Harbor Security System

Harbors and ports provide the infrastructure for commercial trade and naval facilities. It is vital to ensure the safety of these locations. The Harbor Security System provides an optical ‘gate’ using underwater lasers and photodetectors. This system allows monitoring of both surface and submarine vessels traveling into and out of the harbor. Also, the system provides real time alerts when unauthorized vessels enter the harbor. This project provides a proof of concept for a Harbor Security System to be implemented in Portsmouth Harbor. A scaled model of the detection system was constructed and tested. This detection system is capable of detecting surface and submarine vessels along with their velocity and length. Results of the study showed that the average error of the size estimate was 15% and the average error of the velocity estimation ratio(slope) was 9%

Smart packaging for laser modules

Treball desenvolupat dins el marc del programa 'European Project Semester'.Most current day packages consist of only a cardboard box and stickers with a postal address. In the case of shipment of very sensitive items, a "FRAGILE" sticker is added. In order to change this state, The Smart Packaging group under the supervision of the Monocrom company and UPC University has been established. The objective is to record several conditions which are present during shipment and to pass history of the events to the customer before opening the package. What is more, the content of the package has to be secured against shocks, ESD and humidity. The following paper shows results done in various realms such as: electronics, sensors, inner foams, outer box, materials and describes the first steps of designing process

Development of a Complex Flow Phantom for Diagnostic Imaging

Literature and market analysis have highlighted the lack of flow phantom technologies able to challenge innovative medical imaging devices, such as Ultrasound and Magnetic Resonance. A novel, cost-effective, compact and robust Complex Flow Phantom prototype was proposed. The design relies on the generation of stable, reproducible, predictable and controllable vortex rings. Vortex rings were chosen because bring together high stability and physiological relevance. The design was tested with multiple and independent measurement methods under challenging working conditions. Overall, it demonstrated to produce reproducible flows with variability always lower than +/- 10 %. This variability was assessed with regards to translational velocity, however, macro-flow reproducibility implies micro-flow stability. Computational Fluid Dynamics (CFD) and optical/video acquisitions were used as first methods to independently validate two early prototypes operating in air and water. CFD overall well approximate theoretical predictions but accuracy was insufficient to provide a reference standard. Overall, the early prototypes demonstrated encouraging stability and a Vortex Ring based Complex Flow Phantom prototype was manufactured. Laser PIV acquisitions were performed to establish flow reference standard values. Optical/video acquisitions were performed and results were compared with Laser PIV to assess the rigour of the methods. Results obtained by the two different measurement methods on two identically manufactured but different systems showed credible consistency. Conventional and advanced (Vector Flow Imaging) Ultrasound acquisitions were also performed on the design. An instrumentation pack was designed and is provided as tool for self-calibrating the phantom and for estimating flow reference values under different generating conditions. An MRI compatible version of the phantom was manufactured and was tested in laboratory. Design and experiments are supported by journal article and conference proceeding publications, poster and oral presentation in international conferences. The phantom is purchasable from Leeds Test Objects Ltd or can be manufactured in laboratory following the specifications provided

Three dimentional control of a diode based laser cutter

Includes bibliographical referencesLaser cutting is a widely used technology in many areas of industry and research. Conventional laser cutters only offer control of two axes and either cut through a material or rudimentary control of the third dimension is possible by varying the power, pulse rate and travel rate of the laser beam. These rudimentary three-dimensional systems (often called 2.5D laser cutters) do not incorporate any feedback mechanism to control the depth of cut. The idea of measuring distance using diode lasers (and other laser technologies) is a relatively mature technology and is common to various consumer and industrial products. Recently diode lasers have become powerful enough to perform as laser cutters allowing a merger of these technologies. The aim of this project is to verify the concept of using a laser diode to achieve both material processing and distance measurement. This would allow the creation of a full three-dimension laser cutting machine that is capable of accurate material processing in all three dimensions. This would also offer the ability to cut non-homogenous materials, such as timber, which current ‘2.5D’ laser cutters are unable to cut with any accuracy. A gantry system was designed and constructed, which was able to move the laser cutting toolhead in the x-y plane, using stepper motors and a belt-driven drive system. A 2W single emitter laser diode was used for both laser cutting and distance measurement. Optics were designed and assembled that focused the laser onto the workpiece and directed light reflected back from the workpiece onto a photodiode. Laser driver circuitry was constructed to control the DC current of the laser and to modulate the laser power at the high frequencies required for accurate phase shift measurements. A photodetector and phase shift measurement circuit was designed, simulated and constructed. The phase shift circuit amplified the signal from the light reflected off the workpiece and then compared that signal to a reference signal in order to determine the phase shift between the two. An Atmel® ATmega2560 microcontroller was used to control the gantry, laser driver circuitry and to measure the phase shift output of the phase detector circuitry. Software written in MATLAB® was used to command the microcontroller and to interpret the data received from the microcontroller The photo sensor circuit was not sensitive enough to detect the weak signals that were present when the workpiece had a low reflectivity but was able to be tested using reflective tape. On the other hand the laser diode was not powerful enough to cut reflective tape as it absorbs very little energy from the laser. Nevertheless, the same laser diode was used, without changing any configuration other than the workpiece material, to measure distance and to cut materials. Testing of both the materials processing ability and the distance measurement ability were carried out. Many aspects of each of these major functions were tested, individually and together, in order to determine the areas that performed well and those that need more research. In conclusion, this project was able to verify the concept of a three-dimensionally controlled diode powered laser cutter. Future work will be needed before a practical and useful laser cutter can be built but this project should prove a good starting point for any such future work

