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Parameter estimation of a supercapacitor model that uses PDEs to describe electrochemical physical phenomena is studied. The model parameters were identified from time domain charge/discharge data and also from frequency domain data in the form of electrical impedance spectroscopy at different open cell voltages. The identified physical model could fairly accurately simulate the experimental data,...
This paper is focused on a two-tank molten salt sensible Thermal Energy Storage (TES) that exchanges heat with a Concentrated Solar Plant (CSP) in a indirect active way. A detailed dynamical model that reproduces the physical behavior of a two-tank molten salt sensible TES is presented first. Then a control strategy is designed to regulate the enthalpy of the CSP fluid after charging or discharging...
In this paper we present a new approach to obtain pointwise Thévenin equivalents from electrical measurements of non-linear sources. The classical technique to obtain the Thévenin equivalent can not find equivalent circuits of nonlinear sources. Using pointwise Thévenin equivalents it is possible to obtain equivalent circuits for non-linear sources point by point of operation. We used a photovoltaic...
This paper explores a control architecture for a solar furnace that uses active cooling to improve the temperature reference tracking during the decreasing phase of the reference. This is done in conjunction with the command of the shutter that adjusts the incident power and compensates sun power variability due to weather conditions. The controller uses exact linerization coupled with a PI controller...
This paper investigates identification of key parameters in a control oriented dynamic model of an absorption heat pump used in a district heating system. Automatic identification or improvement of manually tuned parameters can speed up model development and improve the accuracy of estimation of, e.g., heat transfers in the system, which is important for optimization of the district heating plant...
This paper focuses on the modeling and simulation of parabolic trough solar fields in situations of partial covering of the solar field by clouds. In these situations incident solar radiation on the field is different for each loop of it, so it is necessary to model a field that takes into account this radiation distribution. Then, the effect of passing clouds has been studied in order to show how...
Model-plant mismatch in model predictive controlled industrial processes is a phenomenon that may lead to relevant performance losses. Research in finding a suitable procedure to effectively detect and revert model plant mismatch often uses distillation columns as benchmark testing models. However, it was found that sub optimal distillation columns and control configurations were used in these studies...
This paper describes the steady-state parameter identification process of the components which constitute a vapour-compression refrigeration cycle. Particularly relevant is the heat exchanger steady-state parameter identification due to the refrigerant phase change which occurs during a typical cycle operation. Experimental results that prove the validity of the considered assumptions are shown and...
This paper aims to make the commissioning of an industrial MIMO controller more straightforward by gradually commissioning it from a set of SISO controllers, after the system has been started. For this purpose a stepwise commissioning strategy based on the Youla-Kucera parametrization has been developed. It allows for the gradual transition between any two controllers amongst a set of stabilizing...
Knowledge about where waste water is flowing in waste water networks is essential to optimize the operation of the network pumping stations. However, installation of flow sensors is expensive and requires regular maintenance. This paper proposes an alternative approach where the pumps and the waste water pit are used for estimating both the inflow and the pump flow of the pumping station. Due to the...
The continuous casting (CC) process is a crucial factor in determining quality of steel slabs, therefore directly affecting the scrap percentage and manufacturing costs. By braking or accelerating the liquid steel in the casting mould with the electromagnetic stirring (EMS) technique, the flow speed can remain in an optimal range in terms of slab quality. The EMS device employed in the CC of ArcelorMittal...
This paper studies gain-scheduled composite nonlinear feedback (CNF) control of a continuous stirred tank reactor (CSTR). Inside the reactor, an exothermic chemical reaction occurs, which is commanded from high to low residual concentration. During the transition, the reaction dynamics change through stable-unstable-stable chain while the residual concentration decreases. Therefore, appropriate cooling...
This paper addresses the blended control allocation of the reusable launch vehicles (RLV) during reentry. The continuous aerodynamic control surfaces and the reaction control jets are the two kinds of actuators that provide attitude control moments cooperatively. The blending strategy of the two kinds of actuators is determined using the mixed-integer linear programming method. Due to the strong couplings...
Aeroelastic instabilities due to the interaction between airflow and wings have long constrained the flight envelope of many types of aircrafts. A typical example of these phenomena is fluttering, a self-sustained oscillation in pitch, plunge or flap angle. Control systems and accurate models are then required to describe and suppress this undesired behaviour. However, traditional approaches are based...
Spacecraft autonomy is a crucial aspect of currently developed and future space projects. This paper presents a Markovian Decision Process (MDP) based framework as a way of modeling spacecraft on-board autonomy mechanisms. Its applicability to the three layered autonomous space systems architecture is shown. Special attention is given to its deliberative layer, where Approximate Dynamic Programming...
Future rotorcraft technologies are being researched and developed for the next generation of helicopters that embed active elements in the main rotor blades to improve vibration, noise and performance. On-blade control algorithms restrict the control actions to a finite consecutive number of Fourier coefficients of a periodic control signal. Recently, Quadratic Programming (QP) has been applied to...
In this paper, a novel adaptive failure compensation scheme is designed for near space vehicles (NSVs) which belong to a class of affine nonlinear MIMO systems, prone to actuator float free, stuck and oscillatory failures, unknown in time, pattern and magnitude. The proposed control methodology utilizes a backstepping procedure based on an adaptive finite time disturbance observer to estimate failure...
The objective of this work is to demonstrate the utility of Lyapunov functions in control synthesis for the purpose of maintaining and stabilizing a spacecraft in a circular orbit at the L4 point in the circular restricted three body problem (CR3BP). Incorporating the requirements of a fixed radius orbit and a desired angular momentum, a Lyapunov function is constructed and the requisite analysis...
In order to achieve the best possible performance of a model predictive controller (MPC) for a given set of resources, the software algorithm and computational platform have to be designed simultaneously. Moreover, in practical applications the controller design problem has a multi-objective nature: performance is traded off against computational hardware resource usage, namely time, energy and space...
A combinatorial approach has been recently proposed for multi-parametric quadratic programming and has shown to be more effective in finding the complete solution than existing geometric methods for higher-order systems. In this paper, we propose a method for exploring the combinatorial tree which exploits some of the underlying geometric properties of adjacent critical regions as the supplementary...
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