Passive and dynamic gait measures for biped mechanism: formulation and simulation analysis

SUMMARYUnderstanding and mimicking human gait is essential for design and control of biped walking robots. The unique characteristics of normal human gait are described as passive dynamic walking, whereas general human gait is neither completely passive nor always dynamic. To study various walking motions, it is important to quantify the different levels of passivity and dynamicity, which have not been addressed in the current literature. In this paper, we introduce the initial formulations of Passive Gait Measure (PGM) and Dynamic Gait Measure (DGM) that quantify passivity and dynamicity, respectively, of a given biped walking motion, and the proposed formulations will be demonstrated for proof-of-concepts using gait simulation and analysis. The PGM is associated with the optimality of natural human walking, where the passivity weight functions are proposed and incorporated in the minimization of physiologically inspired weighted actuator torques. The PGM then measures the relative contribution of the stance ankle actuation. The DGM is associated with the gait stability, and quantifies the effects of inertia in terms of the Zero-Moment Point and the ground projection of center of mass. In addition, the DGM takes into account the stance foot dimension and the relative threshold between static and dynamic walking. As examples, both human-like and robotic walking motions during single support phase are generated for a planar biped system using the passivity weights and proper gait parameters. The calculated PGM values show more passive nature of human-like walking as compared with the robotic walking. The DGM results verify the dynamic nature of normal human walking with anthropomorphic foot dimension. In general, the DGMs for human-like walking are greater than those for robotic walking. The resulting DGMs also demonstrate their dependence on the stance foot dimension as well as the walking motion; for a given walking motion, smaller foot dimension results in increased dynamicity. Future work on experimental validation and demonstration will involve actual walking robots and human subjects. The proposed results will benefit the human gait studies and the development of walking robots.

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How Dynamic is Dynamic Walking? Human vs. Robotic Gait

Volume 6: 35th Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2011-47897 ◽

2011 ◽

Cited By ~ 1

Author(s):

Carlotta Mummolo ◽

Joo H. Kim

Keyword(s):

Center Of Mass ◽

Human Walking ◽

Walking Robots ◽

Dynamic Walking ◽

Biped Walking ◽

Walking Motion ◽

Relative Threshold ◽

Normal Human ◽

And Control ◽

Dynamic Gait

For design and control of biped walking robots, it is important to quantify the different level of dynamicity. We propose the Dynamic Gait Measure (DGM) that quantifies the dynamicity of a given biped walking motion. The DGM is associated with the gait stability, and quantifies the effects of inertia in terms of the Zero-Moment Point (ZMP) and the ground projection of center of mass (GCOM). Also, DGM takes into account the stance foot dimension and the relative threshold between static and dynamic walking. Human-like and robotic walking motions are generated for a planar biped system from an optimization problem. The resulting DGMs demonstrate their dependence on the stance foot dimension as well as the walking motion. The DGM results verify the dynamic nature of normal human walking. For a given gait motion, smaller foot dimension results in increased dynamicity. Moreover, the DGMs for normal human walking are greater than those for robotic walking. The proposed results will benefit the development of walking robots.

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Effect of the Motion in Horizontal Plane on the Stability of Biped Walking

Journal of Robotics and Mechatronics ◽

10.20965/jrm.1993.p0531 ◽

1993 ◽

Vol 5 (6) ◽

pp. 531-536

Author(s):

Ryoji Kodama ◽

◽

Toru Nogai ◽

Katsumi Suzuki

Keyword(s):

Horizontal Plane ◽

Sagittal Plane ◽

Frontal Plane ◽

Human Walking ◽

Walking Robots ◽

Biped Walking ◽

3 Dimensional ◽

Pendulum Model ◽

Walking Motion ◽

The Stability

The human act of walking consists of 3-dimensional motion in the sagittal plane, frontal plane, and horizontal plane. However, in a lot of walking robots investigated by many researchers, motions were only considered in the sagittal plane or in the sagittal and frontal planes. If robot walking is modeled to real human walking, then motion in the horizontal plane should also be considered in robot walking. In this paper, our purpose is to investigate the effect of motion in the horizontal plane on biped walking robot. The authors study the effect using an inverse pendulum model. Firstly, we explain horizontal motion in human walking and analyze the walking motion of a robot model. The results of computer simulation are also presented.

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Design of Biomechanical Legs with a Passive Toe Joint for Enhanced Human-like Walking

The Journal of Engineering Research [TJER] ◽

10.24200/tjer.vol14iss2pp166-181 ◽

2017 ◽

Vol 14 (2) ◽

pp. 166 ◽

Cited By ~ 1

Author(s):

Riadh Zaier ◽

A. Al-Yahmedi

Keyword(s):

Design Procedure ◽

Human Walking ◽

Human Gait ◽

Design Parameters ◽

Sultan Qaboos University ◽

Motion Trajectories ◽

Normal Human ◽

Working Principle ◽

Mass Spring ◽

Torsion Springs

This paper presents the design procedure of a biomechanical leg, with a passive toe joint, which is capable of mimicking the human walking. This leg has to provide the major features of human gait in the motion trajectories of the hip, knee, ankle, and toe joints. Focus was given to the approach of designing the passive toe joint of the biomechanical leg in its role and effectiveness in performing human like motion. This study was inspired by experimental and theoretical studies in the fields of biomechanics and robotics. Very light materials were mainly used in the design process. Aluminum and carbon fiber parts were selected to design the proposed structure of this biomechanical leg, which is to be manufactured in the Mechanical Lab of the Sultan Qaboos University (SQU). The capabilities of the designed leg to perform the normal human walking are presented. This study provides a noteworthy and unique design for the passive toe joint, represented by a mass-spring damper system, using torsion springs in the foot segment. The working principle and characteristics of the passive toe joint are discussed. Four-designed cases, with different design parameters, for the passives toe joint system are presented to address the significant role that the passive toe joint plays in human-like motion. The dynamic motion that is used to conduct this comparison was the first stage of the stance motion. The advantages of the presence of the passive toe joint in gait, and its effect on reducing the energy consumption by the other actuated joints are presented and a comparison between the four-designed cases is discussed.

