The aim of the diploma thesis was to design active loudspeakers. The project contains the final solution of the designed loudspeakers that have a digital input of the multichannel audio signal with both sided data communication. In the work, there are also created circuits for processing an audio signal with a following amplification for the loudspeakers. Added functions are an infra acceptor for a remote control and binary outputs for assistant functions - a control of the motor and an indication via LED diodes.

The project describes the design of controlled inverters or power generator simulating one phase of European or American distribution network. The generator is able to enter into an output signal of a certain fault conditions designed to testing the electromagnetic compatibility of connected devices. The text is divided into three main chapters. The first one deals with the design of the power generating low-frequency signal. The second part describes the power source used for this generator. In the third section describes the program management unit. End of text summarizes the results. The annex contains a schematic designs and printed circuit boards.

För att kunna framföra ett fordon på ett säkert sätt är vindrutetorkning är en viktig del. Men, bara för att det är en viktig del i användandet innebär det inte att det är en viktig del i utvecklingen. Detta har visat sig genom att funktionen och designen av vindrutetorkare på lastbilar har varit densamma i årtionden. När hytten till Scanias senaste lastbilsmodell designades så minskades tjockleken på torpedväggen för att spara vikt. Detta minskade även styvheten i hytten, vilket fick de vibrationer som inducerades vid körning av vindrutetorkarna att nå en kritisk gräns. Problemställningen för detta exjobb var därför att förstå ursprunget till dessa vibrationer och hur delsystemen interagerar med varandra genom att utföra modellbaserad utveckling (MBD). Uppgiften var att undersöka vilka ändringar som behövde genomföras i styrningen av vindrutetorkarna och systemspecifikationen för den inbyggda styrenheten för att reducera vibrationerna och säkerställa Scanias position som premiummärke även i framtiden. Vindrutetorkarsystemet modellerades i Simulink, med både Simulink-block och Simscapemodeller. En strömberoende spänningskontroller för rörelsestyrning utvecklades för att sedan verifieras på nuvarande hårdvara. Rekommendationer för framtida arbete på ECU gällande systemfrekvens för mätning samt algoritmdesign gjordes, samt helhetstänket vid design av ett nytt system poängterades. Resultaten visar att styrning av en likströmsmotor med ström som ingångsparameter är komplicerat då strömmen varierar kraftigt på grund av störningar. Algoritmen som behandlar mätdatat måste därför vara väldigt robust eftersom filtrering påverkar systemet genom att lägga till fas i kontrollern, vilket ger eftersläpningar. Kommande arbetsinsatser bör fokusera på hur man väljer komponenter som matchar varandra gällande likströmsmotor och ECU. Desto mer logik som placeras i motorn, desto mindre datorkraft behövs i den inbyggda styrenheten. / Windscreen wiping is an important part of driving safety and vehicle maneuverability. However, importance does not automatically imply progression, and the wiping functionality for heavy commercial vehicles have remained roughly the same through decades. When redesigning the cab for the latest truck generation at Scania, the thickness of the firewall was reduced to save weight.This reduced the stiffness of the cab, which made the vibrations in the throttle pedal from actuating the windscreen wiper rise to a critical level.The problem definition in this thesis was to understand the root-cause and cooperation in the system by doing modelling and Model-Based Design (MBD), rather than starting with experimental verification. The task was to investigate what changes needed to be made in the controlling of the wiper motor and system specification of the ECU to reduce vibrations and ensure Scania's position as a premium brand in the future. The windscreen wiping system was modelled in Simulink, with both Simulink blocks and Simscape models. A current-measuring voltage-controller for motion-profiles was developed and verified on real production hardware. Recommendation for future development of next ECU generation regarding sampling time and controller design was made and the importance of considering the whole system design was emphasized. Results showed that controlling with current measurement of DC-motors as input parameter is avolatile approach due to disturbances. The algorithms depending on this measurement needs to be very robust, since filtering adds unwanted delay to the control loop. Further investigations should be made in the component selection when mapping motors with the correct driver. The more logic placed in the motor, the less need for a complex ECU and vice versa.

