Actuated Dual-Slip Model of Planar Slope Walking

2019 ◽  
Author(s):  
Raul Lema Galindo ◽  
Elise Weimholt ◽  
James P. Schmiedeler
Keyword(s):  
Step Length ◽  
Model Complexity ◽  
Human Walking ◽  
Slip Model ◽  
Step Frequency ◽  
Speed Range ◽  
Planar Slope ◽  
Actuation Scheme ◽  
Future Work ◽  
Flat Ground

Abstract The planar dual spring-loaded inverted pendulum (dual-SLIP) model is a well-established passive template of human walking on flat ground. This paper applies an actuated extension of the model to walking on inclines and declines to evaluate how well it captures the behavior observed in human slope walking. The motivation is to apply the template to improve control of humanoid robot walking and/or intent detection in exoskeleton-assisted walking. Gaits of the actuated planar dual-SLIP model are found via the solution of a constrained nonlinear optimization problem in ten parameters. The majority of those parameters define the actuation scheme that injects energy for incline walking and absorbs energy for decline walking to achieve periodic, nonconservative gaits. Solution gaits across the speed range of 1.0 to 1.6 ms and slope range of −10 to 10 degrees exhibit some of the characteristics of human walking, such as the effect of slope on stance duration, step frequency, and step length. Efforts to reduce the number of parameters optimized by enforcing relationships observed in the solution gaits proved unsuccessful, suggesting that future work must trade off model complexity with fidelity of representation of human behavior.

Preferred step frequency minimizes veering during natural human walking

2011 ◽  
Vol 505 (3) ◽  
pp. 291-293 ◽  
Author(s):  
Azusa Uematsu ◽  
Koh Inoue ◽  
Hiroaki Hobara ◽  
Hirofumi Kobayashi ◽  
Yuki Iwamoto ◽  
...  
Keyword(s):  
Human Walking ◽  
Step Frequency

scholarly journals Disentangling the energetic costs of step time asymmetry and step length asymmetry in human walking

2021 ◽  
Author(s):  
Jan Stenum ◽  
Julia T. Choi
Keyword(s):  
Energy Cost ◽  
Metabolic Cost ◽  
Step Length ◽  
Human Walking ◽  
Metabolic Power ◽  
Healthy Human ◽  
Time Asymmetry ◽  
Double Support ◽  
Post Stroke ◽  
The Cost

The metabolic cost of walking in healthy individuals increases with spatiotemporal gait asymmetries. Pathological gait, such as post-stroke, often has asymmetry in step lengths and step times which may contribute to an increased energy cost. But paradoxically, enforcing step length symmetry does not reduce metabolic cost of post-stroke walking. The isolated and interacting costs of asymmetry in step times and step lengths remain unclear, because previous studies did not simultaneously enforce spatial and temporal gait asymmetries. Here, we delineate isolated costs of asymmetry in step times and step lengths in healthy human walking. We first show that the cost of step length asymmetry is predicted by the cost of taking two non-preferred step lengths (one short and one long), but that step time asymmetry adds an extra cost beyond the cost of non-preferred step times. The metabolic power of step time asymmetry is about 2.5 times greater than the cost of step length asymmetry. Furthermore, the costs are not additive when walking with asymmetric step times and step lengths: metabolic power of concurrent asymmetry in step lengths and step times is driven by the cost of step time asymmetry alone. The metabolic power of asymmetry is explained by positive mechanical power produced during single support phases to compensate for a net loss of center of mass power incurred during double support phases. These data may explain why metabolic cost remains invariant to step length asymmetry in post-stroke walking and suggests how effects of asymmetry on energy cost can be attenuated.

scholarly journals Framework for Developing Bio-Inspired Morphologies for Walking Robots

2020 ◽  
Vol 10 (19) ◽  
pp. 6986
Author(s):  
Peter Billeschou ◽  
Nienke N. Bijma ◽  
Leon B. Larsen ◽  
Stanislav N. Gorb ◽  
Jørgen C. Larsen ◽  
...  
Keyword(s):  
Walking Speed ◽  
Dung Beetle ◽  
Object Manipulation ◽  
Step Length ◽  
Legged Robots ◽  
Walking Robots ◽  
Beetle Species ◽  
Step Frequency ◽  
Development Framework ◽  
Interdisciplinary Collaborations

