Esse trabalho propõe uma unidade central de processamento para o Pegasus AutoPilot, que é um piloto automático para aeronaves não tripuladas de pequeno porte, constituído por quatro módulos: Sistema de Navegação, Unidade Central de Processamento, Gerenciador de Superfícies de Controle e Estação de Controle em Solo. Malhas de controle e algoritmos de guiagem são propostos, utilizando conceitos de chaveamento de ganhos para situações diferentes de voo. Para a validação desses algoritmos foi criado um modelo de aeronave específica, um Piper J-3 Cub 1/6 de escala, no X-Plane, que simula a aeronave. As simulações em Software-In-the-Loop (SIL) foram feitas entre X-Plane e MatLab/Simulink, onde através de uma interface gráfica foram ajustados os parâmetros de controle e guiagem. Posteriormente o sistema foi implementado em um microcontrolador ARM CORTEX M3, permitindo simulações em Hardware-In-The-Loop (HIL). Foi desenvolvido um gerenciamento de dados no microcontrolador que passou a se comunicar com o X-Plane através de portas seriais. São apresentados os resultados das simulações obtidas, comparações de malhas de controles convencionais com as malhas de controles propostas, assim como a simulação de missões totalmente autônomas utilizando o algoritmo de guiagem. É também demonstrado um estudo de consumo de energia do microcontrolador e a comprovação que o sistema atende aos requisitos de tempo real.

Veículos Submarinos Não Tripulados (UUVs Unmanned Underwater Vehicles) possuem muitas aplicações comerciais, militares e científicas devido ao seu elevado potencial e relação custo-desempenho considerável quando comparados a meios tradicionais utilizados para a obtenção de informações provenientes do meio subaquático. O desenvolvimento de uma plataforma de testes e amostragem confiável para estes veículos requer o projeto de um sistema completo além de exigir diversos e custosos experimentos realizados no mar para que as especificações possam ser devidamente validadas. Modelagem e simulação apresentam medidas de custo efetivo para o desenvolvimento de componentes preliminares do sistema (software e hardware), além de verificação e testes relacionados à execução de missões realizadas por veículos submarinos reduzindo, portanto, a ocorrência de potenciais falhas. Um ambiente de simulação preciso pode auxiliar engenheiros a encontrar erros ocultos contidos no software embarcado do UUV além de favorecer uma maior introspecção dentro da dinâmica e operação do veículo. Este trabalho descreve a implementação do algoritmo de controle de um UUV em ambiente MATLAB/SIMULINK, sua conversão automática para código compilável (em C++) e a verificação de seu funcionamento diretamente no computador embarcado por meio de simulações. Detalham-se os procedimentos necessários para permitir a conversão dos modelos em MATLAB para código C++, integração do software de controle com o sistema operacional de tempo real empregado no computador embarcado (VxWORKS) e a estratégia de simulação com Hardware In The Loop (HIL) desenvolvida - A principal contribuição deste trabalho é apresentar de forma racional uma estrutura de trabalho que facilite a implementação final do software de controle no computador embarcado a partir do modelo desenvolvido em um ambiente amigável para o projetista, como o SIMULINK. / Unmanned Underwater Vehicles (UUVs) have many commercial, military, and scientific applications because of their potential capabilities and significant costperformance improvements over traditional means of obtaining valuable underwater information The development of a reliable sampling and testing platform for these vehicles requires a thorough system design and many costly at-sea trials during which systems specifications can be validated. Modeling and simulation provide a cost-effective measure to carry out preliminary component, system (hardware and software), and mission testing and verification, thereby reducing the number of potential failures in at-sea trials. An accurate simulation environment can help engineers to find hidden errors in the UUV embedded software and gain insights into the UUV operation and dynamics. This work describes the implementation of a UUV\'s control algorithm using MATLAB/SIMULINK, its automatic conversion to an executable code (in C++) and the verification of its performance directly into the embedded computer using simulations. It is detailed the necessary procedure to allow the conversion of the models from MATLAB to C++ code, integration of the control software with the real time operating system used on the embedded computer (VxWORKS) and the developed strategy of Hardware in the loop Simulation (HILS). The Main contribution of this work is to present a rational framework to support the final implementation of the control software on the embedded computer, starting from the model developed on an environment friendly to the control engineers, like SIMULINK.

This thesis aims to propose multiple methods for performing a hardware-in-the-loop simulation, providing the hardware and software tools necessary for design and execution. For this purpose, methods of modeling commonly encountered dynamical system components are explored and techniques suitable for calculating the states of the modeled system are presented. Modules and subsystems that enable the realization of a hardware-in-the-loop simulation application and its interfacing with external controller hardware are explained. The thesis also presents three different simulation scenarios. Solutions suitable for these scenarios are provided along with their implementations. The details and specifications of the developed software packages and hardware platforms are given. The provided results illustrate the advantages and disadvantages of the approaches used in these solutions.

