This paper addresses the iterative tuning method of PID control for the robot manipulator based on the responses of the closed loop system. Several properties of the robot control are used, such as any PD control can stabilize a robot in regulation case, the colsed-loop system of PID control can be approximated by a linear system, and the control torque to the robot manipulator is linearly independent of the robot dynamic. By using these properties, a novel systematic turning method for the PID control is proposed. Simulations and experimental results of an upper limb exoskeleton give validation of this PID tuning method.

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Imagine a world where orthotics are not simple passive supports for physically challenged people, but rather highly cooperative, smart devices. They are lightweight and simple to don and doff, respond to the user’s intent and enable normal healthy limb like use. They can help users relearn natural movement pathways following stroke and injury, or provide exercise tailored to the user’s specific disabilities. A new generation of soft and active orthotics is proposed for a broad range of applications in physical therapy and rehabilitation. As part of the AIP SPS funded project, we began development of such orthopedic braces through physics based biomechanical simulation, human subject experiments, data analysis and experimentation with a biologically-inspired shoulder-arm model and a preliminary sensor network. A joint work with collaborators at the Harvard University shows that the proposed braces can be successfully actuated with biologically-realistic forces [1]. Furthermore, our recent results demonstrate that arm angular position can be accurately estimated with inexpensive, piezoelectric flex sensors embedded in the brace.

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Fatigue induces changes to running form; therefore movement is not as effective or efficient. Reducing the amount of fatigue or its effects on form would be ideal to improve performance while running. Compressive clothing has unknown effects on musculature, however it claims to reduce fatigue. The aim of this study was to see the changes in running form while running to exhaustion and to see how compression tights can effect these changes. Eleven runners ran at their current five-kilometer race pace on a treadmill to voluntary exhaustion in a repeated measures design wearing compression tights and regular shorts while their kinematics, kinetics, heart rate and rate of perceived exhaustion were recorded. There was not a significant difference in time to exhaustion. Fatigue general effects were significant from beginning to end in knee and ankle angle at initial contact with the knee becoming less extended and the ankle less dorsiflexed. Vertical ground reaction loading rate and impact peak were significantly different from beginning to mid point and beginning to end across conditions. Heart rate and rate of perceived exertion increased significantly with fatigue as well in both conditions. Condition effects were significant in stride length and rate with a decreased stride length with compression tights and an increased stride rate with compression tights. The hip experienced a decreased range of motion in the compression tights compared to running shorts. These results indicate that there are effects of fatigue on performance and differences between conditions. These differences did not affect the overall outcome of run as measured in time to exhaustion.

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An exoskeleton is a distinctive kind of robot to be worn as an overall, effectively supporting or, in some cases substituting for, the user’s own movements. The development of exoskeletons can lead to important changes in the rehabilitation of disabled people by introducing an alternative to wheelchairs. Exoskeletons can be an efficient tool in gait re-education and in the restoration of upper limb functions, and they can support therapists and caregivers in tasks that require major physical effort. The functionality of exoskeleton can easily be extended by a “disabled person integrated IT environment”, described by authors. Exoskeletons can also be easily adapted to the needs of severely ill or aged people.

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The convergence of haptic technology with the understanding of human perception is opening new possibilities for immersive virtual experiences. This work addresses the role of haptics in the design of systems for supporting embodiment in virtual and real environments. The paper presents haptic interfaces for embodiment by analyzing them in terms of the three main feedback types: proprioceptive, kinesthetic and tactile. Each category is discussed by first analyzing embodiment requirements and then the available haptic technology. This review is closed by some considerations in the domain of capturing and encoding for covering the whole embodiment pipeline.

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