Development of Laser Cutting and Engraving Machine

Basically in laser engraving the laser beam burns the top layer of the surface to be engraved. The burnt area is left uncoloured which makes it appear different from the surrounding surface. While in laser cutting laser beam has to penetrate through the surface. This can be achieved by prolonging the beam on a particular area for a long period of time, duration being decided on the strength of material to be cut. We are still collecting data from different resources to know this topic more in depth. In our project we have decided to develop working model of laser cutting and engraving machine. This machine is very useful in our department since it’s a kind of rapid prototyping machine. It can cut out paper patterns and thermoplastic sheets to produce desired shape and patterns. Till now we have collected information on laser cutting, laser and what engraving is. Laser cutting is different from laser engraving, in case of engraving very low intensity laser torch is used as compared to laser cutting. We got a brief introduction on laser, how it works, what are its properties, how to generate it and how to control its intensity. The machine is made using a ~200mW red laser. It might nut cut through chunks of wood but surely burn the top layer. Simulation analyses are performed in CAD software ‘CATIA V6’ in order to simulate each part of the machine. It was helpful for remodelling the moving bed or the job holder, if any errors found during the simulation. Additionally, experiments are performed for the develop laser cutting engraving machin

Agenator: An open source computer-controlled dry aging system for beef

Dry aging of beef is a process where beef is exposed to a controlled environment with the ultimate goal of drying the beef to improve its quality and value. Comprehensive investigations into the effects of various environmental conditions on dry aging are crucial for understanding and optimizing the process, but the lack of affordable equipment focused on data collection makes it difficult to do so. The Agenator was thus developed as an open source system with a suite of features for investigating dry aging such as: measuring and recording relative humidity, temperature, mass, air velocity, and fan rotational speed; precise control within 1% for relative humidity and 50 rpm for fan rotational speed; robust signal integrity preservation and data recovery features; modular design for easy addition and removal of individual chamber units; and non-permanent fixtures to allow easy adaptation of the system for other applications such as investigating dehydration of food products. The open source system comes with user-friendly computer software for interfacing with the system and creating sophisticated environmental control programs. The Agenator is available to the public at https://osf.io/87nck/

SINGLE-DEGREE-OF-FREEDOM EXPERIMENTS DEMONSTRATING ELECTROMAGNETIC FORMATION FLYING FOR SMALL SATELLITE SWARMS USING PIECEWISE-SINUSOIDAL CONTROLS

This thesis presents a decentralized electromagnetic formation flying (EMFF) control method using frequency-multiplexed sinusoidal control signals. We demonstrate the EMFF control approach in open-loop and closed-loop control experiments using a single-degree-of-freedom testbed with an electromagnetic actuation system (EAS). The EAS sense the relative position and velocity between satellites and implement a frequency-multiplexed sinusoidal control signal. We use a laser-rangefinder device to capture the relative position and an ARM-based microcontroller to implement the closed-loop control algorithm. We custom-design and build the EAS that implements the formation control in one dimension. The experimental results in this thesis demonstrate the feasibility of the decentralized formation control algorithm between two satellites

Concept and development of an autonomous wearable micro-fluidic platform for real time pH sweat analysis

In this work the development of an autonomous, robust and wearable micro-fluidic platform capable of performing on-line analysis of pH in sweat is discussed. Through the means of an optical detection system based on a surface mount light emitting diode (SMD LED) and a light photo sensor as a detector, a wearable system was achieved in which real-time monitoring of sweat pH was performed during 55 minutes of cycling activity. We have shown how through systems engineering, integrating miniaturised electrical components, and by improving the micro-fluidic chip characteristics, the wearability, reliability and performance of the micro-fluidic platform was significantly improved

Control system implementation on an AFM prototype

Tese de Mestrado Integrado, Engenharia Física, 2022, Universidade de Lisboa, Faculdade de CiênciasThis work deals with the implementation of a fine and coarse tip-sample distance control as well as with the tuning of several other features that will make one AFM prototype more user friendly. The main goal was to design and integrate a PI (Proportional-Integral) Analog Controller with digitally controllable gains. The development of the controller started by identifying and characterizing the system, with emphasis on the Z-axis Scanner’s response, which in turn allowed to build models for all the different components that make up the AFM. The PI Controller’s gains were arranged to be independently tuned via a digital potentiometer in conjunction with an analog multiplexer. The digital potentiometer provides a fine gain adjustment while the analog multiplexer increments the gains by an order of magnitude. These devices receive instructions from a microcontroller. In parallel, several other important enhancements were carried out, which include an implementation of an Auto-Approach functionality that automatically approaches the probe and sample without crashing onto each other. In order to achieve this, it was conducted an experimental study of the instrument’s motorized coarse motion structure. All the new features developed here were integrated in the existing prototype via the Arduino platform. To interface the signals outputted by the AFM circuitry and the microcontroller, as well as providing robust tolerance against faulty use, additional circuitry was included. This allows the reading of important signals within the instrument’s context, such as the deflection signal, amplitude signal and controller output. By taking advantage of the microcontroller’s features, it was designed a voltage source that serves as an adjustable setpoint via the PWM outputs from the Arduino. Finally, it was design and developed a GUI providing the user direct control of the tasks mentioned above and also displaying some quantitative and qualitative data, acquired by the microcontroller, about the state of the AFM