<p>This thesis work contains a litterature study about electrical motors in general and how PWM-patterns for brushless DC-motors can be made. A suitable method has been implemented as a simulation model in VHDL. A simulation model of a brushless DC-motor which describes the phasecurrents, torque and angular velocity has also been made. The motor model made simulations easier for the complete PWM-system. </p><p>The design was synthesised and tested with a prototypeboard including a SPARTAN II FPGA. In order to test the design, a powerstage and a motor was included. The tests showed that the design was working as expected according to the previous simulations. </p><p>A study about an alternative way to control a brushless DC-motor has also been made. This alternative is best suited when the generated back-EMK for the motor is sinusoidal. A simulation model for a part of a system like this has been made, and it has been synthesised in order to examine if it is possible to implement using a FPGA availible today.</p>

<p>Denna rapport behandlar utveckling av en tvåhjulig balanserande robot. En PID-regulator är implementerad i en mikrokontroller, som även AD-omvandlar en sensorsignal, samt styr motorer via H-bryggor med pulsbreddsmodulering. I rapporten förklaras framtagning av diskret PID-regulator, processorkort, motorkort, val av komponenter och sensor för att mäta robotens vinkel mot ett vertikalplan.</p><p>Roboten kan balansera stillastående, men behöver kompletteras ytterligare med hjulåterkoppling för att kunna balansera medan den kör. Roboten balanserar med mätdata från en mekanisk golvavkännare (potentiometer). Andra sorters sensorer diskuteras också, t ex accelerometer, gyro och optisk sensor.</p> / <p>This report explain the development of a two wheel balancing robot. A PID-regulator is implemented in a microcontroller, which also AD-converts a sensor signal, and generate pulse width modulated signals to drive H-bridges. It is discussed how to develop a discretisized PID regulator, microcontroller and H-bridge circuit boards, as well as how to chose components and suitable sensors for measuring the robots angle against a vertical plane.</p><p>The robot is able to balance on its own when standing still, but it need to have feedback from its wheel position if it should be able to maintain balancing when moving. The robot use a mechanical floor feeler (potentiometer). Other sensors are also discussed, e g accelerometer, rate gyro and optical sensor.</p>

<p>In this thesis a predefined design parameters are used to present theoretical guidelines for design of low voltage, and low power DC-DC converter with high power efficiency and low levels of EMI (Electro-Magnetic Interference). This converter is used to alter the DC voltage supplied by the power source. Several DC-DC converters of different types and topologies are described and analyzed. Switched converter of buck topology is found to satisfy the design criteria most adequately and therefore is chosen as the solution for the task of the thesis. Three control schemes are analysed PWM (Pulse-Width Modulation), PFM (Phase-Frequency Modulation), and Sliding control. PWM is found to be most appropriate for implementation with this type of converter. Further, basic operation of the buck converter which includes two modes of operation CCM (Continuous-Conduction Mode) and DCM (Discontinuous-Conduction Mode) is described. Power losses associated with it are analysed as well. Finally several techniques for power conversion improvement are presented.</p>

<p>The purpose with the report is to show that it is possible to design a class-D amplifier, using a programmable FPGA mounted on a developing card from Xess and a H-bridge. The FPGA was programmed in VHDL which is the language the software from Xilinx use to implement a logical function into the FPGA The logical function corresponds to a modeling of the music signal and the modeling can be described as a comparator which compare the music signal with a triangle wave and as a out signal produce a pulse width modulated (PWM) signal. The report is also a review and evaluating of two different modulating technologies, AD- modeling and BD-modeling. A detailed part about how the H-bridge was designed and how it works. The result of this project is a working audio amplifier to a significant lower price than the products in todays market.</p>

