Download or read book Design of Soft Knee Exoskeleton and Modeling Effects of Variable Stiffness for Advanced Space Suits and Planetary Exploration written by Allison Paige Porter and published by . This book was released on 2020 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: Existing gas-pressurized space suit designs aim to provide astronauts with a wide range of joint motion while minimizing joint torque during extra-vehicular activity (EVA). However, current space suits have stiff joints with limited range, which impede performance. Future designs should consider that some joint torque can be beneficial in storing elastic energy for locomotion in reduced gravity planetary EVAs. Though current gas-pressurized space suits restrict astronaut movement, they are capable of partially supporting their own mass and storing elastic energy in the lower body, allowing metabolic cost reduction during locomotion in reduced gravity, such as on Mars or the moon. The BioSuit[superscript TM] developed by the Massachusetts Institute of Technology (MIT), is an advanced, skin-tight compression garment concept, which exerts mechanical counterpressure (MCP) directly on the astronaut’s skin with the benefits of increasing range of motion and performance while also reducing mass when compared to gas-pressurized space suits. A BioSuit[superscript TM] soft knee exoskeleton with tunable knee stiffness was developed to minimize metabolic expenditure during locomotion in partial gravity and maximize mobility. Musculoskeletal modeling simulated predicted soft knee exoskeleton stiffness at the knee during walking in Earth and Lunar gravity. This thesis summarizes the design and development of prototype actuation in a soft exoskeleton in collaboration with the D-Air Lab (Vicenza, Italy) that applies variable knee stiffness. Soft knee exoskeleton design criteria, fabrication techniques, and simulated impacts on joint kinematics and metabolic cost are discussed. The soft knee exoskeleton was shown to exert tunable knee stiffness via airbags. Prototypes were developed to minimize partial gravity locomotion metabolic cost and space suit inflexibility. An OpenSim software pipeline was shown to be capable of torsional spring stiffness modeling at the knee analogous with predicted soft knee exoskeleton stiffness. Integration of 1G and 0.17G walking data enabled comparison of energetics trends between exoskeleton conditions within each gravity level. The results of this thesis demonstrate the ability to integrate a soft knee exoskeleton into the BioSuit[superscript TM] to improve space suit design and enable longer, safer, and more complex EVAs in partial gravity.
Download or read book Space Exploration Challenges written by Bradley Thomas Holschuh and published by . This book was released on 2010 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis addresses two challenges associated with advanced space and planetary exploration: characterizing and improving the mobility of current and future gas pressurized space suits; and developing effective domestic Planetary Protection policies for the emerging private space industry. Gas-pressurized space suits are known to be highly resistive to astronaut movement. As NASA seeks to return to planetary exploration, there is a critical need to improve full body space suit mobility for planetary exploration. Volume effects (the torque required to displace gas due to internal volume change during movement) and structural effects (the additional torque required to bend the suit materials in their pressurized state) are cited as the primary contributors to suit rigidity. Constant volume soft joints have become the design goal of space suit engineers, and simple joints like the elbow are believed to have nearly achieved such performance. However, more complex joints like the shoulder and waist have not yet achieved comparable optimization. As a result, it is hypothesized that joints like the shoulder and waist introduce a third, and not well studied, contributor to space suit rigidity: pressure effects (the additional work required to compress gas in the closed operating volume of the suit during movement). This thesis quantifies the individual contributors to space suit rigidity through modeling and experimentation. An Extravehicular Mobility Unit (EMU) space suit arm was mounted in a -30kPa hypobaric chamber, and both volume and torque measurements were taken versus elbow angle. The arm was tested with both open and closed operating volumes to determine the contribution of pressure effects to total elbow rigidity. These tests were then repeated using a full EMU volume to determine the actual impact of elbow pressure effects on rigidity when connected to the full suit. In both cases, structural and volume effects were found to be primary contributors to elbow joint rigidity, with structural effects dominating at low flexion angles and volume effects dominating at high flexion angles; pressure effects were detected in the tests that used only the volume of the arm, but were found to be a secondary contributor to total rigidity (on average 5%). These pressure effects were not detected in the tests that used the volume representative of a full EMU. Unexpected structural effects behavior was also measured at high ( 75°) flexion angles, suggesting that the underlying mechanisms of these effects are not yet fully understood, and that current models predicting structural effects behavior do not fully represent the actual mechanisms at work. The detection of pressure effects in the well-optimized elbow joint, even if only in a limited volume, suggests that these effects may prove significant for sub-optimized, larger, multi-axis space suit joints. A novel, fast-acting pressure control system, developed in response to these findings, was found to be capable of mitigating pressure spikes due to volume change (and thus, pressure effects). Implementation of a similar system in future space suit designs could lead to improvements in overall suit mobility. A second study, which focused on the implications of the development of the US private space industry on domestic Planetary Protection policy, is also presented. As signatories of the 1967 Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space (commonly known as the Outer Space Treaty), the United States is responsible for implementing Planetary Protection procedures designed to prevent biological contamination of the Solar System, as well as contamination of the Earth by any samples returned from extra-terrestrial bodies. NASA has established policies and procedures to comply with this treaty, and has successfully policed itself independently and autonomously since the signing of the treaty. However, for the first time in the history of the American space program, private entities outside of NASA have developed the capability and interest to send objects into space and beyond Earth orbit, and no current protocol exists to guarantee these profit-minded entities comply with US Planetary Protection obligations (a costly and time-consuming process). This thesis presents a review of US Planetary Protection obligations, including NASA's procedures and infrastructure related to Planetary Protection, and based on these current protocols provides policy architecture recommendations for the emerging commercial spaceflight industry. It was determined that the most effective policy architecture for ensuring public and private compliance with Planetary Protection places NASA in control of all domestic Planetary Protection matters, and in this role NASA is charged with overseeing, supporting, and regulating the private spaceflight industry. The underlying analysis and architecture tradeoffs that led to this recommendation are presented and discussed.
Download or read book Engineering a Robotic Exoskeleton for Space Suit Simulation written by Forrest Edward Meyen and published by . This book was released on 2013 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel methods for assessing space suit designs and human performance capabilities are needed as NASA prepares for manned missions beyond low Earth orbit. Current human performance tests and training are conducted in space suits that are heavy and expensive, characteristics that constrain possible testing environments and reduce suit availability to researchers. Space suit mock-ups used in planetary exploration simulations are light and relatively inexpensive but do not accurately simulate the joint stiffness inherent to space suits, a key factor impacting extravehicular activity performance. The MIT Man-Vehicle Laboratory and Aurora Flight Sciences designed and built an actively controlled exoskeleton for space suit simulation called the Extravehicular Activity Space Suit Simulator (EVA S3), which can be programmed to simulate the joint torques recorded from various space suits. The goal of this research is to create a simulator that is lighter and cheaper than a traditional space suit so that it can be used in a variety of testing and training environments. The EVA S3 employs pneumatic actuators to vary joint stiffness and a pre-programmed controller to allow the experimenter to apply torque profiles to mimic various space suit designs in the field. The focus of this thesis is the design, construction, integration, and testing of the hip joint and backpack for the EVA S3. The final designs of the other joints are also described. Results from robotic testing to validate the mechanical design and control system are discussed along with the planned improvements for the next iteration of the EVA S3. The fianl EVA S3 consists of a metal and composite exoskeleton frame with pneumatic actuators that control the resistance of motion in the ankle, knee, and hip joints, and an upper body brace that resists shoulder and elbow motions with passive spring elements. The EVA S3 is lighter (26 kg excluding the tethered components) and less expensive (under $600,000 including research, design, and personnel) than a modem space suit. Design adjustments and control system improvements are still needed to achieve a desired space suit torque simulation fidelity within 10% root-mean-square error.
