Design of an under-actuated wrist based on adaptive synergies

An effective robotic wrist represents a key enabling element in robotic manipulation, especially in prosthetics. In this paper, we propose an under-actuated wrist system, which is also adaptable and allows to implement different under-actuation schemes. Our approach leverages upon the idea of soft synergies - in particular the design method of adaptive synergies - as it derives from the field of robot hand design. First we introduce the design principle and its implementation and function in a configurable test bench prototype, which can be used to demonstrate the feasibility of our idea. Furthermore, we report on results from preliminary experiments with humans, aiming to identify the most probable wrist pose during the pre-grasp phase in activities of daily living. Based on these outcomes, we calibrate our wrist prototype accordingly and demonstrate its effectiveness to accomplish grasping and manipulation tasks

Artificial Intelligence and Ambient Intelligence

This book includes a series of scientific papers published in the Special Issue on Artificial Intelligence and Ambient Intelligence at the journal Electronics MDPI. The book starts with an opinion paper on “Relations between Electronics, Artificial Intelligence and Information Society through Information Society Rules”, presenting relations between information society, electronics and artificial intelligence mainly through twenty-four IS laws. After that, the book continues with a series of technical papers that present applications of Artificial Intelligence and Ambient Intelligence in a variety of fields including affective computing, privacy and security in smart environments, and robotics. More specifically, the first part presents usage of Artificial Intelligence (AI) methods in combination with wearable devices (e.g., smartphones and wristbands) for recognizing human psychological states (e.g., emotions and cognitive load). The second part presents usage of AI methods in combination with laser sensors or Wi-Fi signals for improving security in smart buildings by identifying and counting the number of visitors. The last part presents usage of AI methods in robotics for improving robots’ ability for object gripping manipulation and perception. The language of the book is rather technical, thus the intended audience are scientists and researchers who have at least some basic knowledge in computer science

Proceedings of the NASA Conference on Space Telerobotics, volume 4

Papers presented at the NASA Conference on Space Telerobotics are compiled. The theme of the conference was man-machine collaboration in space. The conference provided a forum for researchers and engineers to exchange ideas on the research and development required for the application of telerobotic technology to the space systems planned for the 1990's and beyond. Volume 4 contains papers related to the following subject areas: manipulator control; telemanipulation; flight experiments (systems and simulators); sensor-based planning; robot kinematics, dynamics, and control; robot task planning and assembly; and research activities at the NASA Langley Research Center

Soft pneumatic actuators: a review of design, fabrication, modeling, sensing, control and applications

Soft robotics is a rapidly evolving field where robots are fabricated using highly deformable materials and usually follow a bioinspired design. Their high dexterity and safety make them ideal for applications such as gripping, locomotion, and biomedical devices, where the environment is highly dynamic and sensitive to physical interaction. Pneumatic actuation remains the dominant technology in soft robotics due to its low cost and mass, fast response time, and easy implementation. Given the significant number of publications in soft robotics over recent years, newcomers and even established researchers may have difficulty assessing the state of the art. To address this issue, this article summarizes the development of soft pneumatic actuators and robots up until the date of publication. The scope of this article includes the design, modeling, fabrication, actuation, characterization, sensing, control, and applications of soft robotic devices. In addition to a historical overview, there is a special emphasis on recent advances such as novel designs, differential simulators, analytical and numerical modeling methods, topology optimization, data-driven modeling and control methods, hardware control boards, and nonlinear estimation and control techniques. Finally, the capabilities and limitations of soft pneumatic actuators and robots are discussed and directions for future research are identified

Small business innovation research. Abstracts of completed 1987 phase 1 projects

Non-proprietary summaries of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA in the 1987 program year are given. Work in the areas of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robotics, computer sciences, information systems, spacecraft systems, spacecraft power supplies, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered

Vibration reponse analysis in orthopaedics and its application at the lumbar spine

