scholarly journals Using the Generalized Inverted Pendulum to Generate Less Energy-Consuming Trajectories for Humanoid Walking

2016 ◽  
Vol 63 (2) ◽  
pp. 245-262 ◽  
Author(s):  
Sahab Omran ◽  
Sophie Sakka ◽  
Yannick Aoustin
Keyword(s):  
Energy Consumption ◽  
Inverted Pendulum ◽  
Center Of Pressure ◽  
Ground Level ◽  
Vertical Position ◽  
Pivot Point ◽  
Joint Torques ◽  
Walking Gait ◽  
Consequent Reduction ◽  
New Feature

AbstractThis paper proposes an analysis of the effect of vertical position of the pivot point of the inverted pendulum during humanoid walking. We introduce a new feature of the inverted pendulum by taking a pivot point under the ground level allowing a natural trajectory for the center of pressure (CoP), like in human walking. The influence of the vertical position of the pivot point on energy consumption is analyzed here. The evaluation of a 3D Walking gait is based on the energy consumption. A sthenic criterion is used to depict this evaluation. A consequent reduction of joint torques is shown with a pivot point under the ground.

Effects of COM Vertical Oscillation on Joint Torques During 3D Walking of Humanoid Robots

2016 ◽  
Vol 13 (04) ◽  
pp. 1650019 ◽  
Author(s):  
Sahab Omran ◽  
Sophie Sakka ◽  
Yannick Aoustin
Keyword(s):  
Humanoid Robot ◽  
Inverted Pendulum ◽  
Center Of Mass ◽  
Vertical Motion ◽  
Humanoid Robots ◽  
Dynamics Simulation ◽  
Vertical Oscillation ◽  
Human Beings ◽  
Joint Torques ◽  
Consequent Reduction

This paper proposes an analysis of the effect of vertical motion of the center of mass (COM) during humanoid walking. The linear inverted pendulum (LIP) model is classically used to deal with humanoid balance during walking. The effects on energy consumption of the COM height remaining constant for humanoid robots, or varying like human beings are studied here. Two approaches are introduced for the comparison: the LIP which offers the great advantage of analytical solving (i.e., fast and easy calculations), and a numerical solving of the IP dynamics, which allows varying the height of the center of mass during walking. The results are compared using a sthenic criterion in a 3D dynamics simulation of the humanoid robot Romeo (Aldebaran Robotics Company) and show a consequent reduction of the robot torque solicitation when the COM oscillates vertically.

Comparing Standing Balance at Real and Virtual Elevated Environments

2002 ◽  
Vol 46 (26) ◽  
pp. 2169-2173
Author(s):  
Peter Simeonov ◽  
Hongwei Hsiao ◽  
Brian Dotson ◽  
Douglas Amnions
Keyword(s):  
Postural Balance ◽  
Occupational Safety ◽  
Center Of Pressure ◽  
Ground Level ◽  
Occupational Safety And Health ◽  
Visual Simulation ◽  
Mean Velocity ◽  
Deformable Surfaces ◽  
Safety And Health ◽  
Anterior Posterior

The study evaluated the efficacy of a surround-screen virtual reality (SSVR) system in simulating heights for studying human postural balance at elevation. Twenty four subjects performed standing tasks at 9-m elevation and ground level, on firm and deformable surfaces, in a real environment (RE) and a comparable virtual environment (VE). The RE was the interior of the high-bay laboratory at the National Institute for Occupational Safety and Health (NIOSH) in Morgantown, West Virginia; the VE simulated this environment in the SSVR system. Medial-lateral and anterior-posterior body sways and mean velocity of the human center-of-pressure displacement were collected using a force platform. The results indicated that the sway parameters were similar in VE and RE at elevation on both firm and deformable surfaces. At ground level, the sway parameters were significantly increased in the VE compared to the RE on a deformable surface, but not on a firm surface. It appears that visual simulation of elevated environments within a SSVR is adequate for studying the risk factors leading to losing balance and fall incidents.