Download or read book Innovative Hand Exoskeleton Design for Extravehicular Activities in Space written by Pierluigi Freni and published by Springer. This book was released on 2014-06-23 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental conditions and pressurized spacesuits expose astronauts to problems of fatigue during lengthy extravehicular activities, with adverse impacts especially on the dexterity, force and endurance of the hands and arms. A state-of-the-art exploration in the field of hand exoskeletons revealed that available products are unsuitable for space applications because of their bulkiness and mass. This book proposes a novel approach to the development of hand exoskeletons, based on an innovative soft robotics concept that relies on the exploitation of electroactive polymers operating as sensors and actuators, on a combination of electromyography and mechanomyography for detection of the user’s will and on neural networks for control. The result is a design that should enhance astronauts’ performance during extravehicular activities. In summary, the advantages of the described approach are a low-weight, high-flexibility exoskeleton that allows for dexterity and compliance with the user’s will.
Download or read book Engineering Design Study of a Space Suit with an Integrated Environmental Control System written by Douglas C. Howard and published by . This book was released on 1968 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Equipotential Space suit Design Concept and Its Application to a Space suit Elbow Joint written by Donald E. Barthlome and published by . This book was released on 1969 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Space Suit Simulator for Partial Gravity Extravehicular Activity Experimentation and Training written by Andrea Lynn Gilkey and published by . This book was released on 2012 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: During human space exploration, mobility is extremely limited when working inside a pressurized space suit. Astronauts perform extensive training on Earth to become accustomed to space suit-imposed high joint torques and limited range of motion. Space suit experimentation is difficult for researchers because the current suit is expensive, bulky, heavy, hard to don/doff, and in very short supply. The main objective of this thesis is to develop a wearable space suit simulator (S3) exoskeleton that can mimic the joint torques and reduced mobility of various pressurized space suit designs. A space suit simulator exoskeleton is a novel method for simulating joint torques while offering a lightweight, portable, and easily accessible design. This thesis describes early work towards development of the S3 exoskeleton. A space suit joint database was developed, which includes joint torque and angle range of motion information for multiple pressurized space suits, degrees of freedom, and pressurization levels. The space suit joint database was used to set the joint torque and angle range of motion requirements for the S3 exoskeleton. Additionally, various actuators that have been used in previous exoskeleton designs were compared according to weight and bulk characteristics to select actuators for the S3 exoskeleton. The conceptual designs of the S3 knee and hip components are presented. Finally, the S3 computer simulation is described, which allows users to input the geometries and locations of the S3 exoskeleton components. The computer simulation outputs the space suit hysteresis curves to compare S3 joint design performance to actual space suit performance. Feasible design solutions for the S3 exoskeleton joints can be determined from designs that minimize the root-mean-square error of the hysteresis curves.
Download or read book Kinematic Analysis and Joint Hysteresis Modeling for a Lower body Exoskeleton style Space Suit Simulator written by Anthony J. Nejman and published by . This book was released on 2011 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mechanical exoskeleton has the capacity to replicate the properties of a pressurized space suit with regards to motion resistance. Using such an exoskeleton for ground based mission training and research provides a lower-cost, less operationally-complex alternative to using a space suit. To that end, NASA is supporting the development of such a device, termed a Space Suit Simulator (S3). The S3 must be designed to allow the wearer the same range of motion allowed in a space suit, and the joints must be actuated to produce the experienced resistive torques. The challenge moving forward is to develop a lower limb (ankle, knee, hip) exoskeleton and then a whole-body exoskeleton that includes multiple interconnected joints with some joints having multiple degree-of-freedom, such as the hip and shoulder. A kinematic design of the lower-body exoskeleton was developed by using Denavit-Hartenberg notation and transformation matrices to derive the Jacobian matrix, which was in turn used to develop a method of testing for singular configurations along a given path of motion. The S3 was tested for singularities while operating through a standard walking gait cycle, and no singularities were uncovered. Translational manipulability of the S3 end effector was analyzed at near-singular configurations along the gait cycle to determine directions of motion which may result in increased joint torques or loss of freedom of motion. A graphical representation of the leg and S3 end effector workspace verified that the S3 allows the human leg to move within the operational envelope anticipated during space suit use. The four degree-of-freedom exoskeleton design eliminates constrictive singularities by aligning human and exoskeleton joint axes. A computational algorithm, based on the Preisach hysteresis model, was used to mimic space suit joint hysteresis behavior in knee flexion and hip abduction/adduction, and it was demonstrated that linear actuators may be used to produce the required joint torque resistance. The kinematic design and computational hysteresis algorithms will support the further development of a physical space suit simulator.
