Optical encoders are being widely suggested for precise mobile navigation. Combining such sensor information with Global Positioning System (GPS) is a practical solution for reducing the accumulated errors from encoders and moving the navigational base into global coordinates with high accuracy. This thesis presents integration methods of GPS and optical encoders for a mobile vehicle that is controlled by microcontroller. The system analyzed includes a commercial GPS receiver, dsPIC microcontroller and mobile vehicle with optical encoders. Extended kalman filtering (EKF), real time curve matching, GPS filtering methods are compared and contrasted which are used for integrating sensors data. Moreover, computer interface, encoder interface and motor control module of dsPIC microprocessor have been used and explained. Navigation quality on low speeds highly depends greatly upon the processing of GPS data. Integration of sensor data is simulated for both EKF and real time curve matching technique and different behaviors are observed. Both methods have significantly improved the accuracy of the navigation. However, EKF has more advantages on solving the localization problem where it is also dealing with the uncertainties of the systems.

In this report we focus on the use of an economical way on how Scalar Network Analyzer (SNA) works instead of Vector Network Analyzer (VNA) to estimate the phase angle of signals in indoor channel. This is detailed in RMS delay theory and simulation section, experimental is designed in the according Experiment Design section, where we also state the required measurements known from the math part. In our work, data are recorded both from two different channel characteristics. Method of achieving amplitude is by using deconvolution theory. The condition of applying Hilbert transform are highlighted as impulse response h(t) in time domain should be causal.  The recorded data amplitude is computed by Hilbert Transform, and therefore validate the condition using Inverse Discrete Fourier Transform (IDFT) back to time domain to achieve h(t). Power delay profile P(t) is therefore presented afterwards. In paper calculations of rms delay τrms  of the channel which is the most important variable are also performed, the results calculated from different windowing truncation and the LOS and NLOS characteristics are compared in discussion and conclusion section, it also includes Opinions of window functions chosen for the phase estimation.

Wireless sensor network is an intelligent network system which has the self-monitoring functionality. It consists of many low-cost, low-power and small-sized sensor nodes that can communicate with each other to perform sensing and data processing. Acting as an important role in the system, network coverage usually has a huge effect on the system’s lifetime.In this thesis, particle swarm algorithm was used as a method to optimize the coverage in the coverage of wireless sensor network. A network coverage optimization strategy based on particle swarm optimization was proposed and MATLAB was used as a tool to apply the algorithm. The model used in this thesis is the probability sensing model and the coverage type is area coverage. Effectiveness of the algorithm is proved by simulation. The simulation of the algorithm suggests the optimal deployment can be determined if a certain parameter which in this thesis is the sensing range is given.

ABB:s MACH2 system uses a number of currents to ignite thyristors for AC/DC-trassfformation and they are measured for control and protection. The measurement methods used today has major drawbacks. Two alternative techniques are investigated, one based on the Hall-Effect (HED) and the other based on Anisotropic Magnetoreistanse (AMR), both techniques sensing the magnetic field produced by currents in a conductor. The HED hawe low sensitivity so some kind of flux concentrators is needed. This adds volume, costs and complexity to the device. The AMR technique is much more sensitive than the HED. Unfortunately AMR are also much more sensitive for high over currents that may damage the devise, and they are not as common on te market. By testing linearity, step response and frequency dependency for some components, my conclusion is that HED components with toroidal flux concentrators utilizing magnetic feedback (Closed Loop, CL) may be used in this particular application. A drawback with CL are that they, when measuring sharp edged step signals, suffer from overshoots at the output that might activate the over current protection.

<p>The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less disturbances and interrupts would lead to large amounts of money savings.</p><p>Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.</p><p>The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3^rd, 5^th, 7^th and 9^th harmonics. In most cases, when the harmonics are very small it is not necessary to compensate for them. There are though cases when compensation for the harmonics is necessary.</p><p>This thesis focuses on finding the best method to extract the content of a sampled signal regarding both simplicity and speed. Both amplitude and phase of each harmonic must be calculated. Is the proposed method suitable for the current computer system and how can it easily be implemented.</p><p>Because the fundamental frequency is known and the harmonics are all multiples of the fundamental frequency it makes the task less complex. It is not necessary to use the FFT algorithm. The DFT can be calculated using correlation. Both phase and amplitude can be calculated very precisely with few samples and not so many computer operations.</p>

Spectrally pure signals are an indispensable requirement when the Signal Generator (SG) is to be used as part of a test bed. However, even sophisticated equipment may not comply with the needs imposed by certain applications. This work approaches the problem by using Digital Pre-Distortion (DPD) based on a polynomial memory-less model obtained for the SG. Using the SG in arbitrary mode (ARB) an input signal is computer-generated and reproduced by the SG. Measurement accuracy is ensured using coherence sampling and grid matching to the Signal Analyzer (SA). Finally, careful time alignment is used to compare the transmitted and received three-tone signals to obtain the polynomials coefficients. Results show that the accuracy of the model and the effectiveness of pre-distortion may vary depending on the amplitude of the three-tone signal. However, using polynomials of 5th and 9th degrees up to 15dB reduction of the 3rd order Inter-Modulation products can be obtained, and spurious powers may be lowered down to 70dBc.

