Re-configurable Mechatronic Platform

To meet the increasing need of the multi-disciplinary engineering education and to provide a re-configurable mechatronic experiment platform, the team seeks to plan, design, and validate a mechatronic platform that allows simple model re-assembling and re-configuration. This platform also employs the concept of modular and expandable design. It consists of re-configurable mechanical structures, diverse sensor applications, microcontroller and motor controller control system, and graphical user interfaces on PC terminal for multi-disciplinary learning experience

A smart mechatronic base isolation system using earthquake early warning

Earthquake is one of the most devastating natural disasters. In the last few decades, many seismic mitigation techniques have been developed. They include passive, semi-active and active control which have been proven their effectiveness in events of earthquakes. Among them, base isolation has been regarded as a mature technology and commercialisation is common in earthquake-prone countries. This technology decouples the main structure from its foundation and effectively lengthens the natural period of vibration, away from resonance vibration. However, the lateral stiffness of base isolation devices is generally too low to resist serviceability lateral forces such as wind and flood which may cause unacceptable lateral movements of the structure. Added lateral stiffness and/or damping is usually required. On the other hand, the Earthquake Early Warning (EEW) system which uses different arrival time of seismic P and S waves is readily available in Japan, Taiwan, parts of China and Europe. This technology offers more possibilities for improvement of earthquake mitigation technique. This project develops a smart mechatronic base isolation system which can be triggered by the EEW system. It uses the earthquake early warning signals and nearby monitoring signals to determine the situation and automatically switches to the appropriate anti-seismic mode. In the first phase of research, a one-dimensional system is developed and tested on an electrical shake table. A prototype smart mechatronic base isolation system is developed. In this prototype design, electromagnetic shear keys which lock the base isolator are released either by simulated EEW signals or on-site accelerometers. The advantage of this design gives the main structure a very strong stiffness under in-service condition (i.e. when there is no ground motion) while maximizing the effectiveness of base isolation when ground motion is anticipated. The system is fully automated, and the main structure is re-entered once ground motion ceases. In the second stage, a two-dimensional base isolation, created by low-friction linear bearings is developed and activation of base isolation is carried out by linear actuators. In the third stage, the system is developed further. Light Detection and Ranging (LIDAR) sensors are added to monitor position of base isolator in real-time, an active control strategy is added into the microcontroller and actuation is carried out by stepper motors. Using the feedbacks provided by the sensor the active base-isolation system re-position the main structure in real-time. The research presented in this thesis opens up new opportunities in future seismic risk mitigation of civil structures. By connecting the EEWS and mechatronic devices, the performance of traditional base isolation system can be enhanced

Investigation of a mechatronic device for the remedial treatment of brain injured children.

To speed the recovery of brain injured children using the method of patterning; it must be made efficient. Efficiency can be achieved by automating the manual method, which will provide the patients with the necessary stimuli needed to help them enhance/restore their natural mobility. This thesis describes research into a novel moderate-cost single-axis Mechatronics device for the remedial treatment of brain injured patients. The device will enhance and/or improve their natural mobility by stimulating the undamaged brain cells responsible for mobility in the central nervous system through physical activity. A detailed review of rehabilitation robotics was undertaken, covering more than seventy projects relating to disabled people. This review helped to identify the main areas of this research regarding the most suitable structure of the machine and setting up the design specifications for the device. A critical investigation of past and present patterning machines and workstations helped avoid the mistakes made by previous designers in not including brain-injured patients in the initial stages of the design. Use of high technology video equipment has made practicable the development of mathematical expressions based on experimental data for the movements of human arms, feet and head. Measurements taken and ergonomic data used made it possible to implement a realistic practical novel kinematic arrangement for the patterning machine. A thorough review of direct drive electrical actuators, and surveys and measurements of the human body with respect to the kinematic arrangements, resulted in the selection of the most appropriate actuator for each axis. The selection of the motor and gearbox was based on the mass of each part of the human body in the prone position, the criteria of high peak torque to motor ratio, low cost, minimum maintenance, safety and compatibility. A computer model of the kinematic arrangement designed was created including the necessary motion constrains, using ADAMS and 3D Working Model simulation packages to test, verify and analyse the static and dynamic stability of the kinematic arrangements and the force interaction between the system and the patient. The simulation results led to some modification in the design regarding the kinematics and dynamic stability of the system by varying different design variables. A walking model of a human was created to simulate the real patient. The model was placed on two units where the feet were the only contact points with the moving belts; the model torso was supported by a harness to hold it in the upright standing position. The results obtained showed the movements of both feet (knees. hips and ankles) in addition to the right and left elbows. The system hardware was designed and implemented using custom-made safety critical software to control the device to carry out the desired tasks. Safety is considered to be one of the main issues that this research program has developed and implemented. An optimal control strategy was developed to drive the prototype. Smooth movements of the system were achieved through a PD control system enhanced with velocity feed forward gain with position accuracy of ± 0.168 mm. The desired positional accuracy of the Patterner Machine was ± 0.632 mm

