A novel dynamic walker with heel, ankle, and toe rocker motions

Robotica ◽  
2011 ◽  
Vol 29 (6) ◽  
pp. 883-893 ◽  
Author(s):  
R. Prasanth Kumar ◽  
Abdullah Özer ◽  
Gabsoon Kim ◽  
Jungwon Yoon
Keyword(s):  
Energy Efficiency ◽  
Numerical Simulations ◽  
Ankle Joint ◽  
Mass Distribution ◽  
Equations Of Motion ◽  
Dynamic Walking ◽  
Leg Length ◽  
Passive Dynamic Walking ◽  
Flat Foot ◽  
Low Speed

SUMMARYThis paper proposes a novel dynamic walker capable of walking with heel, ankle, and toe rocker motions. The heel and toe rocker motions are obtained by using inelastic stoppers between leg and foot, which limit the range of rotation of the foot about the ankle joint. A generalized set of equations of motion and associated transition equations applicable for multiple foot segments is derived. Passive dynamic walking is studied with equal heel and toe strike angles for the case of symmetric foot walking. It is shown that by including the ankle joint, low-speed walking is made possible. The energy efficiency of the proposed walker is studied theoretically and through numerical simulations. Finally, three different underactuated modes of active walking that do not require toe and heel actuation are presented. In order to implement these modes of walking, the proposed walker can be constructed with little modification from an existing flat-foot walker that uses ankle rocker motion alone. Results show that substantial benefits can be obtained in efficiency and stability compared to point/flat-foot walker of the same leg length and mass distribution.

Efficient dynamic bipedal walking using effects of semicircular feet

Robotica ◽  
2010 ◽  
Vol 29 (3) ◽  
pp. 351-365 ◽  
Author(s):  
Fumihiko Asano ◽  
Zhi-Wei Luo
Keyword(s):  
Ankle Joint ◽  
High Speed ◽  
Joint Torque ◽  
Bipedal Walking ◽  
Convex Curve ◽  
Driving Mechanism ◽  
Dynamic Walking ◽  
Passive Dynamic Walking ◽  
Biped Robots ◽  
Flat Feet

SUMMARYAchieving energy-efficient and high-speed dynamic walking has become one of the main subjects of research in the area of robotic biped locomotion, and passive dynamic walking has attracted a great deal of attention as a solution to this. It is empirically known that the convex curve of the foot, which characterizes passive–dynamic walkers, has an important effect on increasing the walking speed.This paper mainly discusses our investigations into the driving mechanism for compass-like biped robots and the rolling effect of semicircular feet. We first analyze the mechanism for a planar fully actuated compass-like biped model to clarify the importance of ankle-joint torque by introducing a generalized virtual-gravity concept. A planar underactuated biped model with semicircular feet is then introduced and we demonstrate that virtual passive dynamic walking only by hip-joint torque can be accomplished based on the rolling effect. We then compare the rolling effect with a flat feet model through linear approximation, and show that the rolling effect is equivalent to virtual ankle-joint torque. Throughout this paper, we provide novel insights into how zero-moment-point-free robots can generate a dynamic bipedal gait.

scholarly journals Experimental verification of the characteristic behaviors in passive dynamic walking

2021 ◽  
Author(s):  
Masatsugu Iribe ◽  
Ryoichi Hirouji ◽  
Daisuke Ura ◽  
Koichi Osuka ◽  
Tetsuya Kinugasa
Keyword(s):  
Numerical Simulations ◽  
Experimental Verification ◽  
Chaotic Behavior ◽  
Adaptive Behaviors ◽  
Robot Design ◽  
Legged Robot ◽  
Dynamic Walking ◽  
Passive Dynamic Walking ◽  
Environment Changes

AbstractIt is well known that passive dynamic walking shows chaotic behavior owing to changes in the environment. In addition, when the environment changes continuously during walking, passive dynamic walking shows “adaptive behaviors” in which the stride angle changes itself in an attempt to keep walking. These behaviors are very interesting and useful for the legged robot design. However, the studies on passive dynamic walking are preceded only by numerical simulations. For this reason, it is very important to confirm, by actual experiments, whether these characteristic behaviors appear. In this paper, we verify the existence of these behaviors by several actual experiments.

