Signal Processing Commons^™

Directional Speaker, Gabriel Tramontina Ceribelli, Vincent Trevor Pierce

Electrical Engineering

Parametric Acoustic Arrays (PAA) are highly directional soundwaves whose attenuation and spread are much less affected by distance from the source as compared to traditional speakers. A well-known application for PAA is the directional speaker. Studies show that noise directly affects health and decreasing noise pollution can help improve the quality of life for millions of people. Directional speakers can revolutionize society by coupling space with sound. This project encodes audio into two RF-Pulse Width Modulated (PWM) waves to drive a transducer array. Each RF-PWM wave interferes with the other in air to generate a Single Sideband (SSB) frequency spectrum …

Bearing Health Detector, Natalie N. Tokhmakhian, Alexander J. Davis

Electrical Engineering

Bearings, a common component in rotating machinery, are essential components of modern rotating machines; thus, monitoring their health is crucial when reducing downtime and boosting production efficiency. The Bearing Health Detector (BHD), a hand-held device, captures and processes the sound of a machine under test in real time and estimates the level of wear and tear by comparing the sound to previous tests. The BHD encompasses audiences involved with roller bearings in rotating machinery and is designed to provide the diagnosis of wear through the universal detection of good, satisfactory, and very poor with the following color scheme: green, yellow, …

Multi-Effects Analog Guitar Pedal, Carson J. Bryan

Electrical Engineering

The Multi-FX Analog Guitar Pedal includes the analysis, design, performance, PCB layout, and packaging of an industry-standard effects pedal for an electric guitar. This project takes an analog input signal and utilizes analog circuitry to give the user the option to customize the way that their playing sounds. Effects include the options to add equalization filtering and distortion. The EQ filtering will allow the user to attenuate or gain certain frequencies divided into the 3 standard audio bands: bass (20-300 Hz), middle (300-4000 Hz), and treble (4-20 kHz). The soft-clipping distortion stage will allow the user to move around the …

Practical Podcasting: A Technical Guide To Producing Studio-Quality Podcasts, Jacob Sarmiento

Liberal Arts and Engineering Studies

Podcasting exists at the intersection of the technical aspects of audio engineering and disciplines such as journalism and story-telling. Podcasts at KCPR, the student radio station, cover a wide range of topics including the soundscape of the DIY music scene in San Luis Obispo (SLO) on SLO-Fi, the intricacies of navigating SLO on Cal Poly 101, the best of Cal Poly Athletics on The Gallop, and the voices of underrepresented populations on campus on Different Matters. KCPR utilizes podcasts to entertain and inform its audience of the various experiences possible as a Cal Poly student. As a student-run entity, KCPR …

Programmable Vibration Table Retrofit With Eagle Medical, Jonathan Ilagan, Madhav Asok, Max Lewter

Biomedical Engineering

This project aimed to repair and upgrade a vibration table used for package testing for the sponsor, Eagle Medical - a medical packaging and sterilization company based in Paso Robles, California. The current vibration table is not programmable and lacks circuit diagrams, making it difficult to repair. In addition, it is not functional due to internal circuitry issues and power requirements. To address these issues, the team will implement several upgrades to improve the product and allow for better random cyclic vibration testing. A full assessment of the existing vibration table will be conducted to ensure the viability of these …

Diy Cell Incubator, Hayden James Jeanor

Electrical Engineering

The purpose of creating a cell Incubator is for the development of cell and tissue production in laboratory settings. Large scale research projects and the medical community grow cells for various reasons, including experiments and creating tissue for patients. However, they cannot simply depend on growing cells in a petri dish that sit on a rack at room temperature. To grow heathy cells in the fastest way possible, they use cell incubators. Cell incubators create an atmosphere within the incubation bay that is designed to promote cell growth. The three main components that need to be constantly regulated, using a …

Iris Detection Authenticator, Nathan D. Tang, Bryan K. Chau

Electrical Engineering

The development of iris biometric identification recognition is presented. Iris recognition differs from other methods because data acquisition is non-physical and is more accessible. It has been proven that the iris does not change as an individual ages and is well protected from external damages due to the eyelid and cornea, acting as a shield to the iris. In addition, the iris is almost impossible to forge due to its complex patterns and the current limitations in technology. Using Canny Edge Detection, Hough Transform, rubber-sheet normalization, Histogram of Gradient feature extraction, and the MultiMedia University iris database as our subjects, …

Music Visualization Using Source Separated Stereophonic Music, Hannah Eileen Chookaszian

Master's Theses

This thesis introduces a music visualization system for stereophonic source separated music. Music visualization systems are a popular way to represent information from audio signals through computer graphics. Visualization can help people better understand music and its complex and interacting elements. This music visualization system extracts pitch, panning, and loudness features from source separated audio files to create the visual. Most state-of-the art visualization systems develop their visual representation of the music from either the fully mixed final song recording, where all of the instruments and vocals are combined into one file, or from the digital audio workstation (DAW) data …