Double wheel crusher prototype

Abstract. This thesis presents a proof of concept for a new testing device. The prototype device was commissioned as a part of a project to develop a fast, low-cost, and reliable breakage characterization test for geo-metallurgical modelling. One of the key processes involved in minerals extraction is comminution: mineral ores are broken down with crushing and grinding machinery. Comminution testing can be used for the purposes of optimizing these processes. Various testing methods used in the industry subject rock particles to varying levels of crushing impact to measure the amount of fine materials liberated relative to the input energy. The role of mechatronic engineering in this context is to design and develop intelligent machines that ease the work of the researchers and technicians performing these tests. The structure of the new device was proposed as a variation of an instrumented roll crusher with an adjustable gap. The trial operation of the prototype was done using rocks from different mine sites around Finland. The test set resulted in data with a clearly identifiable correspondence of energy to the amount of breakage, proving the plausibility of the device. Some issues were found with the accuracy of energy measurements. The programming error behind the fault was corrected and the improved device was found to produce a standard deviation of measurement of 1.07 Joules. Means to further improve the accuracy of the energy and force measurements are discussed, with recommendations and suggestions for other improvements to the device in the future.Kaksoispyörämurskaimen prototyyppi. Tiivistelmä. Tässä työssä koetetaan uuden mittauslaiteen konseptia. Prototyyppilaite tilattiin osana projektia, jonka tarkoituksena on kehittää uusi nopea, varma, ja edullinen menetelmä mineraalien hienontumisen testaamiseen geometallurgisen mallinnuksen tarpeisiin. Eräs mineraalien louhinnan ja jalostamisen keskeisistä prosesseista on malmin hienontaminen murskaus- ja jauhatuskoneilla. Hienonnustestausta voidaan hyödyntää näiden prosessien optimointiin. Kaivosteollisuudessa käytetyissä testausmenetelmissä kivipartikkeleihin kohdistetaan erisuuruisia iskuvoimia, joiden hienonnusvaikutusta mitataan suhteessa syötetyn energian määrään. Mekatronisen suunnittelun tehtävä tässä yhteydessä on kehittää älykkäitä laitteita helpottamaan näitä kokeita suorittavien tutkijoiden ja teknikkojen työtä. Uuden laitteen rakenne mukailee telamurskaimen toimintaperiaatetta. Prototyyppiä testattiin murskaamalla eri puolelta Suomea tuotuja kivinäytteitä. Testin tuloksista on selvästi tunnistettavissa käytetyn energian vaikutus murtumismäärään. Testien aikana havaittiin ongelmia energiamittauksen tarkkuudessa. Vian aiheuttanut ohjelmointivirhe korjattiin ja parannellun laitteiston mittaustuloksen hajonnaksi todettiin 1,07 Joulea. Työn lopussa esitetään ehdotuksia energian ja voiman mittaustarkkuuden parantamiseksi, sekä muita mahdollisia parannuksia laitteen jatkokehitystä varten

THE DEVELOPMENT OF A MECHATRONICS AND MATERIAL HANDLING COURSE: LABORATORY EXPERIMENTS AND PROJECTS

Mechatronic systems integrate technologies from a variety of engineering disciplines to create solutions to challenging industrial problems. The material handling industry utilizes mechatronics to move, track, and manipulate items in factories and distribution centers. Material handling systems, because of their use of programmable logic controllers (PLC), PLC networks, industrial robotics, and other mechatronic elements, are a natural choice for a college instructional environment. This thesis offers insight and guidance for mechatronic activities introduced in a laboratory setting. A series of eight laboratory experiments have been created to introduce PLCs, robotics, electric circuits, and data acquisition fundamentals. In-depth case studies synthesize the technologies and interpersonal skills together to create a flexible material handling system. Student response to the course and laboratory material was exceptional. A pre and post course questionnaire was administered which covered topics such as teamwork, human factors, business methods, and various engineering related questions. Quantitative scores resulting from these questionnaires showed a marked improvement by students, especially in regards to technical/engineering questions. The responses from students generally indicated an excitement about course material and a thorough understanding of the various syllabus topics. In this thesis, the multi-disciplinary mechatronics (and material handling systems) laboratory will be presented. An in-depth examination of each laboratory will be offered as well as the discussion of two material handling case studies. The Appendixes contain the PLC and robot code for a order fulfillment case study

