The goal of this diploma thesis is to verify the practical applicability of the Raspberry Pi platform in control applications. The work consists of choosing a suitable operating system and implementing a discrete PID algorithm. An important part of the work was the Linux OS modification and compilation. Measurement has demonstrated the usability of the platform in control applications. The result of this work is a discreet PID controller implemented as a Linux kernel module. The solution also includes a web interface as a human-machine interface.

Táto diplomová práca sa zaoberá návrhom a realizáciou výukového modelu pre študentov mechatroniky na vysokej škole. Úvod práce sa zaoberá krátkym uvedením do problematiky používania univerzálnej sériovej zbernice a jej implementáciou pre komunikáciu s mikrokontrolérom. Druhá časť je venovaná hardwaru zariadenia, medzi čo patrí voľba vhodného motoru, návrh vhodných elektronických komponentov, návrh dosiek plošných spojov a taktiež mechanickej konštrukcie celého zariadenia. Nasleduje softwarová časť, popisujúca praktickú realizáciu komunikácie, program v mikrokontroléry, a Toolbox, ktorý umožňuje užívateľovi jednoduchú interakciu s hardwarom a to jak z Matlabu. tak zo Simulinku. Kombinácia navrhnutých hardwarových a softwarových prvkov umožňuje jednoduchú cestu k zlepšeniu vedomostí študentov v oblastiach programovania, riadenia a modelovaní sústav. Pre tieto účely je práca rozšírená o pracovný list, ktorý dopĺňa navrhnuté zariadenie o sadu experimentálnych úloh, zameraných na vybrané mechatronické problémy.

Orientador: Marcos Silveira / Coorientador: Mauricio Becerra Vargas / Banca: Douglas Domingues Bueno / Banca: Fabricio Cesar Lobato de Almeida / Resumo: Robôs paralelos ou robôs de cadeia cinemática fechada vêm ganhando destaque no cenário industrial e acadêmico, principalmente diante da necessidade de robôs com altas acelerações e velocidades, alta relação capacidade de carga/peso e alta rigidez e precisão, motivo pelo qual são usados em simuladores de voo e robôs pick-and-place. Muitos trabalhos foram publicados tratando sobre o controle de posição de robôs paralelos, porém muitos mantiveram-se restritos ao estudo teórico, sem considerar algumas limitações na aplicação prática. Neste contexto, esta dissertação apresenta o projeto e a implementação prática de um controlador PD (Proporcional-Derivativo) independente para cada junta de um robô paralelo de seis graus de liberdade do tipo 6-UPUR (universal-prismáticauniversal- rotational) acionado por atuadores lineares eletromecânicos. Inicialmente foi realizada a calibração e o acondicionamento do sinal dos sensores de realimentação, do driver e dos atuadores eletromecânicos. Posteriormente, modelos matemáticos do comportamento dinâmico dos atuadores lineares foram identificados e, finalmente, considerando critérios de desempenho específicos para simuladores de voo, foram projetados os controladores para cada atuador. O desempenho de cada controlador foi avaliado por meio de sinais de entrada em degrau, rampa e parábola em coordenadas cartesianas e, por meio da cinemática inversa, foram calculadas as entradas desejadas para cada atuador. O desempenho do robô na frequência foi ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Parallel robots or closed kinematic chain robots has gained more attention from both in industry and in academic research, especially in view of the need for robot whith high velocities and accelerations, high payload-weight ratio, high stiffness and accuracy. That is why they are used in flight simulators and robots pick-and-place. Many studies have been published addressing the problem of motion control of parallel robots, but many are limited to the theoretical study, without considering some limitations in practical application. In this context, this dissertation presents the design and practical imple- mentation of independent-joint PD (Proportional-Derivative) controller for a 6-UPRU (universal-prismatic-universal-rotational) degree-of-freedom parallel manipulator driven by electromechanical linear actuators. First, the feedback sensors, drive and electrome- chanical actuators are calibrated, and their signals are processed. Later, mathematical models of the dynamical behaviour of the linear actuators are identified. Then, conside- ring specific performance criteria for flight simulators, the controller for each actuator is designed. The performance of each controller was evaluated for step, ramp and parabolic inputs in cartesian coordinates, then the cartesian trajectory is converted to desired actu- ator trajectory by using inverse kinematics. The perfomance of the robot was evaluated in frequency domain using sinousoidal inputs in cartesian coordinates, describing fu... (Complete abstract click electronic access below) / Mestre

This research project develops a low-cost high-cycle fatigue (HCF) testing system comprised of an AC motor, variable frequency drive (VFD), eccentric cam, and feedback controller. The system acts as a forced harmonic oscillator leveraging mechanical resonance to vibrate a specimen at a frequency required to induce the testing's strain amplitudes. This system depends highly on the material being tested. As such, the controller incorporates material characteristics. A frequency sweep measures the strain amplitude to characterize the specimen. Additionally, other measurements such as acceleration can be used as a proxy control variables for strain. A function converts the control variable to frequency. This function tunes a proportional integral derivative (PID) controller to emphasize stable control. This function, coupled with a tuned PID controller, converts the correction update into a voltage signal that commands a motor speed to reach the desired strain amplitude. Testing showed that a longer feedback loop time of 5 seconds was necessary to adequately control the system since the control variables are oscillatory by nature and need to be averaged over time to estimate accurate updates. Also, specimens with low damping are more subject to transient effects; consequently, rapid updates degrade system performance. Overall, the system tested over 250,000 cycles and various specimens. The main limitation of the system is a maximum strain amplitude limited by the specific specimen resonant peak. However, adjusting the system's fixed displacement enables transferring more force to the specimen, changing the shape of the resonant peak.

