Este trabalho apresenta o desenvolvimento de um modelo simplificado dos membros inferiores de um robô bípede, composto basicamente por uma cintura, dois fêmures, duas tíbias e dois pés. A estrutura mecânica do modelo em questão, possui seis graus de liberdade e tem as dimensões aproximadas de um ser humano de estrutura mediana. Seu sistema de controle e de geração de trajetórias é desenvolvido utilizando funcionalidades disponíveis no Robot Operating System (ROS), porém ao contrário da maioria dos controladores existentes no ROS, este projeto propõe implementar um pacote contendo um controlador multivariável (multi-input, multi-output (MIMO)), utilizando a técnica de controle por torque calculado. Para a geração de trajetórias das pernas do robô, implementam-se três tipos diferentes de geração, a interpolação linear, cubica e de quinto grau. Para os testes de validação do sistema de controle e de geração de trajetórias utiliza-se o simulador Gazebo. / This work presents the development of a simplified model of a biped robot’s lower limbs, composed basically by the waist, two femurs, two tibia and two feet. The model’s mechanical structure has six degree of freedom and its dimensions are comparable to a human being’s body. Its control and trajectory generation systems are developed making use of some features available in the Robot Operation System (ROS) tool. However, contrary to most of the controllers offered by ROS, this project suggests the implementation of a new package, including a MIMO (multi-input multi-output) controller, making use of the calculated torque technique. As for the trajectory generation system, three different methodologies are applied of the interpolation: linear, cubic and polynomial quintic. To validate both control and trajectory generation systems, the Gazebo simulator is used.

Este trabalho apresenta o desenvolvimento de um modelo simplificado dos membros inferiores de um robô bípede, composto basicamente por uma cintura, dois fêmures, duas tíbias e dois pés. A estrutura mecânica do modelo em questão, possui seis graus de liberdade e tem as dimensões aproximadas de um ser humano de estrutura mediana. Seu sistema de controle e de geração de trajetórias é desenvolvido utilizando funcionalidades disponíveis no Robot Operating System (ROS), porém ao contrário da maioria dos controladores existentes no ROS, este projeto propõe implementar um pacote contendo um controlador multivariável (multi-input, multi-output (MIMO)), utilizando a técnica de controle por torque calculado. Para a geração de trajetórias das pernas do robô, implementam-se três tipos diferentes de geração, a interpolação linear, cubica e de quinto grau. Para os testes de validação do sistema de controle e de geração de trajetórias utiliza-se o simulador Gazebo. / This work presents the development of a simplified model of a biped robot’s lower limbs, composed basically by the waist, two femurs, two tibia and two feet. The model’s mechanical structure has six degree of freedom and its dimensions are comparable to a human being’s body. Its control and trajectory generation systems are developed making use of some features available in the Robot Operation System (ROS) tool. However, contrary to most of the controllers offered by ROS, this project suggests the implementation of a new package, including a MIMO (multi-input multi-output) controller, making use of the calculated torque technique. As for the trajectory generation system, three different methodologies are applied of the interpolation: linear, cubic and polynomial quintic. To validate both control and trajectory generation systems, the Gazebo simulator is used.

For many years OSE has been a common used operating system, with real time extensions enhancements, in embed-ded systems. But in the last decades, Linux has grown and became a competitor to common operating systems and, in recent years, even as an operating system with real time extensions. With this in mind, ÅF was interested in replacing the quite expensive OSE with some distribution of the open source based Linux on a PowerPC MPC8360. Therefore, our purpose with thesis is to implement Linux on the named platform and make some tests to see if it is possible to replace OSE with Linux. Using Linux has several advantages, for example it is free of charge to use and over the years the popularity of Linux within the developer community has resulted in numerous tools and utilities available for free. As a result, this study shows that Linux with real time extensions on the MPC8360 PowerPC platform is a viable alternative to OSE regarding cost efficiency, flexibility, adaptability and competence available on the market. Further studies can be done towards benchmarking for I/O systems and implementing support for more hardware on the MPC8360 AF platform.

Este trabalho apresenta o desenvolvimento de um modelo simplificado dos membros inferiores de um robô bípede, composto basicamente por uma cintura, dois fêmures, duas tíbias e dois pés. A estrutura mecânica do modelo em questão, possui seis graus de liberdade e tem as dimensões aproximadas de um ser humano de estrutura mediana. Seu sistema de controle e de geração de trajetórias é desenvolvido utilizando funcionalidades disponíveis no Robot Operating System (ROS), porém ao contrário da maioria dos controladores existentes no ROS, este projeto propõe implementar um pacote contendo um controlador multivariável (multi-input, multi-output (MIMO)), utilizando a técnica de controle por torque calculado. Para a geração de trajetórias das pernas do robô, implementam-se três tipos diferentes de geração, a interpolação linear, cubica e de quinto grau. Para os testes de validação do sistema de controle e de geração de trajetórias utiliza-se o simulador Gazebo. / This work presents the development of a simplified model of a biped robot’s lower limbs, composed basically by the waist, two femurs, two tibia and two feet. The model’s mechanical structure has six degree of freedom and its dimensions are comparable to a human being’s body. Its control and trajectory generation systems are developed making use of some features available in the Robot Operation System (ROS) tool. However, contrary to most of the controllers offered by ROS, this project suggests the implementation of a new package, including a MIMO (multi-input multi-output) controller, making use of the calculated torque technique. As for the trajectory generation system, three different methodologies are applied of the interpolation: linear, cubic and polynomial quintic. To validate both control and trajectory generation systems, the Gazebo simulator is used.

