A designação de estruturas próprias de sistemas dinâmicos com retroação completa de estados ou saídas foi objeto de estudo de muitos pesquisadores durante a segunda metade do século XX. Os trabalhos mais relevantes sobre o tema foram revisados e serviram como base para a elaboração da metodologia apresentada neste trabalho. Que consiste na designação de estruturas próprias desejadas para um sistema linear em malha aberta com a modificação de parâmetros do sistema através da pseudo retroação de saídas devidamente definidas. O método foi aplicado na coxinização de um veículo de passeio. No qual os modos de vibrar de modelos lineares com 7 e 8 graus de liberdade do veículo foram adequados com o intuito de reduzir as acelerações verticais de chassi, características do fenômeno shake de motor e câmbio (faixa de frequência entre 7 e 25 Hz). Para tanto, reduziu-se a participação do grau de liberdade vertical de chassi nos modos com grande participação dos graus de liberdade de motor e massa não suspensa. Os resultados obtidos com a aplicação da metodologia na coxinização foram valores de rigidezes, amortecimentos e características de coxins hidráulicos que resultam na redução significativa da aceleração vertical de chassi, que implica em uma melhora perceptível para o consumidor na qualidade do conforto do veículo. / Eigenstructure assignment using full state or output feedback control had been object of study of many researchers during the second half of XX century. The most important works about eigenstructure assignment were reviewed, specially some applications within aerospace industry, that was the responsible for developing all the theory concerning pole and eigenvector placement. The review of the related theory was also based on the pioneering and most expressive works and were base for the methodology developed and described in this work. Which consists basically on the assignment of some desired eigensctructure of open loop linear systems modifying some parameters of the systems by means pseudo feedback of some outputs into inputs specifically defined. This methodology was applied to a 8 DOF vehicle model, a case of study, in order to adequate the system modes changing engine mounts parameters to improve the vehicle ride comfort, mainly eigenstructures about powertrain shake range frequencies.

With the exponential development of more sustainable automotive powertrains, new gearbox technologies must also be created and tested extensively. Scania employs dynamometer testbeds to conduct such tests, but this plethora of new and rapidly developed gearboxes pose many problems for testbed technicians. Regulating oil temperature during tests is vital and controllers must be developed for each gearbox configuration; this is difficult given system complexity, nonlinear dynamics, and time limitations. Therefore, technicians currently resort to a manually tuned controller based on real-time observations; a time-intensive process with sub-par performance. This master thesis breaks down this predicament into two research questions. The first employs a replicate study to investigate whether linear system identification methods can model the oil conditioning system adequately. A test procedure is developed and executed on one gearbox setup to capture system behavior around a reference point and the resulting models are compared for best fitment. Results from this study show that such data-driven modeling methods can sufficiently represent the system. The second research question investigates whether the derived model can then be used to create a better-performing model-based controller through pole placement design. To draw a comparison between old and new controllers, both are implemented on the testbed PLC while conducting a nominal test procedure varying torque and oil flow. Results from this study show that the developed controller does regulate temperature sufficiently, but the original controller is more robust in this specific test case. / Med den exponentiella utvecklingen av mer hållbara drivlinor i fordonsindustrin måste nya växellådsteknologier skapas och testas på en omfattande skala. Scania använder sig utav dynamometer testbäddar för att utföra sådana tester, men denna uppsjö av nya och snabbt utvecklade växellådor skapar utmaningar för testbäddsteknikerna. Reglering av oljetemperaturen under testerna är avgörande och därmed måste nya regulatorer utvecklas för varje växellådskonfiguration; detta är problematiskt med tanke på systemkomplexitet, olinjär dynamik samt tidsbegränsning. På grund av detta använder sig testbäddsteknikerna för tillfället av en manuell metod för att ta fram parametrarna till regulatorerna baserat på realtidsobservationer vilket är en tidskrävande process som ofta leder till en underpresterande regulator. Det här masterarbetet bryter ner den nämnda problematiken i två forskningsfrågor. Den första behandlar en replikationsstudie för att undersöka om linjära systemidentifikations metoder kan modellera oljekonditioneringssytemet på ett adekvat sätt. En testprocedur utvecklas och utförs på en växellådskonfiguration för att ta fram en modell för systemet kring en referenspunkt. De resulterande modellerna jämförs för att fastställa vilken metod som bäst beskriver systemet. Resultatet från denna studie visar att sådana data-drivna modelleringsmetoder kan beskriva systemet på ett tillfredsställande sätt. Den andra forskningsfrågan undersöker om den härledda modellen kan användas för att skapa en bättre presterande modellbaserad regulator med hjälp av polplaceringsmetoden. För att kunna göra en jämförelse mellan gamla samt nya regulatorer implementeras båda på testbäddens PLC varvid en nominell testprocedur utförs som varierar vridmoment och oljeflöde. Resultatet från denna studie visar att den framtagna regulatorn kan reglera oljetemperaturen på ett tillfredsställande sätt, däremot är den ursprungliga regulatorn mer robust i det behandlade testfallet.

