Prototyping and Testing a Miniaturized Floating Spacecraft Simulator

Floating spacecraft simulators are robotic vehicles which imitate satellite movement in space. The use of floating spacecraft simulators permits experimental validation of Guidance, Navigation and Control (GNC) algorithms on Earth, before applying them in space, where errors could be catastrophic. Furthermore, FSS constitute an important research and educational tool for university students in space systems engineering curricula. However, all FSS currently in use are custom developed and expensive items. This master thesis covers the development, assembling and testing process of a new Floating Spacecraft Simulator for teaching and research purposes, named MyDAS, standing for Mini Dynamic Autonomous Spacecraft Simulator. By introducing MyDAS, a small, simple and affordable FSS enables broader utilization of FSS for research and education at university and high-school levels. Different propulsion configurations for MyDAS and their corresponding equations of motion are discussed. For one specific configuration, off-the-shelf pneumatic and electronic components are selected and tested. A modular and standardized 3D printed frame holds all parts together, creating a final rigid vehicle. In the end, MyDAS is tested in a variety of experiments with full hardware functionality accomplished.Universität der Bundeswehr Hamburg Fakultät für Maschinenbau Professur für Mechatronik Holstenhofweg 85 22043 Hamburg, GermanyGerman Armed ForcesApproved for public release; distribution is unlimited

A survey of non-prehensible pneumatic manipulation surfaces : principles, models and control.

International audienceMany manipulation systems using air flow have been proposed for object handling in a non-prehensile way and without solid-to-solid contact. Potential applications include high-speed transport of fragile and clean products and high-resolution positioning of thin delicate objects. This paper discusses a comprehensive survey of state-of-the-art pneumatic manipulation from the macro scale to the micro scale. The working principles and actuation methods of previously developed air-bearing surfaces, ultra-sonic bearing surfaces, air-flow manipulators, air-film manipulators, and tilted air-jet manipulators are reviewed with a particular emphasis on the modeling and the control issues. The performance of the previously developed devices are compared quantitatively and open problems in pneumatic manipulation are discussed

