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2187 Uppsatser om Digital Signal Processing - Sida 1 av 146

Grafisk utvecklingsplattform för signalbehandling - Design och implementation

We have different kinds of signal processing everywhere around us in our everyday life, in our cellphones, when we are listening to music, watching TV etc. This makes signal processing a very interesting and important technical area, where the demand of skilled engineers sets the limit of what is possible.Working with signal processing requires in-depth knowledge in areas such as mathematics, physics, electronics, and other related areas. For this, it has traditionally been demanded by a talented developer to also master the advanced programming languages such as C / C + + and Assembler.This has begun to change; today there are several companies that offer graphical development environments for signal processing, environments where programming skills are not needed anymore, and the focus can be on signal processing instead.The goal with this project is to build a corresponding graphical development environment to reach an understanding of what is required of these systems, and also to grasp what opportunities that are available within graphic programming. Inspiration for the work has partly arise from some of the tools available on the market, and partly from previous theses that have been written about graphic programming.The challenge lies in creating a program that can execute signal diagrams in real time from given signal blocks, and be able to handle feedback loops in an efficient way and to do so at the lowest "cost" in terms of clock cycles as possible. This should also be compared against to code, compile and run a complete signal diagram directly.To increase the usability it should also be possibility to externally manage in real time the parameters of the signal diagram during execution.The interface is a separate program, which is to some extent similar to Matlab Simulink, where a signal diagram is drawn up graphically by connecting wires between different signal blocks.

Utvärdering av grafisk utvecklingsmiljö för programmering av signalprocessor

This work aims to evaluate the possibility of using a graphical programming language to develop software for a digital signal processor. A fixed-point digital signal processor called Blackfin BF-537 is used for this. Instead of using conventional programming languages, like C or assembler, for software development the possibilities to use a graphical environment to fill the same purpose are examined. The development environment primarily used is NI LabVIEW, but also the use of Mathworks Matlab Simulink is investigated. A variety of programs consisting of various signal processing operations and utilities are developed using these development environments.

Utveckling av projektlaborationför signalbehandling : med digital signalprocessor programmeradmed LabVIEW och Matlab

This report describes how to process audio signals in real time with a digital signalprocessor. The digital signal processor used in the thesis and described in the reportare the Blackfin processor ADSP-BF537 from Analog Devices.In the body of this report there is theory of the processor characteristics and thevarious programming languages used. All experiments that were made on theprocessor are described, these descriptions also help in understanding the annexeswhere the experiments will be presented. The body of this report also describes theprogram used to do experiments. Testing the CPU limit was done and the results arepresented to get a good view of what it can handle.

Programmerbar signalanpassning

The data acquisition system COMET developed by Saab AB contains a unit for signal conditioning and A/D conversion, called KSM. The varieties in signal conditioning constitutes of a number of specific PBAs and maintenance as well as reconfiguration of these are complicated not to mention costly. This thesis has aimed to investigating whether the signal conditioning circuits can be replaced by a general purpose, programmable solution. If so, how can this be done? The development has been carried out by evaluating ideas through the use of a laboratory environment and has resulted in an analog design for laboratory purpose.

Konstruktion av sök/räddningsrobot

Volvo Human Monitoring (VHM) is an ongoing project at Volvo Cars where they measure, amongst other parameters, inhalation and exhalation through a device called Respiratory Inductance Plethysmograph (RIP), on drivers. RIP measures changes in the cross-sectional area of the chest and abdomen. When the driver is in motion, such as when she is turning the vehicle, the cross-sectional area changes and noise in the RIP signal may arise.The noise results in a large number of manual adjustments in the analysis of the RIP signal, which is very time consuming and the validity of the device for measuring inhalation and exhalation is questioned.The purpose of this study was to improve the efficiency of the analysis of the RIP signal. The goal was to create a new data processing tool in Matlab that automatically detects inhalation and exhalation from a RIP signal with higher validity compared to the previous data processing tool.In this study, nine tests were performed on drivers while they were driving in different scenarios such as highway, country road and in city traffic. Inhalation and exhalation was measured using a RIP, a pneumotachograph with a tightly sealed facemask and a thermocouple placed between the nose and mouth, which was used as reference to the RIP.The result of this study was a data processing tool that automatically detects inhalation and exhalation with higher validity compared to the previous data processing tool.

Detektering av in- och utandning vil bilkörning med hjälp av Matlab

Volvo Human Monitoring (VHM) is an ongoing project at Volvo Cars where they measure, amongst other parameters, inhalation and exhalation through a device called Respiratory Inductance Plethysmograph (RIP), on drivers. RIP measures changes in the cross-sectional area of the chest and abdomen. When the driver is in motion, such as when she is turning the vehicle, the cross-sectional area changes and noise in the RIP signal may arise.The noise results in a large number of manual adjustments in the analysis of the RIP signal, which is very time consuming and the validity of the device for measuring inhalation and exhalation is questioned.The purpose of this study was to improve the efficiency of the analysis of the RIP signal. The goal was to create a new data processing tool in Matlab that automatically detects inhalation and exhalation from a RIP signal with higher validity compared to the previous data processing tool.In this study, nine tests were performed on drivers while they were driving in different scenarios such as highway, country road and in city traffic. Inhalation and exhalation was measured using a RIP, a pneumotachograph with a tightly sealed facemask and a thermocouple placed between the nose and mouth, which was used as reference to the RIP.The result of this study was a data processing tool that automatically detects inhalation and exhalation with higher validity compared to the previous data processing tool.