Asymptotic Realization of Desired Control Performance by Body Adaptation of Passive Dynamic Walker

2017 ◽  
Vol 29 (3) ◽  
pp. 480-489 ◽  
Author(s):  
Daisuke Ura ◽  
◽  
Yasuhiro Sugimoto ◽  
Yuichiro Sueoka ◽  
Koichi Osuka
Keyword(s):  
Design Method ◽  
Step Length ◽  
Physical Parameters ◽  
Legged Robot ◽  
Dynamic Walking ◽  
Trial And Error ◽  
Leg Length ◽  
Passive Dynamic Walking ◽  
Variable Parameters ◽  
Passive Dynamic Walker

[abstFig src='/00290003/03.jpg' width='300' text='Schematic of the proposed design method' ] This article proposes a design method of legged walking robot hardware capable of performing passive dynamic walking with its desirable characteristics. Passive dynamic walking has a relatively good energy efficiency, and is said to be similar to the walking style of animals. However, most legged robot hardware capable of passive dynamic walking is designed through trial and error on the basis of experience. One of the major problems of designing through trial and error is the difficulty of verifying walking for the legged robot hardware that has many degree of freedom. It is relatively easy to determine the initial condition for compass-type robot hardware. However, it often takes long time to determine the appropriate initial conditions and slope angles for complicated robots such as legged robots with knees. We proposed and verified a method to design a legged robot with knees that has a desired leg length and leg mass from a compass-type legged robot. In this article, we propose a method to design a passive dynamic walker that has a desired leg angle, step length, leg mass, etc., and verify the resulting design. More specifically, the physical parameters, such as the leg length, leg mass, and joint friction, are defined as “physical parameters” and the parameters acquired as the result of walking, such as the leg angle, step length, and walking cycle, are defined as “variable parameters.” By observing variable parameters while the robot is walking and by changing the physical parameters according to the observed variable parameters, the variable parameters are indirectly changed to desired values.

Estimation of the Stable Fixed Point of Passive Dynamic Walking with BP Neural Network

ROBOT ◽  
2010 ◽  
Vol 32 (4) ◽  
pp. 478-483 ◽  
Author(s):  
Xiuhua NI ◽  
Weishan CHEN ◽  
Junkao LIU ◽  
Shengjun SHI
Keyword(s):  
Neural Network ◽  
Fixed Point ◽  
Bp Neural Network ◽  
Stable Fixed Point ◽  
Dynamic Walking ◽  
Passive Dynamic Walking

INFLUENCE OF FOOT INSOLE ON THE GAIT PERFORMANCE IN SUBJECTS WITH FLAT FOOT DISORDER

2019 ◽  
Vol 19 (06) ◽  
pp. 1950050
Author(s):  
M. T. KARIMI ◽  
R. B. TAHMASEBI ◽  
B. SATVATI ◽  
F. FATOYE
Keyword(s):  
Range Of Motion ◽  
Ankle Joint ◽  
Lower Limb ◽  
Walking Speed ◽  
Force Plate ◽  
Flat Foot ◽  
Gait Performance ◽  
Positive Effects ◽  
Significant Difference ◽  
Foot Disorder

Flat foot is the most common foot disorder that influences the alignment of the lower limb structure. It is controversial whether the use of foot insole influences kinetic and kinematic of the leg or not. Therefore, this study investigated the influence of foot insole on the gait performance in subjects with flat foot disorder. A group of flat foot subject was recruited into this study (the number of subjects was 15). The motion of the leg joints was determined using the Qualysis motion analysis system. Moreover, the force applied on the lower limb was recorded by a Kistler force plate. The range of motion of the lower limb joints, the moments applied on the lower limb joints and force transmitted through the leg were the parameters used in this study. The difference between these parameters during walking with and without insole was evaluated using the paired [Formula: see text]-test. Significant value was set at [Formula: see text]. There was no significant difference between the range of motion of ankle joint while walking with and without insole. However, the medial directed force applied on the leg decreased significantly [Formula: see text]. The use of foot insole did not influence the moments transmitted through the hip and knee joints. The walking speed of the subjects improved while walking with foot insole. Use of foot insole influenced the magnitude of the force applied on the leg and the adductor moment of ankle joint due to its influence on foot alignment. As the walking speed of the improved subjects follows the use of insole, it can be concluded that it may have a positive effects on the performance of flat foot subjects.

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