Ultrasound contrast agents composed of micro-bubble filled with gas are introduced to increase the backscattered power from blood. Their intravenously injection results in the improved contrast in the images. The aim of this master thesis project is to manufacture MB suspension at varied temperature and shear forces and to inspect the size distribution and concentration of the PVA-shelled micro-bubble with standard methods according to the developed protocol. A pulser-receiver (Panametrics PR 5072) setup combined with two transducers (2.25 MHz and 5 MHz) was used to investigate the backscattered enhancement of the micro-bubble suspension. Images were collected with transmission optical microscope (OLYMPUS IX71) with the aid of counting chamber. The diameter and concentration of the micro-bubbles were analyzed by Image J. The pulser-receiver setup was used to test the acoustic response. The mean diameter of micro-bubbles was from 2.03 to 4.38 µm with a standard deviation between 0.40 and 1.12 µm and the micro-bubble concentration varied from 0.07× to 5.22× MBs/ml. The enhancement of the ultrasound backscattered power was greater than 20 dB or even reached 30 dB when the energy was increased. / 3MiCRON

Några vanligt förekommande symtom vid neuromuskulära sjukdomar är muskelsvaghet, skakningar och balanssvårigheter. Dessa symptom medför ett behov av mobilitetshjälpmedel, till exempel elektriska rullstolar. Olika neuromuskulära sjukdomar innebär oftast olika symptom, vilket i sin tur ofta medför olika behov. Att individanpassa elektriska rullstolar till personer med olika typer av neuromuskulära sjukdomar och behov är därför ett viktigt mål för att hjälpa till att förenkla vardagen för dem som lider av en neuromuskulär sjukdom. För att den ovan nämnda individanpassningen till olika neuromuskulära sjukdomar ska kunna ske behövs kunskap om området och en kartläggning över vilka behov som finns för respektive sjukdom samt hur man kan bistå behoven. Detta examensarbete undersöker vilka behov som finns och vilka symtom tolv olika neuromuskulära sjukdomar ger upphov till, samt hur en individanpassning av elektriska rullstolar skulle kunna utformas. För att möjliggöra den ovan nämnda individanpassningen studeras funktionalitet och lämplighet hos fyra olika sensorer. Utifrån dessa fyra sensorer i kombination med bakgrundsinformation gällande respektive neuromuskulär sjukdom sker en utvärdering av lämpligheten hos en sensor för styrning av det tekniska mobilitetshjälpmedlet av en individ som drabbats av någon av de i examensarbetet studerade neuromuskulära sjukdomarna. Detta medför en påbörjad individanpassning av det tekniska mobilitetshjälpmedlet. Innan en medicinteknisk produkt kan komma ut på marknaden måste det tillverkande företaget genomgå vissa steg. Efterforskning kring patientbehov och tekniska alternativ på marknaden är en viktig aspekt inför en introduktion på marknaden. Att den medicintekniska produkten har en CE-märkning och är certifierad med relevanta standarder är viktiga kriterier för att produkten ska kunna handlas med fritt på den nationella marknaden. Inför en introduktion på marknaden är det således viktigt för företag och ingenjörer att ha kunskap om dessa områden. Detta examensarbete beskriver de steg som är nödvändiga innan en medicinteknisk produkt kan komma ut på den nationella marknaden och presenterar resultaten i form av bland annat flödesscheman som beskriver riskklassificering av en medicinteknisk produkt.

Försvagad muskelkraft hos äldre är ett stort samhällsproblem med betydande sjukvårdskostnader och försämrad livskvalité för de drabbade. För att bland annat kunna beräkna vridmomentet vid dessa personers armlyft skapade Erik Almgren ett mätinstrument som kunde mäta upp flera parametrar vid armförflyttning. Till denna apparat saknades det dock lämplig programvara som kunde möjliggöra användandet av tekniken i vården. För att bidra till det övergripande syftet om att skapa ett datorprogram som oberoende av andra program kan användas inom ortopedin, utvecklades i detta arbete ett datorprogram i programmeringsspråket Python med ett anpassat grafiskt gränssnitt. Programmet visualiserade kurvor över axelns vridmoment och armens abduktionsvinkel i realtid samt stödde inmatning av persondata, jämförelse av kurvor och sparande av mätdata och grafer. Den utvecklade produkten gav därför en god grund till ett grafiskt gränssnitt för en framtida utveckling av ett fullständigt datorprogram som kan användas i medicinskt syfte eller inom forskning.

Muscle driven devices are controlled or powered with muscle activation. These devices open up the possibility of offering patients with limited muscle function to automatically control assistive devices - for instance exoskeletons - with input from their own muscles. This solution would help a number of patient groups suffering from common conditions, such as spinal cord injuries, stroke and cerebral palsy. To use muscle activation as input it is necessary to have a way to communicate with the mus- cles. Electromyography (EMG) is a technology used to gain information about muscle function and activation. It is performed by measuring and analyzing electrical signals conducted by the muscles during activation. Activation and activation level can be seen from analyzed EMG signal. EMG signals are frequently measured and analyzed afterwards, however, to use it as a controlling an assistive devices, real time analysis is necessary. In this thesis real time acquisi- tion and analysis of EMG was performed. The measured signal was used as an input to control a simple MATLAB computer game. The EMG of a muscle of the forearm, Brachioradialis, was measured with Myon Aktos sys- tem. The measured signal was written to a server as soon as the measurements were acquired. MATLAB was used to connect to the server and performing the signal analysis. The analysis was kept simple in order to limit delay. The result showed that it was possible to acquire real time signal with this method. The delay was negligible, both for the testing and for the game play. Showing that it is possible to play a game with muscle activation supports the idea of a motor that can be controlled automatically with muscle input. Future work should focus on understanding movement intent with respect to EMG and on analyzing multiple signals from different muscles at the same time.