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729 Uppsatser om Signal processing - Sida 1 av 49

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.

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.

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.

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.

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..

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.

Signal- och bildbehandling på moderna grafikprocessorer

En modern grafikprocessor är oerhört kraftfull och har en prestanda som potentiellt sett är många gånger högre än för en modern mikroprocessor. I takt med att grafikprocessorn blivit alltmer programmerbar har det blivit möjligt att använda den för beräkningstunga tillämpningar utanför dess normala användningsområde. Inom det här arbetet utreds vilka möjligheter och begränsningar som uppstår vid användandet av grafikprocessorer för generell programmering. Arbetet inriktas främst mot signal- och bildbehandlingstillämpningar men mycket av principerna är tillämpliga även inom andra områden.Ett ramverk för bildbehandling implementeras och några algoritmer inom bildanalys realiseras och utvärderas, bland annat stereoseende och beräkning av optiskt flöde. Resultaten visar på att vissa tillämpningar kan uppvisa en avsevärd prestandaökning i en grafikprocessor jämfört med i en mikroprocessor men att andra tillämpningar kan vara ineffektiva eller mycket svåra att implementera..

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.

PWM Effekt Audioförstärkare

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..

Förhållandet mellan barns populära status, individuella bearbetningsstil och arbetsminneskapacitet

This study was conducted to investigate the relationship between perceived popularity, social information processing and working memory. With the intentions of examining popularity 209 (98 female, 111 male) children in second and fourth grade were presented with a roster of their classmates and were to nominate whom they liked and whom they disliked. To study working memory capacity a working memory test, that places demands on the participant to work both with and store the given information, was used. To examine children's cognitive processing of empathy-provoking information a cognitive appraisal interview was conducted. The results imply (a) that working memory increases with age, (b) that there is a weak relation between working memory capacity and popularity, and between popularity and cognitive processing styles and (c) that there are some strong correlations between working memory and cognitive processing styles..

Aktiv bullerdämpning i ventilationssystem

Active headsets have been on the market for years and now it is time for something else to enter the stage. The technology of active noise reduction can for exmple also be used in ventilation systems for reducing ventilation noise. An active control system principally consists of four important components, namely the downstream error microphone, the upstream detection or reference microphone, the digital signal processor (DSP) and a loudspeaker. The upstream reference microphone listen to the primary ventilation noise and sends it to the DSP which makes a phase shift to the signal and sends it to the loudspeaker. The loudspeaker sends out the opposite waveform of the incoming one and reduce the primary ventilation noise.

Utvärdering av försvarsspecifika radiovågformer

To be able to evaluate different radio waveforms in a laboratory environment FOI in Linköping has developed an experimental system for radio communication called Rasmus. The system consists of a transmitter, a channel emulator and a receiver. The transmitter modulates a digital signal to a desired analogue waveform. The channel emulator is used to simulate a real radio channel. The channel emulator distorts the signal by splitting it up in several propagation paths.

Undersökning av mätsystem och regulatorstrukturer för industriella tillämpningar

This thesis is divided in to two different parts. The first part includes examination of the measurementsystem of an industrial robot using a resolver sensor. The main focus is on methods for suppressing noise in the angularvelocity signal without increasing timedelay. Five different methods are investigated. Three of these are based on oversampling: burstsamplingmethod, meanvaluemethod and correlationmethod.

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