Industry 4.0 holds many promises for manufacturers; however, a shortage of qualified employees has prevented a swift adoption of the revolution's new technologies. Engineer and Economist Klaus Schwab argues Education 4.0 is the key to addressing the employee shortage and preparing future generations for the shifting labor market. To support Education 4.0, classes must allow students to engage emerging technologies that help bridge Operational Technology (OT) and Informational Technology (IT). The thesis detailed an educational laboratory that demonstrates the application of data analytics (an IT tool) and optimize the performance of a cyber-physical system composed of industrial (OT) components. The lab experience focuses on a disc's controlled positioning (levitating) using a PLC-based PID controller and a VFD. The activity requires students to capture data of a moving discs, create a machine learning function representing the disc's movement, and use the machine learning function for classification and PID optimization problems. A comparative analysis of a PID cycle ensures a regressions model accurately represents the physical model using measurements including peak-overshoot, rise time, settling time, and the flight plots' Means of their Squared Error. Further, the study examines multiple ML models each built using various features to identify the systems relevant and redundant data.<br>

The motivation behind this thesis is to consolidate and evaluate the most common Proportional Integral Derivative (PID) controller tuning techniques used in industry. These are the tuning techniques used when the plant transfer function is not known. Many of these systems are poorly tuned because such consolidated information is not easily found in one single source such as this thesis. Once one of the tuning methods are applied almost always there will be further fine tuning needed to bring the system into the required design criteria. The purpose here is to find out which tuning technique will yield the lowest percent overshoot and the shortest settling time for all situations. This will give the engineer a good starting point; to minimally further adjust parameters to achieve the desired design criteria. There will also be discussion on the various algorithms used in industry. Four tuning methods will be evaluated based on their ability to control different style plants. The comparison criteria will be percent overshoot and settling time for an applied step input. The tuning methods chosen were the Ziegler-Nichols Open Loop method, the CHR method for 0% overshoot, the Ziegler-Nichols Closed Loop method, and the Rule of Thumb method. It is shown that for a second order plant with a lag and pure integration in its transfer function, the Open Loop method yielded the lowest results in terms of percent overshoot, yet the Closed Loop method had the shortest settling time. For systems of higher order than two it was shown that the CHR method gave the best performance however as the order increased the Closed Loop method gave a shorter settling time. For systems of higher order with varying lags in series the CHR method gave the best results. The Rule of thumb method usually gave similar results to that of the Closed Loop method; however for higher order systems the Rule of Thumb method gave less percent overshoot but with a longer settling time than the Closed Loop method. Since these tuning methods are used when the plant transfer function is not known, and none of the rules were found to give consistently the lowest percent overshoot, and settling time for all plants tested, there can not be a recommendation as to which method an engineer should choose to use. If the plant transfer function is known or can be reasonably modeled then the following recommendations can be followed. When tuning systems with pure integrations in their transfer function the Open Loop or Closed Loop method be used. When tuning systems of order higher than two the CHR or Closed Loop method should be used, however with high order systems with varying lags the CHR method should be used. It is the responsibility of the engineer to know how and when to implement each of the tuning rules properly.

No description available.

No description available.

No description available.

Power converters are electronic circuits for conversion, control and regulation of electric power for various applications, such as from tablet computers in milliwatts to electric power systems at megawatts range. There are three basic types of power converters: buck (output voltage less than the input voltage), boost (output voltage higher than the input voltage) and buck-boost converters. The reliability of the power converters has become an essential focus of industrial applications. This research presents modeling and control of DC/DC boost converter using several control methods, such as Proportional-Integral (PI), Linear Quadratic Regulator (LQR) control, and nonlinear control concepts. Based on standard circuit laws, a mathematical model of the boost converter is derived which is expressed as a bilinear system. First a small signal model of the converter is derived to analyze the small deviations around the steady-state operating point which is used to develop closed loop control using the PI and the LQR methods. Simulation results show that the performance of the converter is good for operation around the operating state, however is unacceptable if there are large variations in the load or the reference input. To improve the performance of the closed loop system, the nonlinear control concept is used which shows excellent closed loop performance under large variations of load or setpoint. Comparative simulation results are presented for closed loop performance under various types of disturbances including random variations in load. / Electrical and Computer Engineering