This paper presents the analysis of three gait pattern adaptation algorithms applied to trajectory control of an exoskeleton for lower limbs. The proposed exoskeleton is based on a commercially available orthosis. The main dynamic characteristics of the orthosis-patient system are considered in MatLab and ADAMS simulations. Also, three gait-pattern adaptation algorithms are implemented considering the proposed model. These algorithms lead to a reduction of the estimated interaction forces between the human and the robot, allowing patients to change the gait-pattern according to their degree of voluntary locomotor capability. The first one is based on the inverse dynamics and minimizes a functional computed from interaction forces and orthosis-patient dynamics. In the second, based on the direct dynamics, the human-robot interaction forces are translated into a desired change in trajectory accelerations. The third one minimizes the interaction forces by controlling the impedance between the orthosis and the patient. Experimental joint trajectories obtained from the orthosis are considered as initial trajectories for the gait-pattern algorithms.

Категория: Ищем научные статьи | Нет комментариев »

A study was conducted to evaluate performance of a man-machine interface system consisting of a human wearing a passiveexoskeleton device. This experiment obtained some crude measures of human response characteristics treating the exoskeletondevice as a complicated sensor array. A Fitt’s law paradigm was used to help evaluate human performance. Fitt’s law is commonly used in human performance studies and it characterizes human response in terms of speed-accuracy tradeoffs that occur as humans perform tasks. Empirical data were collected during tests involving five subjects run using five levels of speed-accuracy tasks. The results are analyzed

Категория: Ищем научные статьи | Нет комментариев »

To automatically align exoskeleton axes to human anatomical axes, we propose to decouple the joint rotations from the joint translations. Decoupling can reduce setup times and painful misalignment forces, at the cost of increased mechanical complexity and movement inertia. The decoupling approach was applied to the Dampace and Limpact exoskeletons.

Категория: Ищем научные статьи | Нет комментариев »

The effect of a twist dimension on the dexterity of double pointing systems is studied. It is found that as the twist increases from 0° the dexterity of the double pointing system is continually reduced. However a twist dimension of up to 81° allows for a dexterous exoskeleton shoulder joint workspace large enough to accommodate the range of shoulder joint motion in the typical human. This amount of twist greatly simplifies the design of the shoulder joint exoskeleton, allowing room for hardware such as gearing

Категория: Ищем научные статьи | Нет комментариев »

Naval Aeronautical Engineering Institute Exoskeleton Suit (NAEIES) is a kind of human-machine robot which combines the human’s intelligence with the powerful energy of mechanism. It can help people to carry heavy load, walking on kinds of terrains. A prototype of NAEIES is proposed in this paper. When human walking, his (her) forearm has a similar motion trajectory with knee joint. So the forearm motion is measured by a potentiometer as the control signal of the knee joint. The hip joint motion is realized by a gas spring. This is the simplest method to realize the motion of NAEIES. The principle of the method was illustrate in the paper and for the further study a control techniques based on the feedback of angle acceleration is proposed and simulated with the one-Dof and two-Dof model of NAEIES leg.

Категория: Ищем научные статьи | Нет комментариев »