This thesis presents the design and development of a UV-C LED-based seed treatment machine aimed at enhancing seed quality by the extermination of pathogens. The research covers design choices, including a round irradiation pattern, consisting of two rings with three and nine LEDs for the inner and outer ring respectively, the use of a quartz plate as a holding plate for seeds for its high UV-C light permeability capabilities, the use of a vibration motor underneath the main operational stack for seed movement, and the use of Ethernet ports for power distribution and communication. The thesis discusses a comparative study between square and circular plate configurations, evaluating their performance using simulation results. Safety considerations were prioritized in the design, and appropriate precautions were implemented throughout the design process. The thesis also highlights the iterative design process for the mechanical system, discussing challenges encountered and improvements made to achieve a functional and robust prototype. Results demonstrate successful integration of components and achievement of objectives. The thesis concludes with discussions on the strengths, limitations, and future enhancements of the UV-C LED-based seed treatment machine. The research presented in this thesis provides valuable insights for further advancements in seed treatment technology, contributing to sustainable agricultural practices. Due to time constraints, conclusive results of testing on seed with this machine could not be obtained yet.

This is a bachelor thesis about the design and development of an observation and sensing module for the Deci Zebro robot that is being developed at the EEMCS faculty of Delft University of Technology. This part of the thesis is about the development of a cliff- and obstacle detection system, as well as the designanddevelopmentofafittingplasticenclosureforthemoduleandthedesignofaPCBthatintegrates the module’s electronics. The report explores and compares different types of distance sensors and concludes that the best option is to use two infrared-based distance sensors on the left and the right of the robot for cliff detection, and a rotating ultrasonic transceiver on a servo motor to detect obstacles. For easy debugging and to allow communication with nearby humans, a LED ring was also fitted to the top of the module. The design process and the implementation of these components is described in detail. The module’s enclosure is designed using SolidWorks software and afterwards printed using a 3D-printer. The PCB is designed using the opensource KiCad software.

This report details the design and development of an agar/NaCl gel-like tissue phantom mimicking the electrical properties of wet human skin. The skin phantom provides a reliable, reproducible testing ground for dry-contact polydimethylsiloxane (CNT/PDMS) electrodes, with the aim of recording electroencephalograms (EEGs) and stimulating brain activity in a controlled environment. These electrodes are being designed for the development of an in-ear brain-computer interface (BCI). The electrical properties of biological tissue are referred to as the conductivity σ and permittivity ε and denote the ability for a material to conduct and trap electric charge respectively. These properties are frequency dependent and particularly for EEGs, a frequency range of 1-1000 Hz is of interest (with some added leeway). Wet skin hereby has a conductivity of around 0.1 Siemens to 0.2 Siemens in the 1-1000 Hz frequency range whereas the permittivity ranges from 5.7 * 10^5 to 5.2 * 10^5. Different agar and agar/NaCl solutions are created to try and obtain solutions with the mentioned electric properties. Specifically, NaCl is added to improve the conductivity and obtain a non-linear frequency response similar to that of human skin. The electrical properties of the phantoms were verified/measured using the parallel plate method. This method is essentially sandwiching a material under test (MUT) (in this case the fabricated gel-like agar and agar/NaCl solutions) between two conducting plates. This method is most suited for measurements in the lower frequency spectrum. The skin phantom consisting of 3.04 mass fraction weight (wt.%) agar and 0.539 wt.% NaCl shows the closest similarity to the conductivity of wet skin. Namely, a conductivity of ~ 0.1 Siemens to 0.45 Siemens in the frequency range of 1-1000 Hz. A decrease of 0.250 wt.% NaCl will most likely achieve the desired conductivity response of 0.1 Siemens to 0.2 Siemens in the frequency range of 1-1000 Hz. The skin phantom consisting of 3.00 wt.% agar and 1.02 wt.% NaCl showed the permittivity closest to that of wet skin, but might have been a noisy outlier. Its permittivity ranges from 10 * 10^6 and 7.5 * 10^6. This is still a large error margin from the desired 5.7 * 10^5 to 5.2 * 10^5. Additional fillers like glycine or Al powder need to be added to the solutions to obtain a permittivity close to that of wet human skin. Multi-day and difference in applied pressure measurements are performed to check the sensitivity and reproducibility of the phantoms. Applied pressure hereby has little to no influence whereas a longer life-span of the fabricated phantom shows a drastic decrease of the electrical properties of the phantoms after day 1. The changes then seem to settle. Worth mentioning is that the change is only drastic when the solution has a high conductivity. This is generally not the case for solutions with conductivities close to wet skin.

