Economic MPC with periodic terminal constraints of nonlinear differential-algebraic-equation systems: Application to drinking water networks

© 2026 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksIn this paper, an Economic Model Predictive Control (EMPC) strategy with periodic terminal constraints is addressed for nonlinear differential-algebraic-equation systems with an application to Drinking Water Networks (DWNs). DWNs have some periodic behaviours because of the daily seasonality of water demands and electrical energy price. The periodic terminal constraint and economic terminal cost are implemented in the EMPC controller design for the purpose of achieving convergence. The feasibility of the proposed EMPC strategy when disturbances are considered is guaranteed by means of soft constraints implemented by using slack variables. Finally, the comparison results in a case study of the D-Town water network is provided by applying the EMPC strategy with or without periodic terminal constraints.Accepted versio

CMOS 2.4μm chaotic oscillator: Experimental verification of chaotic encryption of audio

The Letter reports the first experimental verification of chaotic encryption of audio using custom monolithic chaotic oscillators. We use Gm-C techniques to realise a chaotic modulator/ demodulator IC that implements a 3rd-order nonlinear differential equation. This has been fabricated in 2.4μm double-poly technology and includes on-chip tuning circuitry based on amplitude detection. Measurements demonstrate how to exploit the synchronisation between two of these ICs for encrypted transmission

Live demonstration: Real-time high dynamic range video acquisition using in-pixel adaptive content-aware tone mapping compression

This demonstration targets the acquisition of realtime video sequences involving High Dynamic Range (HDR) scenes. Adaptation to different illumination conditions while preserving contrast is achieved by using a sensor chip, which implements an adaptive content-aware tone mapping compression algorithm by using in-pixel circuitry. Its response gets adapted to changing illumination conditions by using at each frame a statistical estimation of the light distribution, which is derived from the HDR histogram calculated at the previous frame. This method allows adaptive HDR video, while capable to capture very large DR scenes including moving objects.Office of Naval Research (USA) N000141410355Ministerio de Economía y Competitividad IPT-2011-1625-430000Junta de Andalucía TIC 2338-201

Economic health-aware LPV-MPC based on system reliability assessment for water transport network

This paper proposes a health-aware control approach for drinking water transport networks. This approach is based on an economic model predictive control (MPC) that considers an additional goal with the aim of extending the components and system reliability. The components and system reliability are incorporated into the MPC model using a Linear Parameter Varying (LPV) modeling approach. The MPC controller uses additionally an economic objective function that determines the optimal filling/emptying sequence of the tanks considering that electricity price varies between day and night and that the demand also follows a 24-h repetitive pattern. The proposed LPV-MPC control approach allows considering the model nonlinearities by embedding them in the parameters. The values of these varying parameters are updated at each iteration taking into account the new values of the scheduling variables. In this way, the optimization problem associated with the MPC problem is solved by means of Quadratic Programming (QP) to avoid the use of nonlinear programming. This iterative approach reduces the computational load compared to the solution of a nonlinear optimization problem. A case study based on the Barcelona water transport network is used for assessing the proposed approach performance.Peer ReviewedPostprint (published version

SpotEgg: An image-processing tool for automatised analysis of colouration and spottiness

Colouration and patterning are widespread amongst organisms. Regarding avian eggs, colouration (reflectances) has been previously measured using spectrometers whereas spottiness has been determined using human-based scoring methods or by applying global thresholding over the luminance channel on photographs. However, the availability of powerful computers and digital image-processing algorithms and software offers new possibilities to develop systematised, automatable, and accurate methods to characterise visual information in eggs. Here, we provide a computing infrastructure (library of functions and a Graphical User Interface) for eggshell colouration and spottiness analysis called SpotEgg, which runs over MATLAB. Compared to previous methods, our method offers four novelties for eggshell visual analysis. First, we have developed a standardised non-human biased method to determine spottiness. Spottiness determination is based on four parameters that allow direct comparisons between studies and may improve results when relating colouration and patterning to pigment extraction. Second, researcher time devoted to routine tasks is remarkably reduced thanks to the incorporation of image-processing techniques that automatically detect the colour reference chart and egg-like shapes in the scene. Third, SpotEgg reduces the errors in colour estimation through the eggshell that are created by the different angles of view subtended from different parts of the eggshell and the optical centre of the camera. Fourth, SpotEgg runs automatic Fractal Dimension analysis (a measure of how the details in a pattern change with the scale at which this pattern is measured) of the spots pattern in case researchers want to relate other measurements with this special spatial pattern. Finally, although initially conceived for eggshell analysis, SpotEgg can also be applied in images containing objects different from eggs as feathers, frogs, insects, etc., since it allows the user to manually draw any region to be analysed making this tool useful not only for oologist but also for other evolutionary biologists.Peer reviewe