On the Thermal Effects in the Design of Tilting-Pad Bearings Subjected to Inlet Pressure Build-Up

1991 ◽  
Vol 113 (3) ◽  
pp. 526-532 ◽  
Author(s):  
K. W. Kim ◽  
C. M. Rodkiewicz
Keyword(s):  
Thermal Effects ◽  
Center Of Pressure ◽  
Load Capacity ◽  
Inlet Pressure ◽  
Maximum Temperature ◽  
Pivot Point ◽  
Temperature Distributions ◽  
Tilting Pad ◽  
Tilting Pad Bearings ◽  
Force Coordinate

The presented analytical consideration of tilting-pad bearings incorporates simultaneously the changes in viscosity (due to viscous dissipation) and in the nonambient inlet pressure (due to momentum depletion within the fore-region). The solution provides the following quantities: film temperature distributions, pressure distribution, maximum temperature of the pad, load capacity, friction force, coordinate of the center of pressure, and coordinate of the pivot point. Comparison with the case when the inlet pressure is assumed to be ambient indicates the significance of the pressure build-up in the fore-region.

Fuzzy Logic Control of Time Periodic Mechanical Systems

1997 ◽  
Author(s):  
Dan Boghiu ◽  
S. C. Sinha ◽  
Dan B. Marghitu
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Control ◽  
Inverted Pendulum ◽  
Controller Design ◽  
Mechanical Systems ◽  
Elastic Beam ◽  
Vertical Position ◽  
Logic Control ◽  
Short Period ◽  
Time Periodic

Abstract The fuzzy logic control of mechanical systems with periodic coefficients is considered. The controller design is illustrated through two examples, which include linear as well as nonlinear systems. For the linear case, a controller is designed such that a single inverted pendulum with a time periodic follower force is stabilized in the vertical position. As an example of the nonlinear system, the flap motion of a parametrically excited rotating elastic beam is considered. The controller is designed such that the deflection of the beam tip vanishes in a short period of time.

Long-Short Term Neural Network Analysis of Center of Pressure of Gait

2020 ◽  
Vol 2 (1) ◽  
pp. 15-34
Author(s):  
Arshia Khan ◽  
Janna Madden
Keyword(s):  
Neural Network ◽  
Vascular Dementia ◽  
Center Of Pressure ◽  
Disease Diagnosis ◽  
Machine Learning Algorithms ◽  
Short Term ◽  
Biometric Data ◽  
Gait Patterns ◽  
Walking Gait ◽  
Early Predictors

Detection of vascular dementia in early stages of cognitive impairment is difficult to do in a clinical setting since the earliest changes are often discrete and physiological in nature. One major aspect of this is gait patterns. This project utilizes force-sensing platforms, motion capture, and EMG sensors to unobtrusively collect biometric data from an individual's walking gait patterns. The data parameters gathered were center of pressure, gait phase and end of unloading/toe-ff events. By quantifying and analyzing machine learning algorithms, specifically deep learning time-series based models, onset patterns of vascular dementia are explored with an overarching goal of creating a system that will assist in understanding and diagnosing cases of vascular dementia. The proposed system provides a tool for which gait can be analyzed and compared over a long period of time and opens opportunity to increased personalization in health monitoring and disease diagnosis and provides an avenue to increase patient-centricity of medical care. Since gait is one of the early predictors of vascular dementia, we developed a long short-term neural network to predict the gait variations from which we can predict the onset of vascular dementia.

scholarly journals Estimation and Closed-Loop Control of COG/ZMP in Biped Devices Blending CoP Measures and Kinematic Information

Robotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 89 ◽  
Author(s):  
Giuseppe Menga ◽  
Marco Ghirardi
Keyword(s):  
Closed Loop ◽  
Inverted Pendulum ◽  
Joint Angle ◽  
Center Of Pressure ◽  
Balance Control ◽  
External Disturbance ◽  
Practical Implementation ◽  
Complex Nature ◽  
Simple Relationship ◽  
Loop Control

