The human arm including the shoulder, elbow, wrist joints and exclu-sion scapular motion has 7 Degrees of Freedom (DOF) while positioning of the wrist in space and orientating the palm is a task that requires 6 DOF. As such it includes one more DOF than is needed to complete the task. Given the redundant nature of the arm, multiple arm configurations can be used to complete a task, which is expressed mathematically by none unique solution for the inverse kinematics. Despite this mathematical difficulty, the motor control provides a unique solution for the arm redundancy as the arm is moved in space. Resolving this redundancy is becoming critical as the human interacts with a wearable robotic system(exoskeleton) which includes the same redundancy as the human arm. Therefore, the inverse kinematics solution resolving the redundancy of these two coupled systems must be identical in order to guarantee an seamless integration. The redundancy of the arm can be formulated kinematically by defining the swivel angle — the rotation angle of the plane including the upper and lower arm around a virtual axis connecting the shoulder and wrist joints which are fixed in space. Analyzing reaching tasks recorded with a motion capture lab indicates that the swivel angle is selected such that when the elbow joint is flexed, the palm points the head. Based on these experimental results, selecting the point around the center of the head as a stationary target allows to calculate the swivel angle and in that way to resolve the human arm redundancy. Experimental results indicated that by using the proposed redundancy resolution criteria the error between the predicted swivel angle and the actual swivel angle adopted by the motor control system is less then 5 Deg. This criterion or a synthesis of several additional criteria may improve the synergistic relationships between an operator and a wearable robotic system.

(далее…)

Категория: Научные статьи | Нет комментариев »

Целью настоящей работы является проектирование экзоскелетонов -ассистентов приседания и вставания для пациентов с опорно-двигательными нарушениями без особых усилий с их стороны. Обеспечение снижения двигательных усилий пациента достигается пружинным статическим уравновешиванием. В рамках статьи не рассматриваются вопросы общего равновесия тела человека. Используются линейные цилиндрические пружины растяжения и сжатия, развивающие большие усилия при их малых размерах и массах, что делает экзоскелетоны портативными и применимыми как для физиотерапии, так и для перманентного использо-вания.

(далее…)

Категория: Научные статьи | Нет комментариев »

In this study, an energy-efficient gait pattern and swing trajectory of the powered robotic exoskeleton was proposed through function distribution analysis and the dynamic-manipulability ellipsoid (DME). The exoskeleton has 3 DOF at each side, and it is possible to determine the minimum energy consumption of the joint torques under level-ground walking and stair ambulation conditions. To verify its feasibility and the effect of the proposed optimal gait pattern from the point view of the integrated system (human and exoskeleton), simulations were performed in the cases of walking on level ground and stair ascent/descent. Experiments such as on the metabolic cost of the human body with or without the assistance of the exoskeleton were conducted, and the power consumption of the exoskeleton was assessed, with the aim of improving the efficiency of the integrated system.

(далее…)

Категория: Научные статьи | Нет комментариев »

We aim to develop the Hybrid Assistive Lims (HAL) in order to enhance and upgrade the human capabilities based on the frontier science Cybernics. Cybernics is a new domain of interdisciplinary research centered on cybernetics, mechatronics, and informatics, and integrates neuroscience, robotics, systems engineering, information technology, “kansei” engineering, ergonomics, physiology, social science, law, ethics, management, economics etc. Robot Suit HAL is a cyborg type robot that can expand, augment and support physical capability. The robot suit HAL has two types of control systems such as “Cybernic Voluntary Control System” and “Cybernic Autonomous Control System”. The application fields of HAL are medical welfare, heavy work support and entertainment etc. In this paper, the outline of HAL and some of the important algorithms and recent challenges are described.

(далее…)

Категория: Научные статьи | Нет комментариев »

A new and alternative method to measure the interaction force between the user and a lower-limb gait rehabilitation exoskeleton is presented. Instead of using a load cell to measure the resulting interaction force, we propose a distributed measure of the normal interaction pressure over the whole contact area between the user and the machine. To obtain this measurement, a soft silicone tactile sensor is inserted between the limb and commonly used connection cuffs. The advantage of this approach is that it allows for a distributed measure of the interaction pressure, which could be useful for rehabilitation therapy assessment purposes, or for control. Moreover, the proposed solution does not change the comfort of the interaction; can be applied to connection cuffs of different shapes and sizes; and can be manufactured at a low cost. Preliminary results during gait assistance tasks show that this approach can precisely detect changes in the pressure distribution during a gait cycle.

(далее…)

Категория: Научные статьи | Нет комментариев »