An actuator system for extending and flexing a joint, including a multi-motor assembly for providing a rotational output, a rotary-to-linear mechanism for converting the rotational output from the multi-motor assembly into an extension and flexion of the joint, and a controller for operating the actuator system in several operational modes. The multi-motor assembly preferably combines power from two different sources, such that the multi-motor assembly can supply larger forces at slower speeds (“Low Gear”) and smaller forces at higher speeds (“High Gear”). The actuator has been specifically designed for extending and flexing a joint (such as an ankle, a knee, an elbow, or a shoulder) of a human. The actuator system may, however, be used to move any suitable object through any suitable movement (linear, rotational, or otherwise).

(далее…)

Категория: Патенты | Нет комментариев »

A lower extremity exoskeleton (100) includes: at least one power unit (201); two leg supports (101, 102) designed to rest on the ground (130); two knee joints (107, 108) configured to allow flexion and extension between respective shank (105, 106) and thigh links (103, 104) of the leg supports (101, 102); an exoskeleton trunk (109) rotatably connectable to the leg supports (101, 102); and two hip actuators (145, 146) configured to create torques between the exoskeleton trunk (109) and the leg supports (101, 102). In use, the hip actuators (145, 146) create a torque to move the leg supports (101, 102) backward relative to the exoskeleton trunk ( 109) during a stance phase, which pushes the exoskeleton trunk (109) forward. A second torque may be used to move the leg supports (101, 102) forward relative to the exoskeleton trunk (109) into a swing phase. Additionally, a swing torque may be generated during the swing phase to move the leg support (101, 102) forward relative to the exoskeleton trunk (109). This results in decreased oxygen consumption and heart rate of a user wearing the exoskeleton (100).

(далее…)

Категория: Патенты | Нет комментариев »

Human-robot control interfaces have received increased attention during the past decades. With the introduction of robots in everyday life, especially in providing services to people with special needs (i.e., elderly, people with impairments, or people with disabilities), there is a strong necessity for simple and natural control interfaces. In this paper, electromyographic (EMG) signals from muscles of the human upper limb are used as the control interface between the user and a robot arm. EMG signals are recorded using surface EMG electrodes placed on the user’s skin, making the user’s upper limb free of bulky interface sensors or machinery usually found in conventional human-controlled systems. The proposed interface allows the user to control in real time an anthropomorphic robot arm in 3-D space, using upper limb motion estimates based only on EMG recordings. Moreover, the proposed interface is robust to EMG changes with respect to time, mainly caused by muscle fatigue or adjustments of contraction level. The efficiency of the method is assessed through real-time experiments, including random arm motions in the 3-D space with variable hand speed profiles.

(далее…)

Категория: Научные статьи | Нет комментариев »

This paper is aimed at developing a smart actuator for assistive knee braces to provide assistance to disabled or elderly people with mobility problems. A magnetorheological (MR) actuator is developed to be used in assistive knee braces to provide controllable torque. The MR actuator can work as a brake or a clutch. When active torque is needed, 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 prototype of the developed MR actuator is fabricated and experiments are carried out to investigate the characteristics of the MR actuator. The results show that the MR actuator is able to provide sufficient torque needed for normal human activities. Adaptive control is proposed for controlling the MR actuator. Anti-windup strategy is used to achieve better control performance. Experiments on the MR actuator under control are also performed to study the torque tracking ability of the system.

Категория: Ищем научные статьи | 40 комментариев »

На основе уравнений Лагранжа-Максвелла разработан метод решения задачи оп-тимального управления манипуляторами с последовательной и параллельной структурами, рассматриваемыми как элек-тромеханические системы. Метод позволяет без введения дополнительных сил, изменением лишь напряжений в элек-троприводах, спланировать требуемые оптимальные движения механизмов, что существенно упрощает системы их управления.

(далее…)

Категория: Научные статьи | Нет комментариев »