Macromodelling for analog design and robustness boosting in bio-inspired computing models

Setting specifications for the electronic implementation of biological neural-network-like vision systems on-chip is not straightforward, neither it is to simulate the resulting circuit. The structure of these systems leads to a netlist of more than 100.000 nodes for a small array of 100×150 pixels. Moreover, introducing an optical input in the low level simulation is nowadays not feasible with standard electrical simulation environments. Given that, to accomplish the task of integrating those systems in silicon to build compact, low power consuming, and reliable systems, a previous step in the standard analog electronic design flux should be introduced. Here a methodology to make the translation from the biological model to circuit-level specifications for electronic design is proposed. The purpose is to include non ideal effects as mismatching, noise, leakages, supply degradation, feedthrough, and temperature of operation in a high level description of the implementation, in order to accomplish behavioural simulations that require less computational effort and resources. A particular case study is presented, the analog electronic implementation of the locust's Lobula Giant Movement Detector (LGMD), a neural structure that fires a collision alarm based on visual information. The final goal is a collision threat detection vision system on-chip for automotive applications.European Union IST-2001-38097, TIC2003 - 09817-C02-0

Integrated Circuitry to Detect Slippage Inspired by Human Skin and Artificial Retinas

This paper presents a bioinspired integrated tactile coprocessor that is able to generate a warning in the case of slippage via the data provided by a tactile sensor. Some implementations use different layers of piezoresistive and piezoelectric materials to build upon the raw sensor and obtain the static (pressure) as well as the dynamic (slippage) information. In this paper, a simple raw sensor is used, and a circuitry is implemented, which is able to extract the dynamic information from a single piezoresistive layer. The circuitry was inspired by structures found in human skin and retina, as they are biological systems made up of a dense network of receptors. It is largely based on an artificial retina , which is able to detect motion by using relatively simple spatial temporal dynamics. The circuitry was adapted to respond in the bandwidth of microvibrations produced by early slippage, resembling human skin. Experimental measurements from a chip implemented in a 0.35-mum four-metal two-poly standard CMOS process are presented to show both the performance of the building blocks included in each processing node and the operation of the whole system as a detector of early slippage.Ministerio de Economía y Competitividad TEC2006-12376-C02-01Gobierno de España TEC2006- 1572

ACE16K: A 128×128 focal plane analog processor with digital I/O

This paper presents a new generation 128×128 focal-plane analog programmable array processor (FPAPAP), from a system level perspective, which has been manufactured in a 0.35 μm standard digital 1P-5M CMOS technology. The chip has been designed to achieve the high-speed and moderate-accuracy (8b) requirements of most real time early-vision processing applications. It is easily embedded in conventional digital hosting systems: external data interchange and control are completely digital. The chip contains close to four millions transistors, 90% of them working in analog mode, and exhibits a relatively low power consumption-<4 W, i.e. less than 1 μW per transistor. Computing vs. power peak values are in the order of 1 TeraOPS/W, while maintained VGA processing throughputs of 100 frames/s are possible with about 10-20 basic image processing tasks on each frame

A processing element architecture for high-density focal plane analog programmable array processors

The architecture of the elementary Processing Element - PE- used in a recently designed 128×128 Focal Plane Analog Programmable Array Processor is presented. The PE architecture contains the required building blocks to implement bifurcated data flow vision algorithms based on the execution of 3 × 3 convolution masks. The vision chip has been implemented in a standard 0.35μm CMOS technology. The main PE related figures are: 180 cells/mm2, 18 MOPS/cell, and 180 μW/cell.Office of Naval Research (USA) N68171-98-C-9004Euopean Union IST-1999-19007Comisión Interministerial de Ciencia y Tecnología TIC1 999-082

Integrated circuit interface for artificial skins

Artificial sensitive skins are intended to emulate the human skin to improve the skills of robots and machinery in complex unstructured environments. They are basically smart arrays of pressure sensors. As in the case of artificial retinas, one problem to solve is the management of the huge amount of information that such arrays provide, especially if this information should be used by a central processing unit to implement some control algorithms. An approach to manage such information is to increment the signal processing performed close to the sensor in order to extract the useful information and reduce the errors caused by long wires. This paper proposes the use of voltage to frequency converters to implement a quite straightforward analog to digital conversion as front end interface to digital circuitry in a smart tactile sensor. The circuitry commonly implemented to read out the information from a piezoresistive tactile sensor can be modified to turn it into an array of voltage to frequency converters. This is carried out in this paper, where the feasibility of the idea is shown through simulations and its performance is discussed.Gobierno de España TEC2006-12376-C02-01, TEC2006-1572