A study of the effect of structural damping on gait stability in quadrupedal locomotion using a musculoskeletal robot

2012 ◽  
Author(s):  
Kenji Miki ◽  
Katsuyoshi Tsujita
Keyword(s):  
Structural Damping ◽  
Gait Stability ◽  
Quadrupedal Locomotion ◽  
Musculoskeletal Robot

scholarly journals Gait Stability Measurement by Using Average Entropy

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 412
Author(s):  
Han-Ping Huang ◽  
Chang Francis Hsu ◽  
Yi-Chih Mao ◽  
Long Hsu ◽  
Sien Chi
Keyword(s):  
Postural Stability ◽  
Multiscale Entropy ◽  
Gait Stability ◽  
Eyes Closed ◽  
Stride Interval ◽  
Step Interval ◽  
Stability Measurement ◽  
Eyes Open ◽  
Two Measures ◽  
Better Than

Gait stability has been measured by using many entropy-based methods. However, the relation between the entropy values and gait stability is worth further investigation. A research reported that average entropy (AE), a measure of disorder, could measure the static standing postural stability better than multiscale entropy and entropy of entropy (EoE), two measures of complexity. This study tested the validity of AE in gait stability measurement from the viewpoint of the disorder. For comparison, another five disorders, the EoE, and two traditional metrics methods were, respectively, used to measure the degrees of disorder and complexity of 10 step interval (SPI) and 79 stride interval (SI) time series, individually. As a result, every one of the 10 participants exhibited a relatively high AE value of the SPI when walking with eyes closed and a relatively low AE value when walking with eyes open. Most of the AE values of the SI of the 53 diseased subjects were greater than those of the 26 healthy subjects. A maximal overall accuracy of AE in differentiating the healthy from the diseased was 91.1%. Similar features also exists on those 5 disorder measurements but do not exist on the EoE values. Nevertheless, the EoE versus AE plot of the SI also exhibits an inverted U relation, consistent with the hypothesis for physiologic signals.

The Effect of Damping on Seismic Performance of Steel Frame

2014 ◽  
Vol 580-583 ◽  
pp. 1477-1480
Author(s):  
Xin Wu Wang ◽  
Chang Jiao Hu
Keyword(s):  
Seismic Performance ◽  
Frame Analysis ◽  
Dynamic Test ◽  
Steel Frame ◽  
Structural Damping ◽  
Panel Zone ◽  
Story Drift

To study the effect of damping on seismic performance of steel frame, using the pseudo dynamic test by inputting damping and no damping to analyze the seismic performance of semi-rigid steel frame. Analysis was focused on the effect of damping on the panel zone strain, story drift and interlayer force.The conclusion was that under the more severe earthquake, the structural damping had effects on the seismic performance of semi-rigid steel frame.

Dynamic Characteristics of a Piezoelectric Transducer with Structural Damping

2013 ◽  
Vol 198 ◽  
pp. 633-638 ◽  
Author(s):  
Marek Płaczek
Keyword(s):  
Piezoelectric Transducer ◽  
Piezoelectric Materials ◽  
Research Centre ◽  
Structural Damping ◽  
Mechatronic Systems ◽  
Mathematical Algorithm ◽  
Analysis And Synthesis ◽  
The Matrix ◽  
Piezoelectric Stacks ◽  
Future Work

Work presents a proposal of an analysis method of the piezoelectric transducer. The considered system is a longitudinally vibrating single PZT plate. The main aim of this work is to designate characteristics of the considered PZT plate. Using constitutive equations of piezoelectric materials and an equation of the plates motion a matrix of characteristics of the system was obtained. Relations between mechanical and electrical parameters (forces, displacements, electric current and voltage) that describe behaviour of the system are included in the matrix of characteristics. A dynamic flexibility relation between the plates deformation and a force applied to the system is considered. A structural damping of the plates material was being taken into consideration and its influence on the plates dynamic flexibility is analysed. This work is an introduction to a task of analysis of complex systems. In future work the developed model and proposed mathematical algorithm will be used to analyse piezoelectric stacks. Non-classical methods will be used. It is a part of research works of Gliwice research centre related with an analysis and synthesis of mechanical and mechatronic systems [4-7,9,10,16-18]. Passive and active mechanical and mechatronic systems with piezoelectric transducers were analysed [1-3]. Works were also supported by computer-aided methods [8]. Both classical and non-classical methods were being considered. The discussed subject is important due to increasing number of applications of both simple and reverse piezoelectric phenomena in various modern technical devices.

The Study on the Influence of Pipe-Soil Interaction on VIV for Different Free Span Types

2017 ◽  
Author(s):  
Chongyao Zhou ◽  
Gang Xu ◽  
Zhiming Huang ◽  
Dagang Zhang ◽  
Naiquan Ye ◽  
...  
Keyword(s):  
Time Domain ◽  
Cross Flow ◽  
Sensitivity Study ◽  
Structural Damping ◽  
Flexible Pipe ◽  
Wake Oscillator Model ◽  
Wake Oscillator ◽  
Different Types ◽  
Main Factors ◽  
Parameter Influence

Subsea pipeline laid on the seabed will experience free span when the lay path is long and seabed is rugged. Hydrodynamic loads caused by the currents around the pipeline can induce oscillations in both cross-flow and in-line directions. This phenomenon is called vortex-induced vibration (VIV) which is the most common case that could induce serious fatigue problems. The pipe-soil interaction is one of the main factors that influence the vibration. In this paper, a study focusing on the effect of pipe-soil interaction on VIV for different types of free span is presented. The Milan wake oscillator is applied to calculate the dynamic response induced by VIV in Orcaflex, and the results are compared with experimental data to identify its validity. A sensitivity study is also performed to study the parameter influence of the Milan wake oscillator model. Four types of free span (including the multiple free spans) are modeled in Orcaflex and time domain VIV analysis is carried out to study the influence of pipe-soil interaction. Comparison among different types of free span is discussed. The influence of structural damping is studied for flexible pipe only because its influence on steel pipe is negligible. The influence of structural damping on flexible pipe is studied by means of a predefined moment-curvature curve. In addition, several cases are studied to investigate the influence of tension on VIV by Milan wake oscillator.

Sign in / Sign up

Export Citation Format

Share Document