Reconstruction Synthesis of the Lost Subsystem for the Planetary Motions of Antikythera Mechanism

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Hong-Sen Yan ◽  
Jian-Liang Lin
Keyword(s):  
Kinematic Analysis ◽  
Original Structure ◽  
Mechanism Analysis ◽  
Technology Standards ◽  
Design Constraints ◽  
Design Concepts ◽  
Detail Design ◽  
Time Period ◽  
Minimum Numbers ◽  
Planetary Theories

The mechanism for the planetary motions contained in the lost subsystem of Antikythera mechanism is a strict challenge of the reconstruction design. This work presents a systematic procedure of the reconstruction design to synthesize all feasible designs which agree with the science and technology standards of the subject’s time period. Based on the kinematic analysis of ancient planetary theories, the anomaly planetary motions could be formulated. By the mechanism analysis, two types of feasible topological structures with the minimum numbers of members are obtained, and the relationships of teeth for the inferior and superior planets are derived. Through the study of the historical literature, the astronomical theories and the existing designs, the required design constraints are concluded. For the two reconstruction designs, one, the design by Edmunds and Morgan, and three feasible design concepts are, respectively, synthesized in accordance with the concepts of generalization and specialization. Focusing on each feasible design concepts, this work derives the relationships of teeth. Furthermore, one feasible combination of these feasible designs for different planets is adopted for detail design. And, it could be the original structure for the planetary motions of the lost subsystem of Antikythera mechanism.

Reconstruction Synthesis of the Lost Subsystem for the Planetary Motions of Antikythera Mechanism

2011 ◽  
Author(s):  
Hong-Sen Yan ◽  
Jian-Liang Lin
Keyword(s):  
Planetary Motion ◽  
Mechanism Analysis ◽  
Design Concepts ◽  
Design Specifications ◽  
Solid Reconstruction ◽  
Time Period ◽  
Minimum Numbers ◽  
Planetary Theories

The mechanism for the planetary motions contained in the lost subsystem of Antikythera mechanism is a strict challenge of the reconstruction design and attracts many scholars’ attentions. In the modern time, Edmunds and Morgan, and Wright successively presented the design concepts, even the solid reconstruction models. To focus on the study of lost mechanisms, this work provides a systematic procedure of the reconstruction design to synthesize all feasible designs describing the planetary motion in the lost subsystem. And all synthesized designs agree with the science and technology standards of the subject’s time period. Based on the kinematic analysis of the planetary theories in the time of Antikythera mechanism, the anomaly planetary motions that could be demonstrated by a pin-in-slot device are completely understood. By the mechanism analysis and the design concept with the minimum numbers of the members, two types of the feasible topological structures and the corresponding design specifications are obtained: Type 1 is a four-bar mechanism with five joints; Type 2 is a five-bar mechanism with seven joints. In addition, the relations of the teeth for the inferior and superior planets are discussed in each possible combination of the planet gears. Moreover, through the study of the historical literature, the astronomical theories and the existing designs, the required design constraints are concluded further. For Type 1 and Type 2 reconstruction designs, one, the design by Edmunds and Morgan, and three feasible designs are respectively synthesized in accordance with the concepts of generalization and specialization. And all feasible designs are identified further for the suitable planets through the identifications of the input types. In conclusion, all generated designs are consistent with the scientific theories and techniques of the subject’s time period and match the surviving evidences.

STRUCTURAL SYNTHESIS OF ANCIENT CHINESE DRAWLOOM FOR PATTERN-WEAVING

2011 ◽  
Vol 35 (2) ◽  
pp. 291-308 ◽  
Author(s):  
Kuo-Hung Hsiao ◽  
Hong-Sen Yan
Keyword(s):  
Structural Characteristics ◽  
Structural Synthesis ◽  
Design Constraints ◽  
Reconstruction Process ◽  
Design Concepts ◽  
Logical Foundation ◽  
Time Period

This work synthesizes the mechanism structures of the drawloom for pattern-weaving, which was illustrated unclearly in many ancient Chinese literatures. Based on the analysis of mechanism, the structural characteristics and design constraints of the mechanism with uncertain members and joints are concluded. Then, according to the concepts of generalization and specialization subject to the concluded design constraints, all feasible structures of mechanism that meet the technological standards of the subject’s time period are reconstructed including 16 and 8 design concepts for the heddle foot-falling device and the heddle foot-raising device, respectively. This reconstruction process provides a logical foundation to deal with the issue of the ancient mechanical drawings with uncertain members and joints.