Morphology is a defining trait of any walking entity, animal or robot, and is crucial in obtaining movement versatility, dexterity and durability. Collaborations between biologist and engineers create opportunities for implementing bio-inspired morphologies in walking robots. However, there is little guidance for such interdisciplinary collaborations and what tools to use. We propose a development framework for transferring animal morphologies to robots and substantiate it with a replication of the ability of the dung beetle species Scarabaeus galenus to use the same morphology for both locomotion and object manipulation. As such, we demonstrate the advantages of a bio-inspired dung beetle-like robot, ALPHA, and how its morphology outperforms a conventional hexapod by increasing the (1) step length by 50.0%, (2) forward and upward reach by 95.5%, and by lowering the (3) overall motor acceleration by 7.9%, and (4) step frequency by 21.1% at the same walking speed. Thereby, the bio-inspired robot has longer and fewer steps that lower fatigue-inducing impulses, a greater variety of step patterns, and can potentially better utilise its workspace to overcome obstacles. Hence, we demonstrate how the framework can be used to develop legged robots with bio-inspired morphologies that embody greater movement versatility, dexterity and durability.

scholarly journals KINEMATICAL STRATEGY TO REGAIN BALANCE DURING A FORWARD FALL ON A SLIPPERY FLOOR

2001 ◽  
Vol 13 (01) ◽  
pp. 27-32 ◽  
Author(s):  
PEI-HSI CHOU ◽  
YOU-LI CHOU ◽  
SHANG-LIN LEE ◽  
JIA-YUAN YOU ◽  
FONG-CHIN SU ◽  
...  
Keyword(s):  
Response Time ◽  
Horizontal Plane ◽  
Step Length ◽  
Human Walking ◽  
Motion Analysis System ◽  
Related Factors ◽  
Lean Angle ◽  
Foot Strike ◽  
Analysis System ◽  
Biomechanical Factors

Slips and falls often occur in the industrial environments. They are not only caused by environmental hazards but also by some biomechanical factors related to deficient ability of postural control to arrest impending falls. The purpose of this study is to simulate the slip condition in human walking and to find out the possible related factors of biomechanics. Eleven male and 9 female recruited were healthful without any musculoskeletal and neurological impairments. In order to provide different disturbance level, three lean angles of tilting boards were designed as 10, 20, 30 degrees with respect to horizontal plane. Subjects wore a safety harness, stood on the tilting board and were released without awareness. A forceplate applied a soap patch was in front of the tilting board to serve the slippery perturbation and to measure the fool/floor reactions. Movements of body segments were measured using the motion analysis system. The results were shown that lean angle had a significant effect to all parameters except step length, response time, maximum ankle forward velocity, hip forward velocity, and ankle flex angle. The gender significantly affected on the step length, response time, maximum ankle forward velocity, and knee forward velocity. Larger lean angle made subjects to take a more rapid step. In order to absorb the shock in foot strike, subjects flexed more their knee and increased the foot landing angle in larger lean angle. Male tended to adopt the long step-length strategy to respond to the slippery perturbation and female tended to use the short step-length strategy instead. The results of maximum ankle forward velocity suggested that short step-length strategy could be belter to reduce the foot slip than long step-length strategy.

Lower-Leg Compression, Running Mechanics, and Economy in Trained Distance Runners

2015 ◽  
Vol 10 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Abigail S.L. Stickford ◽  
Robert F. Chapman ◽  
Jeanne D. Johnston ◽  
Joel M. Stager
Keyword(s):  
Step Length ◽  
Lower Leg ◽  
Running Economy ◽  
Treadmill Running ◽  
Individual Response ◽  
Distance Runners ◽  
Step Frequency ◽  
Time Step ◽  
The Individual ◽  
Running Mechanics

The efficacy of and mechanisms behind the widespread use of lower-leg compression as an ergogenic aid to improve running performance are unknown. The purpose of this study was to examine whether wearing graduated lower-leg compression sleeves during exercise evokes changes in running economy (RE), perhaps due to altered gait mechanics. Sixteen highly trained male distance runners completed 2 separate RE tests during a single laboratory session, including a randomized-treatment trial of graduated calf-compression sleeves (CS; 15–20 mm Hg) and a control trial (CON) without compression sleeves. RE was determined by measuring oxygen consumption at 3 constant submaximal speeds of 233, 268, and 300 m/min on a treadmill. Running mechanics were measured during the last 30 s of each 4-min stage of the RE test via wireless triaxial 10-g accelerometer devices attached to the top of each shoe. Ground-contact time, swing time, step frequency, and step length were determined from accelerometric output corresponding to foot-strike and toe-off events. Gait variability was calculated as the standard deviation of a given gait variable for an individual during the last 30 s of each stage. There were no differences in VO2 or kinematic variables between CON and CS trials at any of the speeds. Wearing lower-leg compression does not alter the energetics of running at submaximal speeds through changes in running mechanics or other means. However, it appears that the individual response to wearing lower-leg compression varies greatly and warrants further examination.