O presente trabalho apresenta um método de projeto de controlador com alocação de pólos em sistemas fuzzy utilizando funções de Lyapunov por partes e contínuas no espaço de estado. A idéia principal é utilizar controladores chaveados no espaço de estado para obter uma resposta transitória satisfatória do sistema, obtida pela localização dos pólos. A modelagem fuzzy Takagi-Sugeno é utilizada para representar um sistema não-linear em diversos pontos de linearização através de uma aproximação por vários modelos locais lineares invariantes no tempo. A análise de estabilidade e o projeto de sistemas de controle podem se formulados em termos de desigualdades matriciais lineares (em inglês, linear matrix inequalities (LMIs)), as quais são resolvidas por técnicas de programação convexa. Na análise de estabilidade ou na síntese de um controlador em sistemas fuzzy é necessário resolver um número determinado de LMIs de acordo com o número de modelos locais. Encontrar uma função de Lyapunov comum a todos os modelos locais pode ser inviável, especialmente quando se impõem critérios de desempenho, que aparecem como restrições no contexto de LMIs. A proposta de uma função de Lyapunov por partes objetiva diminuir o conservadorismo na busca de um controlador que leve os pólos de malha fechada à uma região desejada. Resultados de análise e síntese da teoria de sistemas lineares por partes contribuíram para a construção do resultado apresentado. Exemplos com simulação ilustram o método proposto. / This work presents a controller design method for fuzzy dynamic systems based on piecewise Lyapunov functions with constraints on the closed-loop pole location. The main idea is to use switched controllers to locate the poles of the system to obtain a satisfactory transient response. The pole placement strategy allows to specify the performance in terms of the desired time response of the feedback system. The Takagi-Sugeno fuzzy model can approximate the nonlinear system in several linearization points using linear time invariant systems. Thus, a global fuzzy model can be obtained from a fuzzy combination of these linear systems. Stability analysis and design of fuzzy control systems can be efficiently carried out in the context of linear matrix inequalities (LMIs). If the fuzzy system is described by many local models, the resulting set of LMIs may be infeasible. The search for a Lyapunov function in the fuzzy pole placement problem may be easier to be satisfied in a piecewise framework. Some results from piecewise linear systems theory have contributed to the development of the presented technique. Some examples are given to illustrate the proposed method.

O presente trabalho apresenta um método de projeto de controlador com alocação de pólos em sistemas fuzzy utilizando funções de Lyapunov por partes e contínuas no espaço de estado. A idéia principal é utilizar controladores chaveados no espaço de estado para obter uma resposta transitória satisfatória do sistema, obtida pela localização dos pólos. A modelagem fuzzy Takagi-Sugeno é utilizada para representar um sistema não-linear em diversos pontos de linearização através de uma aproximação por vários modelos locais lineares invariantes no tempo. A análise de estabilidade e o projeto de sistemas de controle podem se formulados em termos de desigualdades matriciais lineares (em inglês, linear matrix inequalities (LMIs)), as quais são resolvidas por técnicas de programação convexa. Na análise de estabilidade ou na síntese de um controlador em sistemas fuzzy é necessário resolver um número determinado de LMIs de acordo com o número de modelos locais. Encontrar uma função de Lyapunov comum a todos os modelos locais pode ser inviável, especialmente quando se impõem critérios de desempenho, que aparecem como restrições no contexto de LMIs. A proposta de uma função de Lyapunov por partes objetiva diminuir o conservadorismo na busca de um controlador que leve os pólos de malha fechada à uma região desejada. Resultados de análise e síntese da teoria de sistemas lineares por partes contribuíram para a construção do resultado apresentado. Exemplos com simulação ilustram o método proposto. / This work presents a controller design method for fuzzy dynamic systems based on piecewise Lyapunov functions with constraints on the closed-loop pole location. The main idea is to use switched controllers to locate the poles of the system to obtain a satisfactory transient response. The pole placement strategy allows to specify the performance in terms of the desired time response of the feedback system. The Takagi-Sugeno fuzzy model can approximate the nonlinear system in several linearization points using linear time invariant systems. Thus, a global fuzzy model can be obtained from a fuzzy combination of these linear systems. Stability analysis and design of fuzzy control systems can be efficiently carried out in the context of linear matrix inequalities (LMIs). If the fuzzy system is described by many local models, the resulting set of LMIs may be infeasible. The search for a Lyapunov function in the fuzzy pole placement problem may be easier to be satisfied in a piecewise framework. Some results from piecewise linear systems theory have contributed to the development of the presented technique. Some examples are given to illustrate the proposed method.

