Theoretical Study of Global Scale Analysis Method for Agile Bionic Leg Mechanism

Robotica ◽  
2019 ◽  
Vol 38 (3) ◽  
pp. 427-441
Author(s):  
Hongbin Zang ◽  
Dengfeng Zhao ◽  
Lianguan Shen
Keyword(s):  
High Speed ◽  
Simulation Experiment ◽  
Theoretical Study ◽  
Global Scale ◽  
Scale Analysis ◽  
Analysis Method ◽  
Innovative Design ◽  
Analysis Process ◽  
Singular Theory ◽  
Running Robots

SummaryAgile bionic leg mechanism (ABLM) has attracted more and more attention in the development of jumping robots and high-speed running robots. However, theoretical study of the global structure for motility characteristics and its evolution is few. By using the modern mathematical tools such as singular theory, geometric topology, and group theory, a global scale analysis method for kinematic performance of mechanisms is proposed. Taking 6-bar with two rings mechanism as an example, a detailed analysis process is studied. The 6-bar ABLM designed by this theory is verified by virtual prototype simulation experiment. The global scale analysis of 4-bar linkage is also carried out by using this method, and the result is compared with the “Grashof criterion” to verify the correctness of this method. It provides a general theory and method for innovative design and global scale analysis of ABLM.

scholarly journals An Improved Lagrangian-Inverse Method for Evaluating the Dynamic Constitutive Parameters of Concrete

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1871
Author(s):  
Xinlu Yu ◽  
Yingqian Fu ◽  
Xinlong Dong ◽  
Fenghua Zhou ◽  
Jianguo Ning
Keyword(s):  
High Speed ◽  
Inverse Method ◽  
Image Correlation ◽  
Analysis Method ◽  
Stress Strain ◽  
Optical Techniques ◽  
Element Simulation ◽  
Non Linear ◽  
Constitutive Parameters ◽  
Inverse Analysis Method

The dynamic constitutive behaviors of concrete-like materials are of vital importance for structure designing under impact loading conditions. This study proposes a new method to evaluate the constitutive behaviors of ordinary concrete at high strain rates. The proposed method combines the Lagrangian-inverse analysis method with optical techniques (ultra-high-speed camera and digital image correlation techniques). The proposed method is validated against finite-element simulation. Spalling tests were conducted on concretes where optical techniques were employed to obtain the high-frequency spatial and temporal displacement data. We then obtained stress–strain curves of concrete by applying the proposed method on the results of spalling tests. The results show non-linear constitutive behaviors in these stress–strain curves. These non-linear constitutive behaviors can be possibly explained by local heterogeneity of concrete. The proposed method provides an alternative mean to access the dynamic constitutive behaviors which can help future structure designing of concrete-like materials.

Collision-Free Tool Path Generation for Five-Axis High Speed Machining

2011 ◽  
Vol 474-476 ◽  
pp. 961-966 ◽  
Author(s):  
Li Qiang Zhang ◽  
Min Yue
Keyword(s):  
Image Analysis ◽  
Collision Detection ◽  
High Speed ◽  
Tool Path ◽  
Geometric Model ◽  
High Speed Machining ◽  
Analysis Method ◽  
Geometric Information ◽  
Detection Approach ◽  
Five Axis

Collision detection is a critical problem in five-axis high speed machining. Using a combination of process simulation and collision detection based on image analysis, a rapid detection approach is developed. The geometric model provides the cut geometry for the collision detection and records a dynamic geometric information for in-process workpiece. For the precise collision detection, a strategy of image analysis method is developed in order to make the approach efficient and maintian a high detection precision. An example of five-axis machining propeller is studied to demonstrate the proposed approach. It has shown that the collision detection task can be achieved with a near real-time performance.

ANALISIS SEMIOTIKA POS STRUKTURAL PADA FOTO RHEIN II (A POST-STRUCTURAL SEMIOTICS ANALYSIS OF THE PHOTOGRAPH RHEIN II)

2021 ◽  
Vol 4 (1) ◽  
pp. 37
Author(s):  
Markus Jiuhanteng ◽  
Acep Iwan Saidi ◽  
R. Drajatno Widi Utomo
Keyword(s):  
Text Analysis ◽  
Analysis Method ◽  
Semiotic Analysis ◽  
Creation Process ◽  
Interpretive Study ◽  
Analysis Process ◽  
Process Creation ◽  
Visual Text ◽  
Visual Element ◽  
Semiotic Theory

