Common actuators have important drawbacks for use in an exoskeleton type of rehabilitation (training) robot. Either the actuators are heavy, complex or poor torque sources. A new actuation system is proposed and tested that combines a lightweight joint and a simple structure with adequate torque source quality. It consists of a servomotor, a flexible Bowden cable transmission, and a force feedback loop based on a series elastic element. Measurements show that performance is sufficient for use in a gait rehabilitation robot.

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Ankle exoskeleton with an artificial pneumatic actuator, which is intended for the assistance and enhancement of muscular activity, was developed. In this study, the effectiveness of the system was investigated during plantarflexion motion of ankle joint. To find an effectiveness of the system, the subjects performed maximal voluntary isokinetic plantarflexion contraction on a Biodex-dynamometer. Plantarfexion torque of the ankle joint is assisted by subject’s soleus muscle that is generated when ankle joint do plantarflexion motion. We used the muscular stiffness signal of a soleus muscle for feed-forward control of ankle-foot orthosis as physiological signal. For measurement of this signal, we made the muscular stiffness force sensor. We compared a muscular stiffness force of a soleus muscle between with feed-forward control and without it and a maximal plantarflexion torque between not wearing a ankle-foot orthosis, without feed-forward control wearing it and with feed-forward control wearing it in each ten elderly adults. The experimental result showed that a muscular stiffness force of a soleus muscle with feed-forward control was reduced and plantarflexion torque of an ankle joint only wearing ankle-foot orthosis was reduced but a plantarflexion torque with feed-forward control was increased. The amount of a increasing with feed-forward control is higher than the amount of a decreasing only wearing it. Therefore, we confirmed the effectiveness of the developed ankle-foot orthosis with feed-forward control.

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Robotics is emerging as a promising tool for training of human functional movement. The current research in this area is focused primarily on upper extremity movements. This paper describes novel designs of three lower extremity exoskeletons, intended for gait assistance and training of motor-impaired patients. The design of each of these exoskeletons is novel and different. Force and position sensors on the exoskeleton provide feedback to the user during training. The exoskeletons have undergone limited tests on healthy and stroke survivors to assess their potential for treadmill walking. GBO is a gravity balancing un-motorized orthosis which can alter the gravity acting at the hip and knee joints during swing. ALEX is an actively driven leg exoskeletonwhich can modulate the foot trajectory using motors at the joints. SUE is a bilateral swing-assist un-motorized exoskeleton to propel the leg during gait.

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In this paper, we proposed a novel approach to control the famous PUMA manipulator with an arm exoskeleton which has been developed to enable force-feedback teleoperation and has totally different structures and dimensions from PUMA. We presented the hardware configuration and software implementation of the whole system, and then a particular issue was associated with workspace matching, which proved to be the key step for different structure based master/slave manipulator control. Finally, the conclusion was discussed, as well as the prospect of future work.

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Force feedback from the virtual world can greatly enhance the sense of immersion even for simple applications. The ISU force reflecting exoskeleton enables the user to interact dynamically with simulated environments by providing an electromagnetic haptic interface between the human and the environment. The paper describes the high bandwidth electromagnetic haptic interface and how it has been used to provide the sense of contact in the synthetic environment. The air gap between the magnetics, carried by the robot, and the coils attached to the human’s digits, allows for small relative motion between the human and the robot without affecting the transmission of forces. This flexibility allows the robot to track the human as well as develop appropriate forces from the virtual world. Three different typical synthetic environments are programmed and tested using the ISU force reflecting exoskeleton haptic interface device. The experimental results shows that the magnetic interface gives adequate force levels for perception of virtual objects, enhancing the feeling of immersion in the virtual environment

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