This thesis is about the simulation of the permanent magnet motors of the Nuna Solar Car in order to find their fundamental motor parameters. These parameters can then be used in a Field-Oriented control algorithm to be used in a new motorcontroller for the team. A finite element analysis is done on the two current motors of the Nuna solar car, a radial flux Mitsuba motor and an axial flux Marand motor, with the intend to find the fundamental motor parameters, the phase resistance, the inductance and the motor constant. The model is presented and the simulation results are discussed. Also some variations to the current design have been made to test the adaptability of the simulation. Also some work is done to simulate the entire drive system of the car.

In order to make offshore working conditions safer, Ampelmann B.V. builds platforms that stay stable by compensating for a ship’s motion. These platforms are controlled via motion reference units (MRUs). In order to test the performances of these MRUs, a linear motion MRU test setup was developed. The system was divided into three parts: hardware, software and MRU assessment. This thesis focuses on the design and implementation of the MRU assessment part and on testing MRUs with the complete prototype setup. Ampelmann supplied the MRU with which the test were conducted. Validation tests have been done with a simulator and with the setup itself. Included in the assessment of the MRUs was the latency, signal-tonoise ratio and low-frequency behaviour, compared to a ground truth. Concluded from the tests was that the designed test setup has potential to accurately assess the performance of MRUs. There are some minor improvements to be made, but the overall system works as intended.

The design, production and testing of the Bluetooth Ultrasimple Gamepad, or BUG for short, is laid out in this report. In the current market, most of the controllers available are multi-button controllers with analogue sticks. These controllers are expensive and can not be used for many web browser games which rely on a keyboard input to work. In order for these controllers to work, a video game or self developed app can be used, but this can be difficult or expensive for many users. In the implementation of the BUG, the controller was made to be used by a single hand, having a clear ”main” button, an intuitive reconfiguration scheme and to have Bluetooth connection which is present in a lot of laptops and PCs currently in use. With this approach, the user can have a cheap, simple and comfortable alternative to existing gamepads. It can be stated that, although not for everybody, the BUG is a good and fun alternative for users. This can be seen because the general user experience is rated at 5 out of 5 points by 50% of the participants, 4 out of 5 by 46.7% of the participants and only 1, or 3.3% of the participants has given a rating of 2 out of 5.

In this bachelor thesis the design process of the audio and intermediate frequency amplifiers for a wireless FM tranceiver is documented and explained. The project was done using only descrete components for educational purposes.

This report discusses one part of a project consisting of three parts. The goal of the project is to design a battery less sensor powered by RF energy fields present in an office environment. The sensor is able to measure the temperature and is able to communicate wirelessly using a low power communication protocol.In this report the energy conversion and storage of the system will be discussed. A high-frequency signal coming from an antenna must be converted to an output signal which is functional for the communication module. Therefore a steady 3.3 V DC output needed to be created with a rectifier circuit. In order to achieve maximum power transfer to the load, a matching circuit with the RF energy harvesting antenna needed to be designed. The main challenges were to achieve a high enough input voltage to reach the threshold voltage of the diodes of the rectifier and to rectify the AC input as efficient as possible. To tackle these challenges a design with a Greinacher rectifier with low-threshold Schottky diodes and a DC/DC booster is presented.

