scholarly journals Control of power-augmenting lower extremity exoskeleton while walking with heavy payload

2019 ◽  
Vol 16 (1) ◽  
pp. 172988141983053 ◽  
Author(s):  
Byunghun Choi ◽  
Changhoon Seo ◽  
Sanghoon Lee ◽  
Byungun Kim
Keyword(s):  
Lower Extremity ◽  
Control Strategy ◽  
Hybrid Control ◽  
Mechanical Impedance ◽  
Torque Control ◽  
Maximum Speed ◽  
Weight Shift ◽  
Gait Phase ◽  
And Control ◽  
Direct Feedback

This article presents a design and control framework for a prototype of lower extremity exoskeleton to enhance the human strength during locomotion. The hybrid control strategy is practically applied according to the two gait phases, that is, stance and swing. The weight shift method based on human’s weight shift information was proposed and implemented to acquire the detection of gait phase. In the stance phase, a stiff virtual wall method is applied to support the entire weight of the exoskeleton while carrying a heavy payload. Direct feedback and feed-forward torque control are used to reduce mechanical impedance in the swing phase. In experiments, to verify the performance of the proposed control strategy, a human subject wearing the prototype of power-augmenting lower extremity exoskeleton was able to walk with a 50-kg (110-lb) payload at a maximum speed of 1.67 m/s (6 km/h). Satisfactory results were obtained with regard to walking experiments with the heavy payload.

Bio-inspired control research of a novel lower extremity exoskeleton with a series-parallel mechanism

2014 ◽  
Vol 229 (16) ◽  
pp. 2875-2889 ◽  
Author(s):  
Dalei Pan ◽  
Feng Gao ◽  
Yunjie Miao ◽  
Rui Cao
Keyword(s):  
Lower Extremity ◽  
Control Strategy ◽  
Pid Controller ◽  
Parallel Mechanism ◽  
Simulation Method ◽  
Fuzzy Pid ◽  
Precise Control ◽  
Walking Gait ◽  
Level Walking ◽  
Control Research

This paper proposes a switch-type and parameter self-tuning fuzzy-PID/PID controller for a novel lower extremity exoskeleton with a series-parallel mechanism according to the features of human level walking gait. The novel exoskeleton mechanism was described, the biological characteristics of human legs during the walking cycle were analyzed and a mapping from the positions of human lower extremity joints to the exoskeleton joints was established. Then the schematic of the exoskeleton control strategy was discussed and illustrated. The co-simulation method of ADAMS and MATLAB/SIMULINK was adopted and the fuzzy-PID/PID controller was designed. A 1-DOF rotation control was simulated by both the fuzzy-PID/PID controller and a conventional PID controller for comparison. Finally, the exoskeleton level walking gait was co-simulated by using the bio-inspired control strategy. The results show that the controller can provide a fast, stable and precise control for the exoskeleton system.

Virtual Coupling Based Control Methodology for Lower Extremity Exoskeleton

2014 ◽  
Vol 556-562 ◽  
pp. 2365-2369 ◽  
Author(s):  
Jin Xiang Cui ◽  
Yan He Zhu ◽  
Ben Zhou Xu
Keyword(s):  
Lower Extremity ◽  
Control Strategy ◽  
Degrees Of Freedom ◽  
Virtual Prototype ◽  
Contact Forces ◽  
Admittance Control ◽  
Collaborative Simulation ◽  
Virtual Coupling ◽  
Control Methodology ◽  
Positional Control

As one of the most important examples of human-orientated system, the exoskeleton can improve the strength and endurance of the wearer. The exoskeleton has multi-degrees of freedom. As a result, a stable controller for the exoskeleton is difficult to design. The adoption of a purely positional control strategy may lead to large contact forces. Hence, an admittance control strategy is devised aimed at limiting both internal and contact forces. To verify the rationality and feasibility of the control strategy, we introduce a method utilizing virtual prototype and collaborative simulation.

Dynamics Analysis and Control Strategy Simulation of Lower Extremity of Power Assist Robot

2014 ◽  
Vol 513-517 ◽  
pp. 4098-4101
Author(s):  
Xin Jun Li ◽  
Xi Wang Mao ◽  
Long He ◽  
Xin Rui Wang
Keyword(s):  
Lower Extremity ◽  
Control Strategy ◽  
Lagrange Equation ◽  
Dynamic Control ◽  
Working Environment ◽  
Joint Torque ◽  
Dynamics Analysis ◽  
Heavy Loads ◽  
And Control ◽  
The Relationship

Lower Extremity of Power Assist Robot could add the strength and endurance of robotics to a human's innate adaptability to help the wearer transport heavy loads over rough and unpredictable terrain. Dynamics Analysis and Control Strategy Simulation are the important aspects for the researching of the robot. The dynamics equation of Lower Extremity of Power Assist Robot is built by the Lagrange equation. The relationship between the active joint torque of the robot and plantar pressure is established, which support the theoretical foundation for the dynamic control to achieve the desired effect. Base on the analysis of working environment and the mechanical environment of the robot, the force-location control theory is used to control robot, which is simulated based on Simulink blocks of MATLAB to get a better tracking performance.

