Vehicle lead-acid battery state-of-charge meter

We describe a state-of-charge, or “residual-capacity” meter for lead-acid batteries that intelligently synthesizes coulometric and terminal-voltage methods in a new algorithm to provide reliable, continuous readout of remaining capacity. Novel electronic circuit design eliminates the need to install a shunt in the vehicle. The meter learns the characteristics of a battery to which it is attached, removing the need for setup, customisation, programming or calibration at time of installation or battery replacement. The meter can thus be installed by unqualified personnel. Initial measurements suggest the design to be robust and accurate

Fabrication and Characterization of an Affordable Conditioned Bio-specimen Transporter (Conbiport) for Urban Areas

Many biological and biomedical laboratories in the Greater Jakarta have limited facilities. Problems arise when bio-specimen transports are moved from one laboratory to another. These transports may take hours due to traffic in the Greater Jakarta area. Lengthy transport may be problematic to the research at-hand, since many biological specimens will fail to survive if temperatures exceed 37°C for even a few minutes. When this happens, the condition of the specimen may be compromised or even damaged. To address this problem, we fabricated and tested a conditioned bio-specimen transporter (Conbiport). The Conbiport used a Rubbermaid cooler box as a basis, which is made of high-density polyethylene (HDPE), allowing for temperature preservation. The Conbiport was equipped with an Arduino microcontroller, a heater, a temperature sensor, and its peripheral components so that the temperature inside the Conbiport could be steadily maintained. Four different control system configurations were tested: proportional (P-dom), proportional-derivative (PD-dom), proportional-integral-derivative (PID) and on-off. The results showed that the P-dom configuration exhibited the fastest heat rate. This configuration may provide better portability when it comes to specimen testing, despite the tendency of the temperature to offset from the setpoint. On the other hand, the PID controller provided the most stable temperature preservation, although it took a longer time to achieve the setpoint. Nonetheless, we proved that the Conbiport could maintain the temperature required for specimen transportation in urban areas, such as Greater Jakarta

Variable Speed Simulation for Accelerated Industrial Control System Cyber Training

It is important for industrial control system operators to receive quality training to defend against cyber attacks. Hands-on training exercises with real-world control systems allow operators to learn various defensive techniques and see the real-world impact of changes made to a control system. Cyber attacks and operator actions can have unforeseen effects that take a significant amount of time to manifest and potentially cause physical harm to the system, making high-fidelity training exercises time-consuming and costly. This thesis presents a method for accelerating training exercises by simulating and predicting the effects of a cyber event on a partially-simulated control system. A hardware-in-the-loop system comprised of a software-modeled water tank and a commercially-available programmable logic controller is used to demonstrate the feasibility of this method. The results demonstrate the system\u27s speedup capability which allows users to accurately simulate the effects of a cyber event at speeds faster than real-time

Desenvolupament de la modulació SHE en un inversor NPC de 3 nivells

En el present projecte final de carrera s’ha treballat en l’aplicació de la modulació Selective Harmonic Elimination en inversors de tres nivells de la topologia Neutral Point Clamped. La modulació Selective Harmonic Elimination s’empra en convertidors que processen altes potències, això limita la freqüència de commutació dels transistors per evitar al màxim possible les pèrdues per commutació, mantenint, a la vegada, el compromís d’obtenir una ona de tensió alterna a la sortida de l’inversor amb un baix contingut harmònic. El quid de la modulació rau en generar una ona semi-quadrada a la sortida de l’inversor on els instants de commutació d’aquesta permeten eliminar els harmònics desitjats, que normalment són els de més baix ordre, per facilitar el disseny del filtre de sortida del convertidor. La implementació de la modulació s’ha dut a terme sobre una plataforma experimental present en els laboratoris del Grup de Recerca en Electrònica de Potència, usada en anteriors projectes. Aquesta es composa de dos convertidors de tres nivells de la topologia Neutral-Point-Clamped en configuració back-to-back, dels quals només s’utilitza l’etapa inversora d’aquests, juntament amb els equips necessaris per al control dels convertidors i monitoratge dels senyals elèctrics desitjats. L’objectiu principal proposat és l’obtenció d’una ona de tensió a la sortida de l’inversor on els harmònics 5, 7, 11 i 13 s’hagin eliminat mitjançant aquesta modulació. El projecte es desglossa en les següents parts. Inicialment es realitza un estudi matemàtic de la modulació Selective Harmonic Elimination, adaptada al cas particular de l’inversor utilitzat, trobant-se diferents conjunts de solucions (angles de commutació) per a assolir la cancel·lació de els harmònics prèviament seleccionats. Es realitzen simulacions per estudiar el comportament teòric de les tensions a la sortida de l’inversor. Com a pas previ a la realització de les proves experimentals s’ha adaptat la plataforma experimental a les necessitats del projecte. Finalment, s’han realitzat proves experimentals que ens permeten comparar el comportament teòric de les tensions amb el seu comportament real. Comparant els resultats experimentals amb les simulacions realitzades es pot concloure que la modulació funciona correctament sobre l’inversor, acomplint-se l’objectiu principal del projecte