Made available in DSpace on 2014-12-17T14:55:43Z (GMT). No. of bitstreams: 1 EricoCB_DISSERT.pdf: 1960043 bytes, checksum: 7c0ebefa8d09683721a890c3c7d00bbb (MD5) Previous issue date: 2010-03-26 / The Methods for compensation of harmonic currents and voltages have been widely used since these methods allow to reduce to acceptable levels the harmonic distortion in the voltages or currents in a power system, and also compensate reactive. The reduction of harmonics and reactive contributes to the reduction of losses in transmission lines and electrical machinery, increasing the power factor, reduce the occurrence of overvoltage and overcurrent. The active power filter is the most efficient method for compensation of harmonic currents and voltages. The active power filter is necessary to use current and voltage controllers loop. Conventionally, the current and voltage control loop of active filter has been done by proportional controllers integrative. This work, investigated the use of a robust adaptive control technique on the shunt active power filter current and voltage control loop to increase robustness and improve the performance of active filter to compensate for harmonics. The proposed control scheme is based on a combination of techniques for adaptive control pole placement and variable structure. The advantages of the proposed method over conventional ones are: lower total harmonic distortion, more flexibility, adaptability and robustness to the system. Moreover, the proposed control scheme improves the performance and improves the transient of active filter. The validation of the proposed technique was verified initially by a simulation program implemented in C++ language and then experimental results were obtained using a prototype three-phase active filter of 1 kVA / Os m?todos para compensa??o de correntes e tens?es harm?nicas v?m sendo bastante utilizados, visto que esses m?todos permitem reduzir a n?veis aceit?veis as distor??es harm?nicas nas tens?es ou correntes em um sistema el?trico de pot?ncia, e ainda, compensar reativos. A redu??o de harm?nicas e reativos contribuem para: a diminui??o das perdas nas linhas de transmiss?o e nas m?quinas el?tricas, o aumento do fator de pot?ncia e a redu??o de ocorr?ncias de sobretens?es e sobrecorrentes. O filtro ativo de pot?ncia ? o m?todo mais eficiente para compensa??o de correntes e tens?es harm?nicas. No filtro ativo de pot?ncia ? necess?ria a utiliza??o de controladores para as malhas de corrente e tens?o. Convencionalmente, o controle dessas malhas tem sido feito por controladores proporcionais integrativos. Neste trabalho, ? investigado o uso de uma t?cnica de controle adaptativo robusto nas malha de corrente e tens?o, do filtro ativo de pot?ncia em paralelo trif?sico, para aumentar a robustez e melhorar o desempenho desse filtro ativo na compensa??o de harm?nicos. A t?cnica de controle proposta ? baseada na combina??o das t?cnicas de controle adaptativo por posicionamento de p?los e de estrutura vari?vel. As vantagens do m?todo proposto sobre os convencionais s?o: menor taxa de distor??o harm?nica, maior flexibilidade, capacidade de adapta??o e robustez para o sistema. Al?m disso, a t?cnica de controle proposta aumenta o desempenho e melhora o transit?rio do filtro ativo. A valida??o da t?cnica proposta foi verificada inicialmente atrav?s de um programa de simula??o implementado em linguagem C ++ e em seguida foram obtidos resultados experimentais usando um prot?tipo de um filtro ativo trif?sico de 1 kVA

Made available in DSpace on 2014-12-17T14:56:02Z (GMT). No. of bitstreams: 1 FranciscoCSJ.pdf: 396492 bytes, checksum: c7b91bb21a15450749eb2738a17c2f3e (MD5) Previous issue date: 2005-07-28 / There are two main approaches for using in adaptive controllers. One is the so-called model reference adaptive control (MRAC), and the other is the so-called adaptive pole placement control (APPC). In MRAC, a reference model is chosen to generate the desired trajectory that the plant output has to follow, and it can require cancellation of the plant zeros. Due to its flexibility in choosing the controller design methodology (state feedback, compensator design, linear quadratic, etc.) and the adaptive law (least squares, gradient, etc.), the APPC is the most general type of adaptive control. Traditionally, it has been developed in an indirect approach and, as an advantage, it may be applied to non-minimum phase plants, because do not involve plant zero-pole cancellations. The integration to variable structure systems allows to aggregate fast transient