Combining Values

2002 ◽  
Vol 7 (2) ◽  
pp. 1-4, 12 ◽  
Author(s):  
Christopher R. Brigham
Keyword(s):  
Lower Extremity ◽  
Upper Extremity ◽  
Evaluation Method ◽  
Proximal Phalanx ◽  
Common Error ◽  
The Third ◽  
Whole Person ◽  
Impairment Ratings ◽  
Upper Extremity Impairment ◽  
The Individual

Abstract To account for the effects of multiple impairments, evaluating physicians must provide a summary value that combines multiple impairments so the whole person impairment is equal to or less than the sum of all the individual impairment values. A common error is to add values that should be combined and typically results in an inflated rating. The Combined Values Chart in the AMA Guides to the Evaluation of Permanent Impairment, Fifth Edition, includes instructions that guide physicians about combining impairment ratings. For example, impairment values within a region generally are combined and converted to a whole person permanent impairment before combination with the results from other regions (exceptions include certain impairments of the spine and extremities). When they combine three or more values, physicians should select and combine the two lowest values; this value is combined with the third value to yield the total value. Upper extremity impairment ratings are combined based on the principle that a second and each succeeding impairment applies not to the whole unit (eg, whole finger) but only to the part that remains (eg, proximal phalanx). Physicians who combine lower extremity impairments usually use only one evaluation method, but, if more than one method is used, the physician should use the Combined Values Chart.

Quick Reference: Chapter 3: The Musculoskeletal System and Chapter 4: The Nervous System

2000 ◽  
Vol 5 (3) ◽  
pp. 4-4
Keyword(s):  
Nervous System ◽  
Lower Extremity ◽  
Musculoskeletal System ◽  
Multistep Method ◽  
Manual Muscle Testing ◽  
Motor Deficits ◽  
Lower Extremity Weakness ◽  
Residual Symptoms ◽  
Muscle Testing ◽  
Almost All

Abstract Lesions of the peripheral nervous system (PNS), whether due to injury or illness, commonly result in residual symptoms and signs and, hence, permanent impairment. The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, divides PNS deficits into sensory and motor and includes pain in the former. This article, which regards rating sensory and motor deficits of the lower extremities, is continued from the March/April 2000 issue of The Guides Newsletter. Procedures for rating extremity neural deficits are described in Chapter 3, The Musculoskeletal System, section 3.1k for the upper extremity and sections 3.2k and 3.2l for the lower limb. Sensory deficits and dysesthesia are both disorders of sensation, but the former can be interpreted to mean diminished or absent sensation (hypesthesia or anesthesia) Dysesthesia implies abnormal sensation in the absence of a stimulus or unpleasant sensation elicited by normal touch. Sections 3.2k and 3.2d indicate that almost all partial motor loss in the lower extremity can be rated using Table 39. In addition, Section 4.4b and Table 21 indicate the multistep method used for spinal and some additional nerves and be used alternatively to rate lower extremity weakness in general. Partial motor loss in the lower extremity is rated by manual muscle testing, which is described in the AMA Guides in Section 3.2d.

Q&A: Multiple Lower Extremity Impairments and AMA Guides, Third Edition, Revised

2017 ◽  
Vol 22 (2) ◽  
pp. 15-16
Author(s):  
Christopher R. Brigham ◽  
Kathryn Mueller ◽  
Steven Demeter ◽  
Randolph Soo Hoo
Keyword(s):  
Lower Extremity

Spinal Impairment Evaluation: Fifth Edition Changes

2001 ◽  
Vol 6 (1) ◽  
pp. 1-3
Author(s):  
Robert H. Haralson
Keyword(s):  
Spinal Cord ◽  
Lower Extremity ◽  
Range Of Motion ◽  
Upper Extremity ◽  
Spinal Cord Injuries ◽  
Clinical Findings ◽  
Fourth Edition ◽  
Treatment Results ◽  
Standard Terminology ◽  
Made In

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, was published in November 2000 and contains major changes from its predecessor. In the Fourth Edition, all musculoskeletal evaluation and rating was described in a single chapter. In the Fifth Edition, this information has been divided into three separate chapters: Upper Extremity (13), Lower Extremity (14), and Spine (15). This article discusses changes in the spine chapter. The Models for rating spinal impairment now are called Methods. The AMA Guides, Fifth Edition, has reverted to standard terminology for spinal regions in the Diagnosis-related estimates (DRE) Method, and both it and the Range of Motion (ROM) Method now reference cervical, thoracic, and lumbar. Also, the language requiring the use of the DRE, rather than the ROM Method has been strengthened. The biggest change in the DRE Method is that evaluation should include the treatment results. Unfortunately, the Fourth Edition's philosophy regarding when and how to rate impairment using the DRE Model led to a number of problems, including the same rating of all patients with radiculopathy despite some true differences in outcomes. The term differentiator was abandoned and replaced with clinical findings. Significant changes were made in evaluation of patients with spinal cord injuries, and evaluators should become familiar with these and other changes in the Fifth Edition.

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