X-ray microscope performance enhancement through control architecture change

The goal of this thesis is to apply control algorithms to improve the performance of nanopositioning devices used on the beamline in Advanced Photon Source (APS) at Argonne National Laboratory (ANL). A prototype device, better known as the Early User Instrument (EUI) was the subject of this work. It consists of X-ray optics stage group that focuses the X-ray beam as a source-size-limited spot onto a sample held on the sample stage group. The controller algorithms that are used should provide the closed-loop with robust stability, large bandwidth, high resolution, disturbance rejection and noise attenuation. Conveniently, the field of scanning probe microscopes (SPMs) have already flourished on this aspect of controller algorithms proven to give desired closed-loop properties. Controller algorithms such as Proportional Integral Derivative (PID), Glover-McFarlane H-infinty algorithm, and 1DOF H-infinty controller were designed and implemented on the EUI system. The controller hardware used for implementation is National Instruments (NI) CompactRIO hardware that consists of a real-time controller, a FPGA built into the hardware chassis, analog I/O modules, and digital I/O modules. NI LabVIEW, the dedicated software to the NI hardware, was used to represent the discrete controllers as biquads structures that ran in the FPGA as a part of the closed-loop . The largest closed-loop bandwidth achieved is of 65 Hz through the 1DOF H-infinty controller and is a 171% improvement over the traditional PID controller. Highest closed- loop resolution achieved by the EUI with a 50 Hz bandwidth 1DOF H-infinty controller is 1.4 nanometers, which is a 180% improvement over the open loop resolution of 7 nanometers

Desarrollo de software de usuario para sistemas de control predictivo no lineal basado en modelo borroso

Resumen: Los sistemas de control son de gran importancia para poder llevar a operación deseada y óptima los diferentes procesos que generan la cadena productiva de una empresa de manufactura. La implementación de aplicativos de software en la industria presentan entonces una solución para problemas complejos en la operación de dichos procesos. Se plantean entonces en este Trabajo Final de Maestría el desarrollo de un aplicativo de software en el cual se generan sistemas de control predictivo no lineal basado en modelos que hacen uso de métodos de inteligencia artificial para la identificación del proceso y es utilizado dentro del optimizador del controlador debido a la facilidad de operación y la velocidad en el tiempo de respuestaAbstract: In the industry process control systems become very important due to the necessity of maintaining process variables in optimal and desirable values in order to maintain product quality factors and maintain active the productive chain. Implementing software applications in industry also present a solution to complex problems occurring in the processes. In this Master Final Work is shown a development of software application which generate nonlinear predictive control based on models that use artificial intelligence methods for the identification of the process and is used in the controller optimizer, it’s made due the facility of operation and implementation and the improvements of execution speedMaestrí

Modèle de batterie générique et estimation de l'état de charge

Le stockage de l'énergie électrique représente un défi majeur. Actuellement, seuls les condensateurs et les batteries d'accumulateurs sont capables de disposer d'une réserve d'énergie autonome. Il existe plusieurs types d'accumulateurs et plusieurs facteurs électriques et chimiques peuvent affectés leur performance. D'autre part, ces accumulateurs jouent un rôle primordial dans l'industrie, que ce soit dans la nouvelle génération des voitures électriques et hybrides ou dans les appareils électroniques grand publique. Afin de comprendre le comportement de l'accumulateur il est nécessaire de construire un modèle capable de prédire et simuler son fonctionnement. La difficuhé pour la modélisation d'un accumulateur réside dans la nature des phénomènes électrochimiques et dynamiques qui se manifestent pendant son fonctionnement. L'objectif de ce projet de recherche est de proposer un modèle d'accumulateur générique capable de prédire le comportement générale de la batterie pendant son fonctionnement ainsi que la proposition d'un estimateur de l'état de charge appliqué à ce modèle. Le modèle proposé est appliqué sur les quatre types d'accumulateurs majeurs : plomb, nickel-cadmium, les hydrures métalliques de nickel et les ions de lithium. En premier temps le modèle initial proposé, dans lequel la seule variable d'état est l'état de charge de la batterie, est basé sur une source de tension en série avec une résistance variable. Cependant, ce modèle cause un problème de boucle algébrique pendant la simulation. Alors, pour remédier à cet inconvénient un deuxième modèle dérivé du premier a été proposé [I]. Ce dernier est basé sur une source de tension contrôlée en série avec une résistance fixe. Les deux modèles décrivent le comportement électrochimique de la batterie en termes de tension terminale, tension à vide, résistance interne, courant de décharge ou de charge, capacité de la batterie et l'état de charge de la batterie. Notons que ces modèles ne dépendent ni de la température ni de l'âge des batteries et on suppose que les paramètres du modèle sont identiques pour la charge et la décharge. Les deux modèles proposés représentent bien le comportement de la batterie pendant la décharge. La connaissance de l'état de charge de la batterie constitue une clé importante dans le système de gestion d'énergie embarqué dans certains systèmes comme celui des véhicules hybrides. Vu que cette information n'est pas mesurable directement, un estimateur basé sur le filtre de Kalman non linéaire est proposé. Cet estimateur est appliqué sur le deuxième modèle de batterie [1] et donne de bons résultats dans le cas d'un courant constant et d'un courant variable