Less is More - en studie om utformningen av inlägg på sociala medier

Theory has concluded that consumers evaluate advertising not only based on what the advertiser's message aims to communicate, but also how the message is communicated. As the most popular activity on the world's largest social media channels is to upload and share photos, it has become crucial for advertisers to define strategies that maximize the reach of photo posts. Two observed variations of images used in posts are graphical images and digital photographs. The aim of this study is to investigate which of these two strategies that generate most positive impact on the sender and its brand. 230 users of the Chinese Facebook and Twitter counterpart, Sina Weibo, were exposed to manipulated Sina Weibo posts after which they answered a survey.

Kombinerad DSP- och FPGA-lösning för en bildbehandlingsapplikation

This Master's Thesis describes the design of a new system where a digital signal processor has been added to an existing imaging system consisting of field programmable gate arrays. The new system will offer a higher degree of flexibility by considerably shortening the design time and make it possible to implement more complex algorithms than the existing ones. The choice of system architecture and a test implementation are discussed. The test implementation consists of a program for the digital signal processor and VHDL code for one of the field programmable gate arrays. The code for the digital signal processor was designed for testing on an evaluation board from Texas Instruments.

Överföring av digital video via FireWire

Transmission of digital signals is today more frequently used than transmission of analog signals. One reason for this is that a digital signal is less sensitive to noise than an analog, another reason is that almost all signals today are handled in a digital format. This thesis describes the development of a system that receives digital video signals through FireWire. The standard for FireWire, which is a high performance serial bus, is under development. Today the standard of the bus supports transmission of data with a speed of up to 400 Mbit/s.

Datainsamlingskort med Compact PCI Express

In this thesis a prototype board for data aqcusition is designed and manufactured. The board is compliant with Compact PCI Express and it can sample an analog signal with two time interleaved ADC:s. Furthermore, the board is also equiped with one FPGA for the possibility of signal processing. The thesis also include a study for investigation what is needed for a total solution for data aqcusition, represention and managing the sampled data with LabView..

Radiolänk med GNU Radio

At the Department of Technology and Built environment at the University of Gävle there was an interest to study GNU Radio, which is an "open source radio project. The project is based on that most of the radio signal processing is made in an ordinary PC. The idea behind this degree project was that in a laptop there are several radio transmitters/receivers that takes space, generates heat and transmit in varied frequency band etcetera. All these radio transmitters/receivers could be replaced with a Software Defined Radio system. It means that one common, general radio hardware is used to different communications such as: WLAN, Bluetooth, GPRS, 3G etcetera. The waveform is generated in the software, which makes the system very flexible.

Implementering av Constant Fraction Detection vid avståndsmätning

This thesis is performed at Saab Bofors Dynamics in Karlskoga and investigates a technique for ranging with laser pulses. The investigated technique is called Constant Fraction Detection (CFD). Described briefly, the received laser pulse is split into two equal parts, where one part is delayed half the pulse width and inverted. This signal is added to the original pulse. The resulting curve has the shape of a laying S and the detection of the zero level is used to stop the time measurement.

Internetbaserade insamling och behandling av data

AbstractAim of this project was to analyse signals and try to localize the position of source of sound. It is donewith three microphones which have 90 degrees angle to each other. Each microphone detects one partof the sound wave. The microphones are connected toan ADC which turns signals from analogue todigital shape. After that the three signals are transformed to a computer.

En psophometrisk brusmätning

I det här examensarbetet har jag tittat närmare på hur man med hjälp av en transformator kan höja signal/brus-förhållandet för en mikrofonsignal som förstärks av en förstärkarkrets. Arbetet baseras sig på en psykoakustisk brusmätning enligt standarden ITU-468-4.Ett bra förhållande mellan signal och brus är alltid eftersträvat i en krets. När signalen i kretsen är svag kan signalen i värsta fall försvinna i bruset. Arbetet kommer att titta på hur man definierar och mäter signal/brus-förhållanden på en förstärkare samt vad som påverkar signal/brus-förhållandet. Arbetet kommer visa att med hjälp av en spänningstransformering av en in-signal så kan ett bättre signal/brus- förhållande ut från en serie förstärkare erhållas..

Konstruktion av datainsamlingskort för mätsystemet COMET

During test flights SAAB uses the data acquisition system COMET 16. The part of the system that receives the signals from the sensors and converts them is called KSM 15. The purpose of this thesis is to develop a data acquisition module on stacked PC/104 modules with a lower production cost. Our work has been divided into one part about analog signal conditioning and a second part with digital filtering and memory management of the sampled data. The analog part, designed of regular components like instrument amplifiers, voltage references, operational amplifiers and multiplexers, adjusts the sensors signal levels for the ADC?s that converts the signals.

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