This thesis presents the design and development of a novel biomimetic jellyfish robot that features ionic polymer metal composite actuators. The shape and swimming style of this underwater vehicle are based on oblate jellyfish species, which are known for their high locomotive efficiency. Ionic polymer metal composites (IPMC) are used as actuators in order to contract the bell and thus propel the jellyfish robot. This research focuses on translating the evolutionary successes of the natural species into a jellyfish robot that mimics the geometry, the swimming style, and the bell deformation cycle of the natural species. Key advantages of using IPMC actuators over other forms of smart material include their ability to exhibit high strain response due to a low voltage input and their ability to act as artificial muscles in water environment. This research specifically seeks to implement IPMC actuators in a biomimetic design and overcome two main limitations of these actuators: slow response rate and the material low blocking force. The approach presented in this document is based on a combination of two main methods, first by optimizing the performance of the IPMC actuators and second by optimizing the design to fit the properties of the actuators by studying various oblate species. Ionic polymer metal composites consist of a semi-permeable membrane bounded by two conductive, high surface area electrode. The IPMCs are manufactured is several variations using the Direct Assembly Process (DAP), where the electrode architecture is controlled to optimize the strain and stiffness of the actuators. The resulting optimized actuators demonstrate peak to peak strains of 0.8 % in air and 0.7 % in water across a frequency range of 0.1-1.0 Hz and voltage amplitude of 2 V. A study of different oblate species is conducted in order to attain a model system that best fits the properties of the IPMC actuators. The Aequorea victoria is chosen based on its bell morphology and kinematic properties that match the mechanical properties of the IPMC actuators. This medusa is characterized by it low swimming frequency, small bell deformation during the contraction phase, and high Froude efficiency. The bell morphology and kinematics of the Aequorea victoria are studied through the computation of the radius of curvature and thus the strain energy stored in the during the contraction phase. The results demonstrate that the Aequorea victoria stores lower strain energy compared to the other candidate species during the contraction phase. Three consecutive jellyfish robots have been built for this research project. The first generation served as a proof of concept and swam vertically at a speed of 2.2 mm/s and consumed 3.2 W of power. The second generation mimicked the geometry and swimming style of the Aurelia aurita. By tailoring the applied voltage waveform and the flexibility of the bell, the robot swam at an average speed of 1.5 mm/s and consumed 3.5 W of power. The third and final generation mimicked the morphology, swimming behavior, and bell kinematics of the Aequorea victoria. The resulting robot, swam at an average speed of 0.77 mm/s and consumed 0.7 W of power when four actuators are used while it achieved 1.5 mm/s and 1.1 W of power consumption when eight actuators are used. Key parameter including the type of the waveform, the geometry of the bell, and position and size of the IPMC actuators are identified. These parameters can be hit later in order to further optimize the design of an IPMC based jellyfish robot. / Master of Science

In recent years, increased emphasis has been placed on the development of parallel-architecture mechanisms for use as robotic manipulators. Parallel robots offer the benefits of higher load-carrying capacity, greater positioning accuracy and lower weight when compared to serial devices. However, robotic wrist development has traditionally focused on serial mechanisms having a large, spherical workspace and simpler kinematic solutions. The Carpal wrist is a unique parallel mechanism consisting of a fixed base and a movable output plane connected via three serial kinematic chains. The forward and inverse kinematic problems of the Carpal wrist are solved closed-form, making the device suitable for use as a new type of robotic wrist. The closed-form solutions are dependent upon the assumptions that the fixed and moving planes are symmetric about a mid-plane and that the three kinematic chains connecting the planes are identical. This thesis investigates the errors that result from those assumptions being violated due to manufacturing and assembly errors. In the non-ideal model, pose error is found by iteratively solving a system of equations describing the output plane position and orientation and comparing them with the ideal solution. The error model is a tool for predicting the effects of kinematic parameter errors on the positioning accuracy and reachable workspace of the Carpal wrist. In this work, a general error model is developed and validated for a range of parameter error values. Special-case results are presented for errors in the individual parameters. / Master of Science