Download or read book Design of a Lower Extremity Exoskeleton to Increase Knee ROM During Valgus Bracing for Osteoarthritic Gait written by Jennifer M. Cao and published by . This book was released on 2017 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knee osteoarthritis (KOA) is the primary cause of chronic immobility in populations over the age of 65. It is a joint degenerative disease in which the articular cartilage in the knee joint wears down over time, leading to symptoms of pain, instability, joint stiffness, and misalignment of the lower extremities. Without intervention, these symptoms gradually worsen over time, decreasing the overall knee range of motion (ROM) and ability to walk. Current clinical interventions include offloading braces, which mechanically realign the lower extremities to alleviate the pain experienced in the medial compartment of the knee joint. Though these braces have proven effective in pain management, studies have shown a significant decrease in knee ROM while using the brace. Concurrently, development of active exoskeletons for rehabilitative gait has increased within recent years in efforts to provide patients with a more effective intervention for dealing with KOA. Though some developed exoskeletons are promising in their efficacy of fostering gait therapy, these devices are heavy, tethered, difficult to control, unavailable to patients, or costly due to the number of complicated components used to manufacture the device. However, the idea that an active component can improve gait therapy for patients motivates this study. This study proposes the design of an adjustable lower extremity exoskeleton which features a single linear actuator adapted onto a commercially available offloading brace. This design hopes to provide patients with pain alleviation from the brace, while also actively driving the knee through flexion and extension. The design and execution of this exoskeleton was accomplished by 3D computer simulation, 3D CAD modeling, and rapid prototyping techniques. The exoskeleton features 3D printed, ABS plastic struts and supports to achieve successful adaptation of the linear actuator to the brace and an electromechanical system with a rechargeable operating capacity of 7 hours. Design validation was completed by running preliminary gait trials of neutral gait (without brace or exoskeleton), offloading brace, and exoskeleton to observe changes between the different gait scenarios. Results from this testing on a single subject show that there was an observed, significant decrease in average knee ROM in the offloading brace trials from the neutral trials and an observed, significant increase in average knee ROM in the exoskeleton trials when compared to the brace trials as hypothesized. Further evaluation must be completed on the clinical efficacy of this device with a larger, and clinically relevant sample size to assess knee ROM, pain while using the device, and overall comfort level. Further development of this design could focus on material assessment, cost analysis, and risk mitigation through failure mode analysis.
