This paper describes a harness design for transmitting both horizontal and vertical forces to the torso of a user on a locomotion interfaces. For horizontal forces, an exoskeleton-like mechanism distributes forces between the shoulders and hips and accommodates to the complicated motions of the back and shoulders relative to hips. For vertical forces, a body weight support harness is integrated into the exoskeleton-like mechanism. A passive elastic element has been devised that ensures consistent strap tightening. Measurements are presented that shows the stiffness of the mechanical coupling of harness to subject for the purposes of faithful force application to the torso.

(далее…)

Категория: Научные статьи | Нет комментариев »

A high-quality haptic interface is typically characterized by low apparent inertia and damping, high structural stiffness, minimal backlash, and absence of mechanical singularities in the workspace. In addition to these specifications, exoskeleton haptic interface design involves consideration of space and weight limitations, workspace requirements, and the kinematic constraints placed on the device by the human arm. In this paper, the authors present the redesign of an existing five degree-of-freedom haptic arm exoskeleton. The redesign efforts focus primarily on ensuring smooth operation of the exoskeleton’s moving parts to minimize backlash, reducing cost and build time by simplifying the design, and increasing the torque output while continuing to use electric actuators for ease of control. The accompanying computer control system was developed in parallel with the mechanical redesign effort. The newly redesigned exoskeleton presented is capable of providing kinesthetic feedback to the joints of the lower arm and wrist of the operator, and will be used in future work for robot-assisted rehabilitation and training.

(далее…)

Категория: Научные статьи | Нет комментариев »

This paper presents a wearable lower extremity exoskeleton (LEE) developed as a platform for research works on enhancement and assistive the ability of human’s walking and load carrying. The whole process of the first prototype design is introduced together with the sub-systems, inner/outer exoskeleton, the attached flexible waist and footpad with sensors. Simulation model and feedback control with the ZMP method were established using Adams and Matlab. The ultimate goal of the current research work is to design and control a power assisted system, which integrates human’s intellect as the control system for manipulating the wearable power-aided device. The feasibility and initial performance of the designed system are also discussed.

(далее…)

Категория: Научные статьи | Нет комментариев »

The Berkeley Lower Extremity Exoskeleton is the first functional energetically autonomous load carrying human exoskeleton and was demonstrated at U.C. Berkeley, walking at the average speed of 0.9 m/s (2 mph) while carrying a 34 kg (75 lb) payload. The original published controller, called the BLEEX Sensitivity Amplification Controller, was based on positive feedback and was designed to increase the closed loop system sensitivity to its wearer’s forces and torques without any direct measurement from the wearer. This controller was successful at allowing natural and unobstructed load support for the pilot. This article presents an improved control scheme we call “hybrid” BLEEX control that adds robustness to changing BLEEX backpack payload. The walking gait cycle is divided into stance control and swing control phases. Position control is used for the BLEEX stance leg (including the torso and backpack) and a sensitivity amplification controller is used for the swing leg. The controller is also designed to smoothly transition between these two schemes as the pilot walks. With hybrid control, the controller does not require a good model of the BLEEX torso and payload, which is difficult to obtain and subject to change as payload is added and removed. As a tradeoff, the position control used in this method requires the human to wear seven inclinometers to measure human limb and torso angles. These additional sensors require careful design to securely fasten them to the human and increase the time to don and doff BLEEX.

(далее…)

Категория: Научные статьи | Нет комментариев »