and robustness to parametric uncertainties and disturbances, as well. In this work, a variable structure adaptive pole placement control (VS-APPC) is proposed. Therefore, new switching laws are proposed, instead of using the traditional integral adaptive laws. Additionally, simulation results for an unstable first order system and simulation and practical results for a three-phase induction motor are shown / Existem dois m?todos principais para a constru??o de controladores adaptativos. Um deles ? o controle adaptativo por modelo de refer?ncia (MRAC) e o outro ? o controle adaptativo por posicionamento de p?los (APPC). No MRAC, um modelo de refer?ncia ? escolhido para gerar a trajet?ria desejada que o sinal de sa?da da planta deve seguir, e ele pode requerer o cancelamento de zeros da planta. Devido a sua flexibilidade em escolher a metodologia de projeto do controlador (realimenta??o de estado, projeto de compensador, linear quadr?tico, etc.) e a lei adaptativa (m?nimos quadrados, m?todo do gradiente, etc.), o APPC ? o tipo mais geral de controle adaptativo. Tradicionalmente, vem sendo desenvolvido em uma abordagem indireta e, como uma vantagem, pode ser aplicado a plantas de fase n?o-m?nima, j? que n?o envolve cancelamentos de zeros e p?los. A integra??o aos sistemas com estrutura vari?vel permite agregar rapidez no transit?rio e robustez ?s varia??es param?tricas e perturba??es. O objetivo deste trabalho ? desenvolver um controlador adaptativo por posicionamento de p?los e estrutura vari?vel (VS-APPC). Portanto, s?o propostas leis chaveadas em substitui??o ?s leis adaptativas integrais tradicionais. Adicionalmente, s?o apresentadas simula??es para uma planta de primeira ordem inst?vel, assim como simula??es e resultados pr?ticos da aplica??o da t?cnica proposta a um motor de indu??o trif?sico

Made available in DSpace on 2014-12-17T14:56:15Z (GMT). No. of bitstreams: 1 DanielWH_DISSERT.pdf: 3818359 bytes, checksum: ac34198b688307ffda10243b5ad47c74 (MD5) Previous issue date: 2013-09-13 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In the last decade, the renewable energy sources have present a major propulsion in the world due to several factors: political, environmental, financial and others. Within this context, we have in particular the energy obtained through wind, wind energy - that has highlighted with rapid growth in recent years, including in Brazil, mostly in the Northeast, due to it s benefit-cost between the clean energies. In this context, we propose to compare the variable structure adaptive pole placement control (VS-APPC) with a traditional control technique proportional integral controller (PI), applied to set the control of machine side in a conversion system using a wind generator based on Double-Fed Induction Generator (DFIG). Robustness and performance tests were carried out to the uncertainties of the internal parameters of the machine and variations of speed reference. / As fontes de energia renov?veis t?m, na ?ltima d?cada, ganho uma grande propuls?o em todo o mundo devido aos mais diversos fatores: pol?ticos, ambientais, financeiros, entre outros. Dentro deste universo, temos, em especial, a energia obtida atrav?s do vento, energia e?lica - que tem se destacado com um crescimento vertiginoso nos ?ltimos anos, inclusive no Brasil, principalmente na regi?o Nordeste, devido ao seu custo-benef?cio entre as energias "limpas". Neste cen?rio, prop?e-se a compara??o do controlador por posicionamento de polos e estrutura vari?vel (VS-APPC) com o controlador proporcional integral (PI) aplicados em um sistema de convers?o de energia e?lica que utiliza um gerador de indu??o duplamente alimentado (Double-Fed Induction Generator- DFIG). Testes de robustez e desempenho foram realizados com incertezas nos par?metros da m?quina e varia??es de refer?ncia de velocidade

De nos jours, les processus industriels se doivent d’être efficaces, en particulier au niveau de leur production et/ou consommation énergétique.Ce travail vise à améliorer l’efficacité des processus en analysant l’influence des perturbations sur leur comportement, de la phase de conception à la synthèse des contrôleurs/observateurs, ceci dans une approche intégrée.Le problème du Rejet de Perturbation est introduit ainsi que différents types de contrôles permettant d’atténuer et/ou rejeter ces perturbations. Le système de Barre de Torsion est présenté. Une loi de commande basée sur le concept d’état dérivé est présentée et ensuite validée avec comme application le rejet de perturbation. Il est nécessaire d’estimer les grandeurs