Vibration response analysis has been carried out on human lumbar spines in-vitro and in-vivo. Random vibration in the frequency range between 20 Hz and 2 kHz was applied to the L5 spinous process in the antero-posterior direction while motion response was measured at the other spinous processes of the lumbar spine. Transfer mobility which defines the lumbar spine's motion response to vibratory force was evaluated by using the fast Fourier transform and spectral averaging technique. There was high damping during the in-vitro tests and the lumbar spine was found to behave as a segmented beam hinged at the thoracic and sacral ends. Fundamental mode shape was observed at frequencies lower than 150 Hz and this pattern was also observed with simulated fusion of the facet joints and interbody fusion. Mobility summated for the whole range of frequency could be modelled by an exponential expression. Useful parameters have been identified and they were found to relate to the lumbar spine's vibratory characteristics resulting from structural modifications. Vibration testing performed on normal subjects revealed that a relaxed lumbar spine was highly damped and non-resonant. First flexural vibration mode was observed only under the action of the back extensors. Averaged figures have been established for the coefficients of an exponential expression which fits closely to the summated mobility curve. The mobility and its attenuation coefficients in different frequency bands have been evaluated from twelve normal subjects. Localized attenuation of vibration response and the reduction in mobility were observed on a patient with osteoporotic lumbar spine. Mobility in the low frequencies was reduced while the medium and high band mobility were enhanced in patients with postero-lateral fusion and instrumentation for fixation of the lumbar spine. The attenuation pattern of these patients was consistent, and corresponded to the existence of structural enhancement.Vibration response analysis has been carried out on human lumbar spines in-vitro and in-vivo. Random vibration in the frequency range between 20 Hz and 2 kHz was applied to the L5 spinous process in the antero-posterior direction while motion response was measured at the other spinous processes of the lumbar spine. Transfer mobility which defines the lumbar spine's motion response to vibratory force was evaluated by using the fast Fourier transform and spectral averaging technique. There was high damping during the in-vitro tests and the lumbar spine was found to behave as a segmented beam hinged at the thoracic and sacral ends. Fundamental mode shape was observed at frequencies lower than 150 Hz and this pattern was also observed with simulated fusion of the facet joints and interbody fusion. Mobility summated for the whole range of frequency could be modelled by an exponential expression. Useful parameters have been identified and they were found to relate to the lumbar spine's vibratory characteristics resulting from structural modifications. Vibration testing performed on normal subjects revealed that a relaxed lumbar spine was highly damped and non-resonant. First flexural vibration mode was observed only under the action of the back extensors. Averaged figures have been established for the coefficients of an exponential expression which fits closely to the summated mobility curve. The mobility and its attenuation coefficients in different frequency bands have been evaluated from twelve normal subjects. Localized attenuation of vibration response and the reduction in mobility were observed on a patient with osteoporotic lumbar spine. Mobility in the low frequencies was reduced while the medium and high band mobility were enhanced in patients with postero-lateral fusion and instrumentation for fixation of the lumbar spine. The attenuation pattern of these patients was consistent, and corresponded to the existence of structural enhancement

Fourth Annual Workshop on Space Operations Applications and Research (SOAR 90)

The proceedings of the SOAR workshop are presented. The technical areas included are as follows: Automation and Robotics; Environmental Interactions; Human Factors; Intelligent Systems; and Life Sciences. NASA and Air Force programmatic overviews and panel sessions were also held in each technical area

Engineering Dynamics and Life Sciences

From Preface: This is the fourteenth time when the conference “Dynamical Systems: Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and Ministry of Science and Higher Education of Poland. It is a great pleasure that our invitation has been accepted by recording in the history of our conference number of people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to participate in the conference for the first time. With proud and satisfaction we welcomed over 180 persons from 31 countries all over the world. They decided to share the results of their research and many years experiences in a discipline of dynamical systems by submitting many very interesting papers. This year, the DSTA Conference Proceedings were split into three volumes entitled “Dynamical Systems” with respective subtitles: Vibration, Control and Stability of Dynamical Systems; Mathematical and Numerical Aspects of Dynamical System Analysis and Engineering Dynamics and Life Sciences. Additionally, there will be also published two volumes of Springer Proceedings in Mathematics and Statistics entitled “Dynamical Systems in Theoretical Perspective” and “Dynamical Systems in Applications”

