This paper presents the design of ABLE, an anthropomorphic upper limb exoske-leton integrally actuated by highly reversible ball-screw and cable (SCS standing for Screw-and-Cable-System) allowing true joint torque control without force sensor. Their unique kinematics allows their integration in the structure thanks to dedicated mechanical innovations such as the shoulder articulation and the forearm-wrist. The result is an anthropomorphic, lightweight, open architecture which avoids imprisoning the human limb. Applicative projects are briefly presented in: medical rehabilitation, teleoperation and haptics (VR).

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Problem statement: Human arm movement is widely studied nowadays. Some movements of arm are performed frequently in everyday life. Devices that can record the path of movement are important in studying human arm gesture. Approach: This project was performed the five degree-offreedom exoskeleton that was designed and constructed to observe position and orientation values of various movement in x-y-z coordinates of human arm. All joints of the exoskeleton were attached with potentiometers for tracking a human arm trajectory. A dedicated computer with a software application, LabVIEW, obtained the data from arm movement and translated to the end effector coordinate. A calibration method for the exoskeleton was proposed for a particular path, a circle. A value correction for the chosen path was introduced in this calibration process and error of root mean square was used as performance index to measure radial error and geometric error of the exoskeleton. Results: Experiments with a human arm for executing repetitive tasks were performed to study. There were two sets of experiments. With correction factor applied to both experiments, the average Error of Root Mean Square (ERMS) reduced drastically. Conclusion: With the correction factor, this device could use to record particaular movement of human’s arm with small error.

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The goal of this study was to validate the suitability of a novel rotational hydroelastic actuator (rHEA) for use in our new rehabilitation exoskeleton for the upper limbs, the Limpact. The rHEA consists of a rotational hydraulic actuator and a custom-designed symmetric torsion spring in a series-elastic configuration. For rehabilitation therapy and impairment quantification, both compliant impedance control and stiff admittance control modes are possible. In the validation experiments, the torque bandwidth of the rHEA was limited to 18 Hz for a desired 20 N??m reference signal (multisine, constant spectrum) due the transport delays in the long flexible tubes between the valve and cylinder. These transport delays also required changes to existing theoretical models to better fit the models on the measured frequency response functions. The (theoretical) measurable torque resolution was better than 0.01 N ??m and the (validated) delivered torque resolution below 1 N?? m. After the validation experiments, further iterative improvements resulted in a spring design capable of a maximum output torque of 50 N??m with an intrinsic stiffness of 150 N?? m/rad and a slightly higher bandwidth. With the design locked, the maximum measurable isometric torque is 100 N ??m. In conclusion, the rHEA is suitable for upper limb rehabilitation therapy as it matches the desired performance.

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Наука потихоньку догоняет природу, помогая людям возвращаться к нормальной жизни. Ученые из Университета Мичигана (University of Michigan) – Арт Куо (Art Kuo) и Стив Коллинз (Steve Collins) – исследуя проблемы современных протезных систем, пришли к выводу, что наиболее «запущенными» по части удобства для человека являются протезы лодыжки.

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One of the embodiments of the invention is an actuator system for extending and flexing a joint. The actuator system includes a multi-motor assembly for providing a rotational output, a rotary-to-linear mechanism including a screw that accepts the rotational output of the multi-motor assembly and a nut that cooperates with the screw to convert rotational movement of the screw to linear movement of the nut, and a moving rail with a latch that functions to translate linear movement of the nut in both the extension and flexion directions into an extension and flexion of the joint. The actuator has been specifically designed for extending and flexing a joint (such as an ankle, a knee, an elbow, or a shoulder) of a human. The actuator system may, however, be used to move any suitable object through any suitable movement (linear, rotational, or otherwise).

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