<p dir="ltr">Car design is a complex task because of how highly integrated system of systems it is. Fine?designed car models take years of design and optimization and are usually done by specialty teams who are dedicated to each sub-system. This thesis delves into designing a simplified electric race car from scratch with focus on the performance envelope of it. First, a 3D CAD model was done using SolidWorks. That section deals with spatial engineering and strategic placement of major car components for best performance. Having most of the parts in place gives a rough estimate of CoG (Center of Gravity) location, which is needed for vehicle dynamics analysis, which are discussed later in the report. The target for this project car is to have innovative aerodynamics features which might not have been used before because of bulky internal combustion engines restricting available space. One of them is an airfoil-like fascia which makes the center part of the car act as a one big wing. That is believed to give a significant reduction in drag loads on the car. The approach for aerodynamics design and analysis started with a model representing the car’s OML (Outer Mold line) which was simulated separately using Siemens StarCCM+. After understanding the car’s body aero behavior, a rear wing was added to provide extra rear downforce for better handling and stability. The rear wing design was explained in detail. Unfortunately, due to time restrictions as well as software access issues, the aerodynamic analysis of the full car with rear wing is left for future work. After having an estimate about aero loads acting on the car, vehicle dynamics analysis could start. The first subject studied in vehicle dynamics was front-view suspension geometry analysis. Taking the available packaging and geometry into consideration, a 2D model was done in SolidWorks to optimize camber gain. This analysis gave the motion ratio of the front and rear pushrod suspension system which was needed to analyze the performance of the one-eighth car model, ½ car pitch model, and ½ car roll model. These models gave insights into the decision-making process for spring and damping rates to reach a good balance between performance and comfort. This project acts as a hub for further development and studies related to car design.</p>

Robots have an underlying model to control their joints with the aim of reaching a specific pose. The accuracy of a robot is based on the underlying model and its parameters. The parameters of the underlying model of a robot are based on the ideal geometry and set by the manufacturer. If the parameters do not represent the physical robot accurately, the movements of the robot become inaccurate. Methods to optimize the parameters to represent the physical robot more accurately exist and result in an accuracy enhancement. Nevertheless, the underlying model of the manufacturer remains of analytical form and therefore has a limited complexity which hinders the model to represent arbitrary non-linearities and higher degree relations. To further enhance the accuracy of a robot by using a model with a higher complexity, this work investigates the use of a model of the inverse kinematics based on Artificial Intelligence (AI). The accuracy is investigated for a robot with an attached tool. In a first step, the development and initial evaluation of a suitable AI model is conducted in a simulated environment. Afterwards, the uncompensated accuracy of the robot with the tool is assessed and measurements are recorded. Using the measurements, an AI model based on the measurements of physical robot. The model is evaluated on the physical robot with a tool to quantify the achieved accuracy enhancement.

Redundant manipulators are widely used because they have a greater dexterity andversatility than nonredundant manipulators. In the redundant manipulators, thenumber of degrees of freedom are more than the required to manipulate objects atthe task space, which leads to a possibility to generate infinite number of solutions.For this reasons it has been a hot research topic to exploit the redundancy. Thisthesis work is focus on modeling and controlling redundant robot manipulator withseven degree of freedom (LWA 10 kg payload by Schunk). A literature review hasbeen prepared on the existing methods of exploiting the redundancy in the 7-DOFmanipulators at the velocity and position levels. The forward kinematic equationsare derived using the Denavit-Hartenberg method. The inverse kinematic problem issolved and the redundancy is exploited at the position level to avoid the computationalcomplexity and inaccuracy associated with exploiting the redundancy at the velocitylevel. The joint angles of the manipulator are computed in term of a redundancyparameter defining the self-motion in the manipulator. The relation between the jointangles and the redundancy parameter is exploited to avoid selecting the arm anglesthat violate the joint limits. The singularity configurations and robot workspace arealso studied in this thesis. An example is presented on how the self-motion of thearm appears when the end-effector is stationary. The methods are applied to followstraight line trajectories while preventing the joints to exceed the limits. The resultsfound showed how exploiting the redundancy at the position level is being exact withlow computational cost. The validity of the methods is verified by Robotics Toolboxsimulations.