The zero moment point ( Z M P ) and the linearized inverted pendulum model linking the Z M P to the center of gravity ( C O G ) have an important role in the control of the postural equilibrium (balance) of biped robots and lower-limb exoskeletons. A solution for balance real time control, closing the loop from the joint actual values of the C O G and Z M P , has been proposed by Choi. However, this approach cannot be practically implemented: While the Z M P actual value is available from the center of pressure ( C o P ) measured under the feet soles, the C O G is not measurable, but it can only be indirectly assessed from the joint-angle measures, the knowledge of the kinematics, and the usually poorly known weight distribution of the links of the chain. Finally, the possible presence of unknown external disturbance forces and the nonlinear, complex nature of the kinematics perturb the simple relationship between the Z M P and C O G in the linearized model. The aim of this paper is to offer, starting from Choi’s model, a practical implementation of closed-loop balance control fusing C o P and joint-angle measures, eliminating possible inconsistencies. In order to achieve this result, we introduce a model of the linearized inverted pendulum for an extended estimation, not only of C O G and Z M P , but also of external disturbances. This model is then used, instead of Choi’s equations, for estimation and balance control, using H ∞ theory. As the C O G information is recovered from the joint-angle measures, the identification of a statistically equivalent serial chain ( S E S C ) linking the C O G to the joint angles is also discussed.

THE EFFECTS OF DRESS SHOES ON STABILITY DURING QUIET STANDING AND ENERGY CONSUMPTION WHILE WALKING

2012 ◽  
Vol 12 (05) ◽  
pp. 1250029
Author(s):  
SAED MOHSEN MIRBOD ◽  
MOHAMMAD TAGHI KARIMI ◽  
A. ESHRAGHI
Keyword(s):  
Energy Consumption ◽  
Center Of Pressure ◽  
Force Plate ◽  
Normal Subjects ◽  
Quiet Standing ◽  
P Value ◽  
Cost Index ◽  
Mean Values ◽  
Physiological Cost ◽  
The Stability

Footwear is an extremely important clothing item worn by all individuals. Currently, there is insufficient research regarding the influence of dress shoes on standing stability and energy consumption while walking. Therefore, the aim of this study was to evaluate the influence of dress shoes on the performance of normal subjects based on stability and energy consumption analysis. Fifteen normal subjects were recruited in this research study to stand and walk with and without shoes. The stability of the subjects in quiet standing was measured by the use of a force plate based on center of pressure (COP) sway. The energy consumption was evaluated by a heart rate monitoring system (Polar Electro) based on the physiological cost index (PCI). The mean values of PCI while walking with and without shoes were 0.29 ± 0.117 and 0.265 ± 0.112 beats/m, respectively (p-value > 0.05). The amplitudes of COP sways in the mediolateral and anteroposterior directions were 10.4 ± 3.5 and 25 ± 6.92 mm while standing with shoes and 9.3 ± 2.84 and 22.5 ± 5.25 mm in barefoot standing, respectively (p-value > 0.05). It can be concluded that wearing dress shoes does not influence the performance of subjects while standing or walking.

Robust Bipedal Locomotion Based on a Hierarchical Control Structure

Robotica ◽  
2019 ◽  
Vol 37 (10) ◽  
pp. 1750-1767 ◽  
Author(s):  
Jianwen Luo ◽  
Yao Su ◽  
Lecheng Ruan ◽  
Ye Zhao ◽  
Donghyun Kim ◽  
...  
Keyword(s):  
Center Of Pressure ◽  
Center Of Mass ◽  
Hierarchical Control ◽  
Middle Level ◽  
Smooth Transition ◽  
Whole Body ◽  
Joint Torques ◽  
Low Level ◽  
Hybrid Controller ◽  
High Level