Neural Network Based Diagnosis Of Breast Cancer Using The Breakhis Dataset, Ross E. Dalke

Master's Theses

Breast cancer is the most common type of cancer in the world, and it is the second deadliest cancer for females. In the fight against breast cancer, early detection plays a large role in saving people’s lives. In this work, an image classifier is designed to diagnose breast tumors as benign or malignant. The classifier is designed with a neural network and trained on the BreakHis dataset. After creating the initial design, a variety of methods are used to try to improve the performance of the classifier. These methods include preprocessing, increasing the number of training epochs, changing network architecture, …

Standalone Wireless Humming Music Synthesizer, Elizaveta Viktorovna Koush, Conrad Kinsey, Alberto Munoz

Electrical Engineering

This project, called a standalone wireless humming music synthesizer, aimed to provide a tool for musicians to make creating music easier. It did this by removing learning barriers and adding an assistive functionality element that current synthesizers fail to address.

Existing methods for synthesizers typically include a keyboard or some collection of buttons to play melodies on. This requires the knowledge of music theory and a learning curve for the instrument, and this device aims to tackle this barrier. A device that can synthesize your voice into high-quality audio removes this musical knowledge barrier and allows anyone to easily convert …

Signal Adc Converter Simulation On Cadence Virtuoso For Audio Applications, Maxwell Kazuki Fukada

Electrical Engineering

Audio signals are representations of sounds with a mixture of multiple analog signals between the frequency of 20Hz to 20,000Hz. To record snippets of audio data onto a mobile phone or computer, the signal needs to be converted to a digital format. For this purpose, many devices utilize a converter, specifically a sigma-delta modulator with a digital filter. By using a converter, electronics can receive binary data about the audio signal accurately and quickly without losing important signal information. This project aims to simulate a fully functional audio converter with a sigma-delta modulator and decimation filter. The system will receive …

Hum Synthesizer, Daniel Keith Mcfall, Jason Chang

Electrical Engineering

Most modern music, especially the popular and rising genres such as pop music and rap music are more reliant on music synthesizers than ever before. While other instruments are readily used to sample background noises, the main form of sound generation is becoming more digital rather than using acoustic instruments. However, many people that want to make music aren’t familiarized with traditional music theory and would have difficulty using a traditional synthesizer. The Hum Synthesizer aims to allow a wider audience to access the functions of a traditional synthesizer by using voice controls rather than keyboard controls. If the user …

Dynamic Response Of Elastic Two-Story Steel Moment Frame Scaled Structure Equipped With Viscous Dampers, Garrett L. Barker, Alexander L. Poirier

Architectural Engineering

The authors of this report are Architectural Engineering undergraduate students at California Polytechnic State University, San Luis Obispo. Damping is a complex, experimentally derived value that is affected by many structural properties and has a profound effect on the dynamic response of structures. Deducing the inherent damping of a steel moment frame and affecting the damping ratio with viscous dampers are two topics explored in this paper. Dampers are commonly implemented in resilient structures that perform better in a design basis earthquake, reducing the seismic cost and downtime. Undergraduate coursework does not delve into the factors that affect damping and …

Poly Camtracker, Nickolas W. Ogilvie, Shawn W. Thai

Electrical Engineering

With the onset of the post-pandemic virtual classroom world, more and more classes are attempting hybrid-style instruction. To accomplish that, recordings of lectures are widely used, with presentation-sharing & audio recording capability. However, video recordings of lectures, with the ability to see the board, lab equipment, and the professor, are the optimal way to give the virtual students the best experience. Right now, technology is readily available for static camera recordings of lecture halls, but this may not suffice when it comes to larger lecture halls and lab demonstrations, where directed shots of equipment or the whiteboard are needed in …

Indoor Positioning Using Synchronized Ultrasonic Ofdma Signals, Julian Bartolone

Master's Theses

This paper proposes a method of short-range indoor localization using differential phase measurements of synchronized two-tone ultrasonic signals in an Orthogonal Frequency Multiple Access (OFDMA) scheme. This indoor positioning system (IPS) operates at an ultrasonic frequency of approximately 40kHz and synchronizes using an infrared signal. The OFDMA scheme allows for a receiver to process the signals from multiple transmitters continuously without the signals interfering with each other. The phases of the signals are measured using Goertzel Filters, allowing for low-complexity frequency content analysis. A MATLAB simulation using the proposed localization method is performed using four transmitter nodes in the corners …

Chess Piece Detection, Craig Reid Belshe

Electrical Engineering

This project determines the positions of each piece on a physical chessboard, so that a computer can record a game of chess by noting down the piece positions at the end of each turn. It determines each move so that the game can be replayed later without watching actual footage. The project allows for easy viewing of past games. An image of the chessboard is analyzed to detect each square on the board, and each piece's location. This is then done for each turn, so that the system can keep track of an entire game.

