Constrained Inverted Pendulum Model For Evaluating Upright Postural Stability

1982 ◽  
Vol 104 (4) ◽  
pp. 343-349 ◽  
Author(s):  
H. Hemami ◽  
A. Katbab
Keyword(s):  
Postural Stability ◽  
Feedback System ◽  
Linear Feedback ◽  
State Variables ◽  
Inverted Pendulum Model ◽  
Pendulum Model ◽  
Lyapunov’S Second Method ◽  
Angular Velocities ◽  
Reaction Forces ◽  
The Stability

The human torso motion about its upright position is analyzed and modeled by a feedback system where the ground reaction forces and constraint torques are explicitly computed. Further, Euler angles and body angular velocities are selected as state variables to simplify the dynamics. The general stability of this system is considered via Lyapunov’s second method. Two methods of preventing self rotation are discussed: Linear feedback law and holonomic torque constraints. The stability solution is verified by digital computer simulation.

Modeling of Human Posturokinetic Movements by a Linear Feedback System: Relations among Feedback Coefficients

2002 ◽  
Vol 95 (1) ◽  
pp. 308-318 ◽  
Author(s):  
Karen Roux ◽  
Christian Gentil ◽  
Alexander Grishin
Keyword(s):  
Neural Control ◽  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Movement Analysis ◽  
Feedback System ◽  
Whole Body ◽  
Linear Feedback ◽  
State Variables ◽  
Joint Torques ◽  
Angular Velocities

This study describes a method of modeling human trunk and whole body backward bending and suggests a possible neural control strategy. The hypothesis was that the control system can be modeled as a linear feedback system, in which the torque acting at a given joint is a function of the state variables (angular positions and angular velocities). The linear system enabled representation of the feedback system by a gain matrix. The matrix was computed from the kinematics recorded by a movement analysis system and from the joint torques calculated by inverse dynamics. To validate the control model, a comparison was made between the angular kinematics yielded by the model and the experimental data. Moreover, for all subjects, the same relationships between feedback coefficients were found although gain values were different. The study showed that the feedback system is an appropriate model of the strategy from performing an accurate controlled trunk or whole body backward bending in the sagittal plane.

scholarly journals Turning Gait Planning Method for Humanoid Robots

2018 ◽  
Vol 8 (8) ◽  
pp. 1257 ◽  
Author(s):  
Tianqi Yang ◽  
Weimin Zhang ◽  
Xuechao Chen ◽  
Zhangguo Yu ◽  
Libo Meng ◽  
...  
Keyword(s):  
Inverted Pendulum ◽  
Center Of Mass ◽  
Translational Motion ◽  
Humanoid Robots ◽  
Inverted Pendulum Model ◽  
Straight Line ◽  
Pendulum Model ◽  
The Stability ◽  
And Control ◽  
Present Simulation

The most important feature of this paper is to transform the complex motion of robot turning into a simple translational motion, thus simplifying the dynamic model. Compared with the method that generates a center of mass (COM) trajectory directly by the inverted pendulum model, this method is more precise. The non-inertial reference is introduced in the turning walk. This method can translate the turning walk into a straight-line walk when the inertial forces act on the robot. The dynamics of the robot model, called linear inverted pendulum (LIP), are changed and improved dynamics are derived to make them apply to the turning walk model. Then, we expend the new LIP model and control the zero moment point (ZMP) to guarantee the stability of the unstable parts of this model in order to generate a stable COM trajectory. We present simulation results for the improved LIP dynamics and verify the stability of the robot turning.