<p>This report describes the manufacture and control of a flying platform. The report describes the basic and fundamental theories required to get the platform flying. It touches on subjects such as A/D-conversion. PWM-control and PID-control. The sensors used in the platform are a gyro and an accelerometer. The platform is controlled from a ground station through a wireless link. The wireless link is an Xbee-module that implements the ZigBee-protocol. The microprocessor used is the Atmega 128 by Atmel.</p><p>An indirect complementary filter is used to get the angle of the platform. For the platform to be able to balance a more thourough analysis of the gyro is required. This sensor proved to be more difficult to handle than first anticipated. Every component except the gyro worked as expected. Every algorithm and method reported in this work have been implemented and tested in software.</p>

<p>Class D amplifiers are becoming increasingly popular in audio devices. The strongest reason is the high efficiency which makes it advantageous for portable battery-driven products.</p><p>Infineon Technologies is developing products in this area, and has recently filed a patent application regarding an implementation of a part of the class D amplifier. The aim of this Master’s thesis is to evaluate a digital open-loop implementation of a class D amplifier, using the pending patent solution, and discuss the differences from an analog closed-loop implementation.</p><p>The focus has been on generating a high resolution PWM signal with a relatively low clock frequency. To achieve this, a hybrid of a counter and a self-calibrating tapped delay-line are used as a pulse generator. A model of the pulse generator was developed which made it possible to study how sampling frequency and different types of quantization affected quality parameters such as THD and SNR. With the results from the model two systems were implemented and simulated in HDL and as circuit schematics.</p><p>The proposed digital open-loop class D amplifier was found to be useful in voice-band applications and for music. Since the open-loop structure suffers from poor rejection of power supply ripple, either error correction or a regulated power supply is needed. If much effort is put on the different parts of the amplifier the result can be really good but, depending on other constraints on the system, it may be simpler and less time consuming to use the analog circuit with feedback to achieve hi-fi quality.</p><p>In summary, the combination of a counter and a self-calibrating tapped delay-line as a pulse generator is very useful in high resolution low-power systems. To avoid errors the delay-line and calibration can be made very accurate but with the expense of higher power consumption and area. However, the technique benefits from the small and fast logic devices available in deep sub-micron process technologies, which may finally lead to an advantage in power consumption and cost over the closed-loop analog solution.</p>

A multilevel Space Vector PWM (SVPWM) technique is developed for a 3-level 3-phase PWM Voltage Source Inverter using a 3-phase coupled inductor to ensure high performance operation. The selection of a suitable PWM switching scheme for the Coupled Inductor Inverter (CII) topology should be based on the dual requirements for a high-quality multilevel PWM output voltage together with the need to minimize high frequency currents and associated losses in the coupled inductor and the inverter switches. Compared to carrier-based multilevel PWM schemes, the space vector techniques provide a wider variety of choices of the available switching states and sequences. The precise identification of pulse placements in the SVPWM method is used to improve the CII performance. The successful operation of the CII topology over the full modulation range relies on selecting switching states where the coupled inductor presents a low winding current ripple and a high effective inductance between the upper and lower switches in each inverter leg. In addition to these requirements, the CII operation is affected by the imbalance inductor common mode dc current. When used efficiently, SVPWM allows for an appropriate balance between the need to properly manage the inductor winding currents and to achieve harmonic performance gains. A number of SVPWM strategies are developed, and suitable switching states are selected for these methods. Employing the interleaved PWM technique by using overlapping switching states, the interleaved Discontinuous SVPWM (DSVPWM) method, compared to other proposed SVPWM methods, doubles the effective switching frequency of the inverter outputs and, as a result, offers superior performance for the CII topology by reducing the inductor losses and switching losses. The inverter operation is examined by means of simulation and experimental testing. The experimental performance comparison is obtained for different PWM switching patterns. The inverter performance is affected by high-frequency inductor current ripple; the excessive inductor losses are reduced by the DSVPWM method. Additional experimental test results are carried out to obtain the inverter performance as a variable frequency drive when operated in steady-state and during transient conditions. The CII topology is shown to have great potential for variable speed drives. / Power Engineering and Power Electronics