Most mobile exoskeletons use DC motors as actuators and batteries as power sources. While DC motor consumes a lot of power and limits the working time of the exoskeleton, it produces large impedance that would cause discomfort and danger to people. Magnetorheological (MR) fluid is a smart fluid that can change its rheological behavior under applied magnetic field. Devices using MR fluids have the benefits of high torque, good controllability, low power requirement, and safety. In this research, we develop a new MR actuator for leg exoskeleton. The MR actuator consists of a DC motor and an MR brake/clutch. When active torque is desired, the DC motor works and the MR actuator functions as a clutch to transfer the torque generated by the motor to the leg; when passive torque is desired, the DC motor is turned off and the MR actuator functions as a brake to provide controllable passive torque. The results show that the adaptive control can track the needed torque/power of the knee joint very well, even under the variation of parameters.

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A modular approach is proposed for controlling a robotic arm exoskeleton used for shoulder rehabilitation. The joints are partitioned into anthropomorphic sets based on the exercise protocol which are then commanded using separate control modules. The controllers run concurrently and can operate in either impedance or admittance mode. The approach is applied to the MGAexoskeleton, and some preliminary experimental results are given for both iso-lateral and functional training exercises.

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Finger impairment following stroke results in significant deficit in hand manipulation and the performance of everyday tasks. Recent advances in rehabilitation robotics have shown improvement in efficacy of rehabilitation. Current devices, however, lack the capacity to accurately interface with the human finger at levels of velocity and torque comparable to the performance of everyday hand manipulation tasks. To fill this need, we have developed the Actuated Finger Exoskeleton (AFX), a three degree-of-freedom robotic exoskeleton for the index finger. This paper outlines the implementation and initial kinematic analysis of the AFX.

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This paper presents advantages of introducing elbow-joints misalignments in an exoskeleton for upper limb rehabilitation. Typicalexoskeletons are characterized by axes of the device as much as possible aligned to the rotational axes of human articulations. This approach leads to advantages in terms of movements and torques decoupling, but can lead to limitations nearby the elbow singular configuration. A proper elbow axes misalignment between the exoskeleton and the human can improve the quality of collaborative rehabilitation therapies, in which a correct torque transmission from human articulations to mechanical joints of the device is required to react to torques generated by the patient.

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This paper presents ABLE, an innovative exoskeleton for the upper limb currently under development at CEA-LIST Interactive Robotics Unit. Its distinctive high performance mechanical transmissions — screw and cable patented arrangement — and its integrated architecture makes it the very first of its category. The first 4 axis model is described here but more complete models are already planned: a 7 axis model as well as portable versions. Its back-drivable, high efficiency, low inertia actuators provide a high capacity (around 40 N continuous effort at the hand) and allow hybrid force-position control without requiring any force sensor. Its first application is currently a research program in rehabilitation (BRAHMA project) and professional use is already in view. Assistance tasks for disabled persons (carrying a bottle) are also typical tasks to be performed by ABLE as well as intuitive telerobotics, haptic device for VR, and sport training, etc. Furthermore, its versatility and simple design allow industrial versions to become soon available.

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