Разработчики экзоскелета для американской армии передали его военным на полевые испытания. Для непосредственного участия в боевых действиях создаваемый корпорацией Lockheed Martin экзоскелет не предназначен.

(далее…)

Категория: HULC | Нет комментариев »

Background: Significant progress has been made towards the clinical application of human-machine interfaces (HMIs) based on elec-tromyographic (EMG) pattern recognition for various rehabilitation purposes. Making this technology practical and available to pati-ents with motor deficits requires overcoming real-world challenges, such as physical and physiological changes, that result in vari-ations in EMG signals and systems that are unreliable for long-term use. In this study, we aimed to address these challenges by investigating the stability of time-domain EMG features during changes in the EMG signals and identifying the feature sets that would provide the most robust EMG pattern recognition. Methods: Variations in EMG signals were introduced during physical experi-ments. We identified three disturbances that commonly affect EMG signals: EMG electrode location shift, variation in muscle contrac-tion effort, and muscle fatigue. The impact of these disturbances on individual features and combined feature sets was quantified by changes in classification performance. The robustness of feature sets was evaluated by a stability index developed in this study. Results: Muscle fatigue had the smallest effect on the studied EMG features, while electrode location shift and varying effort le-vel significantly reduced the classification accuracy for most of the features. Under these disturbances, the most stable EMG fea-ture set with combination of four features produced at least 16.0% higher classification accuracy than the least stable set. EMG autoregression coefficients and cepstrum coefficients showed the most robust classification performance of all studied time-domain features. Conclusions: Selecting appropriate EMG feature combinations can overcome the impact of the studied disturbances on EMG pattern classification to a certain extent; however, this simple solution is still inadequate. Stabilizing electrode contact loca-tions and developing effective classifier training strategies are suggested to further improve the robustness of HMIs based on EMG pattern recognition.

(далее…)

Категория: Научные статьи | Нет комментариев »

The choice of non-anthropomorphic kinematic solutions for wearable robots is motivated both by the necessity of improving the ergonomics of physical Human-Robot Interaction and by the chance of exploiting the intrinsic dynamical properties of the robotic structure for an optimal interaction with the human body. Under these aspects, this new class of robotic solutions is potentially advantageous over the one of anthropomorphic robotic orthoses. However, the process of kinematic synthesis of non-antrhopomorphic wearable robots is very complex and difficult to be tackled by human intuition and engineering insight alone. A systematic approach is more useful for this purpose, since it allows to obtain the number of independent kinematic solutions with desired properties. In this perspective, this paper presents a method which enables to list the possible kinematic solutions for wearable robotic orthoses, which generalize the set of solutions of the problem of kinematic synthesis of a non-anthropomorphic wearable robot. This method has been implemented to derive the atlas of topologies of robotic kinematic chains which can be employed to support a 1-DOF human joint.

(далее…)

Категория: Научные статьи | Нет комментариев »

A linear-quadratic-Gaussian regulator is proposed for the torque control of flexible robotic joints with built-in torque sensor. The regulator requires the joint-torque sensor information only and features: (1) a Kalman filter that, beside reducing the noise and evaluating the derivative of the torque sensor measure, is able to estimate all the external and internal torques acting on the joint; 2) a controller that optimizes system stability, responsiveness, accuracy and effort. The regulator is implemented on a flexible joint of a rehabilitation exoskeleton. Simulation and experimental results are provided which demonstrate regulator performance and efficacy.

(далее…)

Категория: Научные статьи | Нет комментариев »

This paper presents MoonWalker, a lower limb exoskeleton able to sustain part of a user’s bodyweight. This orthosis can be used for rehabilitation, to help people having weak legs, or to help those suffering from a broken leg, to walk. It can also be used as an assistive device helping people carrying heavy loads. Its main characteristic is that a passive force balancer provides the force to sustain bodyweight. An actuator is also required, but is used only to shift that force the same side as the leg in stance. Consequently, MoonWalker requires very low energy to work on flat terrains. That motor can provide also a part of the energy to climb stairs or slopes. We believe that this approach can help improving energetic autonomy of lower limb exoskeletons.

(далее…)

Категория: Научные статьи | Нет комментариев »