Conceptual Design of Gear Differentials for Automotive Vehicles

1994 ◽  
Vol 116 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Hong-Sen Yan ◽  
Long-Chang Hsieh
Keyword(s):  
Conceptual Design ◽  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Gear Train ◽  
Design Constraints ◽  
Two Degrees Of Freedom ◽  
Design Concepts ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
Gear Differential

An automotive gear differential is a joint-fractionated planetary gear train with two degrees-of-freedom. We summarize the characteristics of planetary gear trains and the design constraints of noncoupled automotive gear differentials to synthesize their corresponding kinematic graphs. Based on these graphs and the proposed respecializing process, we generate the atlas of design concepts for automotive gear differentials with any types of gear pairs. As a result, there are 4, 25, and 156 design concepts for five-, six-, and seven-bar automotive gear differentials, respectively.

Robustness Metrics for Time-Dependent Quality Characteristics

2011 ◽  
Author(s):  
Xiaoping Du
Keyword(s):  
Design Optimization ◽  
Robust Design ◽  
Quality Characteristics ◽  
Time Dependent ◽  
Robust Design Optimization ◽  
Time Interval ◽  
Mechanism Analysis ◽  
Quality Loss ◽  
Time Period ◽  
Robustness Metrics

Quality characteristics (QC’s) are often treated static in robust design optimization while many of them are time dependent in reality. It is therefore desirable to define new robustness metrics for time-dependent QC’s. This work shows that using the robustness metrics of static QC’s for those of time-dependent QC’s may lead to erroneous design results. To this end, we propose the criteria of establishing new robustness metrics for time-dependent QC’s and then define new robustness metrics. Instead of using a point expected quality loss over the time period of interest, we use the expectation of the maximal quality loss over the time period to quantify the robustness for time-dependent QC’s. Through a four-bar function generator mechanism analysis, we demonstrate that the new robustness metrics can capture the full information of robustness of a time-dependent QC over a time interval. The new robustness metrics can then be used as objective functions for time-dependent robust design optimization.

Explicit Evaluation of Design Readiness for Student Refinement of Conceptual Design

2019 ◽  
Author(s):  
Kenji Iino ◽  
Masayuki Nakao
Keyword(s):  
Conceptual Design ◽  
Mechanical Engineering ◽  
Design Concept ◽  
Graduate Schools ◽  
Design Concepts ◽  
Detail Design ◽  
Explicit Evaluation ◽  
The University ◽  
The Way

Abstract Students at three graduate schools of mechanical engineering and adult groups in Japan have been taking conceptual design courses the authors teach. Among the three graduate schools, the 24 hour course, at the University of Tokyo, spread over 13 classes during 4 months, takes the students all the way from identifying their design goals, generating ideas, refining their designs, to building prototypes. The adult course students also spend long hours of building prototypes. Despite strong encouragement by the instructors for detail design, the students often leave their design concepts at rough stages without refining their ideas to the detail level needed for prototype building. Building a prototype from a design concept that is not fully expanded often results in efforts that lead to failure and retrial. Such back and forth between concepts and physical trial is unavoidable in design, however, if possible they better be kept at the minimum. The instructors, in their efforts to better motivate students to refine the designs, developed a metric “Level of Readiness (LOR) index” for evaluating how refined a design is. Students are better motivated to reach higher scores and this index that evaluate the quality of their designs, in terms of how detail they are, in numbers serves as a better incentive for the students than words from the instructors.

Mechanism analysis by matrix reduction. I. Statics

1992 ◽  
Vol 439 (1907) ◽  
pp. 485-495 ◽  
Keyword(s):  
Static Analysis ◽  
Kinematic Analysis ◽  
Rigid Bodies ◽  
Mechanism Analysis ◽  
New Approach ◽  
Matrix Reduction ◽  
New Type ◽  
Articulated Assemblies

A new type of computerized design aid is described, which raises the need to carry out the simple preliminary static analysis of articulated assemblies of rigid bodies by computer; and a matrix-based method is presented for doing this. This method also forms the basis for a new approach to the kinematic analysis of such assemblies, which in turn provides the inertia (D’Alembert) forces for the static analysis.