physiques utilisées dans les différentes expressions de loi de commande. Un observateur à entrées inconnues basé sur la représentation bond graph est rappelé et ensuite étendu au cas multi-variable. C’est la première contribution théorique de ce travail de recherche.Nous comparons ensuite l’efficacité de différentes techniques de commandes pour le rejet de perturbation par simulation sur le système barre de torsion et analysons ainsi l’efficacité de la technique proposée. Une extension théorique au problème du découplage entrée-sortie nous permet de généraliser le problème du rejet de perturbation dans une même démarche intégrée d’analyse et de synthèse. Enfin, ces techniques sont exploitées et analysées sur le système réel. Nous validons ainsi expérimentalement nos résultats.Un modèle très simplifié de centrale hydroélectrique est développé afin d’appliquer les résultats de nos travaux. Un modèle bond graph simplifié est validé par simulation. / Nowadays, industrial processes must be efficient, particularly at the production level and/or energy consumption.This research work aims at improving the process efficiency by analysing the influences of disturbances on their behaviour, from the conception phase to the synthesis of controller/observer, in an integrated approach.The disturbance rejection problem is first introduced as well as different control laws allowing attenuate/reject these disturbances. A control law based on the concept of derivative state variable is presented and validated while applied as disturbance rejection.In order to reject the disturbance, different physical variables must be estimated, such as state variables, derivative state variables as disturbance variables. An unknown input observer based on the bond graph representation is recalled and extended in the multivariable case. It is the first theoretical contribution of this work.We thus compare the efficiency of different so-called «modern control laws» for the disturbance rejection problems by simulation with the Torsion-Bar system example. We analyse the efficiency of our approach. One extension to the Input-Output decoupling problem allows us to extend the disturbance rejection problem to other control law type in an integrated approach. At least, these techniques are applied on the real Torsion-Bar system and compared. We validate our approach.Since this work aims at analysing and developing efficient control laws for industrial processes, a simplified model of a hydroelectric plant is developed, in order to apply our results. A simplified bond graph model is validated with simulations.

Control and balancing of an inverted pendulum has gained a lot of attention over the past few decades due to its unstable properties. This has become a great challenge for control engineers to verify and test the control theory. To control and balance an inverted pendulum, proportional integrated derivative (PID) method or linear quadratic regulator (LQR) method can be used through which a lot of simulations can be done using the represented theories.Since urban population is increasing at a very alarming rate, there is a need to discover new ways of transportation to meet the future challenges and demands. Scania has come up with a new conceptual bus called NXT which aims to develop a modular vehicle that should configure and re-configure themselves between different transportation tasks. NXT vehicle has front and rear drive modules which can be represented as single axle, two-wheeled vehicles which in-turn can be viewed as an inverted pendulum with a huge Center of Gravity. Controlling and balancing of the pod or drive module precisely and accurately is an interesting challenge since it is an unstable inverted pendulum with huge center of gravity (COG). This behaviour of the system has created a research question whether the module is controllable or not.Therefore this thesis focuses on the possibility of controlling the pod which is a two-wheeled inverted pendulum vehicle with a COG offset. Also, the thesis focuses on the construction, mod-elling, testing and validation of a down-scaled model, what sensors are needed to balance the pod precisely, how the sensors must be integrated with the system and how the pod can be controlled remotely from a certain distance by a human. The developed pod houses the technologies like sensors, BLDC motor controllers, hoverboard, Arduino board and Bluetooth transmitters.The Master Thesis starts by presenting an introduction to the inverted pendulum theories, Scania NXT project, information about