Gait motion stabilization tuning approach of biped robot based on augmented reality

SUMMARYZero moment point (ZMP) is the most popular concept that is applied to stabilize the gait motion of a biped robot. This paper utilizes ZMP with the augmented-reality (AR) method to improve the stability of gait motion of a biped robot. The 3ds Max computer software package is used to build a virtual robot. Under an achieved joint angle data of solid robot to produce an animation of the robot's trajectory, the joint angle data are transmitted to the virtual robot to analyze the offset of the trunk. Furthermore, this investigation adopts AR to allow the user to make direct comparisons between the solid and virtual robot before and after the gait motion is corrected. The animated trajectories of the virtual robot are compared and the relevant data provide feedback to the solid robot to adjust the joint angle and further correct its posture. The experimental results reveal that the proposed scheme can improve gait motion, even when the biped robot is affected by an unexpected loading disturbance. As well as improving the stability of gait motion of a biped robot, the results of this study can also be used to teach the application of the proposed method in a robotics class.

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On Solving the Multi-Objective Software Package Upgradability Problem

International Journal of Open Source Software and Processes ◽

10.4018/ijossp.2018040102 ◽

2018 ◽

Vol 9 (2) ◽

pp. 18-38

Author(s):

Noureddine Aribi ◽

Yahia Lebbah

Keyword(s):

Open Source Software ◽

Software Package ◽

Optimization Problem ◽

Mixed Integer ◽

Software Systems ◽

Objective Functions ◽

Multi Objective Optimization ◽

Multi Objective ◽

Before And After ◽

The Stability

Free and open source software (FOSS) distributions are increasingly based on the abstraction of packages to manage and accommodate new features before and after the deployment stage. However, due to inter-package dependencies, package upgrade entails challenging shortcomings of deployment and management of complex software systems, inhibiting their ability to cope with frequent upgrade failures. Moreover, the upgrade process may be achieved according to some criteria (maximize the stability, minimize outdated packages, etc.). This problem is actually a multi-objective optimization problem. Throughout the article, the authors propose a Leximax approach based on mixed integer linear programming (MILP) to tackle the upgradability problem, while ensuring efficiency and fairness requirements between the objective functions. Experiments performed on real-world instances, from the MANCOOSI project, show that the authors' approach efficiently finds solutions of consistently high quality.

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Effect of Additional Weight on Lyapunov Exponents for Human Squat Exercise

Volume 5: Biomedical and Biotechnology ◽

10.1115/imece2020-23943 ◽

2020 ◽

Author(s):

Jose Galarza ◽

Dumitru I. Caruntu

Keyword(s):

Time Series ◽

Lyapunov Exponents ◽

Motion Capture ◽

Software Package ◽

Joint Angle ◽

Knee Angle ◽

Additional Weight ◽

Knee Joint Angle ◽

Squat Exercise ◽

The Stability

Abstract This work deals with the stability of the dynamics of human squat exercise. This is a common exercise. The focus of this investigation is to analyze the knee angle time series and calculate the divergence for different weight added in the exercise. Experiments are conducted and motion capture used for each of the cases. Then the Lyapunov exponents of the time series of the knee joint angle are determined. Matlab software package is used for all calculations. Results are compared with data available in the literature. This work provides insight on the level of stability for added weight on the human squat exercise. This gives an insight on the level of safety of this exercise as weight is added to the human subject.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.463-464.1252 ◽

2012 ◽

Vol 463-464 ◽

pp. 1252-1255 ◽

Cited By ~ 3

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.

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Walking Pattern Filter for Dynamic Biped Robot With SMA Actuators

Aerospace ◽

10.1115/imece2006-15434 ◽

2006 ◽

Author(s):

E. Tarkesh Esfahani ◽

Mohammad Elahinia

Keyword(s):

Biped Robot ◽

Human Motion ◽

Main Criterion ◽

Biped Robots ◽

Sma Actuators ◽

Walking Pattern ◽

Delay Times ◽

Zero Moment ◽

The Stability ◽

The Given

In this paper we present a walking pattern filter for Shape Memory Alloy (SMA) actuated biped robots. SMAs are known for their slow response. The actuation speed limitation can potentially lead to stability problems for biped robots. This filter adapts the human motion for a SMA biped in order to have a stable walking pattern. The Zero Moment Point (ZMP) is used as a main criterion of the filter to guarantee the stability of the motion. The SMA actuators are designed based on the dynamic and kinematics data of the motion. The response time of each SMA actuator is modeled in order to estimate the behavior of the actuator in realizing the given trajectory. After applying the delay times to the motion new trajectories are generated and checked by the ZMP criterion. The output of the filter can generate smooth trajectories for the SMA biped robots. The filter furthermore guarantees the stability while mimicking the human motion. The filter provides a practical way to create stable walking patterns using SMA actuators.

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Stability of biped robotic walking with frictional constraints

Robotica ◽

10.1017/s0263574712000598 ◽

2012 ◽

Vol 31 (4) ◽

pp. 573-588 ◽

Cited By ~ 5

Author(s):

Xuefeng Zhou ◽

Yisheng Guan ◽

Li Jiang ◽

Haifei Zhu ◽

Chuanwu Cai ◽

...