High-bandwidth high-precision robust x-ray microscopy - a control systems approach

In this thesis, a systematic framework for designing control for high-precision positioning stages of Velociprobe X-ray microscope at Advanced Photon Source (APS) at Argonne National Laboratory (ANL) is presented. In particular, our focus is on maintaining a precise position of the optics scanning stages in the XY lateral plane relative to the sample stages, which will ensure that the optics stages scans the focused X-ray spot on the sample along a predefined trajectory. We would also want to maintain a precise relative distance between the optics and sample in Z direction (direction of the X-ray beam) to make sure the X-ray spot size remains constant during a scan. Both precise positioning in lateral XY plane and constant relative displacement in beam direction would influence X-ray image spatial resolution and imaging bandwidth. Our framework facilitates control designs that achieve simultaneously specifications on tracking bandwidth and positioning resolution while guaranteeing robustness of the closed loop device to unmodeled uncertainties. To develop this framework, we used modern control techniques for modeling, quantifying design objectives and system-specific challenges, and designing the control laws. The control designs were implemented on a 3 degree of freedom piezo-actuated parallel kinematics stages dedicated for precision scanning of X-ray optics. Experimental results demonstrate significant improvements in positioning performance with H_∞ optimal controllers; for instance, improvements by over 134%, 149% and 132% in tracking bandwidths along X, Y, and Z stages, respectively, were demonstrated when compared to proportional-integral-derivative (PID) controller designs. Even with these high-bandwidth control designs, the positioning resolution of the order 1-2 nanometers were achieved, which is approximately the same as the PID controllers. Two different X-ray imaging technique, namely step scan and flyscan, were successfully carried out with the controllers. In the step scan technique, the optics stages tracked a typical raster scan pattern and successfully scanned the X-ray spot covering a 1 〖μm〗^2 area on the sample in 2.1 minutes, with NI control hardware and H_∞ control design. This resulted in 8 folds improvement in the imaging bandwidth compared to previously existing methods. In step scan technique, the X-ray spot is first positioned at point on the sample and corresponding diffraction pattern is recorded by the detector, then the X-ray spot is moved to new position in next step and imaging is continued. In contrast, we enabled the flyscan, where the optics stage continuously tracked a custom square snake scan pattern to scan the focused X-ray spot over a 1 〖μm〗^2 area of the sample in 0.01 secs while simultaneously recording the diffraction patterns at the area detector. Flyscan of 1 〖μm〗^2 area was done over 10^4 times faster than step scan with our control design and over 10^5 times faster than previous step scan performance at the APS beamline. In X-ray microscopy it is imperative that the relative position between the optics stage, that carries the X-ray focusing optics, and the sample stage follow a certain trajectory while either the optics or sample stage is being scanned. The state-of-the-art in X-ray microscopy at APS (as explained above) features an H_∞ control architecture applied to only the optics stage or both the optics and sample stage, achieving the objectives of large tracking bandwidth, good positioning resolution, rejection of environmental disturbance, attenuation of measurement noise, good X-ray diffraction image resolution and increased imaging bandwidth. However, the sensors and the fixtures that hold the sensors drift with time due to changing air temperature at the APS beamline. The drift of the sensor affects the lateral position of the zone plate focusing optics in the XY plane during scanning relative to the sample stage and the relative position between the optics and sample along Z direction. This results into imaging artifacts, image ambiguity and reduced image spatial resolution. Here, we identified this limiting factor and countered it by measuring the drift in real time and incorporated that in the optimal control architecture. We have shown that the effects of drift in the closed loop are practically removed. If our proposed method is adopted and applied to the X-ray microscope at APS beamline, it would significantly improve X-ray image spatial resolution and reduce imaging artifacts. We provide estimates of this improvements in this thesis

Dynamics and Controls of Fluidic Pressure-Fed Mechanism (FPFM) of Nanopositioning System

Flexure or compliant mechanisms are employed in many precisions engineered devices due to their compactness, linearity, resolution, etc. Yet, critical issues remain in motion errors, thermal instability, limited bandwidth, and vibration of dynamic systems. Those issues cannot be negligible to maintain high precision and accuracy for precision engineering applications. In this thesis, a novel fluidic pressure-fed mechanism (FPFM) is proposed and investigated. The proposed method is designing internal fluidic channels inside the spring structure of the flexure mechanism using the additive manufacturing (AM) process to overcome addressed challenges. By applying pneumatic/hydraulic pressure and filling media into fluidic channels, dynamic characteristics of each spring structure of the flexure mechanism can be altered or adjusted to correct motion errors, increase operating speed, and suppress vibration. Additionally, FPFM can enhance thermal stability by flowing fluids without affecting the motion quality of the dynamic system. Lastly, the motion of the nanopositioning system driven by FPFM can provide sub-nanometer resolution motion, and this enables the nanopositioning system to have two linear motion in a monolithic structure. The main objective of this thesis is to propose and validate the feasibility of FPFM that can ultimately be used for a monolithic FPFM dual-mode stage for providing high positioning performance without motion errors while reducing vibration and increasing thermal stability and bandwidth