The Effect of the Toe on the Biped Robot

2013 ◽  
Vol 325-326 ◽  
pp. 1076-1082
Author(s):  
Seyed Mehdi Torklarki ◽  
Mohammad Danesh
Keyword(s):  
Reaction Force ◽  
Stability Margin ◽  
Biped Robot ◽  
Body Motion ◽  
Upper Body ◽  
Biped Robots ◽  
Double Support ◽  
The Stability ◽  
Single Support Phase ◽  
Support Phase

Evaluation of 9-DOF biped robots based on designated smooth and stable trajectories with two added toes is a challenging problem that is the focus of this paper. Simultaneously rotation of feet and toes is considered, which allows the robot to walk more efficiently and like a human being. A desired trajectory for the lower body is designed to increase the stability margin. This obtained by fitting proper polynomials at appropriate break points. Then, the upper body motion is planned based on the Zero Moment Point (ZMP) criterion to provide a stable motion for the biped robot. Next, dynamics equations are obtained for both single support phase (SSP) and double support phase (DSP). On the other hand, two biped robots, which one accompanied by toes, are also compared. Simulation results reveal that the biped robots with toes have better stability margin, less power consumption and more vertical reaction force.

scholarly journals Effects of Torso Pitch Motion on Energy Efficiency of Biped Robot Walking

2021 ◽  
Vol 11 (5) ◽  
pp. 2342
Author(s):  
Long Li ◽  
Zhongqu Xie ◽  
Xiang Luo ◽  
Juanjuan Li
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Biped Robot ◽  
Gait Pattern ◽  
Pattern Generation ◽  
Biped Robots ◽  
Pitch Motion ◽  
Double Support ◽  
Gait Parameters ◽  
Support Phase

Gait pattern generation has an important influence on the walking quality of biped robots. In most gait pattern generation methods, it is usually assumed that the torso keeps vertical during walking. It is very intuitive and simple. However, it may not be the most efficient. In this paper, we propose a gait pattern with torso pitch motion (TPM) during walking. We also present a gait pattern with torso keeping vertical (TKV) to study the effects of TPM on energy efficiency of biped robots. We define the cyclic gait of a five-link biped robot with several gait parameters. The gait parameters are determined by optimization. The optimization criterion is chosen to minimize the energy consumption per unit distance of the biped robot. Under this criterion, the optimal gait performances of TPM and TKV are compared over different step lengths and different gait periods. It is observed that (1) TPM saves more than 12% energy on average compared with TKV, and the main factor of energy-saving in TPM is the reduction of energy consumption of the swing knee in the double support phase and (2) the overall trend of torso motion is leaning forward in double support phase and leaning backward in single support phase, and the amplitude of the torso pitch motion increases as gait period or step length increases.

A force-resisting balance control strategy for a walking biped robot under an unknown, continuous force

Robotica ◽  
2014 ◽  
Vol 34 (7) ◽  
pp. 1495-1516
Author(s):  
Yeoun-Jae Kim ◽  
Joon-Yong Lee ◽  
Ju-Jang Lee
Keyword(s):  
External Force ◽  
Control Strategy ◽  
Balance Control ◽  
Biped Robot ◽  
Second Step ◽  
Double Support ◽  
Zero Moment ◽  
External Forces ◽  
Single Support Phase ◽  
Support Phase

SUMMARYIn this paper, we propose and examine a force-resisting balance control strategy for a walking biped robot under the application of a sudden unknown, continuous force. We assume that the external force is acting on the pelvis of a walking biped robot and that the external force in the z-direction is negligible compared to the external forces in the x- and y-directions. The main control strategy involves moving the zero moment point (ZMP) of the walking robot to the center of the robot's sole resisting the externally applied force. This strategy is divided into three steps. The first step is to detect an abnormal situation in which an unknown continuous force is applied by examining the position of the ZMP. The second step is to move the ZMP of the robot to the center of the sole resisting the external force. The third step is to have the biped robot convert from single support phase (SSP) to double support phase (DSP) for an increased force-resisting capability. Computer simulations and experiments of the proposed methods are performed to benchmark the suggested control strategy.