Trajectory optimization inspired pneumatic locomotion on compliant terrains

Thesis (MEng)--Stellenbosch University, 2022.ENGLISH ABSTRACT: In order to achieve true autonomy, robots have to be able to handle complex and rough terrain generally found outside of the lab. Legged robotics has become the focal point in recent years, aided by the developments in trajectory optimization methods. However, a major problem in legged robotics is dealing with hybrid contacts with different terrain types. The difference in dynamics due to the interaction between the foot and the ground makes it increasingly difficult to design controllers that successfully execute on multiple surfaces. This work investigates trajectory optimization methods for a pneumatically actuated mono-pod on rigid and compliant terrain. Trajectory optimization was utilized to obtain trajectories for acceleration, steady-state and deceleration hopping on compliant terrain, as well as rigid terrain surfaces. For the compliant terrain trajectories a novel method was developed to model the specific characteristics of the compliant terrain. Trajectories were generated using this method for two different compliant terrain types, namely: rough gravel and fine gravel. To mimic the pneumatic actuation in the trajectory optimization problem, a simplified mathematical model was developed to accommodate the bang-bang force of the pneumatic actuator. This model used complementarity constraints and node bucketing techniques to mimic the behaviour of a real pneumatic actuator with damping and delay. Once these methods and models were implemented, trajectories were executed, in open-loop, on a fixed body robotic platform that was designed and built for this thesis. The executions were compared to the trajectory results. The rigid terrain trajectories were executed successfully on a hard surface, but failed on gravel surfaces. The compliant terrain trajectories executed successfully on gravel surfaces, indicating that the method developed to model compliant terrain is a more accurate representation of the gravel surfaces compared to the rigid terrain trajectories. After these results showed that the methods used to describe the compliant terrain proved to be accurate, a free body mono-pod robot and support rig was designed and built. The support rig limited the movement of the mono-pod to the sagittal plane to mimic the limitations of the trajectory optimization model. Acceleration, steady-state and deceleration trajectories were generated for the free body mono-pod on compliant terrain surfaces and a rigid terrain surface. From these trajectories a controller was designed with the main sources of feedback being the height of the robot and the angle of the free moving body of the robot. The free body mono-pod robot used the controller to execute hopping from rest back to rest with three steady-state hops in between. For each terrain type the controller was adjusted based on the generated trajectories. The results show successful execution of the trajectories on all terrain types using the controller. Lastly multi-surface hopping was executed on the mono-pod robot platform. The controller was adjusted to hop from a hard surface to a compliant surface and executed these trajectories successfully.AFRIKAANSE OPSOMMING: Om ware outonomie te bewerkstellig, moet robotte komplekse en rowwe terreine, wat gewoonlik buite die laboratorium voorkom, kan hanteer. Been aangedrewe robotika het die afgelope paar jaar ’n fokuspunt geword in die literatuur, aangehelp deur ontwikkelinge in trajek-optimaliseringsmetodes. ’n Groot probleem in been aangedrewe robotika is egter die hantering van verskillende terreintipes. Die verskil in dinamika as gevolg van die interaksie tussen die voet en die grond maak dit steeds moeiliker om beheerders te ontwerp wat suksesvol op verskeie oppervlaktes uitgevoer kan word. Hierdie werk ondersoek optimaliseringsmetodes van trajekte vir ’n pneumaties aange drewe eenbenige robot op stewige en sagte terrein. Trajek-optimalisering is gebruik om versnelling-, bestendige- en vertraging-trajekte te genereer wat op sagte terreine sowel as stewige terreinoppervlakke spring. Hierdie trajekte is uitgevoer op ’n robot platvorm met ’n vaste liggaam en is vergelyk met die trajek resultate. Die stewige terrein trajek is suksesvol uitgevoer op ’n harde oppervlak, maar het op ’n gruisoppervlak misluk. Die sagte terrein is suksesvol uitgevoer op twee gruisoppervlaktes, wat aandui dat dit ’n meer akkurate voorstelling van die gruisoppervlakke is in vergelyking met die rigiede terrein trajek. Om die pneumatiese kragte in die tajekoptimalisering na te boots, is ’n vereenvoudigde wiskundige model ontwikkel om die drukstootbeweging van die pneumatiese aandrywer te akkommodeer. Hierdie model het komplementariteitsbeperkings en knooppunte gebruik om die gedrag van ’n werklike pneumatiese aandrywer na te boots. Nadat hierdie resultate getoon het dat die metodes wat gebruik is om die terrein te beskryf akkuraat is, is ’n eenbenige robot en ’n ondersteuningsplatvorm vir ’n vrye liggaam robot ontwerp en gebou. Die ondersteuningsplatvorm het die beweging van die eenbenige robot tot die sagittale vlak beperk om die beperkings van die trajekoptimaliseringsmodel na te boots. Versnelling-, bestendige- en vertragings-trajekte is gegenereer vir die eenbenige robot met ’n vrye liggaam op sagte terrein en op stewige terrein. Uit hierdie trajekte is ’n beheerder ontwerp, met die belangrikste bronne van terugvoer die hoogte van die robot en die hoek van die vry bewegende liggaam van die robot. Die eenbenige robot het die beheerder gebruik om van rus na rus te spring, met drie bestendige hoppe tussenin. Vir elke terrein tipe is die beheerder aangepas op grond van die gegenereerde trajekte. Die resultate toon ’n suksesvolle uitvoering van die trajekte op alle terreintipes met behulp van die beheerder. Laastens is ’n twee-oppervlakte-hop uitgevoer op die mono-pod robotplatform. Die beheerder is aangepas om van ’n harde oppervlak na ’n sagte oppervlak te spring en hierdie trajekte was suksesvol uitgevoer.Master

Volume 2 – Conference

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group 1 | 2: Digital systems Group 3: Novel displacement machines Group 4: Industrial applications Group 5: Components Group 6: Predictive maintenance Group 7: Electro-hydraulic actuatorsDer Download des Gesamtbandes wird erst nach der Konferenz ab 15. Oktober 2020 möglich sein.:Group 1 | 2: Digital systems Group 3: Novel displacement machines Group 4: Industrial applications Group 5: Components Group 6: Predictive maintenance Group 7: Electro-hydraulic actuator

