scholarly journals A minimized falling damage method for humanoid robots

2017 ◽  
Vol 14 (5) ◽  
pp. 172988141772801 ◽  
Author(s):  
Qingqing Li ◽  
Xuechao Chen ◽  
Yuhang Zhou ◽  
Zhangguo Yu ◽  
Weimin Zhang ◽  
...  
Keyword(s):  
Motion Capture ◽  
Humanoid Robot ◽  
Inverted Pendulum ◽  
Humanoid Robots ◽  
Living Environment ◽  
Second Phase ◽  
Leg Length ◽  
Heuristic Strategy ◽  
Two Phases ◽  
The Impact

In order to better adapt to human living environment for improving the ability of serving people on various occasions, humanoid robots need to prevent themselves from being severely damaged during falling backward. In this article, we have study the law of human falling motion with a motion capture system and propose a minimized falling damage method for humanoid robots. Falling backward is divided into two phases: the falling phase and the touchdown phase. The parametric optimal strategy based on inverted pendulum with flywheel is used to plan the motion of robot in the first phase to reduce the impact. In the second phase, to prevent the robot from bouncing and rolling over, the heuristic strategy including the best ratio of leg length inspired by biomechanical is adopted. The experiments have been tested on the BIT Humanoid Robot 6 prototype platform and the presented method has been validated.

scholarly journals Physics-Based Simulations of Flow and Fire Development Downstream of a Canopy

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 683
Author(s):  
Gilbert Accary ◽  
Duncan Sutherland ◽  
Nicolas Frangieh ◽  
Khalid Moinuddin ◽  
Ibrahim Shamseddine ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Forest Canopy ◽  
Prescribed Burning ◽  
Second Phase ◽  
Flow Conditions ◽  
Developed Turbulence ◽  
Large Eddy ◽  
Long Time ◽  
Two Phases ◽  
The Impact

The behavior of a grassland fire propagating downstream of a forest canopy has been simulated numerically using the fully physics-based wildfire model FIRESTAR3D. This configuration reproduces quite accurately the situation encountered when a wildfire spreads from a forest to an open grassland, as can be the case in a fuel break or a clearing, or during a prescribed burning operation. One of the objectives of this study was to evaluate the impact of the presence of a canopy upstream of a grassfire, especially the modifications of the local wind conditions before and inside a clearing or a fuel break. The knowledge of this kind of information constitutes a major element in improving the safety conditions of forest managers and firefighters in charge of firefighting or prescribed burning operations in such configurations. Another objective was to study the behavior of the fire under realistic turbulent flow conditions, i.e., flow resulting from the interaction between an atmospheric boundary layer (ABL) with a surrounding canopy. Therefore, the study was divided into two phases. The first phase consisted of generating an ABL/canopy turbulent flow above a pine forest (10 m high, 200 m long) using periodic boundary conditions along the streamwise direction. Large Eddy Simulations (LES) were carried out for a sufficiently long time to achieve a quasi-fully developed turbulence. The second phase consisted of simulating the propagation of a surface fire through a grassland, bordered upstream by a forest section (having the same characteristics used for the first step), while imposing the turbulent flow obtained from the first step as a dynamic inlet condition to the domain. The simulations were carried out for a wind speed that ranged between 1 and 12 m/s; these values have allowed the simulations to cover the two regimes of propagation of surfaces fires, namely plume-dominated and wind-driven fires.

HUMANOID ROBOT MOTION GENERATION SCHEME FOR TASKS UTILIZING IMPULSIVE FORCE

2012 ◽  
Vol 09 (02) ◽  
pp. 1250008 ◽  
Author(s):  
TEPPEI TSUJITA ◽  
ATSUSHI KONNO ◽  
SHUNSUKE KOMIZUNAI ◽  
YUKI NOMURA ◽  
TOMOYA MYOJIN ◽  
...  
Keyword(s):  
Humanoid Robot ◽  
Control Method ◽  
Three Dimensional ◽  
Humanoid Robots ◽  
Impulsive Force ◽  
Motion Generation ◽  
Three Dimensional Model ◽  
Large Force ◽  
The Impact ◽  
Impact Motion