scholarly journals Optimal reference trajectories for walking and running of a biped robot

Robotica ◽  
2001 ◽  
Vol 19 (5) ◽  
pp. 557-569 ◽  
Author(s):  
C. Chevallereau ◽  
Y. Aoustin
Keyword(s):  
Biped Robot ◽  
Physical Parameters ◽  
Polynomial Functions ◽  
Minimal Energy ◽  
Double Support ◽  
Cyclic Motion ◽  
Under Construction ◽  
Single Support Phase ◽  
Reference Trajectories ◽  
Support Phase

The objective of this study is to obtain optimal cyclic gaits for a biped robot without actuated ankles. Two types of motion are studied: walking and running. For walking, the gait is composed uniquely of successive single support phases and instantaneous double support phases that are modelled by passive impact equations. The legs swap their roles from one single support phase to the next one. For running, the gait is composed of stance phases and flight phases. A passive impact with the ground exists at the end of flight. During each phase the evolution of m joints variables is assumed to be polynomial functions, m is the number of actuators. The evolution of the other variables is deduced from the dynamic model of the biped. The coefficients of the polynomial functions are chosen to optimise criteria and to insure cyclic motion of the biped. The chosen criteria are: maximal advance velocity, minimal torque, and minimal energy. Furthermore, the optimal gait is defined with respect to given performances of actuators: The torques and velocities at the output of the gear box are bounded. For this study, the physical parameters of a prototype, which is under construction, are used. Optimal walking and running are defined. The running is more efficient for high velocities than the walking with respect to the studied criteria.

The Experimental Study of the Influence of the Foot Articulated Structure on the Biped Robot Walking

2013 ◽  
Vol 461 ◽  
pp. 924-929
Author(s):  
Xiao Chun Hu ◽  
Xiao Peng Li ◽  
Qing Qing Zhang ◽  
Bao Zhao ◽  
Qin Xia
Keyword(s):  
Biped Robot ◽  
Body Motion ◽  
Human Walking ◽  
Future Research ◽  
Bionic Design ◽  
Biped Robots ◽  
Walking Gait ◽  
Comparison Results ◽  
Foot Deformation ◽  
Support Phase

Abstract: Purpose：By investigating the variation of the human walking gait kinematics with respect to the foot deformation constraint, prove that bionic design of feet are the necessity for biped robots to imitate human walking better in terms of flexibility, stability and efficiency. The results will be significant for future research and development of biped robots. Methods: A human being was assumed as a perfect biped robot which had ideal motion drive and control. The walking gait parameters of two healthy men with foot deformation unconstrained and constrained were tested respectively by the inertia motion capture suit, and then they were processed by programming and analyzed by comparison. Results: The data analysis showed that when subjects walked with foot deformation constrained, their angular displacements of lower limb joints generally increased, the curves of angular velocity and accelerations fluctuated in certain walking phases, the walking pace and stride length decreased obviously, the single support phase shortened while the double support phase lengthened. At the same time, subjects felt subjectively that their body motion was less flexible, the walking posture was difficult to control, and the walking stability was more strenuous to keep. Conclusion: Combining the logical analogies with the detailed experimentation results, it is inferred that biped robots with rigid feet will have to suffer awkward and unstable walking gait, heavier and strenuous steps, and lower energy efficiency while walking. The paper concludes the necessity of bionic design of the robot feet for improving the walking quality of the biped robots. The conclusion and the experiment data will be of significant value for future work of robot design and evaluation.