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ADAPTIVE NEURAL NETWORK CONTROL OF A HUMAN SWING LEG AS A DOUBLE-PENDULUM CONSIDERING SELF-IMPACT JOINT CONSTRAINT

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2015-0015 ◽

2015 ◽

Vol 39 (2) ◽

pp. 201-219 ◽

Cited By ~ 2

Author(s):

Yousef Bazargan-Lari ◽

Mohammad Eghtesad ◽

Ahmad R. Khoogar ◽

Alireza Mohammad-Zadeh

Keyword(s):

Neural Network ◽

Primary Objective ◽

Network Control ◽

Knee Joints ◽

Human Walking ◽

Human Gait ◽

Double Pendulum ◽

Adaptive Neural Network ◽

Adaptive Neural Network Control ◽

Normal Human

For human walking, the swing leg is usually modeled as a double pendulum. Considering a joint self-impact constraint at the knee joint of the double pendulum model is the main difference in this study. The primary objective of this research is to propose a nonlinear Adaptive Neural Network (ANN) for this system. By using Gaussian RBF networks, asymptotically stable tracking is attained. We will use the available data of normal human walking for the desired trajectories of the hip and knee joints. By simulation of the system, we perceive that the swing leg tracks the normal human gait with a negligible and tolerable error.

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Quantifying Dynamic Characteristics of Human Walking for Comprehensive Gait Cycle

Journal of Biomechanical Engineering ◽

10.1115/1.4024755 ◽

2013 ◽

Vol 135 (9) ◽

Cited By ~ 36

Author(s):

Carlotta Mummolo ◽

Luigi Mangialardi ◽

Joo H. Kim

Keyword(s):

Dynamic Characteristics ◽

Gait Cycle ◽

Center Of Mass ◽

The Body ◽

Human Walking ◽

Static Balance ◽

Time Varying ◽

Biped Walking ◽

Foot Model ◽

Normal Human

Normal human walking typically consists of phases during which the body is statically unbalanced while maintaining dynamic stability. Quantifying the dynamic characteristics of human walking can provide better understanding of gait principles. We introduce a novel quantitative index, the dynamic gait measure (DGM), for comprehensive gait cycle. The DGM quantifies the effects of inertia and the static balance instability in terms of zero-moment point and ground projection of center of mass and incorporates the time-varying foot support region (FSR) and the threshold between static and dynamic walking. Also, a framework of determining the DGM from experimental data is introduced, in which the gait cycle segmentation is further refined. A multisegmental foot model is integrated into a biped system to reconstruct the walking motion from experiments, which demonstrates the time-varying FSR for different subphases. The proof-of-concept results of the DGM from a gait experiment are demonstrated. The DGM results are analyzed along with other established features and indices of normal human walking. The DGM provides a measure of static balance instability of biped walking during each (sub)phase as well as the entire gait cycle. The DGM of normal human walking has the potential to provide some scientific insights in understanding biped walking principles, which can also be useful for their engineering and clinical applications.

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Energy expenditure of a biped walking robot: instantaneous and degree-of-freedom-based instrumentation with human gait implications

Robotica ◽

10.1017/s0263574715000983 ◽

2016 ◽

Vol 35 (5) ◽

pp. 1054-1071 ◽

Cited By ~ 4

Author(s):

Dustyn Roberts ◽

Joseph Quacinella ◽

Joo H. Kim

Keyword(s):

Energy Expenditure ◽

Dynamic Balance ◽

Biped Robot ◽

Human Gait ◽

Walking Robots ◽

Time Duration ◽

Cost Of Transport ◽

Biped Walking ◽

Double Support ◽

Robotic Gait

SUMMARYEnergy expenditure (EE) is an important criterion for design and control of biped walking robots. However, the cause-effect analyses enabled by total EE, which is lumped over a time duration and all system degrees-of-freedom (DOFs), are limited. In this study, robotic gait energetics is evaluated through a DOF-based instrumentation system designed for instantaneous evaluation of bidirectional current and applied voltage at each joint actuator. The instrumentation system includes a dual-module arrangement of buffers and attenuators, and accommodates and synchronizes the voltage and current measurements from multiple actuators. For illustrative purposes, this system is implemented at each DC servomotor in a biped robot, DARwIn-OP, to analyze the electrical EE rates for walking at various speeds. In addition, a DOF-based model of instantaneous human EE rate is employed to enable quantitative characterization of robotic walking EE relative to that of humans. The robot's instantaneous lower-body EE rates are consistent with its periodic walking cycle, and their relative trends between single and double support phases are analogous to those of humans. The robotic cost of transport (COT) curve as a function of normalized speed is also consistent with the human COT in terms of its convexity. Conversely, the contrasting distributions of EE throughout the robot and human DOFs and the robotic COT curve's considerably larger magnitudes, smaller speed ranges, and higher sensitivity to speed illustrate the energetic consequences of stable but inefficient static walking in the biped robot relative to the more efficient dynamic walking of humans. These energetic characteristics enable the identification of the joints and gait cycle phases associated with inefficiency in biped robotic gait, and reflect the noticeable differences in the system parameters (rigid and flat versus segmented feet) and gait control strategies (bent versus straight knees, instants of peak ankle actuator torques, static versus dynamic balance stability). The proposed general instrumentation provides a quantitative approach to benchmarking human gait as well as general guidelines for the development of energy-efficient walking robots.

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