Dsp Guitar Fx Pedal, Stephen P. Rock

Electrical Engineering

A guitar effects (FX) pedal, also referred to as a stomp box, manipulates the electric signal produced by guitars to produce a variety of different sounds for the application of music. Musicians use guitar effects to produce sonically different and interesting sounds for the sake of performance, creation, and art. Although the different types of effects are numerous, the basic effects fall into either distortion, modulation, or delay. The use of guitar pedals allows the musician to accurately perform desired pieces of music or compose new songs.

The current guitar pedal market includes many effects by many manufacturers, however many …

Comparison Of Hilbert Transform And Derivative Methods For Converting Ecg Data Into Cardioid Plots To Detect Heart Abnormalities, Robert George Goldie

Master's Theses

Electrocardiogram (ECG) time-domain signals contain important information about the heart. Several techniques have been proposed for creating a two-dimensional visualization of an ECG, called a Cardioid, that can be used to detect heart abnormalities with computer algorithms. The derivative method is the prevailing technique, which is popular for its low complexity, but it can introduce distortion into the Cardioid plot without additional signal processing. The Hilbert transform is an alternative method which has unity gain and phase shifts the ECG signal by 90 degrees to create the Cardioid plot. However, the Hilbert transform is seldom used and has historically been …

Ecg Arrhythmia Classification Using Discrete Wavelet Transformation, Hannah E. Chookaszian, Nathan D. Diekema

Electrical Engineering

Cardiovascular diseases (CVDs) are the highest leading cause of death worldwide with an approximate 17.9 million related deaths every year according to the World Health Organization (WHO). Electrocardiographic (EKG or ECG) signals are electrical signals measured in the heart and are the main indicator for pre-existing cardiac conditions. The application of deep learning methods such as artificial neural networks (ANN) will assist in the automated detection and classification of ECG signals. The current methods for ECG analysis are lacking in accuracy and reliability considering the level of risk involved with CVDs and the importance of a correct diagnosis. Clinicians use …

An Exploratory Study Of Pulse Width And Delta Sigma Modulators, Logan B. Penrod

Master's Theses

This paper explores the noise shaping and noise producing qualities of Delta-Sigma Modulators (DSM) and Pulse-Width Modulators (PWM). DSM has long been dominant in the Delta Sigma Analog-to-Digital Converter (DSADC) as a noise-shaped quantizer and time discretizer, while PWM, with a similar self oscillating structure, has seen use in Class D Power Amplifiers, performing a similar function. It has been shown that the PWM in Class D Amplifiers outperforms the DSM [1], but could this advantage be used in DSADC use-cases? LTSpice simulation and printed circuit board implementation and test are used to present data on four variations of these …

Ofdm Simulation, Joseph W. Bednar

Electrical Engineering

The project objective is to provide a tool that will allow the user to simulate an adaptive OFDM (Orthogonal Frequency-Division Multiplexing) communication system in the presence of various types of interference and noise. The open-source code allows students and engineers to adjust the modulation, threshold settings, and distortion effects in the channel while observing the output bit error rate. The results the simulation provides will aid researchers in attempting to characterize the interference of OFDM based systems and their effectiveness in the presence of noise.

Indoor Positioning Using Acoustic Pseudo-Noise Based Time Difference Of Arrival, Nicholas J. Luong

Master's Theses

The Global Positioning System (GPS) provides good precision on a global scale, but is not suitable for indoor applications. Indoor positioning systems (IPS) aim to provide high precision position information in an indoor environment. IPS has huge market opportunity with a growing number of commercial and consumer applications especially as Internet of Things (IoT) develops. This paper studies an IPS approach using audible sound and pseudo-noise (PN) based time difference of arrival (TDoA). The system’s infrastructure consists of synchronized speakers. The object to be located, or receiver, extracts TDoA information and uses multilateration to calculate its position. The proposed IPS …

Distance Estimation Using Ofdm Signals For Ultrasonic Positioning, Kyman Huang

Master's Theses

This paper describes a method of estimating distance via Time-of-Flight (TOF) measurement using ultrasonic Orthogonal Frequency Division Multiplexing (OFDM) signals. Using OFDM signals allows the signals and their sub-carriers to remain orthogonal to each other while continuously transmitting. This estimation method is based on the change of phase of a traveling wave as it propagates through a medium (air for ultrasonic signals). By using signals containing multiple tones, the phase change between each frequency component is slightly different. This phase difference is dependent on the distance traveled and can thus be used to estimate distance. This paper studies the impact …