Optimization-based gait planning and control for biped robots utilizing the optimal allowable ZMP variation region

2018 ◽  
Vol 45 (4) ◽  
pp. 469-480 ◽  
Author(s):  
Hongbo Zhu ◽  
Minzhou Luo ◽  
Jingzhao Li
Keyword(s):  
Energy Efficiency ◽  
Stability Margin ◽  
Biped Robot ◽  
Step Length ◽  
Geometric Constraints ◽  
Average Height ◽  
Biped Robots ◽  
Gait Planning ◽  
Content Type ◽  
Double Support

Purpose The purpose of this study is to present an optimization-based gait planning method for biped robots according to the conditions of terrain, which takes fully the relationship between walking stability margin and energy efficiency into account. Design/methodology/approach First, the authors newly designed a practical gait motion synthesis algorithm by using the optimal allowable zero moment point (ZMP) variation region (OAZR), which can generate different gait motions corresponding to different terrains based on the modifiability of ZMP in lateral (y-axis) direction. Second, an effective gait parameter optimization algorithm is performed to find the optimal set of key gait parameters (step length, duration time of gait cycle, average height of center of mass (CoM), amplitude of the vertical CoM motion and double support ratio), which maximizes either the walking stability margin or the energy efficiency with certain walking stability margin under practical constraints (mechanical constraints of all joint motors, geometric constraints, friction force limit and yawing moment limit) according to the conditions of terrain. Third, the necessary controllers for biped robots have been introduced briefly. Findings The experiment data and results are described and analyzed, showing that the proposed method was verified through simulations and implemented on a DRC-XT biped robot. Originality/value The main contribution is that the OAZR has been defined based on AZR, which could be used to plan and generate the various feasible gait motions to help a biped robot to adapt effectively to various terrains.

scholarly journals Multiphase Trajectory Generation for Planar Biped Robot Using Direct Collocation Method

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yubin Liu ◽  
Shuai Heng ◽  
Xizhe Zang ◽  
Zhenkun Lin ◽  
Jie Zhao
Keyword(s):  
Energy Efficiency ◽  
Collocation Method ◽  
Biped Robot ◽  
Contact Forces ◽  
Two Phase ◽  
Double Support ◽  
Direct Collocation ◽  
Direct Collocation Method ◽  
The Stability ◽  
Support Phase

Stability and energy efficiency are the main focuses in the bipedal robot field. In this paper, we apply a multiphase gait, which is different from the widely used two-phase gait, to improve the stability at the moment, when a biped robot transfers from the double support phase to the single support phase. Then, we create dynamic equations with contact forces in each phase using Lagrangian formulation. Furthermore, the direct collocation method is utilized to generate the optimal trajectory toward both stability and energy efficiency. Finally, the comparison between multiphase gait and two-phase gait is performed with numerical simulations. The results prove that multiphase gait increases the stability margin in the cost of slightly decreasing energy efficiency. Besides, both gaits show a similar human-like characteristic in hip height variation during walking.

Gate Planning and Control of a Nine-Link Biped Robot with Toe Joints via Impact Effects

2019 ◽  
Vol 16 (01) ◽  
pp. 1950001 ◽  
Author(s):  
Vahid Mobinipour
Keyword(s):  
Stability Margin ◽  
Biped Robot ◽  
Forward Algorithm ◽  
Double Support ◽  
Model Based ◽  
Planning And Control ◽  
Ground Conditions ◽  
Hip Motion ◽  
Two Parameters ◽  
Support Phase

The adaptation of a biped’s foot motion to the ground conditions and maintaining stability of the robot is an undeniable necessity that is the focus of this research. In this research, dynamics equations will be obtained for single support phase (SSP), double support phase (DSP), and impact. The results of impact dynamics have been used to correlate the gait parameters with the contact event following impact. In this study, in addition to explaining impact equations for a nine-link biped robot with toe and heel in first and second impact phases, a clear response for the external impulses is obtained in a compact form for the first time. In this paper, the trajectory of the foot and toe is done by determining the constraints of motion parameters with and without impact effect. Then, a method based on smooth hip motion with the largest stability margin using only two parameters, is implemented through iterative calculations, to ensure stability of the robot in accordance with the criterion of zero-moment point (ZMP). Finally, the response of a model-based controller, called feed-forward algorithm (FA), and a non-model-based controller, called the transposes Jacobian algorithm (TJ), will be used to control the robot.