A mobile robot needs to know its pose (position and orientation) in order to navigate and perform useful tasks. The problem of determining this pose with respect to a global or local frame is called localisation, and is a key component in providing autonomy to mobile robots. Thus, localisation answers the question Where am I? from the robot’s perspective. Localisation involving a single robot is a widely explored and documented problem in mobile robotics. The basic idea behind most documented localisation techniques involves the optimum combination of noisy and uncertain information that comes from various robot’s sensors. However, many complex robotic applications require multiple robots to work together and share information among themselves in order to successfully and efficiently accomplish certain tasks. This leads to research in collaborative localisation involving multiple robots. Several studies have shown that when multiple robots collaboratively localise themselves, the resulting accuracy in their estimated positions and orientations outperforms that of a single robot, especially in scenarios where robots do not have access to information about their surrounding environment. This thesis presents the main theme of most of the existing collaborative, multi-robot localisation solutions, and proposes an alternative or complementary solution to some of the existing challenges in multirobot localisation. Specifically, in this thesis, a heuristically tuned Extended Kalman Filter is proposed to localise a group of mobile robots. Simulations show that when certain conditions are met, the proposed tuning method significantly improves the accuracy and reliability of poses estimated by the Extended Kalman Filter. Real world experiments performed on custom-made robotic platforms validate the simulation results.

This thesis deals with certain properties of real time operating systems (RTOS) Ardence PharLap ETS, WindRiver VxWorks and LabVIEW RT module. Three methodologies of RTOS quality comparison are proposed, two of which are practically tested with described experiments on CompactRIO hardware from NI. Furthermore, there is explained need for RTOS usage and experimental comparison of jitter error influence on total harmonic distortion THD defined by two definitions.

Modern computer hardware platforms are moving towards high core-count and heterogeneous Instruction Set Architecture (ISA) processors to achieve improved performance as single core performance has reached its performance limit. These trends put the current monolithic SMP operating system (OS) under scrutiny in terms of scalability and portability. Proper pairing of computing workloads with computing resources has become increasingly arduous with traditional software architecture. One of the most promising emerging operating system architectures is the Multi-kernel. Multi-kernels not only address scalability issues, but also inherently support heterogeneity. Furthermore, provide an easy way to properly map computing workloads to the correct type of processing resources in presence of heterogeneity. Multi-kernels do so by partitioning the resources and running independent kernel instances and co-operating amongst themselves to present a unified view of the system to the application. Popcorn is one the most prominent multi-kernels today, which is unique in the sense that it runs multiple Linux instances on different cores or group of cores, and provides a unified view of the system i.e., Single System Image (SSI). This thesis presents four contributions. First, it introduces a filesystem for Popcorn, which is a vital part to provide a SSI. Popcorn supports thread/process migration that requires migration of file descriptors which is not provided by traditional filesystems as well as popular distributed file systems, this work proposes a scalable messaging based file descriptor migration and consistency protocol for Popcorn. Second, multi-kernel OSs rely heavily on a fast low latency messaging layer to be scalable. Messaging is even more important in heterogeneous systems where different types of cores are on different islands with no shared memory. Thus, another contribution proposes a fast-low latency messaging layer to enable communication among heterogeneous processor islands for Heterogeneous Popcorn. With advances in networking technology, newest Ethernet technologies are able to support up to 40 Gbps bandwidth, but due to scalability issues in monolithic kernels, the number of connections served per second does not scale with this increase in speed.Therefore, the third and fourth contributions try to address this problem with Snap Bean, a virtual network device and Angel, an opportunistic load balancer for Popcorn's network system. With the messaging layer Popcorn gets over 30% performance benefit over OpenCL and Intel Offloading technique (LEO). And with NetPopcorn we achieve over 7 to 8 times better performance over vanilla Linux and 2 to 5 times over state-of-the-art Affinity Accept. / Master of Science

This thesis presents the design and evaluation of an object-oriented (OO) operating system kernel for real-time embedded systems based on dataflow architecture. Dataflow is a software architecture that is well suited to applications that involve signal flows and value transformations. Typically, these systems comprise numerous processes with heavy inter-process communications. The dataflow style has been adopted for the control software for PEBB (Power Electronic Building Block) systems by the Center for Power Electronic Systems (CPES), Virginia Tech., which is involved in a research effort to modularize and standardize power electronic components. The goal of our research is to design and implement an efficient object-oriented kernel for the PEBB system and compare its performance vis-à-vis that of a non-OO kernel. It presents strategies for efficient OO design and a discussion of how OO performance issues can be ameliorated. We conclude the thesis with an evaluation of the advantages gained by using the OO paradigm both from the standpoint of the classically cited advantages of OO programming and other crucial aspects. / Master of Science

This thesis presents the design and evaluation of an operating system kernel specially designed for dataflow software. Dataflow is a style of software architecture that is well suited for control and "signal flow" applications. This architecture involves many small processes and lots of inter-process communication, which impose too much overhead on traditional RTOSes. This thesis describes design and implementation of the Dataflow Architecture Real-time Kernel (DARK). DARK is a reconfigurable, multithreaded and preemptive operating system kernel that introduces a special data-driven scheduling strategy for dataflow applications. It uses the underlying hardware for high-speed context switching between the kernel and applications, which is five times faster than the ordinary context switch. The features of the kernel can be configured according to performance requirements without change to the applications. Along with the performance evaluation of DARK, the performance comparison results of DARK with two commercial RTOSes: MicroC/OS-II and Analog Devices VDK++ are also provided. / Master of Science

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