Medical robots for MRI guided diagnosis and therapy

Magnetic Resonance Imaging (MRI) provides the capability of imaging tissue with fine resolution and superior soft tissue contrast, when compared with conventional ultrasound and CT imaging, which makes it an important tool for clinicians to perform more accurate diagnosis and image guided therapy. Medical robotic devices combining the high resolution anatomical images with real-time navigation, are ideal for precise and repeatable interventions. Despite these advantages, the MR environment imposes constraints on mechatronic devices operating within it. This thesis presents a study on the design and development of robotic systems for particular MR interventions, in which the issue of testing the MR compatibility of mechatronic components, actuation control, kinematics and workspace analysis, and mechanical and electrical design of the robot have been investigated. Two types of robotic systems have therefore been developed and evaluated along the above aspects. (i) A device for MR guided transrectal prostate biopsy: The system was designed from components which are proven to be MR compatible, actuated by pneumatic motors and ultrasonic motors, and tracked by optical position sensors and ducial markers. Clinical trials have been performed with the device on three patients, and the results reported have demonstrated its capability to perform needle positioning under MR guidance, with a procedure time of around 40mins and with no compromised image quality, which achieved our system speci cations. (ii) Limb positioning devices to facilitate the magic angle effect for diagnosis of tendinous injuries: Two systems were designed particularly for lower and upper limb positioning, which are actuated and tracked by the similar methods as the first device. A group of volunteers were recruited to conduct tests to verify the functionality of the systems. The results demonstrate the clear enhancement of the image quality with an increase in signal intensity up to 24 times in the tendon tissue caused by the magic angle effect, showing the feasibility of the proposed devices to be applied in clinical diagnosis

New Mechatronic Systems for the Diagnosis and Treatment of Cancer

Both two dimensional (2D) and three dimensional (3D) imaging modalities are useful tools for viewing the internal anatomy. Three dimensional imaging techniques are required for accurate targeting of needles. This improves the efficiency and control over the intervention as the high temporal resolution of medical images can be used to validate the location of needle and target in real time. Relying on imaging alone, however, means the intervention is still operator dependent because of the difficulty of controlling the location of the needle within the image. The objective of this thesis is to improve the accuracy and repeatability of needle-based interventions over conventional techniques: both manual and automated techniques. This includes increasing the accuracy and repeatability of these procedures in order to minimize the invasiveness of the procedure. In this thesis, I propose that by combining the remote center of motion concept using spherical linkage components into a passive or semi-automated device, the physician will have a useful tracking and guidance system at their disposal in a package, which is less threatening than a robot to both the patient and physician. This design concept offers both the manipulative transparency of a freehand system, and tremor reduction through scaling currently offered in automated systems. In addressing each objective of this thesis, a number of novel mechanical designs incorporating an remote center of motion architecture with varying degrees of freedom have been presented. Each of these designs can be deployed in a variety of imaging modalities and clinical applications, ranging from preclinical to human interventions, with an accuracy of control in the millimeter to sub-millimeter range

Hybrid additive manufacturing platform for the production of composite wind turbine blade moulds

This dissertation discusses the application of additive manufacturing technologies for production of a large-scale rapid prototyping machine, which will be used to produce moulds for prototype composite turbine blades for the emerging renewables energy industry within the Eastern Cape region in South Africa. The conceptualization and design of three complete printer builds resulted in the amalgamation of a final system, following stringent theoretical design, simulation, and feasibility analysis. Following the initial product design cycle stage, construction and performance testing of a large-scale additive manufacturing platform were performed. In-depth statistical analysis of the mechatronic system was undertaken, particularly related to print-head locational accuracy, repeatability, and effects of parameter variation on printer performance. The machine was analysed to assess feasibility for use in the mould-making industry with accuracy and repeatability metrics of 0.121 mm and 0.156 mm rivalling those produced by some of the more accurate fused deposition modellers commercially available. The research data gathered serves to confirm that rapid prototyping is a good alternative manufacturing method for wind turbine blade plug and mould production