Today, the investigation of fuel economy improvements in internal combustion engines (ICEs) has become the most significant research interest among the automobile manufacturers and researchers. The scarcity of natural resources, progressively increasing oil prices, carbon dioxide taxation and stringent emission regulations all make fuel economy research relevant and compelling. The enhancement of engine performance solely using incylinder techniques is proving increasingly difficult and as a consequence the concept of exhaust energy recovery has emerged as an area of considerable interest. Three main energy recovery systems have been identified that are at various stages of investigation. Vapour power bottoming cycles and turbo-compounding devices have already been applied in commercially available marine engines and automobiles. Although the fuel economy benefits are substantial, system design implications have limited their adaptation due to the additional components and the complexity of the resulting system. In this context, thermo-electric (TE) generation systems, though still in their infancy for vehicle applications have been identified as attractive, promising and solid state candidates of low complexity. The performance of these devices is limited to the relative infancy of materials investigations and module architectures. There is great potential to be explored. The initial modelling work reported in this study shows that with current materials and construction technology, thermo-electric devices could be produced to displace the alternator of the light duty vehicles, providing the fuel economy benefits of 3.9%-4.7% for passenger cars and 7.4% for passenger buses. More efficient thermo-electric materials could increase the fuel economy significantly resulting in a substantially improved business case. The dynamic behaviour of the thermo-electric generator (TEG) applied in both, main exhaust gas stream and exhaust gas recirculation (EGR) path of light duty and heavy duty engines were studied through a series of experimental and modelling programs. The analyses of the thermo-electric generation systems have highlighted the need for advanced heat exchanger design as well as the improved materials to enhance the performance of these systems. These research requirements led to the need for a systems evaluation technique typified by hardware-in-the-loop (HIL) testing method to evaluate heat exchange and materials options. HIL methods have been used during this study to estimate both the output power and the exhaust back pressure created by the device. The work has established the feasibility of a new approach to heat exchange devices for thermo-electric systems. Based on design projections and the predicted performance of new materials, the potential to match the performance of established heat recovery methods has been demonstrated.

This thesis introduces an alternative potentially low cost solution for hardware-in-the-loop (HIL) simulation based on the waveform relaxation (WR) method. The WR tech-nique is extended so that, without the need for a real-time simulator, the behaviour of an actual piece of physical hardware can nevertheless be tested as though it were connected to a large external electrical network. This is achieved by simulating the external network on an off-line electromagnetic transients (EMT) simulation program, and utilizing iterative exchange of waveforms between the simulation and the hardware by means of a spe-cialized Real-Time Player/Recorder (RTPR) interface device. The approach is referred to as waveform relaxation based hardware-in-the-loop (WR-HIL) simulation. To make the method possible, the thesis introduces several new innovations for stabi-lizing and accelerating the WR-HIL algorithm. It is shown that the classical WR shows poor or no convergence when at least one of the subsystems is an actual device. The noise and analog-digital converters’ quantization errors and other hardware disturbances can affect the waveforms and cause the WR to diverge. Therefore, the application of the WR method in performing HIL simulation is not straightforward and the classical WR need to be modified accordingly. Three convergence techniques are proposed to improve the WR-HIL simulation con-vergence. Each technique is evaluated by an experimental example. The stability of the WR-HIL simulation is studied and a stabilization technique is proposed to provide suffi-cient conditions for the simulation stability. The approach is also extended to include the optimization of the parameters of power system controllers located in geographically distant places. The WR-HIL simulation technique is presented with several examples. At the end of the thesis, suggestions for the future work are presented. / February 2016