Download or read book Mechanical Counter pressure Space Suit Design Using Active Materials written by Bradley Thomas Holschuh and published by . This book was released on 2014 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical counter-pressure (MCP) space suits have the potential to greatly improve the mobility of astronauts as they conduct planetary exploration activities; however, the underlying technologies required to provide uniform compression in an MCP garment at sucient pressures (29.6 kPa) for space exploration have not yet been demonstrated, and donning and dong of such a suit remains a signicant challenge. This research effort focuses on the novel use of active material technologies to produce a garment with controllable compression capabilities to address these problems. We the describe the modeling, development, and testing of low spring index (C = 3) nickel titanium (NiTi) shape memory alloy (SMA) coil actuators designed for use in wearable compression garments. Several actuators were manufactured, annealed, and tested to assess their de-twinning and activation characteristics. We then describe the derivation and development of a complete two-spring model to predict the performance of hybrid compression textiles combining passive elastic fabrics and integrated SMA coil actuators based on 11 design parameters. Design studies (including two specifically tailored for MCP applications) are presented using the derived model to demonstrate the range of possible garment performance outcomes based on strategically chosen SMA and material parameters. Finally, we present a novel methodology for producing modular 3D-printed SMA actuator cartridges designed for use in compression garments, and test 5 active tourniquet prototypes (made using these cartridges and commercially available fabrics) to assess the eect of SMA actuation on the tourniquet compression characteristics. Our results demonstrate that hybrid active tourniquet prototypes are highly effective, with counter-pressures increasing by an average of 81.9% when activated (taking an average of only 23.7 seconds to achieve steady state). Maximum average counter-pressures reached 34.3 kPa, achieving 115.9% of the target MCP counter-pressure. We observed signicant spatial variability in the active counter-pressure profiles, stemming from high friction, asymmetric fabric stretching, and near-field pressure spikes/voids caused by the SMA cartridge. Modifications to reduce tourniquet friction were effective at mitigating a proportion of this variability. System performance and repeatability were found to depend heavily on the passive fabric characteristics, with performance losses attributable to irrecoverable fabric strain, degradation in fabric elastic modulus, and non-linear modulus behavior. The results of this research open the door to new opportunities to advance the field of MCP spacesuit design, as well as opportunities to improve compression garments used in healthcare therapies, competitive athletics, and battlefield medicine.
Download or read book Evaluation of the Mark III Spacesuit written by Conor Ryan Cullinane and published by . This book was released on 2018 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spacesuit Assemblies (SSAs) provide life support for human operators performing extravehicular activities (EVAs). The overall goal of this research was to investigate three research questions to address gaps in the field of spacesuit assembly (SSA) evaluations: [1] What are the mobility and agility limitations causing operators to experience performance decrements when wearing a SSA?; [2] What is causing operators to experience increased joint torques?; and [3] How does the distributed weight of an SSA, transferred to the operator, affect performance? This research leveraged both experimental and computational modeling capabilities to evaluate SSAs with a human-centered focus, in ways previously unachievable. The space suit evaluated for this research was NASA's Mark III (MkIII) Planetary Technology Demonstrator SSA, built to test the next generation in planetary exploration capabilities, improving upon Apollo era technology. The hip brief assembly (HBA) is built with three nested bearings, each with a single rotational degree of freedom that together provide the range of motion, walking efficiency, and kneeling capabilities. An initial investigation, combining a pilot study and supporting modeling, revealed limitations in the current human-SSA system that may impair the operator's mobility/stability and agility. Limitations identified and investigated in this thesis include SSA degrees of freedom (DOFs), the SSA range of motion (ROM) envelope, the bearing resistances, the SSA component's inertial effects, the SSA mass load transfer dynamics, and suit fit. The SSA architecture was modeled as part of the thesis, creating a tool that was useful in the investigation of the human-suit system. The model relied on SSA component geometries and inherent mass/inertia and bearing resistance characteristics to output joint dynamics, rather than requiring those dynamics as an input (which would require extensive experimental setups). The model was used to isolate components that contribute to the measured operator performance degradations and to quantify the extent of their contributions. These investigations lead to suggestions for design requirements and evaluation techniques that can guide future SSA development and evaluations.
Download or read book On the Deformation of Human Skin for Mechanical Counter Pressure Space Suit Development written by Edward William Obropta (Jr.) and published by . This book was released on 2015 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploration of planetary bodies requires space suits that do not inhibit astronaut mobility. Gas pressurized suits are typically bulky and stiff to operate or require unnatural human motion. Development of mechanical counter pressure (MCP) space suits can change the current space suit design paradigm. The primary goal of this thesis is to develop methodology to quantify strain and deformation of human skin to inform how to make a MCP space suit, or second skin, that maximizes mobility and minimizes human energy expenditure. Specific emphasis was placed on joint mobility, therefore, the Lines of Non-Extension (LoNE) was investigated in detail throughout the deformation of the human elbow joint. This goal was driven by three research objectives: develop a system to measure human skin deformation and strain, develop a rigorous method to compute LoNE, and examine the variation of skin strain between multiple subjects. The contributions of this thesis are the development of a multi-camera system to measure skin deformation at 1 mm2, a streamline approach for calculating LoNE, strain data at the elbow joint and a methodology moving forward to measure more sections of the human body. The results from the six subjects showed that skin deformation can be similar in magnitude between subjects of varying anthropometrics, but the principal strain directions and LoNE maps can vary. The elbow data was flattened to 2D and normalized by anthropometrics to allow comparisons between subjects. This skin deformation data informs material selection, material placement, and suit patterning. This data is relevant to any compression garment or device that interacts with human skin.