Kinematics Characteristic of Exoskeleton Walking Robot for Older People

2014 ◽  
Vol 644-650 ◽  
pp. 167-170 ◽  
Author(s):  
Yong Chen ◽  
Sheng Lin ◽  
Rong Hua Li ◽  
Lian Dong Zhang
Keyword(s):  
Older People ◽  
High Speed ◽  
Video Camera ◽  
Step Length ◽  
Walking Robot ◽  
Step Frequency ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Gait Parameters ◽  
The Impact

The movement processes of the older people during walking on level ground were captured by the high-speed video camera with the speed of 500 frames per second. The gait parameters of the older people during walking on level ground were obtained by the quantitative analysis of the successive photographs captured by the high-speed video camera. Kinematics features of the older people during walking on level ground were discussed. Along with the growth of the age, step velocity, step frequency and step length were reduced, and gait cycle was rising. According to the morphology of the older people during walking on level ground, a mechanical model was put forward to aid the design of the exoskeleton walking robot. The couple walking characteristics between the older wearer and the exoskeleton walking robot was studied. In the single support phase of the exoskeleton walking robot, the change of the hip joint was gradually decreased to provide the driving force for the stable walk, the change of the knee joint was increased and following decreased and then increased to forward the older people's body center of gravity, and the change of the ankle joint was gradually increased to reduce the impact force of the ground. The results would provide the basic theory to bionic references for improving the reasonable properties of the exoskeleton walking robot. This work would provide certain theoretical and practical base in developing the exoskeleton walking robot on bionic structural design.

Differences in spatiotemporal parameters during 200-m sprint between bilateral and unilateral transfemoral amputees

2018 ◽  
Vol 42 (6) ◽  
pp. 567-570 ◽  
Author(s):  
Hiroaki Hobara ◽  
Sakiko Saito ◽  
Satoru Hashizume ◽  
Yuta Namiki ◽  
Yoshiyuki Kobayashi
Keyword(s):  
Clinical Relevance ◽  
Step Length ◽  
Classification Rules ◽  
Step Frequency ◽  
Average Speed ◽  
Race Time ◽  
Performance Differences ◽  
Spatiotemporal Parameters ◽  
Transfemoral Amputees

Background and aim: Although Paralympic T42 class Men’s 200 m sprints are currently competed by athletes with bilateral and unilateral transfemoral amputations, there may be performance differences between the groups. This study aimed to compare the spatiotemporal parameters of a 200-m sprint between bilateral and unilateral transfemoral amputees wearing running-specific prostheses. Technique: We analyzed 29 races (nine sprinters) with bilateral or unilateral transfemoral amputations from publicly available Internet broadcasts. For each sprinter’s race, the average speed, step frequency, and step length were calculated using the number of steps in conjunction with the official race time. Discussion: Average speed of bilateral transfemoral amputees was 5.7% greater than in unilateral transfemoral amputees. Bilateral transfemoral amputees exhibited lower step frequency (–8.9%) but longer step length (16.3%) than unilateral transfemoral amputees. Therefore, even in the same Paralympic classification (T42), different spatiotemporal strategies exist between bilateral and unilateral transfemoral amputees wearing running-specific prostheses during 200-m sprints. Clinical relevance Since different spatiotemporal strategies exist between bilateral and unilateral transfemoral amputees during 200-m sprints, our data supports recent revisions of classification rules (1st January, 2018), which each population was allocated into the different classification (T61 and T63, respectively).

scholarly journals Insect–computer hybrid legged robot with user-adjustable speed, step length and walking gait

2016 ◽  
Vol 13 (116) ◽  
pp. 20160060 ◽  
Author(s):  
Feng Cao ◽  
Chao Zhang ◽  
Hao Yu Choo ◽  
Hirotaka Sato
Keyword(s):  
Walking Speed ◽  
Step Length ◽  
Legged Robot ◽  
Step Frequency ◽  
Locomotion Control ◽  
Insect Locomotion ◽  
Implanted Electrodes ◽  
Walking Gait ◽  
Leg Muscles ◽  
Adjustable Speed

We have constructed an insect–computer hybrid legged robot using a living beetle ( Mecynorrhina torquata ; Coleoptera). The protraction/retraction and levation/depression motions in both forelegs of the beetle were elicited by electrically stimulating eight corresponding leg muscles via eight pairs of implanted electrodes. To perform a defined walking gait (e.g. gallop), different muscles were individually stimulated in a predefined sequence using a microcontroller. Different walking gaits were performed by reordering the applied stimulation signals (i.e. applying different sequences). By varying the duration of the stimulation sequences, we successfully controlled the step frequency and hence the beetle's walking speed. To the best of our knowledge, this paper presents the first demonstration of living insect locomotion control with a user-adjustable walking gait, step length and walking speed.

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