High-Efficient Biped Walking Based on Flat-Footed Passive Dynamic Walking with Mechanical Impedance at Ankles

2012 ◽  
Vol 24 (3) ◽  
pp. 498-506 ◽  
Author(s):  
Yuta Hanazawa ◽  
◽  
Masaki Yamakita
Keyword(s):  
Energy Efficient ◽  
Mechanical Impedance ◽  
Biped Robot ◽  
Dynamic Walking ◽  
Passive Dynamic Walking ◽  
Biped Robots ◽  
Biped Walking ◽  
Double Support ◽  
High Efficient ◽  
Support Phase

In this paper, we present novel biped walking based on flat-footed Passive Dynamic Walking (PDW) with mechanical impedance at the ankles. To realize biped robot achieving high-efficient walking, PDW has attracted attention. Recently, flat-footed passive dynamic walkers with mechanical impedance at the ankles have been proposed. We show that this passive walker achieves fast, energy-efficient walking using ankle springs and inerters. For this reason, we propose novel biped walking control that mimics PDW to realize biped robots achieving fast, energy-efficient walking on level ground. First, we design a flat-footed biped robot that achieves fast, energy-efficient PDW. To achieve walking based on PDW, the biped robot then takes advantage of a virtual gravitational field that is generated by actuators. The biped robot also pushes off with the foot in the double-support phase to restore energy. By walking simulation, we show that a flat-footed biped robot achieves fast, energy-efficient walking on level ground by the proposed method.

GA Based Trajectory Generation for a 7-DOF Biped Robot by Considering Feet Rotation during Double Support Phase

2012 ◽  
Vol 463-464 ◽  
pp. 1252-1255 ◽  
Author(s):  
Farsam Farzadpour ◽  
Mohammad Danesh
Keyword(s):  
High Speed ◽  
Trajectory Generation ◽  
Biped Robot ◽  
Bipedal Walking ◽  
Double Support ◽  
Straight Line ◽  
Zero Moment ◽  
The Stability ◽  
Support Phase ◽  
Double Support Phase

This paper presents a trajectory generation approach for a 7-DOF biped robot on level ground. Simultaneously rotation of feet in double support phase is considered which leads to high-speed and more similar to human being walking. The zero moment point (ZMP) stability criterion is used to ensure the stability of the bipedal walking robot. Since ZMP trajectory in human walking does not stay fixed, it needs to be a straight line shaped forward ZMP trajectory to have a natural walk. A genetic algorithm based method is proposed to obtain key parameters in trajectory generation such that the ZMP follows a predefined trajectory while minimizing power consumption. Simulation results demonstrate the effectiveness of the proposed method.

When is Vestibular Information Important During Walking?

2004 ◽  
Vol 92 (3) ◽  
pp. 1269-1275 ◽  
Author(s):  
Leah R. Bent ◽  
J. Timothy Inglis ◽  
Bradford J. McFadyen
Keyword(s):  
Gait Cycle ◽  
Vestibular Stimulation ◽  
Upper Body ◽  
Foot Placement ◽  
Double Support ◽  
Vestibular Information ◽  
Heel Contact ◽  
Somatosensory Input ◽  
Single Support Phase ◽  
Support Phase

Locomotion relies on vision, somatosensory input, and vestibular information. Both vision and somatosensory signals have been shown to be phase dependently modulated during locomotion; however, the regulation of vestibular information has not been investigated in humans. By delivering galvanic vestibular stimulation (GVS) to subjects at either heel contact, mid-stance, or toe-off, it was possible to investigate when vestibular information was important during the gait cycle. The results indicated a difference in the vestibular regulation of upper versus lower body control. Upper body responses to GVS applied at different times did not differ in magnitude for the head ( P = 0.2383), trunk ( P = 0.1473), or pelvis ( P = 0.1732) showing a similar dependence on vestibular information for upper body alignment across the gait cycle. In contrast, foot placement was dependent on the time when stimulation was delivered. Changes in foot placement were significantly larger at heel contact (during the double support phase) than when stimulation was delivered at mid-stance (in the single support phase of the gait cycle; P = 0.0193). These latter results demonstrate, for the first time, evidence of phase-dependent modulation of vestibular information during human walking.

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