This thesis primarily uses submillimetre molecular line data from HARP, a heterodyne array on the James Clerk Maxwell Telescope (JCMT), to further investigate star formation in the Ophiuchus L1688 cloud. HARP was used to observe CO J = 3-2 isotopologues: 12CO, 13CO and C18O; and the dense gas tracer HCO+ J = 4-3. A method for calculating molecular line contamination in the SCUBA-2 450 and 850 μm dust continuum data was developed, which can be used to convert 12CO J =6-5and J =3-2 maps of integrated intensity (K km s−1) to molecular line flux (mJy beam−1) contaminating the continuum emission. Using HARP maps of 12CO J = 3-2, I quantified the amount of molecular line contamination found in the SCUBA-2 850 μm maps of three different regions, including NGC 1333 of Perseus and NGC 2071 and NGC 2024 of Orion B. Regions with ‘significant’ (i.e. > 20%) molecular line contamination correspond to molecular outflows. This method is now being used to remove molecular line contamination from regions with both SCUBA-2 dust continuum and HARP 12CO map coverage in the Gould Belt Legacy Survey (GBS). The Ophiuchus L1688 cloud was observed in all three CO J = 3-2 isotopologues. I carried out a molecular outflow analysis in the region on a list of 30 sources from the Spitzer ‘c2d’ survey [Evans et al., 2009]. Out of the 30 sources, 8 had confirmed bipolar outflows, 20 sources had ‘confused’ outflow detections and 2 sources did not have outflow detections. The Ophiuchus cloud was found to be gravitationally bound with the turbulent kinetic energy a factor of 7 lower than the gravitational binding energy. The high-velocity outflowing gas was found to be only 21% of the turbulence in the cloud, suggesting outflows are significant but not the dominant source of turbulence in the region. Other factors were found to influence the global high-velocity outflowing gas in addition to molecular outflows, including hot dust from nearby B-type stars, outflow remnants from less embedded sources and stellar winds from the Upper Scorpius OB association. To trace high density gas in the Ophiuchus L1688 cloud, HCO+ J = 4-3 was observed to further investigate the relationship between high column density and high density in the molecular cloud. Non-LTE codes RADEX and TORUS were used to develop density models corresponding to the HCO+ emission. The models involved both constant density and peaked density profiles. RADEX [van der Tak et al., 2007] models used a constant density model along the line-of-sight and indicated the HCO+ traced densities that were predominantly subthermally excited with den- sities ranging from 10^3–10^5 cm^−3. Line-of-sight estimates ranged from several parsecs to 90 pc, which was unrealistic for the Ophiuchus cloud. This lead to the implementation of peaked density profiles using the TORUS non-LTE radiative transfer code. Initial models used a ‘triangle’ density profile and a more complicated log-normal density probability density function (PDF) profile was subsequently implemented. Peaked density models were relatively successful at fitting the HCO+ data. Triangle models had density fits ranging from 0.2–2.0×10^6 cm^−3 and 0.1–0.3×10^6 cm^−3 for the 0.2 and 0.3 pc cloud length models re- spectively. Log-normal density models with constant-σ had peak density ranges from 0.2–1.0 ×10^5 cm^−3 and 0.6–2.0×10^5 cm^−3 for 0.2 and 0.3 pc models respectively. Similarly, log-normal models with varying-σ had lower and upper density limits corresponding to the range of FWHM velocities. Densities (lower and upper limits) ranged from 0.1–1.0 ×10^6 and 0.5–3.0 ×10^5 cm^-3 for the 0.2 and 0.3 pc models respectively. The result of the HCO+ density modelling indicated the distributions of starless, prestellar and protostellar cores do not have a preference for higher densities with respect to the rest of the cloud. This is contrary to past research suggesting the probability of finding a submillimetre core steeply rises as a function of column density (i.e. density; Belloche et al. 2011; Hatchell et al. 2005). Since the majority of sources are less embedded (i.e Class II/III), it is possible the evolutionary state of Ophiuchus is the main reason the small sample of Class 0/I protostars do not appear to have a preference for higher densities in the cloud.

[Truncated abstract] Measuring the kinematics of joints and implants following orthopaedic surgery is important since joint motion directly influences the functional outcome of the patient and the longevity of the implant. Radiostereometric Analysis (RSA) has been used to assess the motion over time of various joints and implant designs following corrective orthopaedic and joint replacement surgery for more than 20 years in more than 10,000 patients around the world. While the use of RSA reduces the risk of implanting potentially inferior prostheses on a large scale, conventional methodological procedures are based on the acquisition of static, stereographic x-ray images that are not suitable for measuring skeletal kinematics in a dynamic manner. The purpose of this thesis was to design, validate and test a novel technique for dynamically assessing the skeletal motion of human subjects using RSA and single-plane digital x-ray video fluoroscopy. The validation procedure utilised two in-vitro phantom models of human joints capable of simulating normal kinematic motion. These phantom models were supplied with realistic spatial displacement protocols derived from cadaveric specimens. The spatial positions of a series of tantalum markers that were implanted in each skeletal segment were measured using RSA. Skeletal motion was determined in x-ray fluoroscopy images by minimising the difference between the markers measured and projected in the single image plane. Accuracy was determined in terms of bias and precision by analysing the deviation between the applied displacement protocol and measured pose estimates. ... The RSA and low dose single-plane fluoroscopy technique developed, validated and tested in this thesis is capable of dynamically measuring the kinematics of any joint in the human body, following the implantation of small metallic markers in the surrounding bone during corrective orthopaedic surgery. The kinematics of joints with replacement prostheses, such as the total knee replacement (TKR), can be analysed in addition to the kinematics of joints without replacement prostheses, such as the sacroiliac joint. The technique may be used in the future on groups of human subjects enrolled in controlled trials that are designed to analyse the kinematics of the shoulder, spine, hip, knee, patella or ankle joints for the purposes of quantitatively comparing the kinematics of different prosthesis designs and various corrective orthopaedic procedures.

