Search results for "loop"
showing 10 items of 608 documents
Testing of cooperative tasks for Unmanned Aerial and ground platforms
2014
In the last years the Model Based Design for Unmanned Systems aided the safe and rational release of applications running on unmanned systems. In particular in this paper we focus on a hybrid methodology that merges Software in the Loop (SIL) and Model in the Loop (MIL) strategies for cooperative tasks performed by aerial and ground autonomous vehicles. The proposed work flow covers the design and testing of Ground Control Station (GCS) modelled by a finite state machine, the design and testing of navigation code running on UAV and UGV and the testing of cooperative missions. The work-flow is based on a realistic 3D physical simulator interfaced with Matlab-Simulink-Stafeflow. The proposed …
A model of goal dynamics in technology-based organizations
2011
The purpose of the present work is to build a suitable system dynamics model for goal dynamics in organizations, as proposed by Barlas and Yasarcan (2008). The proposed model does not bear any ambition of being exhaustive: the main objective of this paper is to propose a model of goal dynamics in which Goal Setting, Management by Objectives and Training are viewed as human resource practices able to enhance workers' goal commitment, and therefore, improve organizational performance. In the first part of this paper, an analysis of the Goal Setting Theory and the role of goal setting practices, in bettering worker's performance, are stressed. In the second part, a case-study, the causal loop …
Synchronization techniques for power quality instruments
2004
The measurement of voltage characteristics in power systems requires the accurate estimation of the power supply frequency and signal synchronization, even in the presence of disturbances. The authors developed and tested two innovative techniques for instrument synchronization. The first is based on signal spectral analysis techniques performed by means of the Chirp-Z transform analysis. The second is a phase-locked loop (PLL) software based on a time-domain coordinate transformation and an innovative phase-detection technique. To evaluate how synchronization techniques are adversely affected by the application of a disturbing influence, experimental tests were carried out, taking into acc…
Performances Comparison for a Rotating Shaft Suspended by 4-Axis Radial Active Magnetic Bearings via 𝜇 -Synthesis, Loop-Shaping Design, and Sub ( 𝐻…
2011
The control systems applied on active magnetic bearing are several. A perfect levitation is characterized by maintaining the operating point condition that is characterized by the center of stator coincident with the geometric center of shaft. The first controller implemented for this purpose is PID controller that is characterized by an algorithm that leads the amplifier to produce control current until the operating point condition is not reached, this is obtained by an integration operator. The effect of an integrator is essential but not necessary for a centered levitation for example in the robust control characterized by a dynamic model depended on plant of system so that it depends o…
Linear parameter‐varying modelling and control of an offshore wind turbine with constrained information
2014
This study deals with linear parameter-varying modelling and output-feedback H ∞ control design for an offshore wind turbine. The controller is designed with consideration that not all the information in the feedback loop will be used. This constraint is incorporated into the design procedure. Constrained information means that a special zero-non-zero pattern is forced upon the gain matrix. The constrained controller is obtained based on parameter-dependent Lyapunov functions and formulated in terms of linear-matrix inequalities. Since the functions are dependent on the wind speed and accurate wind speed measurements are rarely available in practice, an extended Kalman filter is used to est…
Fiber - Optic Loop Network With Active Nodes For An Electrical Power Plant
1990
This paper presents a fiber optic loop network for a measurement and control system of an electric power plant. The network consists of the central computer terminal, the set of specially distributed digital FO links and local station installed at the important power facilities. The well-known FO link advantages contribUte to high reliability and safety of work of the system. The operation of the loop network, treated as an autonomous one, is controlled by a microcomputer system. Transmission protocols and the cooperation with the local station are also described. The proposed loop network model is illustrated with an example of the laboratory - scale system.
Adaptation of two-state (binary) optical fibre loop sensors for industrial use
2005
The paper presents an attempt to unify the construction of two state optical fibre loop sensor and possibility of adapting it to the various traditional constructions and casings of industrial sensors. This enables module structure of sensors based on construction of industrial application (master) and mensurative optical fibre loop (slave). Mensurative properties are determined by traditional (mainly mechanical) measuring system ex. temperature, displacement, and optical properties are determined by characteristics of auxiliary optical system (standardised and unified). Such attitude to a subject is illustrated in this paper by the examples of threshold displacement sensor, temperature, vo…
ARIANNA: a smartphone-based navigation system with human in the loop
2014
In this paper we present a low cost navigation system, called ARIANNA, primarily designed for visually impaired people. ARIANNA (pAth Recognition for Indoor Assisted NavigatioN with Augmented perception) permits to find some points of interests in an indoor environment by following a path painted or sticked on the floor. The path is detected by the camera of the smartphone which also generates a vibration signal providing a feedback to the user for correcting his/her direction. Some special landmarks can be deployed along the path for coding additional information detectable by the camera. In order to study the practical feasibility of the ARIANNA system for human users that want to follow …
Mitigation of 50 Hz magnetic field produced by an overhead transmission line
2015
Power transmission utilities are challenged by the need to expand transmission system capacity to meet growing energy demands. The impact of high voltage overhead transmission lines on the environment represents a hot topic in the context of transport and distribution of electrical energy. In particular, interest towards the effects of extra low frequency (ELF) magnetic fields generated by high-voltage power transmission lines has been increasing significantly during the last decade, giving rise to a number of policy initiatives and research activities. Therefore, the evaluation of the magnetic field generated by conductors of overhead lines is of primary importance in order to develop meth…
Hidden oscillations in aircraft flight control system with input saturation
2013
Abstract The presence of actuator saturation can dramatically degrade the system performance. Since the feedback loop is broken when the actuator saturates the unstable modes of the regulator may then drift to undesirable values. The consequences are that undesired nonlinear oscillations appear and that the settling time may unacceptably increase. Rigorous analysis of nonlinear aircraft models is a very difficult task, that is why a numerical simulation is often used as an analysis and design tool. In this paper difficulties of numerical analysis related to the existence of hidden oscillations in the aircraft control system are demonstrated.