SummaryTo improve biped locomotion’s robustness to internal and external disturbances, this study proposes a hierarchical structure with three control levels. At the high level, a foothold sequence is generated so that the Center of Mass (CoM) trajectory tracks a planned path. The planning procedure is simplified by selecting the midpoint between two consecutive Center of Pressure (CoP) points as the feature point. At the middle level, a novel robust hybrid controller is devised to drive perturbed system states back to the nominal trajectory within finite cycles without chattering. The novelty lies in that the hybrid controller is not subject to linear CoM dynamic constraints. The hybrid controller consists of two sub-controllers: an oscillation controller and a smoothing controller. For the oscillation controller, the desired CoM height is specified as a sine-shaped function, avoiding a new attractive limit cycle. However, this controller results in the inevitable chattering because of discontinuities. A smoothing controller provides continuous properties and thus can inhibit the chattering problem, but has a smaller region of attraction compared with the oscillation controller. A hybrid controller merges the two controllers for a smooth transition. At the low level, the desired CoM motion is defined as tasks and embedded in a whole body operational space (WBOS) controller to compute the joint torques analytically. The novelty of the low-level controller lies in that within the WBOS framework, CoM motion is not subject to fixed CoM dynamics and thus can be generalized.

scholarly journals Constrained Quadratic Programming and Neurodynamics-Based Solver for Energy Optimization of Biped Walking Robots

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Liyang Wang ◽  
Ming Chen ◽  
Xiangkui Jiang ◽  
Wei Wang
Keyword(s):  
Energy Consumption ◽  
Quadratic Programming ◽  
Energy Optimization ◽  
Biped Robot ◽  
High Energy ◽  
Walking Robots ◽  
Biped Robots ◽  
Biped Walking ◽  
Joint Torques ◽  
Force Moment

The application of biped robots is always trapped by their high energy consumption. This paper makes a contribution by optimizing the joint torques to decrease the energy consumption without changing the biped gaits. In this work, a constrained quadratic programming (QP) problem for energy optimization is formulated. A neurodynamics-based solver is presented to solve the QP problem. Differing from the existing literatures, the proposed neurodynamics-based energy optimization (NEO) strategy minimizes the energy consumption and guarantees the following three important constraints simultaneously: (i) the force-moment equilibrium equation of biped robots, (ii) frictions applied by each leg on the ground to hold the biped robot without slippage and tipping over, and (iii) physical limits of the motors. Simulations demonstrate that the proposed strategy is effective for energy-efficient biped walking.

scholarly journals Humanoid standing control: learning from human demonstration

2002 ◽  
Vol 12 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Andreas Hofmann ◽  
Marko Popovic ◽  
Hugh Herr
Keyword(s):  
Ground Reaction Force ◽  
Center Of Pressure ◽  
Human Subjects ◽  
Reaction Force ◽  
Morphological Data ◽  
Human Model ◽  
Joint Torques ◽  
Double Support ◽  
High Level ◽  
Force Data

A three-dimensional numerical model of human standing is presented that reproduces the dynamics of simple swaying motions while in double-support. The human model is structurally realistic, having both trunk and two legs with segment lengths and mass distributions defined using human morphological data from the literature. In this investigation, model stability in standing is achieved through the application of a high-level reduced-order control system where stabilizing forces are applied to the model's trunk by virtual spring- damper elements. To achieve biologically realistic model dynamics, torso position and ground reaction force data measured on human subjects are used as demonstration data in a supervised learning strategy. Using Powell's method, the error between simulation data and measured human data is minimized by varying the virtual high-level force field. Once optimized, the model is shown to track torso position and ground reaction force data from human demonstrations. With only these limited demonstration data, the humanoid model sways in a biologically realistic manner. The model also reproduces the center-of-pressure trajectory beneath the foot, even though no error term for this is included in the optimization algorithm. This indicates that the error terms used (the ones for torso position and ground reaction force) are sufficient to compute the correct joint torques such that independent metrics, like center-of-pressure trajectory, are correct.

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