Thesis (MEng) Stellenbosch University, 2014 / ENGLISH ABSTRACT: An Attitude Determination and Control System (ADCS) demonstrator and testing platform was required for satellite engineering students. The ADCS demonstrator and testing platform will allow students to develop insight into the concepts and challenges of ADCS design and implementation. The existing model nano-satellite EyasSAT was used as a design platform for a new ADCS demonstrator. A new ADCS module (ADCS_V2) was developed to replace the existing EyasSAT ADCS module. The new module allows for three-axis ADCS and the demonstration of the ADCS on an air bearing platform. The air bearing allows full freedom of movement for yaw rotations with limited pitch and roll rotations. The actuators and sensors required for the ADCS were developed and integrated into EyasSAT. In addition a new PCB was designed to form the ADCS_V2 module. Attitude determination algorithms and attitude control algorithms were implemented and tested using MATLAB Simulink simulations. These algorithms were then implemented on the ADCS_V2 module. The ADCS was tested using Hardware In the Loop (HIL) techniques and an air bearing. The yaw attitude of EyasSAT could be controlled within 0.4 degrees accuracy with all the sensors active. In order to stabilize the air bearing platform, the pitch and roll angles were rate controlled. The pitch and roll rates were damped to within 6 mrad/s. / AFRIKAANSE OPSOMMING: ’n Oriëntasiebepaling en Beheerstelsel (OBBS) demonstrasie en toets platform was benodig vir satellietingenieurswese studente. Die nuwe OBBS sal studente toelaat om insig te ontwikkel met betreking tot die idees en uitdagings wat verband hou met die ontwikkeling en implementering van ’n OBBS. Die huidige nano-sateliet model EyasSAT was gebruik as ’n ontwerpsbasis vir die nuwe OBBS. Die nuwe OBBS was ontwikkel om die huidige module van EyasSAT te vervang. Die nuwe OBBS laat oriëntasiebepaling en -beheer in drie asse toe. Die nuwe OBBS en EyasSAT kan die werking van ’n OBBS demonstreer op ’n luglaerplatform. Die luglaer laat vrye rotasie om die gierhoek toe terwyl die rol- en stygings-as beperk word. Die aktueerders en sensors wat benodig word vir die OBBS is ontwikkel en geïntegreer in EyasSAT saam met ’n nuwe gedrukte stroombaanbord om die nuwe OBBS te vorm. Orientasiebepaling en orientasiebeheer algoritmes is geïmplementeer en getoets met die hulp van MATLAB Simulink simulasies. Die algoritmes was op die OBBS module geïmplementeer en getoets deur gebruik te maak van HIL tegnieke en praktiese toetse op die luglaer. Die rotasie hoek van EyasSAT kan met ’n akkuraatheid van 0.4 grade beheer word indien al die sensors gebruik word. Die rol en stygingshoeksnelheid was gekanselleer om die luglaer stabiel te hou. Die hoeksnelheid van die twee asse kon tot kleiner as 6 mrad/s beheer word.

Veículos Submarinos Não Tripulados (UUVs Unmanned Underwater Vehicles) possuem muitas aplicações comerciais, militares e científicas devido ao seu elevado potencial e relação custo-desempenho considerável quando comparados a meios tradicionais utilizados para a obtenção de informações provenientes do meio subaquático. O desenvolvimento de uma plataforma de testes e amostragem confiável para estes veículos requer o projeto de um sistema completo além de exigir diversos e custosos experimentos realizados no mar para que as especificações possam ser devidamente validadas. Modelagem e simulação apresentam medidas de custo efetivo para o desenvolvimento de componentes preliminares do sistema (software e hardware), além de verificação e testes relacionados à execução de missões realizadas por veículos submarinos reduzindo, portanto, a ocorrência de potenciais falhas. Um ambiente de simulação preciso pode auxiliar engenheiros a encontrar erros ocultos contidos no software embarcado do UUV além de favorecer uma maior introspecção dentro da dinâmica e operação do veículo. Este trabalho descreve a implementação do algoritmo de controle de um UUV em ambiente MATLAB/SIMULINK, sua conversão automática para código compilável (em C++) e a verificação de seu funcionamento diretamente no computador embarcado por meio de simulações. Detalham-se os procedimentos necessários para permitir a conversão dos modelos em MATLAB para código C++, integração do software de controle com o sistema operacional de tempo real empregado no computador embarcado (VxWORKS) e a estratégia de simulação com Hardware In The Loop (HIL) desenvolvida - A principal contribuição deste trabalho é apresentar de forma racional uma estrutura de trabalho que facilite a implementação final do software de controle no computador embarcado a partir do modelo desenvolvido em um ambiente amigável para o projetista, como o SIMULINK. / Unmanned Underwater Vehicles (UUVs) have many commercial, military, and scientific applications because of their potential capabilities and significant costperformance improvements over traditional means of obtaining valuable underwater information The development of a reliable sampling and testing platform for these vehicles requires a thorough system design and many costly at-sea trials during which systems specifications can be validated. Modeling and simulation provide a cost-effective measure to carry out preliminary component, system (hardware and software), and mission testing and verification, thereby reducing the number of potential failures in at-sea trials. An accurate simulation environment can help engineers to find hidden errors in the UUV embedded software and gain insights into the UUV operation and dynamics. This work describes the implementation of a UUV\'s control algorithm using MATLAB/SIMULINK, its automatic conversion to an executable code (in C++) and the verification of its performance directly into the embedded computer using simulations. It is detailed the necessary procedure to allow the conversion of the models from MATLAB to C++ code, integration of the control software with the real time operating system used on the embedded computer (VxWORKS) and the developed strategy of Hardware in the loop Simulation (HILS). The Main contribution of this work is to present a rational framework to support the final implementation of the control software on the embedded computer, starting from the model developed on an environment friendly to the control engineers, like SIMULINK.