Keyword(s):

Stability Analysis ◽

Closed Form ◽

Contact Area ◽

Frictional Force ◽

Biped Robot ◽

Biped Locomotion ◽

Stability Criteria ◽

Closed Form Solutions ◽

Zero Moment ◽

The Stability

SUMMARYTipping-over and slipping, which are related to zero moment point (ZMP) and frictional constraint respectively, are the two most common instability forms of biped robotic walking. Conventional criterion of stability is not sufficient in some cases, since it neglects frictional constraint or considers translational friction only. The goal of this paper is to fully address frictional constraints in biped walking and develop corresponding stability criteria. Frictional constraints for biped locomotion are first analyzed and then the method to obtain the closed-form solutions of the frictional force and moment for a biped robot with rectangular and circular feet is presented. The maximum frictional force and moment are calculated in the case of ZMP at the center of contact area. Experiments with a 6-degree of freedom active walking biped robot are conducted to verify the effectiveness of the stability analysis.

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On Solving the Multi-Objective Software Package Upgradability Problem

Research Anthology on Usage and Development of Open Source Software ◽

10.4018/978-1-7998-9158-1.ch007 ◽

2021 ◽

pp. 133-155

Author(s):

Noureddine Aribi ◽

Yahia Lebbah

Keyword(s):

Linear Programming ◽

Integer Linear Programming ◽

Mixed Integer Linear Programming ◽

Software Package ◽

Mixed Integer ◽

Software Systems ◽

High Quality ◽

Multi Objective ◽

Before And After ◽

The Stability

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Methods for Analyzing the Stability of an Earthen Dam Slope

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.969.245 ◽

2014 ◽

Vol 969 ◽

pp. 245-248 ◽

Cited By ~ 9

Author(s):

Eva Panulinova ◽

Slavka Harabinova

Keyword(s):

Slope Stability ◽

Software Package ◽

Computer Software ◽

Critical Factors ◽

Earthen Dam ◽

Essential Component ◽

The Stability

The slope stability of a water construction in four cross-profiles is analyzed in the article and the factors of safety reviewed. The GEO 5 software package for slope stability calculations is an essential component of work. The computer software was employed to simulate and calculate the stability in the particular profiles of the downstream and upstream slopes of the Domaša Dam. Bishop, Petterson and Sarma methods were applied to determine the critical factors of safety.

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The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171742 ◽

1994 ◽

Vol 52 ◽

pp. 802-803

Author(s):

Y. Feng ◽

X. Y. Cai ◽

R. J. Kelley ◽

D. C. Larbalestier

Keyword(s):

Single Crystals ◽

Oxygen Content ◽

Basal Plane ◽

Flux Pinning ◽

Pinning Centers ◽

Before And After ◽

Anomalous Peak ◽

Basal Plane Dislocation ◽

The Stability ◽

Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

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Sorbitol enhances the physicochemical stability of B12 vitamers

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000578 ◽

2020 ◽

Vol 90 (5-6) ◽

pp. 439-447 ◽

Cited By ~ 1

Author(s):

Andrew Hadinata Lie ◽

Maria V Chandra-Hioe ◽

Jayashree Arcot

Keyword(s):

Ascorbic Acid ◽

Uv Light ◽

Heat Exposure ◽

Water Soluble ◽

Uv Exposure ◽

Physicochemical Stability ◽

Before And After ◽

The Stability

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.

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Experimental and Numerical Study of Fracture Behavior of Rock-Like Material Specimens with Single Pre-Set Joint under Dynamic Loading

Materials ◽

10.3390/ma14102690 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2690

Author(s):

Bo Pan ◽

Xuguang Wang ◽

Zhenyang Xu ◽

Lianjun Guo ◽

Xuesong Wang

Keyword(s):

Crack Initiation ◽

Crack Propagation ◽

Joint Angle ◽

Simulation Software ◽

Dissipated Energy ◽

Energy Structure ◽

Joint Angles ◽

Crack Penetration ◽

Before And After ◽

The Impact

The Split Hopkinson Pressure Bar (SHPB) is an apparatus for testing the dynamic stress-strain response of the cement mortar specimen with pre-set joints at different angles to explore the influence of joint attitudes of underground rock engineering on the failure characteristics of rock mass structure. The nuclear magnetic resonance (NMR) has also been used to measure the pore distribution and internal cracks of the specimen before and after the testing. In combination with numerical analysis, the paper systematically discusses the influence of joint angles on the failure mode of rock-like materials from three aspects of energy dissipation, microscopic damage, and stress field characteristics. The result indicates that the impact energy structure of the SHPB is greatly affected by the pre-set joint angle of the specimen. With the joint angle increasing, the proportion of reflected energy moves in fluctuation, while the ratio of transmitted energy to dissipated energy varies from one to the other. NMR analysis reveals the structural variation of the pores in those cement specimens before and after the impact. Crack propagation direction is correlated with pre-set joint angles of the specimens. With the increase of the pre-set joint angles, the crack initiation angle decreases gradually. When the joint angles are around 30°–75°, the specimens develop obvious cracks. The crushing process of the specimens is simulated by LS-DYNA software. It is concluded that the stresses at the crack initiation time are concentrated between 20 and 40 MPa. The instantaneous stress curve first increases and then decreases with crack propagation, peaking at different times under various joint angles; but most of them occur when the crack penetration ratio reaches 80–90%. With the increment of joint angles in specimens through the simulation software, the changing trend of peak stress is consistent with the test results.

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