Download or read book Wearable Robots written by José L. Pons and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wearable robot is a mechatronic system that is designed around the shape and function of the human body, with segments and joints corresponding to those of the person it is externally coupled with. Teleoperation and power amplification were the first applications, but after recent technological advances the range of application fields has widened. Increasing recognition from the scientific community means that this technology is now employed in telemanipulation, man-amplification, neuromotor control research and rehabilitation, and to assist with impaired human motor control. Logical in structure and original in its global orientation, this volume gives a full overview of wearable robotics, providing the reader with a complete understanding of the key applications and technologies suitable for its development. The main topics are demonstrated through two detailed case studies; one on a lower limb active orthosis for a human leg, and one on a wearable robot that suppresses upper limb tremor. These examples highlight the difficulties and potentialities in this area of technology, illustrating how design decisions should be made based on these. As well as discussing the cognitive interaction between human and robot, this comprehensive text also covers: the mechanics of the wearable robot and it’s biomechanical interaction with the user, including state-of-the-art technologies that enable sensory and motor interaction between human (biological) and wearable artificial (mechatronic) systems; the basis for bioinspiration and biomimetism, general rules for the development of biologically-inspired designs, and how these could serve recursively as biological models to explain biological systems; the study on the development of networks for wearable robotics. Wearable Robotics: Biomechatronic Exoskeletons will appeal to lecturers, senior undergraduate students, postgraduates and other researchers of medical, electrical and bio engineering who are interested in the area of assistive robotics. Active system developers in this sector of the engineering industry will also find it an informative and welcome resource.
Download or read book Backpacker written by and published by . This book was released on 2004-03 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Backpacker brings the outdoors straight to the reader's doorstep, inspiring and enabling them to go more places and enjoy nature more often. The authority on active adventure, Backpacker is the world's first GPS-enabled magazine, and the only magazine whose editors personally test the hiking trails, camping gear, and survival tips they publish. Backpacker's Editors' Choice Awards, an industry honor recognizing design, feature and product innovation, has become the gold standard against which all other outdoor-industry awards are measured.
Download or read book Interactive Aerospace Engineering and Design written by Dava J. Newman and published by McGraw-Hill Companies. This book was released on 2002 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text contains an integrated bound-in CD-ROM, and has a strong emphasis on design. Its active visual approach and inclusion of space-orientated engineering make it an interesting examination of the aerospace engineering field.
Download or read book After LM written by John F. Connolly and published by . This book was released on 2020 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wearable Robotics written by Jacob Rosen and published by Academic Press. This book was released on 2019-11-16 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wearable Robotics: Systems and Applications provides a comprehensive overview of the entire field of wearable robotics, including active orthotics (exoskeleton) and active prosthetics for the upper and lower limb and full body. In its two major sections, wearable robotics systems are described from both engineering perspectives and their application in medicine and industry. Systems and applications at various levels of the development cycle are presented, including those that are still under active research and development, systems that are under preliminary or full clinical trials, and those in commercialized products. This book is a great resource for anyone working in this field, including researchers, industry professionals and those who want to use it as a teaching mechanism. Provides a comprehensive overview of the entire field, with both engineering and medical perspectives Helps readers quickly and efficiently design and develop wearable robotics for healthcare applications