Hydropower is a flexible energy source that is essential for balancing the electrical power system on all timescales, from seconds to years. In addition to intra-hour regulation, it provides frequency containment reserves (FCR-N,FCR-D) and frequency restoration reserves (mFRR, aFRR) to the grid. The turbine governor is a device responsible for controlling the power output and delivering frequency control to the system. The aim of this Master’s Thesis project is to develop a new hydropower turbine governor in MATLAB/Simulink, which contains all critical functionality from the existing governor and with the same performance. The new governor should as far as possible comply to the well-established communication standard IEC 61850. A working model of the turbine governor has been built in Simulink that supports normal operation with frequency control, start and stop, load rejection, operation mode as synchronous condenser and more. Validations of the model against data from Akkats powerplant shows that the model behaves as a real governor during normal operation. Validations of the start sequence showed deviations during sequence 3 and 4 which can be explained by usage of different PID parameters. Using IEC 61850 as a nomenclature and as a way of structuring functions in the governor has also been possible. Implementing the whole standard for communication, requires that the control system also is renewed according to IEC 61850. Certain functions, as sequencing has thus not been done according to the standard. MATLAB and Simulink provide tools for building, simulating and testing implementations of the turbine governor. The contributions this platform can provide are; ease of implementation, optimization and testing of control strategies. Simulink also provides a graphical interface, which reduce system complexity. An optimal implementation requires a hardware with support for Simulink to get a transparent platform. Ultimately, these benefits could result in better frequency quality at a lower cost, which is essential for successful and cost-effective integration of other renewable energy sources such as wind- and solar power.

As the development of vehicles moves towards shorter development time, new ways of verifying the vehicle performance is needed in order to begin the verification process at an earlier stage. A great extent of this development regards active safety, which is a collection name for systems that help both avoid accidents and minimize the effects of a collision, e.g brake assist and steering control systems. Development of these active safety functions requires extensive testing and verification in order to guarantee the performance of the functions in different situations. One way of testing these functions is to include them in a Hardware in the Loop simulation, where the involved hardware from the real vehicle are included in the simulation loop. This master thesis investigates the possibility to test lateral active safety functions in a hardware in the loop simulation environment consisting of multiple subsystems working on different frequencies. The subsystems are all dependent of the output from other subsystems, forming an algebraic loop between them. Simulation using multiple hardware and subsystems working on different frequencies introduces latency in the simulation. The effect of the latency is investigated and proposed solutions are presented. In order to enable testing of lateral active safety functions, a steering model which enables the servo motor to steer the vehicle is integrated in the simulation environment and validated.

Recent years have seen the significance of utilizing time-synchronized, high resolution measurements from phasor measurement units (PMUs) to develop and implement wide-area monitoring, protection and control (WAMPAC) systems. WAMPAC systems aim to provide holistic view of the power system and enable detection and control of certain power system phenomena to enhance reliability and integrity of the grid. This thesis focuses on the design, development and experimental validation of WAMPAC applications, and investigates their vulnerability to time synchronization impairment. To this purpose, a state-of-the-art real-time hardware-in-the-loop (RT-HIL) test-bench was established for prototyping of synchrophasor-based applications. This platform was extensively used throughout the thesis for end-to-end testing of the proposed WAMPAC applications. To facilitate the development of WAMPAC applications, an open-source real-time data mediator is presented that parses the incoming synchrophasor stream and provides access to raw data in LabVIEW environment. Within the domain of wide-area protection applications, the thesis proposes hybrid synchrophasor and IEC 61850-8-1 GOOSE-based islanding detection and automatic synchronization schemes. These applications utilize synchrophasor measurements to assess the state of the power system and initiate protection / corrective action using GOOSE messages. The associated communication latencies incurred due to the utilization of synchrophasors and GOOSE messages are also determined. It is shown that such applications can have a seamless and cost-effective deployment in the field.   Within the context of wide-area control applications, this thesis explores the possibility of utilizing synchrophasor-based damping signals in a commercial excitation control system (ECS). For this purpose, a hardware prototype of wide-area damping controller (WADC) is presented together with its interface with ECS. The WADC allows real-time monitoring and remote parameter tuning that could potentially facilitate system operators’ to exploit existing damping assets (e.g. conventional generators) when changes in operating conditions or network topology emerges. Finally the thesis experimentally investigates the impact of time synchronization impairment on WAMPAC applications by designing RT-HIL experiments for time synchronization signal loss and time synchronization spoofing. It is experimentally demonstrated that GPS-based time synchronization impairment results in corrupt phase angle computations by PMUs, and the impact this has on associated WAMPAC application. / <p>QC 20171121</p> / smart transmission grid operation and control (STRONg2rid)