Research in robot-assisted gait rehabilitation has seen significant improvements in human-robot interaction, thanks to high performance actuator technologies and dedicated control strategies. In this context we propose a combination of lightweight, intrinsically compliant, high power actuators (pleated pneumatic artificial muscles, PPAMs) with safe and adaptable guidance along a trajectory by means of proxy-based sliding mode control (PSMC). Treadmill walking experiments performed by a healthy subject wearing a powered knee exoskeleton indicate two main challenges: synchronizing the compliant device and the subject, and tuning the control parameters in view of safe guidance. The exoskeleton is able to compliantly guide the test person’s knee along various target trajectories, while ensuring a smooth response to large perturbations.

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We are developing a wearable exoskeleton rotational haptic interface that will fit the human body. First, we developed a force sensor to measure the rotational moment of rotational tasks at the wrist and measured the rotational moment of important tasks. Then, we tried to develop a prototype of the exoskeleton rotational haptic interface.

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Based on pneumatic artificial muscles, the force feedback dataglove is an important interface designed for dexterous manipulations with virtual environments, which provides force display for every segment of the thumb, index and middle finger. The typical mechanism of exoskeleton structure is adopted to allow full range-of-motion of the hand, with the actuator system placed on the forearm. The exoskeleton structure also serves as the hand position measurement function, by integrating non-contact Anisotropic Magneto-resistive sensors. The actuator consists of the pneumatic muscle and brake system. The contracting force of muscle transmitted through the tendon sheath structure is measured by the cantilevered beam sensor installed inside the pedestal. The single PC-based control interface comprises of an industrial computer, pneumatic valves and electronic ISA-bus cards for reading the sensors and implementing pressure control. The grasping force calculated according to the object deformation as well as its modeled compliance is displayed to the finger by regulating the pressure in the muscles based on the isometric characteristics

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The capability of visualising and touching models of new products or new environments is a key factor in the design to production process. Usually this requires the construction of a physical model of the environment but production of the model can be costly and time consuming. Use of CAD packages can assist with the visualisation process, but proprioceptive and tactile sensations are required to augment this and provide the opportunity to feel the object. This work shows design, construction and testing in a virtual world of a generic 18 DOF proprioceptive input and feedback exoskeleton to monitor the motions of the human arm from sternum/spine to wrist and feedback tactile sensation generated during contact within a virtual world. The design is light, comfortable, and easy to wear for long periods providing an almost complete, unhampered range of input options. The proprioceptive inputs are augmented by tactile feedback of contact pressure (8 sensation points) to the upper and lower arm segments and pressure, texture, slip, edges/ridges/corners and thermal parameters to the hand. The paper shows how the input/feedback exoskeleton can be used to explore CAD designs generated in a commercial package (AutoCad) and imparted directly into a virtual world (WorldToolKit) permitting testing of products/processes before production and thereby improving the design-production process through the enhanced used of concurrent engineering techniques

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This paper presents the design of a direct driven under-actuated portable hand exoskeleton for rehabilitation. The design of the proposed Hand EXOskeleton SYStem (HEXOSYS) was driven by multi-objective optimisation strategy and inspiration from the human hand. The optimisation algorithm resulted in the choice of optimum link lengths of the device. The optimisation criteria are based on dexterity, isotropy and exertion of perpendicular forces on the finger digits. Furthermore, a series of experiments on the human hand using appropriate sensory instrumentation guided the selection of actuators thereby resulting in a rehabilitation device which is compatible with the human hand force capabilities. The provision of force as well as position feedback gives quantitative feedback to the therapist and would imply a more efficient rehabilitation process. The first prototype of the device has been designed and realized.

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