The lower extremity exoskeleton is a wearable device that can increase the strength, speed, and endurance of the wearer. In order to let the exoskeleton moving at desired trajectories, an accurate kinematics model of the mechanism is required. As theexoskeleton has many degrees of freedom (DOFs) and has no fixed base, it is difficult to analyze the kinematics by using conventional methods. In this paper, a generalized kinematics model of lower extremity exoskeletons is proposed by employing coordinate transforming matrix. Meanwhile, the formulation of forward kinematics and the inverse kinematics are discussed in detail. Finally, gait planning is realized according to the results of kinematics analysis. The commercialized dynamics analysis software ADAMS was selected for the modeling and simulation of the generalized lower extremity exoskeleton. To verify the theoretical analysis, a virtual low extremity exoskeleton is built. Based on the inversed kinematics of low extremity exoskeleton, the virtual prototype walks stably in ADAMS by controlled by MATLAB SIMULINK for tracking a desired gait data.

Категория: Ищем научные статьи | Нет комментариев »

Traditional exoskeleton suit need to install many complex sensors between the pilot and the exoskeleton system to measure the human-machine interactive information, which decrease the comfort of the pilot. Sensitivity amplification control can control theexoskeleton suit to trace the pilotpsilas movement as well as need no sensors between the pilot and the exoskeleton. However, sensitivity amplification control seriously relies on the systempsilas dynamic model and it is hard to build the exoskeletonsuitpsilas dynamic model exactly because the exoskeleton suit is a multi-body, multi-degree and nonlinear system. So the dynamic model of the swing leg of exoskeleton suit was identified by BP neural networks, which simplified the procedure of building the system model. Neural network sensitivity amplification control was proposed and its feasibility was validated by simulation based on Simulink and SimMechanics toolbox in Matlab.

Категория: Ищем научные статьи | Нет комментариев »

Single loop adjuster which is realized as a digital adjuster with the function of single loop adjustment by microprocessor, has a vital role in industrial control. This paper puts forward a method of using wireless mode, which sets the injunction to single loop adjuster on remote supervisory computer for centralized control, and has a deep research on hardware and software design of specific system.

Категория: Ищем научные статьи | 1 Комментарий »

This paper presents a design frame of a leg exoskeleton. The performance of an exoskeleton was analyzed by studying a model of a linear coupled 1-DOF human-exoskeleton system. The results showed that a low-impedance, anthropomorphic and well attached mechanical structure is benefit for the control of exoskeleton, and a direct force feedback control could also be implemented to further reduce the impedance. Three kinds of applied sensor interface were compared. A leg exoskeleton called ELEBOT was developed for validating control algorithm. The ELEBOT included four main parts: mechanical structure, hydraulic actuator, sensor and control system and power. The function of such a load-carrying robot is to reduce the injuries associated with the back and lower limbs after a long heavy walk. Experiment results with a simple force controller confirmed that ELEBOT could efficiently assist people walking with 30 kg payload now.

Категория: Ищем научные статьи | 8 комментариев »

Study design:

Multi-center pilot study.

Objectives:

To investigate the use of an upper limb robotic rehabilitation device (Armeo Spring, Hocoma AG, Switzerland) in a subacute cervical spinal cord injury (SCI) population.

Setting:

Two Canadian inpatient rehabilitation centers.

Methods:

Twelve subjects (motor level C4–C6, ASIA Impairment Scale A–D) completed the training, which consisted of 16.1±4.6 sessions over 5.2±1.4 weeks. Two types of outcomes were recorded: (1) feasibility of incorporating the device into an inpatient rehabilitation program (compliance with training schedule, reduction in therapist time required and subject questionnaires) and (2) efficacy of the robotic rehabilitation for improving functional outcomes (Graded and Redefined Assessment of Strength, Sensibility and Prehension (GRASSP), action research arm test, grip dynamometry and range of motion).

Results:

By the end of the training period, the robot-assisted training was shown to require active therapist involvement for 25±11% (mean±s.d.) of the total session time. In the group of all subjects and in a subgroup composed of motor-incomplete subjects, no statistically significant differences were found between intervention and control limbs for any of the outcome measures. In a subgroup of subjects with partial hand function at baseline, the GRASSP-Sensibility component showed a statistically significant increase (6.0±1.6 (mean±s.e.m.) point increase between baseline and discharge for the intervention limbs versus 1.9±0.9 points for the control limbs).

Conclusion:

The pilot results suggest that individuals with some preserved hand function after SCI may be better candidates for rehabilitation training using the Armeo Spring device.

Категория: Ищем научные статьи | Нет комментариев »