Development of an Advanced Model of Passive Dynamic Biped Walking

2013 ◽  
Author(s):  
Derek Koop ◽  
Christine Q. Wu
Keyword(s):  
Mathematical Model ◽  
Friction Model ◽  
Dynamic Walking ◽  
Passive Dynamic Walking ◽  
Biped Robots ◽  
Lugre Friction Model ◽  
Proposed Model ◽  
Invaluable Tool ◽  
Ground Reactions ◽  
Advanced Model

Passive dynamic walking is a manner of walking developed, partially or in whole, by the energy provided by gravity. Studying passive dynamic walking provides insight into human walking and is an invaluable tool for designing energy efficient biped robots. The objective of this research was to develop a continuous mathematical model of passive dynamic walking, in which the Hunt-Crossley contact model and the LuGre friction model were used to represent the normal and tangential ground reactions. A physical passive walker was built to validate the proposed mathematical model. A traditional impact-based passive walking model was also used as a reference to demonstrate the advancement of the proposed passive dynamic walking model. The simulated gait of the proposed model matched the gait of the physical passive walker exceptionally well, both in trend and magnitude.

Passive Dynamic Biped Walking—Part I: Development and Validation of an Advanced Model

2013 ◽  
Vol 8 (4) ◽  
Author(s):  
Derek Koop ◽  
Christine Q. Wu
Keyword(s):  
Mathematical Model ◽  
Friction Model ◽  
Dynamic Walking ◽  
Passive Dynamic Walking ◽  
Biped Robots ◽  
Lugre Friction Model ◽  
Proposed Model ◽  
Invaluable Tool ◽  
Development And Validation ◽  
Advanced Model

Passive dynamic walking is a manner of walking developed, partially or in whole, by the energy provided by gravity. Studying passive dynamic walking provides insight into human walking and is an invaluable tool for designing energy-efficient biped robots. The objective of this research was to develop a continuous mathematical model of passive dynamic walking, in which the Hunt–Crossley contact model, and the LuGre friction model were used to represent the normal and tangential ground reactions continuously. A physical passive walker was built to validate the proposed mathematical model. A traditional impact-based passive walking model was also used as a reference to demonstrate the advancement of the proposed passive dynamic walking model. The simulated gait of the proposed model matched the gait of the physical passive walker exceptionally well, both in trend and magnitude.

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.

Friction Hysteresis Modeling and Force Control in a Constrained Single-link Arm

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
A. Bazaei ◽  
M. Moallem
Keyword(s):  
Control System ◽  
Force Control ◽  
Interaction Force ◽  
Point Interaction ◽  
Friction Model ◽  
End Point ◽  
Lugre Friction Model ◽  
Proposed Model ◽  
Single Link ◽  
Force Control System

In this paper, we study friction characteristics of a constrained planar single-link arm in applications, where control of the end-point interaction force is required. The objective is to improve performance of a force control system by developing an adequate friction model. It is shown that hub friction increases with the applied force with the end-point force exhibiting significant hysteresis behavior. A friction model is presented for capturing these phenomena and compared with the widely used LuGre friction model. Effectiveness of the proposed model for friction compensation is further examined on an experimental force control system testbed.

A Dynamic Tire Friction Model for Combined Longitudinal and Lateral Motion

2001 ◽  
Author(s):  
Joško Deur ◽  
Jahan Asgari ◽  
Davor Hrovat
Keyword(s):  
Normal Pressure ◽  
Friction Model ◽  
Longitudinal Motion ◽  
Extended Model ◽  
Lateral Motion ◽  
State Behavior ◽  
Pressure Distributions ◽  
Lugre Friction Model ◽  
Proposed Model ◽  
Tire Friction

Abstract A dynamic tire friction model based on the comprehensive LuGre friction model has been proposed recently for the case of pure longitudinal motion. An extension of the model for combined longitudinal and lateral motion, including calculation of the self aligning torque, is presented in this paper. The extended model is derived for both uniform and non-uniform normal pressure distributions. The model steady-state behavior is validated with respect to Pacejka static tire model, which served as an “ideal” benchmark. Possible further improvements of the proposed model are also addressed.