Orientadores: Helder Anibal Hermini, Paulo R. G. Kurka / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-10T05:53:08Z (GMT). No. of bitstreams: 1 Mendes_EduardoFelippeAguiar_M.pdf: 4299696 bytes, checksum: d73355f383b74bd0e49b3bc2473e5b6b (MD5) Previous issue date: 2007 / Resumo: Este trabalho visou o estudo de manipuladores à semelhança do membro superior humano. Após o estudo do membro superior humano e dos robôs antropomórficos disponíveis tanto na industria quanto no meio acadêmico, utilizaram-se teorias de modelagem geométrica, cinemática direta e cinemática inversa para realizar o modelo de um manipulador robótico antropomórfico. A partir desse modelo desenvolveu-se um software em LabVIEW de Cinemática Direta e Cinemática Inversa de operação em tempo real. Com a intenção de verificar os acionadores mais apropriados disponíveis atualmente, um estudo de músculos artificiais se seguiu, onde se observou a maior viabilidade do músculo artificial de SMA ativado eletricamente. Um protótipo de junta acionada por músculos artificiais foi desenvolvido e controlado via computador. Como resultado deste trabalho conclui-se que há ainda muito para ser desenvolvido na área de manipuladores antropomórficos, principalmente no que diz respeito aos músculos artificiais / Abstract: This work sought the study of manipulators to the similarity of the human superior member. After the study of human superior member, and of anthropomorphics robotics available in the industries and in the academic middle, it was used theories of geometric modelling, direct kinematics modelling and inverse kinematics modelling to make the model of a anthropomorphic robotic manipulator. With that model it grew a software in LabVIEW of real time Direct Kinematics and Inverse Kinematics. With the intention of verifying the available most appropriate actuators, a study of artificial muscles was proceeded, where the largest viability of the artificial muscle of SMA activated electrically was observed. A joint prototype actuated by artificial muscles was developed and controlled through computer. As a result of this work it is ended that there is still a lot to be developed in the area of anthropomorphic manipulators, mainly in what it concerns the artificial muscles / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Tato diplomová práce má za cíl seznámit čtenáře se stále ještě relativně novou a neznámou oblastí matematiky, s geometrickou algebrou. Nejdříve jsou uvedeny základní definice a poté jsou studovány vlastnosti obecné geometrické algebry. Další velká část textu se věnuje Konformní geometrické algebře, která je v současnosti jedna z nejvíce zkoumaných a aplikovaných geometrických algeber. Jsou popsány její algebraické a geometrické vlastnosti, konkrétně schopnost reprezentovat určité geometrické objekty jako vektory. Taktéž umožňuje počítat jejich průniky a konformní transformace. Další část textu je zaměřena na aplikace Konformní geometrické algebry, nejdříve k popisu kinematiky robotické ruky a poté v binokulárním viděni.

Táto diplomová práca sa zaoberá matematickými aparátmi popisujúcimi doprednú a inverznú kinematiku robotického ramena. Pre popis polohy koncového efektoru, teda doprednej kinematiky, je potrebné zaviesť špeciálnu Euklidovskú grupu zobrazení. Táto grupa môže byť reprezentovaná pomocou matíc alebo pomocou duálnych kvaterniónov. Problém inverznej kinematiky, kedy je potrebné z určenej polohy koncového efektoru dopočítať kĺbové parametre robotického ramena, je v tejto práci riešený pomocou exponenciálnych zobrazení a Grobnerovej bázy. Všetky spomenuté popisy doprednej a inverznej kinematiky sú aplikované na robotické rameno s troma rotačnými kĺbami. Odvodené postupy sú následne implementované a vizualizované v prostredí programu Mathematica.