Implementación de una Celda de Manufactura en el Ensamble de una Torre de Hanói

Technology in the modern world, has become a necessity electronic and mechanical parts are unified to become mechanisms, which are the facilitating devices of human life and work. A common problem in the fabrication of a product is the high costs of personnel and the physical limitations, an example is the production of the tower of Hanoi. Thus, taking into account the knowledge acquired of the different courses at the level of robotics, mechanics, electronics and programming, the design and construction of a manufacturing cell and its operating interface was carried out, which has as its main function the distribution and manipulation of the elements necessary for the assembly of a tower of Hanoi, to know the process that a company requires for the elaboration of a product in an automated way. For the development of this project, four different processes were considered, a supply stage through pneumatic circuits, machine vision algorithms for quality control of the parts involved in the assembly, a selection process and place developed by a Phantom type robot with 4 degrees of freedom and, finally, the delivery of the finished product by means of a conveyor belt for later packaging.La tecnología en el mundo moderno se ha convertido en una necesidad la cual por medio de partes electrónicas y mecánicas se unifican para convertirse en mecanismos los cuales son capaces de facilitar la vida del ser humano y optimizar el trabajo. Un problema común en la producción de un bien son los altos costos del personal y las limitaciones físicas que estos tienen, un ejemplo claro es la producción de la torre de Hanoi. Es así como teniendo en cuenta los conocimientos adquiridos en los diferentes cursos a nivel de robótica, mecánica, electrónica y de programación se realizó el diseño y construcción de una celda de manufactura y su interfaz de operación, la cual tiene como función principal la distribución y manipulación de los elementos necesarios para el ensamblaje de una torre de Hanoi, con el fin de dar a conocer el proceso que requiere una compañía para la elaboración de un producto de manera automatizada. Para el desarrollo del presente proyecto se tuvieron en cuenta cuatro diferentes procesos, una etapa de abastecimiento a través de circuitos neumáticos con su respectivo compresor, algoritmos de visión de máquina en conjunto con una cámara oscura, mitigando los efectos de las variaciones en la luz ambiente, para la selección y el control de calidad de las piezas involucradas en el ensamblaje, un proceso de pick and place desarrollado por un robot de 4 grados de libertad y, por último, la entrega del producto terminado mediante una banda transportadora para su posterior embalaje

Design of a seven degree of freedom arm with human attributes

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaf 24).Studying biological systems has given robotics researchers valuable insight into designing complex systems. This thesis explores one such application of a biomimetic robotic system designed around a human arm. The design of an anthropomorphic arm, an arm that is similar to that of a human's, requires deep insight into the kinematics and physiology of the biological system. Investigated here is the design and completion of an arm with 7 degrees of freedom and human-like range of motion in each joint. The comparison of actuation schemes and the determination of proper kinematics enable the arm to be built at a low cost while maintaining high performance and similarity to the biological analog. Complex parts are built by dividing structures into interlocking 2d shapes that can easily be cut out using a waterjet and then welded together with high reliability. The resulting arm will become part of a bionic system when combined with an existing bionic hand platform that is being developed in the Intelligent Machines Laboratory at MIT. With a well thought out modular design, the system will be used as a test bed for future research involving data simplification and neurological control. The completion of the anthropomorphic arm reveals that is indeed feasible to use simple DC motors and quick fabrication techniques. The final result is a reliable, modularized, and anthropomorphic arm.by Adam Paul Leeb.S.B

Variable stiffness robotic hand for stable grasp and flexible handling

Robotic grasping is a challenging area in the field of robotics. When interacting with an object, the dynamic properties of the object will play an important role where a gripper (as a system), which has been shown to be stable as per appropriate stability criteria, can become unstable when coupled to an object. However, including a sufficiently compliant element within the actuation system of the robotic hand can increase the stability of the grasp in the presence of uncertainties. This paper deals with an innovative robotic variable stiffness hand design, VSH1, for industrial applications. The main objective of this work is to realise an affordable, as well as durable, adaptable, and compliant gripper for industrial environments with a larger interval of stiffness variability than similar existing systems. The driving system for the proposed hand consists of two servo motors and one linear spring arranged in a relatively simple fashion. Having just a single spring in the actuation system helps us to achieve a very small hysteresis band and represents a means by which to rapidly control the stiffness. We prove, both mathematically and experimentally, that the proposed model is characterised by a broad range of stiffness. To control the grasp, a first-order sliding mode controller (SMC) is designed and presented. The experimental results provided will show how, despite the relatively simple implementation of our first prototype, the hand performs extremely well in terms of both stiffness variability and force controllability