The Design, Testing, And Analysis Of A Constant Jammer For The Bluetooth Low Energy (Ble) Wireless Communication Protocol, Aiku Shintani

Master's Theses

The decreasing cost of web-enabled smart devices utilizing embedded processors, sensors, and wireless communication hardware have created an optimal ecosystem for the Internet of Things (IoT). IEEE802.15.4, IEEE802.11ah, WirelessHART, ZigBee Smart Energy, Bluetooth (BT), and Bluetooth Low Energy (BLE) are amongst the most commonly used wireless standards for IoT systems. Each of these standards has tradeoffs concerning power consumption, range of communication, network formation, security, reliability, and ease of implementation. The most widely used standards for IoT are Bluetooth, BLE, and Zigbee. This paper discusses the vulnerabilities in the implementation of the PHY and link layers of BLE. The link …

Biometric Identification With Ecg Signals, Connor Lindstrom, Jonathan Wood, Jacob Torchia, Jonathan Lee

Electrical Engineering

This project introduces a new form of biometric identification with an ECG signal with the use of machine learning concepts. The ECG signal makes a good candidate for identification because of its unique characteristics that make it easy to distinguish individuals from one another. A patient who has previously had ECG scans stored in a database before, can be verified using this program. This project has the capability of identifying a person or verifying a person solely using their ECG signal. Utilizing this biometric identification, hospitals would be able to add to the reliability of their identification process. Additionally, companies …

Visual Speech Recognition Using A 3d Convolutional Neural Network, Matthew Rochford

Master's Theses

Main stream automatic speech recognition (ASR) makes use of audio data to identify spoken words, however visual speech recognition (VSR) has recently been of increased interest to researchers. VSR is used when audio data is corrupted or missing entirely and also to further enhance the accuracy of audio-based ASR systems. In this research, we present both a framework for building 3D feature cubes of lip data from videos and a 3D convolutional neural network (CNN) architecture for performing classification on a dataset of 100 spoken words, recorded in an uncontrolled envi- ronment. Our 3D-CNN architecture achieves a testing accuracy of …

Development Of A Model And Imbalance Detection System For The Cal Poly Wind Turbine, Ryan Miki Takatsuka

Master's Theses

This thesis develops a model of the Cal Poly Wind Turbine that is used to determine if there is an imbalance in the turbine rotor. A theoretical model is derived to estimate the expected vibrations when there is an imbalance in the rotor. Vibration and acceleration data are collected from the turbine tower during operation to confirm the model is useful and accurate for determining imbalances in the turbine.

Digital signal processing techniques for analyzing the vibration data are explored and tested with simulation data. This includes frequency shifts, lock-in amplifiers, phase-locked loops, discrete Fourier transforms, and decimation filters. The …

Pseudo-Stereo Audio Processor, Zachariah David Bunce

Electrical Engineering

Due to both technical and resource limitations, non-professional audio production must often record with a single microphone, creating a mono audio signal. Even some originally multi-channel audio files often combine the separate channels into a single channel to save memory. However, this channel limitation makes any music held within the audio duller during listening. The Pseudo-Stereo Audio Processor remedies this situation, introducing a quadrature phase shift onto a given single-channel audio signal, producing multiple phase shifted output signals. These separate fixed-phase output signals are then recombined to produce a variable phase difference, emulated two-channel version of the input signal, allowing …

Portable Electrocardiogram Device And Signal Processing Design, Ryan F. Blaalid

Electrical Engineering

Full 12-lead electrocardiogram (ECG) measurements require inconvenient and time consuming adhesive electrode placement. This project proposes a design for a Bluetooth based ECG for remote patient measurement. The device is designed to measure up to 6-leads and utilizes 5 dry (non-adhesive) electrodes to accomplish this. The device delivers the ECG data to the user’s mobile smart phone and can then be sent to the patient’s doctor for analysis. Since the contact of the dry electrodes to the skin is not perfect, low-frequency noise called baseline wandering is introduced. A signal processing technique borrowed from image processing called morphological filtering is …

Underwater Remotely Operated Vehicle Controller With Pid Stability Regulation, Christian E. Aguirre

Electrical Engineering

The earth’s oceans and rivers remain widely unexplored. Hobbyists and companies across the globe invest money and resources into remotely operated vehicles (ROV) to further expand underwater knowledge. Each ROV includes a controller that operates motors and monitors other crucial system vitals. The ROV Controller project makes the process of designing an ROV simpler and more affordable by providing a multi-purpose programmable controller.

The ROV controller features programmable digital inputs/outputs and analog inputs. The controller processes control signals from analog joysticks, digital signals from a gyroscope and utilizes a MUX to expand the analog input capabilities of the Arduino. The …