In order to exert a large force on an environment, it is effective to apply impulsive force. We describe the motions in which tasks are performed by applying impulsive force as "impact motions." This paper proposes a way to generate impact motions for humanoid robots to exert a large force and the feedback control method for driving a nail robustly. The impact motion is optimized based on a three dimensional model using sequential quadratic programming (SQP). In this research, a nailing task is taken as an example of impact motion. A dominant parameter for driving a nail strongly is revealed and motions which maximize the parameter are generated considering the robot's postural stability. In order to evaluate the proposed scheme, a life-sized humanoid robot drives nails into a plate made of chemical wood. The optimized motion is compared with a motion designed heuristically by a human. Average driving depth is clearly increased by the proposed method.

scholarly journals Adrian Cowell e a Amazônia Brasileira

2021 ◽  
Author(s):  
Filipe Freitas Chaves
Keyword(s):  
Conflicts Of Interest ◽  
Road Construction ◽  
Indigenous Populations ◽  
Second Phase ◽  
Hydroelectric Dams ◽  
The People ◽  
Rubber Tappers ◽  
Gold Miners ◽  
Two Phases ◽  
The Impact

This article aims to examine two phases of the English director Adrian Cowell (1934-2011), who documented the Brazilian Amazon for 50 years. The first phase that we intend to examine is when he arrives in the country and meets the Villas Bôas brothers, filming the attempt by the sertanista brothers to attract isolated Indians into the interior of the Xingu National Park, in order to save them from civilization. The second phase we want to analyze is when he returns to the country, in 1980, after a season abroad, and films for a decade what would become his most famous series: The Decade of Destruction. Adrian Cowell followed the entire process of development and destruction of the Amazon, conflicts of interest, the impact of major projects, advances in agriculture and livestock, colonization projects, road construction and hydroelectric dams and their consequences in daily life of the people who live in the region: indigenous populations, rubber tappers, farmers, loggers, gold miners and others. The study of his films is extremely important to encourage debate and awareness about socio-environmental issues, aiming at the preservation of the largest forest in the world.

Sensitivity Study of Lower Plenum Boron Injection in a BWR

2009 ◽  
Author(s):  
Jin Yan ◽  
Andrew Mallner
Keyword(s):  
Sensitivity Study ◽  
Operating Conditions ◽  
Second Phase ◽  
Cfd Model ◽  
Technical Approach ◽  
Test Program ◽  
Scale Test ◽  
Water Reactors ◽  
Two Phases ◽  
The Impact

Boiling water reactors (BWRs) are equipped with a standby liquid control system (SLCS). The SLCS is used to inject boron to shutdown the reactor from full power condition in the event that the control rods fail to insert. In order for the SLCS system to shut down the reactor, adequate mixing of the borated solution with the reactor coolant is necessary. In BWRs prior to BWR 5, the boron injection points are located in the lower plenum. The objective of this project is to evaluate the impact of the operating conditions on the boron injection based on the understanding of the behavior of multi-species flow in typical pre-BWR 5 reactors by using computational fluid dynamics (CFD). The project is divided into two phases. At the first phase, a CFD model based on the test configurations of GE 1/6 scale test program was established. The results were validated against measurements conducted by GE during the 1/6 scale test program performed in 1981. The validation shows that the CFD can give accurate predictions of the boron mixing. The technical approach employed in the CFD model was adequate to capture the boron mixing process in the BWR lower plenum. The second phase of the project is the sensitivity study based on the same technical approach developed in the first phase. However, a simplified BWR lower plenum model was used due to the time constrain. In the sensitivity study, the baseline case and four additional cases with different operating conditions were investigated using the same CFD approach.

Assessment of wind power capacity credit in Morocco: Outlook to 2020

2019 ◽  
Vol 44 (2) ◽  
pp. 196-207
Author(s):  
Yassir El Karkri ◽  
Aboubakr El Makrini ◽  
Hassane El Markhi ◽  
Tijani Lamhamdi ◽  
Hassan El Moussaoui
Keyword(s):  
Wind Energy ◽  
Wind Farm ◽  
Electric Energy ◽  
Wind Farms ◽  
Electricity Production ◽  
Second Phase ◽  
Energy Integration ◽  
Production Network ◽  
Two Phases ◽  
The Impact

The present article focuses on the calculation of the wind capacity credit by integrating the Moroccan project on the wind energy of 1000 MW in 2020. After an introduction to the Moroccan Integrated Wind Energy Project, a wind capacity credit assessment program will be implemented on Matlab software including the whole information about “installed capacity, number of plants, failure rate, types of installed units, peak demand etc.” This program will be used to calculate the safety rate of an electrical system as well as the capacity credit of Morocco’s electricity production network. This section will be built in two phases: the first phase will examine the impact of TAZA wind farm with an installed power of 150 MW, while the second phase will focus on the generalization of this study on all the wind farms that will be injected to the Moroccan grid in 2020. The research provides conclusion according to comments and assessment of the impact of this electric energy integration based on the wind generation.

