Search results for "Design"
showing 10 items of 5885 documents
Optimal damping coefficient for a class of continuous contact models
2020
AbstractIn this study, we develop an analytical formula to approximate the damping coefficient as a function of the coefficient of restitution for a class of continuous contact models. The contact force is generated by a logical point-to-point force element consisting of a linear damper connected in parallel to a spring with Hertz force–penetration characteristic, while the exponent of deformation of the Hertz spring can vary between one and two. In this nonlinear model, it is assumed that the bodies start to separate when the contact force becomes zero. After separation, either the restitution continues or a permanent penetration is achieved. Therefore, this model is capable of addressing …
Analysis and simulations of the primary frequency control during a system split in continental europe power system
2021
The occurrence of system separations in the power system of Continental Europe has been observed in recent decades as a critical event which might cause power imbalances higher than the reference incident specified per system design, representing an actual challenge for the stability and safe operation of the system. This work presents an analysis and simulations of the primary frequency control in the Continental Europe synchronous area in conditions of system separation. The adopted approach is based on fundamental aspects of the frequency-containment reserve process. The analysis takes an actual event into consideration, which determined the separation of the system in January 2021. The …
A General Investigation on the Differential Leakage Factor for Symmetrical and Asymmetrical Multiphase Winding Design
2020
This work provides an investigation based on a fast estimation of the degree of unbalance (D.U.%) and the differential leakage factor (&sigma
Evaluating Accessibility and Usability of an Experimental Situational Awareness Room
2018
New advanced emergency management facilities such as a control room which is equipped with advanced ICT technologies should consider universal design principles and ensure the accessibility and usability of some important technical functions available in the room. This paper aims at evaluating the accessibility and usability of an experimental control room. This room has a flexible architecture, i.e., the information displays are interchangeable through drag-drop system on a control-panel. We used a complementary heuristic and user testing approach. A video analysis, open questionnaire and discussion with testers were applied to detect technology usage barriers. The results show that the pr…
Precise vs General Feedback in Reducing Field-Dependence
1980
Summary.-To investigate the effect of feedback on performance of the Rod-and-frame Test the standard test procedure mas altered. The result of the alteration was a procedure which was called the Rod-and-frame Test as a Learning Task. On this task the subiect has to adjust the rod to the vertical twice in succession from each tilting position, whereby he is permitred a maximum of 10 trials in each tilting position and a range of tolerance of elo. After each trial the subject is given feedback about his performance. An experiment was conducted with 30 male and 30 female students to investigate whether a precise feedback giving both the direction and the degree of the rod's deviation from the …
Model Based Design Optimization of Operational Reliability in Offshore Boom Cranes
2013
AbstractThis paper presents a model based approach for design of reliable electro-hydraulic motion control systems for offshore material handling cranes. The approach targets the system engineer and is based on steady-state computations, dynamic time domain simulation and numerical optimization.In general, the modelling takes into account the limited access to component data normally encountered by engineers working with system design. A system model is presented which includes the most important characteristics of both mechanical system and hydraulic components such as the directional control valve and the counterbalance valve.The model is used to optimize the performance of an initial des…
Analysis of Offshore Knuckle Boom Crane - Part Two: Motion Control
2013
In this paper design of electro-hydraulic motion control systems for offshore knuckle boom cranes is discussed. The influence of the control valve bandwidth along with the ramp time for the control signal are investigated both analytically with simplified system models and numerically with an experimentally verified crane model. The results of both types of investigations are related to general design rules for selection of control valves and ramp times and the relevance of these design rules is discussed. Generally, they are useful but may be too conservative for offshore knuckle boom cranes. However, as demonstrated in the paper, the only proper way to determine this is to evaluate the mo…
A boundary controllability approach in optimal shape design problems
2005
We indicate a formulation of optimal shape design problems as boundary control problems, based on some approximate controllability-type results. Numerical examples and a comparison with the standard method are included.
Controllability-type properties for elliptic systems and applications
1991
We consider approximate and exact controllability results for elliptic problems. These results enable one to formulate optimal shape design problems in a fixed domain with certain boundary conditions.
Quantized State-Feedback Stabilization for Delayed Markovian Jump Linear Systems with Generally Incomplete Transition Rates
2014
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2014/961925 open Access This paper is concerned with the robust quantized state-feedback controller design problem for a class of continuous-time Markovian jump linear uncertain systems with general uncertain transition rates and input quantization. The uncertainties under consideration emerge in both system parameters and mode transition rates. This new uncertain model is more general than the existing ones and can be applicable to more practical situations because each transition rate can be completely unknown or only its estimate value is known. B…