During gradual speed changes, humans exhibit a sudden discontinuous switch from walking to running at a specific speed, and it has been suggested that different gaits may be associated with different functioning of neuronal networks. Here we recorded the EMG activity of leg muscles at slow increments and decrements in treadmill belt speed and at different levels of body weight unloading. In contrast to normal walking at 1 g, at lower levels of simulated gravity (<0.4 g) the transition between walking and running was generally gradual, without systematic abrupt changes in either intensity or timing of EMG patterns. This phenomenon depended to a limited extent on the gravity simulation technique, though the exact level of the appearance of smooth transitions (0.4-0.6 g) tended to be lower for the vertical than for the tilted body weight support system. Furthermore, simulations performed with a half-center oscillator neuromechanical model showed that the abruptness of motor patterns at gait transitions at 1 g could be predicted from the distinct parameters anchored already in the normal range of walking and running speeds, while at low gravity levels the parameters of the model were similar for the two human gaits. A lack of discontinuous changes in the pattern of speed-dependent locomotor characteristics in a hypogravity environment is consistent with the idea of a continuous shift in the state of a given set of central pattern generators rather than the activation of a separate set of central pattern generators for each distinct gait.

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Force-Reflected Telepresence Teleoperation system has been widely used. Generally, force and torque sensors are installed on the robot to realize haptic perception. Control commands and force-reflected information from the robot are transmitted by communication link, such as internet. However, this structure not only brings difficulties of installation and commissioning, but also reduces the system flexibility and makes control more difficult. And it is prone to interfered in microenvironment. This paper presents a new type of energy transfer method to achieve it by power line instead of internet between the Master-slave Manipulators. This method achieves the consistency of force-reflected without using sensors to measure the conditions. In practical application, it requires to design an energy managed controller to insure the stability and obtain precision in synchronization between the master part and slave part. This paper gives the theory, the system structure and control method of force telepresence teleoperation based on power line.

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Assistive devices and exoskeletons have critical importance for people with manipulative and locomotive disabilities. One of the major purposes of such devices when used for lower extremities is to help provide the postural or gait stability of the user. However, current lower extremity exoskeletons available lack the sufficient foot support area to guarantee a safe operation for the rehabilitation of patients, and normal posture/gait for users carrying heavy loads on backpack. As a result, these devices may require an intensive control effort to supply the posture or gait stability and can demand additional therapist help during rehabilitation. In this paper, we proposed a novel adaptive foot system to enhance the required stability of lower extremity exoskeletons as an add-on device. The method essentially aims to automatically extend the support area behind the heel during walking. The proposed adaptive foot system can extend passively during stance and retract during the toe rocker phase, which allows increased support areas during stance and prevent collisions to the level ground during swing. It is practical to implement and can be employed without necessitating an actuation power. The proposed wearable system will particularly be valuable in rehabilitation for enhancing the stability where safety of patients is particularly critical. It is also anticipated that the system can be a complementary device for current exoskeletons or humanoid robots to enhance their stability. A detailed description and numerical analysis of the stability in sagittal plane is presented for postural and gait cases in this paper. Experiments have been also conducted to prove the effectiveness of the adaptive wearable device for postural and gait stability.

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