This bachelor thesis is written as part of the curriculum for the bachelor Electrical Engineering at the Delft University of Technology. The thesis is part of the course EE3L11 - Bachelor Afstudeer Project and took place from April 2017 until July 2017. This document describes the development of a system that is able to drive electric drum brakes, the brake control unit (BCU). The BCU is a subsystem of a larger project; a braking system that minimizes the force between a trailer and a car when braking. The ultimate goal is to let the trailer completely brake for itself. To achieve this, two other subgroups have designed a control algorithm and a force sensor readout circuit that measures the force. The BCU receives a desired braking force from the control algorithm that should be exerted in order to eliminate the force between car and trailer. This input force covers a certain range, so the BCU should be designed such that the braking force of the brakes can be regulated. For this purpose a power supply, current controller and lookup table are designed. The developed power supply is able to provide a constant voltage to the solenoids inside the electric brakes. The power supply consists of a DC/DC converter, which is powered from a car battery. As a consequence, the input voltage of the DC/DC converter is dependent on the state of charge of the battery. Nevertheless, the output of the designed converter is able to provide a constant DC voltage with a maximum current of 8 A. The designed current controller makes use of a PWM driven current source, which controls the output current of the DC/DC converter. Besides this source, an algorithm that estimates the duty cycle of the PWM signal is derived, based on the desired current through the solenoid. Last, a lookup table is implemented that determines which current is needed for specific input forces. The table makes use of inter- and extrapolation between measured test results to calculate the right current for every input force.

This document describes the design process the prototype of a measurement light bulb which is able to project spherical harmonics of orders 0-1-2. Photographs of these projections can be combined to represent many light distributions. The measurement light bulb can be used in the field of research focused on the computation of the illumination impact of lighting, more specifically, simulating different light sources. Our prototype consists of a laser beam rotating over two axes, which allows the device to project onto a sphere around itself. The device can be controlled wirelessly using Bluetooth. The lamp can project spherical harmonics in a resolution of 4 degree and 256 monochrome light levels. The time one projection takes is about one second, which allows for quick measurements. The dimensions and the weight of the lamp are such that it is portable. At this stage, the prototype can only operate in a dark environment, due to the use of a low powered laser. In this document, the focus will be on the design of control, communication and the PCB.

The increase in non-linear loads of modern electronics raises concerns over power quality. Additionally, existing power-quality analyzers are expensive and not intended for household use. This thesis aims to develop a single-phase, user-friendly power-quality analyzer using a Raspberry Pi 4 Model B with an emphasis on low cost and class S specifications. The design was split into modules consisting of analog to digital conversion, voltage sensing, and current sensing. Sub-modules were added for circuit protection and PCB. Various approaches are discussed before circuit design, simulation, and testing occur. A functioning prototype was assembled on a dedicated PCB while not exceeding the set budget of €250.00. However, it could not be determined whether the class S specifications were achieved due to insufficient testing. A variety of improvements have been suggested.

This thesis tries to find a solution for the problem of managing and monitoring the banana shelf in a supermarket using IoT. The research focuses on using a wireless sensor that detects some features of the banana shelf while being non-intrusive. The three main features that are examined of the shelf are the quality and quantity of the bananas and the quality of the shelf. First a research was conducted to find the best sensor to use for these measurements. The chosen sensor is a color image sensor, the platform for the IoT device is a Raspberry Pi. Using the python programming language in combination with the openCV library image processing was used to detect the features. The image is first smoothed using a Gaussian filter, afterwards the foreground is segmented. The different segmentation methods are researched and adaptive thresholding is used. To determine the quantity of the bananas and quality of the shelf the stickers on the bananas are detected. This detection is implemented using different filtering methods ranging from spectral filtering to color thresholding. With the segmented foreground the quality of the bananas is assessed using a color histogram. This information is then sent to a communication module that is connected to a IoT dashboard for user interpretation. With the proposed design the status of the shelf including the percentage of the shelf filled, the quality of the bananas on the shelf and the neatness of the shelf are available for a supermarket manager to better organize his supermarket. This sensor makes it possible to better organize the banana shelf and act preemptive instead of reactive.