Lyapunov-stable control of mechatronic systems

2005 ◽  
Vol 219 (2) ◽  
pp. 173-185 ◽  
Author(s):  
O Enge ◽  
P Maißer
Keyword(s):  
Inverse Dynamics ◽  
Dynamic Control ◽  
Linear Feedback ◽  
Mechatronic Systems ◽  
Electromechanical Systems ◽  
Starting Point ◽  
Reaction Forces ◽  
The Stability ◽  
Lagrange Formalism ◽  
Stable Control

In this paper, a method for controlling mechatronic systems using inverse dynamics is proposed. The starting point is a unified mathematical approach to modelling electromechanical systems based on Lagrange formalism. This mathematical theory is used to represent such systems taking into account all interactions between their substructures. The concept of Lagrange formalism for electromechanical systems is given and the complete governing equations are presented. The Voronetz equations of a partially kinematically controlled electromechanical system (EMS) are derived. The corresponding reaction forces and voltages following from the Voronetz equations are determined. Using these reactions with small modifications, a so-called ‘augmented proportional-derivative (PD) dynamic control law’ is generated. This controller consists of a non-linear feedforward - based on inverse dynamics - and a linear feedback. The stability of the controller is proved using a Lyapunov function. The controller can also be applied to pure multibody systems or a sheer electrical system, both of which are borderline cases of mechatronic systems.

scholarly journals Postural stability in human running with step-down perturbations: an experimental and numerical study

2020 ◽  
Vol 7 (11) ◽  
pp. 200570 ◽  
Author(s):  
Özge Drama ◽  
Johanna Vielemeyer ◽  
Alexander Badri-Spröwitz ◽  
Roy Müller
Keyword(s):  
Postural Stability ◽  
Stance Phase ◽  
Numerical Study ◽  
Centre Of Mass ◽  
Trunk Motion ◽  
Inverted Pendulum Model ◽  
Reaction Forces ◽  
Step Down ◽  
Virtual Point ◽  
Human Running

Postural stability is one of the most crucial elements in bipedal locomotion. Bipeds are dynamically unstable and need to maintain their trunk upright against the rotations induced by the ground reaction forces (GRFs), especially when running. Gait studies report that the GRF vectors focus around a virtual point above the centre of mass (VP A ), while the trunk moves forward in pitch axis during the stance phase of human running. However, a recent simulation study suggests that a virtual point below the centre of mass (VP B ) might be present in human running, because a VP A yields backward trunk rotation during the stance phase. In this work, we perform a gait analysis to investigate the existence and location of the VP in human running at 5 m s −1 , and support our findings numerically using the spring-loaded inverted pendulum model with a trunk. We extend our analysis to include perturbations in terrain height (visible and camouflaged), and investigate the response of the VP mechanism to step-down perturbations both experimentally and numerically. Our experimental results show that the human running gait displays a VP B of ≈−30 cm and a forward trunk motion during the stance phase. The camouflaged step-down perturbations affect the location of the VP B . Our simulation results suggest that the VP B is able to encounter the step-down perturbations and bring the system back to its initial equilibrium state.

DERIVATION AND VALIDATION OF A SPATIAL MULTI-LINK HUMAN POSTURAL STABILITY MODEL

2016 ◽  
Vol 40 (2) ◽  
pp. 155-167
Author(s):  
Nicholas R. Bourgeois ◽  
Robert G. Langlois
Keyword(s):  
Postural Stability ◽  
Inverted Pendulum ◽  
Dynamic Models ◽  
Alternative Methods ◽  
Ship Motions ◽  
Inverted Pendulum Model ◽  
Pendulum Model ◽  
Stability Model ◽  
Human Balance ◽  
Naval Engineering

In naval engineering and related disciplines, it is common for dynamic models of the human body to be used in conjunction with quantitative records of body and ship motions, in order to study human balance behaviour while performing various shipboard activities. Research in this area can lead to improvements in ship operations and designs that improve crew safety and efficiency. This paper presents the development of a new spatial 18 degree-of-freedom (DOF)1 ship-inverted pendulum model that incorporates 6 DOF ship motion and 3 DOF joints representing ankle, knee, hip, and neck motions. The derived model is then validated by comparing it to similar models derived using alternative methods but simulated under equivalent input conditions.