Implantable Electrodes for Upper Limb Prosthetic Control

This thesis describes a study investigating implantable interfaces with muscles and peripheral nerves. Current prostheses for upper limb amputees do not provide intuitive control over hand, wrist and elbow motion. By implanting electrodes for recording and stimulating onto muscles and into nerves in the amputation stump a greater number of control signals may be made available, signals which will be used to control dextrous hand movements. An implantable epimysial interface was developed using a bone-anchored device to hard-wire signals across the skin barrier. In a single ovine model pilot study the bone-anchor was implanted transtibially and the epimysial electrode was place superficially to m. peroneus teritus. Physiological signals were obtained over 12 weeks during treadmill walking. The external connector on the bone-anchor failed at 12 weeks, correlating with a drop in signal quality in an otherwise robust interface integrated with bone and skin tissue. The ovine bone-anchor model was repeated in 6 sheep for 19 weeks, with epimysial recordings made regularly. Increasing signal quality was seen during the study and was significantly greater from implanted electrodes compared with skin surface electrodes at 19 weeks (p = 0.016). Some complications with skin-implant integration were observed in proximally located implants. Crosstalk between muscles was assessed using pre-terminal nerve stimulation, and was found to be dependent upon muscle location and innervation. The ovine m. peroneus teritus model was used to assess recovery following targeted muscle reinnervation. Muscle signal recovery was observed approximately one month after surgery correlating with the start of functional recovery (assessed by force plate analysis). These studies indicate that a suitably modified bone-anchored device may be suitable for signal transmission in human patients, providing a stable, long-term solution to both prosthesis attachment and control. The potential of nerve interfaces for prosthetic control was investigated. The microchannel neural interface (MNI) was chosen because it overcomes limitations with other neural microarray designs: signal strength; cross-talk, and the locations of Nodes of Ranvier. MNIs confine regenerating nerves to small, ∼ 100 µm diameter, insulating tubes, this increases the length within which nerve signals can be recorded and amplifies the recorded signals. However, in vivo MNIs can become occluded by fibrosis that reduces or prevents axon regeneration. Two in vitro studies of neurocompatibility were carried out to investigate strategies for improving axon regeneration within microchannels. The first in vitro study compared the effect of different adsorbed endoneurial basement membrane proteins on PC-12 cell neurite extension on silicone substrates. The optimal protein coating concentrations for poly-D-lysine, collagen-IV and laminin-2,(-4) were determined. The optimal concentrations were compared with mixtures of basement membrane proteins, the effect of mixture coating order and constitution were investigated. It was found that endoneurial BM proteins significantly enhance neurite outgrowth compared with controls. Two coatings were suggested as most suited for improving neural regeneration within microchannels: a single layer coating of 10 µg/cm2 collagen-IV; and a mixed coating of 10 µg/cm2 collagen-IV, 1 µg/cm2 laminin-2,(-4), and 0.175 µg/cm2 nidogen-1. The second in vitro study investigated the effect of grooved, roughened and multi-scale silicone surfaces on on PC-12 cell neurite extension. Deeper, narrower grooves were shown to increase the extent of neurite alignment, while resulting in fewer, longer, neurites. Roughening surfaces was shown to increase the amount of protein (collagen-IV) which adsorbed from solution and increase the number of neurites each cell extended. Surfaces with multiscale topographies synergistically increased the number and length of neurites and guided neurite growth along the groove direction. MNIs were manufactured for in vivo testing. These MNIs were used to determine the effect of adsorbed endoneurial basement membrane proteins on nerve regeneration in vivo, but the multiscale topographies were not applied during manufacturing. Four alternative manufacturing methods were investigated and iterative improvements were made to create a stacked interface with multiple microchannel layers. Microchannel layers were created by laser patterning silicone and metal foil components, followed by plasma bonding to create a 3-dimensional structure with 150 µm deep, 200 µm wide microchannels. Electrode impedances of 27.2 ± 19.8 kΩ at 1kHz were achieved by DC etching. The method overcomes some current limitations on electrode connectivity and microchannel sealing, and may improve recording capabilities over single layer designs by increasing the ratio of electrodes to microchannels. Manufactured MNIs were tested in a rat sciatic nerve transection model. Following implantation nerves were allowed to regenerate for one and two months. First, suture and fibrin glue were compared as MNI fixation methods for one month, the nerve regenerated within the fibrin glue, outside the interface lumen, therefore sutures were chosen as a long term fixation method. The influence of endoneurial basement membrane protein coatings, identified previously, on nerve regeneration with MNIs was investigated. Nerves regenerated through the MNIs over two months and began to reinnervate the distal limb. Improvements in the sciatic function index were observed over two months, with no significant differences between protein coated and control interfaces. Some weak histological evidence for the use of protein coatings was found, with axon diameters increased distal to protein coated MNIs. Electromyographic and electroneurographic recordings demonstrated similar signal amplitudes to previous studies. In order to bring the research described in this thesis to clinical practice further engineering improvements to the design and manufacture of electrodes, which utilise materials or coatings to enhance neurocompatibility, is required. Avenues for further research are discussed and additional experiments and investigations are described. By combining developments in implantable muscle and nerve interfaces with surgical techniques and improvements in neurocompatibility the promise of upper limb prosthetic control may be realised

Proceedings of the NASA Conference on Space Telerobotics, volume 1

The theme of the Conference was man-machine collaboration in space. Topics addressed include: redundant manipulators; man-machine systems; telerobot architecture; remote sensing and planning; navigation; neural networks; fundamental AI research; and reasoning under uncertainty