Internet of things (IoT) applications become more and more prominent in our modern society. IoT has the potential to improve business processes and change the ways we live. KPN New Business has a high affinity with IoT projects and supplied the problem definition that this project builds on. The project has been done in close collaboration with KPN. This document describes the design process for a stand-alone obstruction detection system for supermarket environments. The focus lies on obstructions near emergency exits, where they pose safety threats and obstructions in shopping aisle, where they hinder customers. The system should detect obstructions and communicate the presence of an obstruction to a central server. The communication is however not within the scope of this design report. Five sensing techniques were considered for the detection system, ultrasonic ranging sensor were deemed the most suitable for this application. Ultrasonic sensors lend themselves well for IoT applications as they are easy to implement, cheap and operate on low power. A MaxBotix MB1300 sensor was chosen for the implementation of the prototype as it offers an Analog Envelope (AE) output of the measurements. This allows for multiple objects to be detected in a single measurement. Furthermore, the MB1300 sensor has the largest beam width in the AE product line and can thus cover the most surface area. The processing of the measurements in the prototype is done using an Arduino Mega 2560. The Arduino board allows for easy prototyping and has sufficient memory on-board to store and process the measurements. The measurements are sampled using the built-in ADC of the Arduino at a sampling frequency of approximately 8.93 kHz. The sampling frequency is a trade-off between the spatial resolution of the system and the memory required to store the measurements. An algorithm is developed for the detection of objects from the sampled measurements. The process involves the windowing of the measurements to only look at relevant samples. A background subtraction is performed to avoid the detection of scenic objects, and the objects are detected using a threshold. A data structure was created in order to store the detected objects. An algorithm was developed to check whether detected objects remain static. If an object is repeatedly detected it is marked as an obstruction. If an object goes unseen for a certain period, the object is removed from the memory. Thresholds for when an object is marked as an obstructions, the deletion of objects and measurement intervals are suggested for emergency exits and shopping aisle systems. These should however be verified in further development. The performance of the system was evaluated in testing environments for the emergency exits and shopping aisles. Testing results showed that the system performs well on most design criteria. The area covered by a single sensor was however below expectations. This could be problematic for the implementation of the system in shopping aisles, as lots of sensors would be required to cover entire shopping aisles. Also some false positives occurred in the detection of obstructions. This could however easily be solved with minor changes to the detection algorithm. Based on the testing results the conclusion is drawn that the design goals are partially met. The system is able to detect obstructions, but does not yet operate as a stand-alone unit. This design goal was however considered in every design choice. Power consumption of the prototype remains to be tested, this however is also dependant on the communication system. Recommended is to further look into the power consumption of the system, the implementation of a multi-sensor system to cover more floor area in shopping aisles, and to reconsider CCTV images for the detection of obstructions in shopping aisles.

In this thesis, a test device is designed for the company Momo Medical. Momo Medical is developing a system that can be used to prevent pressure ulcers and adding more functionality is being investigated. For this system they need a device to test the functionality of the six piezoelectric sensors that are used in their product. The sensors’ response to a known pulse needs to be tested in order to give a pass/fail indication of the sensor quality. First, different ways of testing the sensors are investigated. Based on the results of the investigation, a final test setup is chosen and characterized. The test system developed in this thesis is based on a pneumatic setup, using a solenoid valve to control well-defined air pulses directed towards the sensors. Due to the addition of a reference load cell with custom designed read-out electronics, the device is able to test all six sensors one at the time and provides detailed feedback about the individual sensor quality. The test is performed using GUI-based software written in MATLAB, connected to a microcontroller. The software offers a broad variety of settings and can be configured according to Momo Medical’s wishes. After configuration, the test can be performed at the click of a button. The standard deviation of the device precision over three hours is sigma = 4.16, which equals a variation of cv = 0.82% of the mean μ = 504.8. This easily satisfies the requirements set byMomoMedical.