Search results for "Model-based"

Design of a robust controller for DC/DC converter–electrolyzer systems supplied by μWECSs subject to highly fluctuating wind speed

2020

Abstract A buck-based, isolated, high-voltage-ratio DC/DC converter that allows supplying a proton exchange membrane (PEM) electrolyzer from a micro-wind energy conversion system ( μ WECS) has been recently presented. It exhibits low ripple at the switching frequency on the output voltage and current and represents an attractive solution for low-cost hydrogen production. In this paper, a more accurate mathematical model of such a converter is derived and discussed. Then, a model-based robust controller is designed in the frequency domain using the Internal Model Control structure and in the context of H 2 ∕ H ∞ optimal control. The controller satisfies the condition of robust stability and …

Model-based design of RNA hybridization networks implemented in living cells

2017

[EN] Synthetic gene circuits allow the behavior of living cells to be reprogrammed, and non-coding small RNAs (sRNAs) are increasingly being used as programmable regulators of gene expression. However, sRNAs (natural or synthetic) are generally used to regulate single target genes, while complex dynamic behaviors would require networks of sRNAs regulating each other. Here, we report a strategy for implementing such networks that exploits hybridization reactions carried out exclusively by multifaceted sRNAs that are both targets of and triggers for other sRNAs. These networks are ultimately coupled to the control of gene expression. We relied on a thermo-dynamic model of the different stable…

Abductive Reasoning and Linguistic Meaning

2006

Register data in sample allocations for small-area estimation

2018

The inadequate control of sample sizes in surveys using stratified sampling and area estimation may occur when the overall sample size is small or auxiliary information is insufficiently used. Very small sample sizes are possible for some areas. The proposed allocation based on multi-objective optimization uses a small-area model and estimation method and semi-collected empirical data annually collected empirical data. The assessment of its performance at the area and at the population levels is based on design-based sample simulations. Five previously developed allocations serve as references. The model-based estimator is more accurate than the design-based Horvitz–Thompson estimator and t…

Analysis and Visualization of Product Memory Layout in IP-XACT

2017

Modern ASIC and FPGA based embedded products use model based design, in which both hardware and software are developed in parallel. Previously HW was completed first and the information handed over to SW team, typically in the form of register tables. The information was even manually copied to SW code, making any changes error-prone and laborious. IP-XACT is the most feasible standard to model HW also for the SW needs. The HW design connectivity and overall memory layout may change due to component instantiations, configurations and conditional operation states, which makes it difficult to create register tables even for documentation. Current register design tools fall short in serving th…

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…

Optimal airline seat inventory control for multi‐leg flights

2004

Airline seat inventory control is about “selling the right seats to the right people at the right time”. In this paper, the problem of determining optimal booking policy for multiple fare classes in a pool of identical seats for multi‐leg flights is considered. During the time prior to departure of a multi‐leg flight, decisions must be made concerning the allocation of reserved seats to passengers requesting space on the full or partial spans of the flight. It will be noted that in the case of multi‐leg flights the long‐haul passengers are often unable to obtain seats because the shorter‐haul passengers block them. For large commercial airlines, efficiently setting and updating seat allocat…

Globally convergent adaptive and robust control of robotic manipulators for trajectory tracking

2004

This paper deals with a globally convergent adaptive and robust control of robotic manipulators for trajectory tracking in the presence of friction modelled as static nonlinearities. Two control loops are designed according to the cascade control scheme: (a) an inner adaptive control loop, which includes computed torque and PD control actions and friction compensation and (b) an outer robust control loop for unmodelled dynamics compensation. With reference to item (a), two friction compensation schemes are presented; one of them uses both the reference and the actual velocities, whereas the other employs only the actual velocity. Experimental tests carried out on a two-link SCARA manipulato…

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 …

Penalization and data reduction of auxiliary variables in survey sampling

2012

Survey sampling techniques are quite useful in a way to estimate population parameterssuch as the population total when the large dimensional auxiliary data setis available. This thesis deals with the estimation of population total in presenceof ill-conditioned large data set.In the first chapter, we give some basic definitions that will be used in thelater chapters. The Horvitz-Thompson estimator is defined as an estimator whichdoes not use auxiliary variables. Along with, calibration technique is defined toincorporate the auxiliary variables for sake of improvement in the estimation ofpopulation totals for a fixed sample size.The second chapter is a part of a review article about ridge re…