Motion Planning for Humanoid Robots in Complex Environments Based on Stance Sequence and ZMP Reference

2012 ◽  
Vol 197 ◽  
pp. 415-422 ◽  
Author(s):  
Hong Liu ◽  
Qing Sun
Keyword(s):  
Humanoid Robot ◽  
Inverted Pendulum ◽  
Humanoid Robots ◽  
Pattern Generator ◽  
Complex Environments ◽  
Inverted Pendulum Model ◽  
Walking Pattern ◽  
Pendulum Model ◽  
Novel Method ◽  
Zero Moment

It is a great challenge to plan motion for humanoid robots in complex environments especially when the terrain is cluttered and discrete. To address this problem, a novel method is proposed in this paper by planning the gait according to the stance sequence and ZMP (Zero Moment Point) reference. It consists of two components: an adaptive footstep planner and a walking pattern generator. The adaptive footstep planner can generate the stance path according to the walking rules and adjust the orientation of body relevantly. As the footstep locations are determined, Linear Inverted Pendulum Model (LIPM) is used to generate the walking pattern with a moving ZMP reference. As demonstrated in experiments on the humanoid robot HOAP-2, our method can successfully plan footstep trajectories as well as generate the stable and natural-looking gait in typical cluttered and discrete environments.

NATURAL BEHAVIOR GENERATION FOR HUMANOID ROBOTS

2004 ◽  
Vol 01 (04) ◽  
pp. 637-649
Author(s):  
TAKAHIRO MIYASHITA ◽  
HIROSHI ISHIGURO
Keyword(s):  
Humanoid Robot ◽  
Inverted Pendulum ◽  
Humanoid Robots ◽  
Communication Behavior ◽  
Hybrid Generation ◽  
Natural Behavior ◽  
Hybrid Controller ◽  
Wheeled Inverted Pendulum ◽  
Almost All ◽  
Task Oriented

Human behaviors consist of both voluntary and involuntary motions. Almost all behaviors of task-oriented robots, however, consist solely of voluntary motions. Involuntary motions are important for generating natural motions like those of humans. Thus, we propose a natural behavior generation method for humanoid robots that is a hybrid generation between voluntary and involuntary motions. The key idea of our method is to control robots with a hybrid controller that combines the functions of a communication behavior controller and body balancing controllers. We also develop a wheeled inverted pendulum type of humanoid robot, named "Robovie-III," in order to generate involuntary motions like oscillation. This paper focuses on the system architecture of this robot. By applying our method to this robot and conducting preliminary experiments, we verify its validity. Experimental results show that the robot generates both voluntary and involuntary motions.

scholarly journals The Rh-1 Full-Size Humanoid Robot: Design, Walking Pattern Generation and Control

2009 ◽  
Vol 6 (3-4) ◽  
pp. 301-344 ◽  
Author(s):  
M. Arbulú ◽  
D. Kaynov ◽  
L. Cabas ◽  
C. Balaguer
Keyword(s):  
Degrees Of Freedom ◽  
Humanoid Robot ◽  
Inverted Pendulum ◽  
Inverse Dynamics ◽  
Mechanical Design ◽  
Pattern Generation ◽  
Software Architectures ◽  
Second Phase ◽  
Structural Behaviour ◽  
Biped Walking

This paper is an overview of the humanoid robot Rh-1, the second phase of the Rh project, which was launched by the Robotics Lab at the Carlos III University of Madrid in 2002. The robot mechanical design includes the specifications development in order to construct a platform, which is capable of stable biped walking. At first, the robots’ weights were calculated in order to obtain the inverse dynamics and to select the actuators. After that, mechanical specifications were introduced in order to verify the robot’s structural behaviour with different experimental gaits. In addition, an important aspect is the joints design when their axes are crossed, which is called ‘Joints of Rectangular Axes’ (JRA). The problem with these joints is obtaining two or more degrees of freedom (DOF) in small space. The construction of a humanoid robot also includes the design of hardware and software architectures. The main advantage of the proposed hardware and software architectures is the use of standardised solutions frequently used in the automation industry and commercially available hardware components. It provides scalability, modularity and application of standardised interfaces and brings the design of the complex control system of the humanoid robot out of a closed laboratory to industry. Stable walking is the most essential ability for the humanoid robot. The three dimensional Linear Inverted Pendulum Model (3D-LIPM) and the Cart-table models had been used in order to achieve natural and dynamic biped walking. Humanoid dynamics is widely simplified by concentrating its mass in the centre of gravity (COG) and moving it following the natural inverted pendulum laws (3D-LIPM) or by controlling the cart motion (Cart-table model). An offline-calculated motion pattern does not guarantee the walking stability of the humanoid robot. Control architecture for the dynamic humanoid robot walking was developed, which is able to make online modifications of the motion patterns in order to adjust it to the continuously changing environment. Experimental results concerning biped locomotion of the Rh-1 humanoid robot are presented and discussed.