the research methods, thesis outline and structure . It continues by describing related literature about the inverted pendulums, segways, hoverboards, motor controllers and Arduino boards. Afterwards, the process of deriving a mathematical model, together with simulation in Matlab, Simulink and Simscape is described. Later, construction of the pod is made and lot of effort is put to run the pod. Since the pod needs to be controlled remotely by a human, a remote controlled systemis implemented via mobile phone using an app and finally the thesis is finished with a conclusion and ideas for future work. / Reglering och balancering av en inverterad pendel har väckt stor uppmärksamhet över de senaste decennierna på grund av dess instabila egenskaper. Det har skapat stora utmaningar för regleringenjörer eftersom området tillåter test och verifikation av diverese lösningar. För reglering och balansering av en inverterad pendel, så kan en regulator med proportionell, integral och derivat (PID) konstanter eller en linjär kvadratisk regulator (LQR) användas tillsammans med simuleringar för att bekräfta teorin.I och med att stadsbefolkningen ökar i mycket hög takt, så uppstår behovet av att uppfinna nya transportmedel för att lösa framtida utmaningar och krav. Scania har tagit fram en ny konceptbuss som heter NXT, med målet att utveckla ett modulfordon som kommer att konfigurera och rekonfigurera sig själva mellan olika transportuppgifter. NXT-fordonet har fram- och bakdriv-moduler som kan representeras som enaxlade tvåhjuliga fordon, vilka i sin tur kan betraktas som en inverterad pendel med en stor massa. Att reglera och balansera drivmodulen på ett noggrant sätt är en utmaning eftersom det är ett mycket instabilt system med enorm massa och en okänd tyngdpunkt. Systemets beteende har skapat en forskningsfråga om modulen är reglerbar eller inte.Denna uppsats fokuserar därmed på möjligheterna att kunna reglera drivmodulen samt vilka begränsningar det finns. Uppsatsen fokuserar också på konstruktion, modellering, testning och validering av en nedskalad modell, vilka sensorer som krävs för att balansera drivmodulem, samt hur sensorerna måste integreras med systemet för att kunna fjärstyra fordonet från ett visst avstånd. Utveckingen av en sådan nedskalad modell berör olika områden såsom sensorer, BLDC-motorstyrenheter, hoverboard balanserings scootrar, Arduino kretskort och Bluetooth-sändare/mottagare.Uppsasten börjar med en introduction om olika inverterade pendel teorier, Scania NXT project, forskningsmetoder, en översikt och övergripande struktur. Vidare fortsätter beskrivining av relaterade litteratur om inverterade pendel, Segway, hoverboard, borstlösa motor styrenheter och Arduino kretskort. Senare fortsätter processen för att härleda matematiska modeller som beskirver systemet, tillsammans med simuleringar i Matlab, Simulink och Simscape. Därefter beskrivs konstruktionen av en nedskalad modell av drivmodulen och beskrivning av nödvändiga processer för att få hårdvara och mjkukvara att fungera ihop. Då fordonen ska ha möjlighet att fjärrstyras, så implementerades en bluetooth enhet tillsammans med en programmerbar mobil applikation. Slutligen avlutas uppsatsen med resultat, slutsats och diskussioner och förslag till framtida arbeten.

This thesis describes a genetic approach for shaping the dynamic responses of linear state space systems through pole placement. This paper makes further comparisons between this approach and an island approach parallel genetic algorithm (PGA) which incorporates orthogonal mutation vectors to increase sub-population specialization and decrease convergence time. Both approaches generate a gain vector K. The vector K is used in state feedback for altering the poles of the system so as to meet step response requirements such as settling time and percent overshoot. To obtain the gain vector K by the proposed genetic approaches, a pair of ideal, desired poles is calculate first. Those poles serve as the basis by which an initial population is created. In the island approach, those poles serve as a basis for n populations, where n is the dimension of the necessary K vector. Each member of the population is tested for its fitness (the degree to which it matches the criteria). A new population is created each “generation” from the results of the previous iteration, until the criteria are met, or a certain number of generations have passed. Several case studies are provided in this paper to illustrate that this new approach is working, and also to compare performance of the two approaches.