<p>Abstract This paper is a study of Andreas Gursky’s photo Rhein II. In this study, the post-structural semiotic analysis method is used to interpret meaning based on signs on the Rhein II. The post-structural semiotic analysis becomes the basis for interpreting meanings using related references. In the study of Rhein II photo objects, visual text analysis is expected to provide positive benefits for the development of photography, especially academically. Rhein II is a photo by Andreas Gursky. In Rhein II’s photograph, a contemporary photo is presented as a multi-reality representation analyzed using the post-structural semiotic method. The object of research is interpreted as a text that has a layer of meaning that is squeezed out of its essence by semiotics. The deconstruction of the signification system in the visual element is identified by reading the structural postal semiotic theory codes: text analysis process, creation process. The results of semiotic extraction produce an interpretive study of Rhein II which is full of meaning.</p><p>Keyword: imagery, photography, semiotica</p><p>Abstrak Makalah ini merupakan kajian dari foto Rhein II karya Andreas Gursky. Dalam kajian ini digunakan metode analisis semiotika post struktural untuk menginterpretasikan makna berdasarkan tanda-tanda pada Rhein. Analisis semiotika post struktural menjadi landasan dalam menginterpretasikan makna-makna dengan menggunakan referensi terkait. analisis teks visual, dalam kajian objek foto Rhein II diharapkan dapat memberikan kebermanfaatan yang positif bagi perkembangan fotografi khususnya secara akademis. Rhein II adalah foto karya Andreas Gursky. Dalam karya Rhein II, sebuah foto kontemporer dihadirkan sebagai representasi multi realitas yang dianalisis menggunakan metode semiotika post struktural. Objek penelitian dimaknai sebagai teks yang memiliki lapisan makna yang terperas esensinya oleh semiotika. Dekonstruksi sistem penandaan dalam elemen visual diidentifikasikan dengan pembacaan kode-kode teori semiotika pos struktural. Proses analisis teks, proses penciptaan. Hasil ekstraksi semiotika menghasilkan kajian interpretatif Rhein II yang sarat makna.</p><p>Kata kunci: citra imaji, fotografi, semiotika</p>

Adequate Strength for Small High-Speed Vessels

1968 ◽  
Vol 5 (01) ◽  
pp. 63-71
Author(s):  
Philip J. Danahy
Keyword(s):  
Stress Analysis ◽  
High Speed ◽  
Structural Strength ◽  
Integrated Approach ◽  
Suggested Method ◽  
Impact Loads ◽  
Analysis Method ◽  
Safety Factors ◽  
Recreational Vessels

The paper presents a method for the determination of the critical minimum scantlings for small high-speed vessels. Particular attention is given to the shell plating strength for hydrodynamic impact loads. The suggested method uses an integrated approach involving assumed loads, suggested safety factors, and preferred stress-analysis method. The stress analysis uses plastic theory based partly on the works of J. Clarkson and Thein Wah. Included in the paper is a comparison of the relative structural strength of several commercial, military, and experimental hydrofoil vessels along with a few planing boats and a seaplane hull. This shows the variation of existing vessel structures and compares them to the results obtained by the suggested method. Most commercial, military, and recreational vessels exceed the minimum scantlings of the suggested method. The most significant deviation is the hull of the seaplane:

scholarly journals A Cultural Governance Coalition in Regeneration. A Case Study of Historical Quanzhou City

2019 ◽  
pp. 145-164
Author(s):  
Shuxiang Cai
Keyword(s):  
Public Space ◽  
Urban Areas ◽  
Land Reform ◽  
High Speed ◽  
Urban Governance ◽  
Central Government ◽  
Urban Landscape ◽  
Global Scale ◽  
Spatial Transformation ◽  
Common Path

Compared with the gradual and long exploration processes typical of European and American countries, China experienced a period marked by extremely high-speed modernisation and urbanisation, following the Land Reform. This is exemplified by a great number of urban reconstruction projects which have changed the traditional fabric of most cities. Yet, following the trend of cultural consumption since the late 1990s, numerous integrated restoration projects for historic districts were implemented to promote tourism as a promising industry to sustain economic growth. As a consequence of growth-oriented urban entrepreneurship, public spaces in these historic urban areas have also been perceptibly privatised. To a large extent, the capital and the authority of the local government directs the future prospect of the historic urban landscape in Chinese cities. On the other hand, development-oriented urban construction stimulates a rise in awareness of the need for protection strategies to conserve historic urban fabric. On a global scale, the public sector has begun to introspect on urban governance under the spirit of entrepreneurship. The urban renewal has now been extended to urban regeneration and the previous public-private partnership has been substituted with a multi-sectoral cooperative model. In recent years, the Chinese central government has proposed the core concept of “Seeing people, Seeing things, Seeing life”, which is re-orientated towards historic-city regeneration as a way of promoting “Micro-renewal and Micro-disturbance”. Among such activities, the use of exhibitions as a strategy for simultaneous spatial transformation and activation has gradually formed a common path, encouraging many cities to regenerate historic urban areas. This article is based on on this reorientation, taking Quanzhou as an example, making a critical observation on the new form of public space it has produced, and digs into the operational mechanism behind it as well as the possibility for publicness.

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