scholarly journals The impact of non-accessible library and information science journals on research productivity in Pakistan

2016 ◽  
pp. 40-57
Author(s):  
Shamshad Ahmed ◽  
Awais Uzair
Keyword(s):  
Social Networking Sites ◽  
Research Productivity ◽  
Information Science ◽  
Citation Rate ◽  
Journal Citation Report ◽  
Library And Information Science ◽  
Second Phase ◽  
Mixed Method Research ◽  
Two Phases ◽  
The Impact

The purpose of this paper is to identify: (a) Non-accessible library and information science journals from HEC National Digital Library (DL) Subscribed databases, (b) Approaches adopted by the LIS researchers to acquire non-accessible articles, and (c) The impact of non-accessible articles on their research endeavor. A sequential exploratory strategy of mixed method research was applied to identify the impact of non-accessible LIS journals on research. This study was completed in two phases. In the first phase, an online surfing of all HEC subscribed databases was conducted and a list of openly accessible, partially accessible and non-accessible LIS journals was prepared. Impact factor of journals was checked from the list of Journal Citation Report by Thomson Reuter, 2013. In the second phase, a structured questionnaire was prepared to identify the approaches adopted by the researchers to acquire non-accessible articles and their impact on research productivity. Findings of the study show that (a) Emerald, (b) Science Direct, (c) JSTOR, (d) Project Muse, (e) Taylor & Francis, (f) Wiley-Blackwell Journals, and (g) University of Chicago Press, are the HEC subscribed databases which have LIS journals. Study reveals that there are 18 % non-accessible and 37 % partially accessible LIS journals on the HEC subscribed databases. Researchers tried to acquire non-accessible articles through friends, social networking sites (SNS) Groups, BDD and by requesting to authors etc. Respondents agreed that non-accessible journals do impact on research productivity. As a result, citations of non-accessible articles decreases, which negatively impact the quality and quantity of both authors and researchers' work. The outcomes of this study are significant for LIS researchers to become aware of the current situation of non-accessible journals and its impact on their research endeavors. It will also guide the HEC and research institutions to redesign their policy for the subscription of relevant databases that will enable complete access to journals on LIS discipline. It will also help to increase the quality of researchers' work and citation rate of authors' articles. This study may then be replicated in other fields and countries also. There is not enough work analyzing the impact of non-accessible journals on research productivity.

scholarly journals Impact of Twitter Sentiment Related to Bitcoin on Stock Price Returns

2020 ◽  
Vol 26 (6) ◽  
pp. 60-71
Author(s):  
Feda Hassan Jahjah ◽  
Muhanad Rajab
Keyword(s):  
Exchange Rate ◽  
Financial Markets ◽  
Stock Price ◽  
Second Phase ◽  
Digital Currency ◽  
Two Phases ◽  
Negative Sentiment ◽  
The Impact ◽  
Deep Learning Model ◽  
Positive Effect

Twitter is becoming an increasingly popular platform used by financial analysts to monitor and forecast financial markets. In this paper we investigate the impact of the sentiments expressed in Twitter on the subsequent market movement, specifically the bitcoin exchange rate. This study is divided into two phases, the first phase is sentiment analysis, and the second phase is correlation and regression. We analyzed tweets associated with the Bitcoin in order to determine if the user’s sentiment contained within those tweets reflects the exchange rate of the currency. The sentiment of users over a 2-month period is classified as having a positive or negative sentiment of the digital currency using the proposed CNN-LSTM deep learning model. By applying Pearson's correlation, we found that the sentiment of the day (d) had a positive effect on the future Bitcoin returns on the next day (d+1). The prediction accuracy of the linear regression model for the next day's revenue was 78%.

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