Multistage Geared Geneva Mechanism

1979 ◽  
Vol 101 (1) ◽  
pp. 41-46 ◽  
Author(s):  
A. T. Yang ◽  
L. M. Hsia
Keyword(s):  
Kinematic Analysis ◽  
Dwell Time ◽  
Rational Design ◽  
Design Parameters ◽  
Design Concepts ◽  
The Family ◽  
Gear Trains ◽  
N Stage ◽  
Phase Angles ◽  
Fine Tune

Design concepts for an n-stage geared Geneva mechanism, which is an assembly of n Geneva mechanisms connected by (n−1) gear trains, are proposed in this paper. The dwell time produced by the system is a function of (n−1) phase angles, the combined number of slots on all the wheels and the number of pins on all cranks in the system. The introduction of phase angles into the family of design parameters is highly significant: it gives the engineer an added dimension in the design of intermittent mechanisms and it gives him the flexibility to fine-tune their dwell time. For illustrative purposes, the derivation for the dwell time and the kinematic analysis of a two-stage geared Geneva mechanism are treated in detail. It is hoped that the results, which are presented in the form of charts and graphs, would be useful for the rational design of intermittent mechanisms.

Kinematic Analysis of 4-UPU Parallel Mechanism Based on Influence Coefficient

2015 ◽  
Vol 741 ◽  
pp. 691-696 ◽  
Author(s):  
Guang Lan Xia ◽  
Xing Wei Hu ◽  
Bao Lin Yin ◽  
Feng Yu
Keyword(s):  
Numerical Analysis ◽  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Coefficient Matrix ◽  
Degree Of Freedom ◽  
Kinematics And Dynamics ◽  
Influence Coefficient ◽  
Mechanism Analysis ◽  
Acceleration Coefficient ◽  
Mechanism Kinematic

Mechanism kinematic influence coefficient deeply reflects the essence of the kinematics and dynamics mechanism, analysis of the problems of many institutions can use the influence coefficient of clear and clearly expressed. In this paper, with less degree of freedom parallel mechanism as the research object, through the virtual mechanism method to derive one or two order influence coefficient matrix, based on the analysis of the mechanism and influence of speed and acceleration coefficient matrix. Finally, the precision of the method for solving the kinematics is proved by examples of numerical analysis.

Reconstruction Synthesis of the Calendrical Subsystem of Antikythera Mechanism

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Hong-Sen Yan ◽  
Jian-Liang Lin
Keyword(s):  
Systematic Approach ◽  
Ancient Greece ◽  
Analog Computer ◽  
Gear Train ◽  
Ancient Greek ◽  
Design Constraints ◽  
Time Period ◽  
Mediterranean Archaeology

The damaged excavation of the Antikythera mechanism presents the oldest astronomical analog computer in ancient Greece. Its interior mechanism is a complicated gear train with many subsystems in which some are unclear, such as the calendrical subsystem. This work focuses on the reconstruction synthesis of the calendrical subsystem and provides a systematic approach to generate all feasible designs. Based on the studies of historical literatures and existing designs, the required design constraints are concluded. Then, according to the concepts of generalization and specialization of mechanisms, two feasible designs and 14 results of teeth counting, including the existing one by Freeth et al. (2002, “The Antikythera Mechanism: 1. Challenging the Classic Research,” Mediterranean Archaeology & Archaeometry, 2, pp. 21–35; 2002, “The Antikythera Mechanism: 2. Is It Posidonius Orrery?,” Mediterranean Archaeology & Archaeometry, 2, pp. 45–58; 2006, “Decoding the Ancient Greek Astronomical Calculator Known as the Antikythera Mechanism,” Nature (London), 444, pp. 587–591; 2008, “Calendars With Olympiad Display and Eclipse Prediction on the Antikythera Mechanism,” Nature (London), 454, pp. 614–617; 2009, “Decoding an Ancient Computer,” Sci. Am., 301(6), pp. 76–83), which are in consistent with the science theories and techniques of the subject’s time period, are synthesized.

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