scholarly journals Nanomanipulation Modeling and Simulation

2006 ◽  
Author(s):  
Yanto Mualim ◽  
Fathi H. Ghorbel ◽  
James B. Dabney
Keyword(s):  
Friction Model ◽  
Stick Slip ◽  
Interaction Forces ◽  
Mathematical Properties ◽  
Lugre Friction Model ◽  
Novel Approach ◽  
Proposed Model ◽  
Lugre Friction ◽  
Physical Phenomena ◽  
Well Posed

A novel approach to better model nanomanipulation of a nanosphere laying on a stage via a pushing scheme is presented. Besides its amenability to nonlinear analysis and simulation, the proposed model is also effective in reproducing experimental behaviors commonly observed during AFM-type nanomanipulation. The proposed nanomanipulation model consists of integrated subsystems that are identified in a modular fashion. The subsystems consistently define the dynamics of the nanomanipulator tip and nanosphere, interaction forces between the tip and the nanosphere, friction between the nanosphere and the stage, and the contact deformation between the nanomanipulator tip and the nanosphere. The main feature of the proposed nanomanipulation model is the Lund-Grenoble (LuGre) dynamic friction model that reliably represents the stick-slip behavior of atomic friction experienced by the nanosphere. The LuGre friction model introduces a new friction state and has desirable mathematical properties making it a well-posed dynamical model that characterizes friction with fidelity. The proposed nanomanipulation model facilitates further improvement and extension of each subsystem to accommodate other physical phenomena that characterize the physics and mechanics of nanomanipulation. Finally, the versatility and effectiveness of the proposed model is simulated and compared to existing models in the literature.

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.

A New LuGre Friction Model for MR-9000 Type MR Damper

2008 ◽  
Author(s):  
Fan Yang ◽  
Ramin Sedaghati ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Dynamic Behavior ◽  
Large Scale ◽  
Optimization Technique ◽  
Mr Damper ◽  
Least Square Method ◽  
Friction Model ◽  
Least Square ◽  
Lugre Friction Model ◽  
Proposed Model ◽  
Lugre Friction

This paper presents a new hysteresis model, based on the LuGre friction model, to analyze the dynamic behavior of large-scale Magneto-Rheological (MR) damper (MR-9000 type MR-damper [1]) accurately and efficiently. The gradient based optimization technique and the least square method will be utilized to identify the modal parameters. The dynamic behavior of MR-damper under different types of excitation and input current have been predicted using the proposed model and then compared with those predicted using modified Bouc-Wen model to verify the validity of the proposed model.

THE DEVELOPMENT OF THE MATHEMATICAL MODEL OF PREDICTING THE INDICATORS OF ACCREDITATION OF TECHNICAL UNIVERSITIES IN THE RUSSIAN FEDERATION

2017 ◽  
pp. 27-38
Author(s):  
Olga Mikhaylovna Tikhonova ◽  
Alexander Fedorovich Rezchikov ◽  
Vladimir Andreevich Ivashchenko ◽  
Vadim Alekseevich Kushnikov
Keyword(s):  
Mathematical Model ◽  
System Dynamics ◽  
Regression Model ◽  
Oriented Graph ◽  
Real Data ◽  
Educational Process ◽  
Proposed Model ◽  
Linear Differential ◽  
The University ◽  
The Mathematical Model

The paper presents the system of predicting the indicators of accreditation of technical universities based on J. Forrester mechanism of system dynamics. According to analysis of cause-and-effect relationships between selected variables of the system (indicators of accreditation of the university) there was built the oriented graph. The complex of mathematical models developed to control the quality of training engineers in Russian higher educational institutions is based on this graph. The article presents an algorithm for constructing a model using one of the simulated variables as an example. The model is a system of non-linear differential equations, the modelling characteristics of the educational process being determined according to the solution of this system. The proposed algorithm for calculating these indicators is based on the system dynamics model and the regression model. The mathematical model is constructed on the basis of the model of system dynamics, which is further tested for compliance with real data using the regression model. The regression model is built on the available statistical data accumulated during the period of the university's work. The proposed approach is aimed at solving complex problems of managing the educational process in universities. The structure of the proposed model repeats the structure of cause-effect relationships in the system, and also provides the person responsible for managing quality control with the ability to quickly and adequately assess the performance of the system.

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