Digital Study of a Stability Analogy

1967 ◽  
Vol 71 (680) ◽  
pp. 576-579
Author(s):  
B. S. Thornton ◽  
T. M. Park
Keyword(s):  
Digital Computer ◽  
Feedback System ◽  
Linear Feedback ◽  
Phase Lag ◽  
External Perturbations ◽  
Stability Diagrams ◽  
Separating Flow ◽  
Non Linear ◽  
Blade System ◽  
The Stability

An investigation has been made into the stability of compressor blade flutter in separating flow in the presence of external perturbations. The fluttering blade is an example of a hysteretic system governed by a non-linear difference-differential equation for which an analytical approach is not possible and for which the authors originally proposed this new treatment. For design purposes a digital computer has been used to produce stability diagrams under specified conditions including blade torsion. The solution for the response is also available if required. The method involves forming the non-linear feedback analogue to the blade system and which has behaviour governed by the same equation as that studied. The stability is then studied on a digital computer in the presence of small external perturbations by means of a dual input describing function applied to the analogous feedback system with consideration given to the aerodynamic phase lag involved and initially small blade torsional motion.

A Control Method of Four-Legged Robot Stable Walking with Diagonal Gait

2011 ◽  
Vol 148-149 ◽  
pp. 82-87
Author(s):  
Chang Hua Fan ◽  
Zhen Jiang ◽  
Bai Yu He
Keyword(s):  
Dynamic Equation ◽  
Stability Problem ◽  
Inverted Pendulum ◽  
Control Method ◽  
Flip Angle ◽  
Legged Robot ◽  
Motion Stability ◽  
Inverted Pendulum Model ◽  
Pendulum Model ◽  
The Stability

This paper proposes a kind of control method used to solve the stability problem of the trotted robot. Propose the concept of inside flip design four-footed robot and build a double inverted pendulum model. Establish dynamic equation to analyze the factors of affecting the motion stability. During walking, the center of gravity can maintain a proper vibration and have a maximum safety region of flip angle. Finally, use Adams to verify the control method.

scholarly journals Pedalling Technique and Postural Stability During Incremental Cycling Exercise – Relationship with Cyclist FMSTM Score

2016 ◽  
Vol 7 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Indrek Rannama ◽  
Kirsti Pedak ◽  
Karmen Reinpõld ◽  
Kristjan Port
Keyword(s):  
Postural Stability ◽  
Horizontal Plane ◽  
Reaction Force ◽  
The Body ◽  
Functional Movement Screen ◽  
Cycling Exercise ◽  
Functional Movement ◽  
Competitive Cyclists ◽  
Reaction Forces ◽  
The Stability

Abstract Purpose of the present study was to examine the changes in the pedalling kinetics and in the ground reaction forces as a measure of the cycling stability during an incremental cycling exercise. Furthermore, we compared the effectiveness of the pedalling technique and postural stability between the high and low Functional Movement Screen score (FMSTM) cyclists and analysed the relationships between the cycling specific postural stability, pedalling kinetics and cyclists FMSTM test scores. 31 competitive cyclists (18.5±2.1y; 1.81±0.06m; 73.7±7.5kg) were categorized based on the (FMSTM) test results in a low (LS, n=19; FMS≤14) and a high (HS, n=12; FMS>14) score group. The pedalling effectiveness and absolute symmetry indexes, as well the ground reaction force (GRF) were measured during incremental cycling exercise. Cycling specific postural stability was expressed as the body mass corrected standard deviation of 3 linear and 3 angular GRF components during a 30sec cycling at four power levels. We found that during incremental cycling exercise the pedalling effectiveness, smoothness and cyclist’s swaying in all three planes increased according to the combined effect of the workload and fatigue. Cyclists with high FMSTM score showed a lower bilateral pedalling asymmetry and a greater cycling specific postural stability, but showed no differences in the pedalling effectiveness and smoothness compared with the LS cyclists. Cyclist’s FMSTM score were moderately related with the stability components acting along the horizontal plane. The pedalling effectiveness, smoothness and bilateral asymmetry were inversely related to the components acting perpendicularly to the horizontal plane.

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