterized by simplicity, low computational and implementation effort with a consequent enough fast execution, easy control integration with the possibility to use it both in hardware in the loop systems and …
Autonomous patrol and surveillance system using unmanned aerial vehicles
2015
Unmanned aerial vehicles (UAVs) are increasingly popular for civil applications due to their flight capabilities and mobility. This paper proposes an indoor autonomous patrol and surveillance system using unmanned aerial vehicles. The system consists of six components: (1) a low cost vision-based pose estimation of UAVs, (2) vision-based state estimation, (3) UAV patrol path planning, (4) UAV controller to desired waypoints, (5) manual joystick controller and (6) assignment of priority hierarchy to multiple control inputs of a robot. The components were integrated successfully and the designed system was experimented in an indoor setup. Results has shown that the proposed system is suitable…
Zigler-Nicols PID Tuning Method for Position Control of a Mobile Robot
2016
This paper presents the implementation and the tuning of PID controller for a mobile platform with differential steering. It presents a mobile platform built in the Department of Industrial Machinery & Equipment, of the Engineering Faculty of Sibiu for an European contest. In a first phase, a brief introduction to PID controller is made, followed by a description of the various robot's components and traction principles underlying locomotion of mobile platforms. At the end the paper contains several principles of tuning the PID controller for the mobile robot.
Finite Element Method Analysis of a Spur Gear with a Corrected Profile
2007
The difference between the stress value calculated by a two-dimensional finite element model of spur gears and those obtained by the rules in ISO 6336 was evaluated. Hertz theory, which provides information on the extension of the contact area and the maximum value of the contact pressure, was used to choose the dimensions of the elements. The mesh was created using the stress analytical solution relative to a model consisting of two cylinders in contact. Analogous optimization was executed for the mesh of the teeth feet; a mesh of 15 elements was considered optimum, because it minimized the difference to 0.5 per cent in the bending stress calculation. Stress values, obtained using the fin…
Application of an energy model for fatigue life prediction of construction steels under bending, torsion and synchronous bending and torsion
2003
Abstract The paper contains a mathematical model of the material’s behaviour under cyclic loading taking into account the dynamics of the fatigue process, including the number of cycles to failure, induced by the mean stress value. The coefficients in the proposed model have been obtained from experimental tests under symmetrical and nonsymmetrical loading (with the stress ratio R =0). The proposed model has been used in order to modify an energy criterion with the aim of accounting for the influence of the mean stress on the fatigue life. The fatigue tests have been performed for structural steels 10HNAP and 18G2A subjected to cyclic bending, torsion and synchronous bending with torsion, b…
Past, Present and Future of Process Control at Xstrata Nikkelverk
2009
MIC celebrates its 30th anniversary in 2009 and Xstrata Nikkelverk celebrates its 100th anniversary in 2010. Both anniversaries are certainly worth celebrating and with this article Xstrata Nikkelverk salutes MIC at this special occasion. This article is about process control developments at Xstrata Nikkelverk during the last 40 years. We also give an overview of the current status and a view on the current and future trends of process control at the Nikkelverk renery.
daptive Backstepping Control of Nonlinear Hydraulic-Mechanical System Including Valve Dynamics
2010
Published version of an article from the journal: Modeling Identification and Control. Also available from publisher: http://dx.doi.org/10.4173/mic.2010.1.3 The main contribution of the paper is the development of an adaptive backstepping controller for a nonlinear hydraulic-mechanical system considering valve dynamics. The paper also compares the performance of two variants of an adaptive backstepping tracking controller with a simple PI controller. The results show that the backstepping controller considering valve dynamics achieves significantly better tracking performance than the PI controller, while handling uncertain parameters related to internal leakage, friction, the orifice equat…
Load Optimization in Endurance Sports by Means of Antagonistic Dynamical Models
2012
Abstract Prediction of performance dynamics as well as planning and control of corresponding optimal load profiles are difficult tasks in endurance sports. The reason is that fatigue and recovery are effective with delays. I. e. a small overload in the start phase can cause a collapse long time later. Such interaction between load and performance can be modelled by means of antagonistic models like PerPot and then can help to optimize performance together with avoiding overload. Based on a lot of positive results extensions of PerPot have been developed, which are now able to determine the individual anaerobe threshold (IAT) by simulation, giving heart rate oriented load scheduling a new qu…
Finite element analysis of two total knee joint prostheses
2012
Aim of this work is to compare two different total knee prostheses that differ mainly in the shape of the polyethylene (PE) component inserted between the femoral and tibial plates. The best solution between them has been originally reshaped in order to reduce stress peaks. The study procedure has been divided into the following steps. First step is the digitalisation of the shape of the prostheses by means of a 3D laser scanner. The morphology of two prototypes of the prostheses has been acquired by elaborating multiple Moire fringe patterns projected on their surfaces. Second step consisted on the manipulation of these data in a CAD module, that is the interpolation of raw data into NURBS…