Papers by Ichiro Hagiwara
Keisoku Jidō Seigyo Gakkai ronbunshū, 2004
The journal of the INCE of Japan, Jul 1, 2007
The journal of the INCE of Japan, Oct 1, 1994
Transactions of the Japan Society of Mechanical Engineers. C, 2013
This paper presents modeling techniques for deployable meandering tubes with regular designs of f... more This paper presents modeling techniques for deployable meandering tubes with regular designs of fold lines, allowing cutting and removing parts of developed surface. First of all, a cylinder with constant curvature (i.e. a part of torus) is studied on the following conditions; Miura-fold pattern, bellows pattern and a pattern with six fold lines. These three patterns are able to provide deployable designs of fold lines on a developed surface of a part of torus which is approximated to a polyhedron. In addition, Miura-fold pattern and bellow pattern are able to connect with straight cylinders, since they still maintain substantially identical folding designs. Next, the theory is applied on a meandering tube constructed with different curvatures. Since the regularity of fold lines is still maintained, Miura-fold pattern and bellow pattern are able to provide deployable designs on the presupposition that the tube is made of sufficiently flexible material. Regularization of designs by this modeling can have advantages in standardization of product modules and simplification of manufacturing process in industry. Last, by using the conformal transformation, the deployable design is applied on a toroidal cone.
Nihon kikai gakkai ronbunshu, 2017
The existing collision energy absorber of vehicle collapse ideally only 70% deformation and the h... more The existing collision energy absorber of vehicle collapse ideally only 70% deformation and the high initial peak load is a problem. So our group has paid attention to the reversed spiral cylindrical origami structure (RSC) to overcome these two problems, but the energy absorption amount of RSC was low. However, after optimization analysis, the energy absorption amount of optimal RSC has been obtained about 1.4 times of the existing collision energy absorber. But, because the production of RSC is expensive, the industrialization of it is difficult to realize. Here, recently two pairing origami structures are gaining attention: Nojima polyhedron (NP) and Tachi-Miura polyhedron (TMP) are compared from the point of crash absorbing energy characteristics. In this paper, we focus on the investigation of the absorbing energy performance and consider the application of these pairing origami structures to expect to be used as the collision energy absorber of vehicles of steel material. And both are compared with RSC which is manufactured by hydro forming and the conventional rectangular cross section structure.
Nihon kikai gakkai ronbunshu, 2023
The emergency collision avoidance and trajectory planning are investigated in this paper. These a... more The emergency collision avoidance and trajectory planning are investigated in this paper. These are considered to be essential technologies for self-driving cars, which are important in regional revitalization. The collision avoidance by braking is called AEB (Autonomous Emergency Braking), whereas collision avoidance by steering is called AES (Autonomous Emergency Steering). The present research focuses on AES and aims to develop effective control theory based on EOC (Energy Optimal Control theory) with trajectory planning. A theoretical design method for EOC's virtual physical quantities and a method for accurately specifying the target trajectory were proposed. An emergency collision avoidance problem was designed to avoid collisions with vehicles crossing the center line and bicycles encroaching on the roadway on a two-lane road, and the effectiveness of proposed control theory and trajectory planning method are examined. It is found that the present theory can track the specified target trajectory very accurately. And the trajectory planning method proposed here is very simple and can define discontinuous trajectory which is critical for the design of complicated collision avoidance trajectory.
Transactions of Japan Society of Kansei Engineering, 2009
Iyashi is a word that everyone often hears of in Japan. However, is it a feeling? a state? a proc... more Iyashi is a word that everyone often hears of in Japan. However, is it a feeling? a state? a process? The essence of Iyashi has not been clarified. Our target is to clarify the Iyashi structure and to use Iyashi to keep people's minds peaceful any time in the contemporary society to solve various problems by a scientific method. In our previous research, we analyzed and integrated the historical and social usage of Iyashi and several researchers' opinions and defined "Iyashi" as a stimulus and "Iyasareru" as a process. In this paper, we report the analysis of goods and that induce Iyashi to the mind of the observed persons. However, this time the first stage about goods analysis was recorded and we could get the elements of Iyashi goods. The final purpose of the analysis is to extract the main characteristics from goods to develop the machine that can make people's minds calm.
TRENDS IN THE SCIENCES, 2012
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2012
原稿受付 2012 年 2 月 24 日 *1 正員，関西大学(〒564-8680 大阪府吹田市山手町 3-3-35) *2 正員，群馬大学(〒376-8515 群馬県桐生市天神町 1-5-1)... more 原稿受付 2012 年 2 月 24 日 *1 正員，関西大学(〒564-8680 大阪府吹田市山手町 3-3-35) *2 正員，群馬大学(〒376-8515 群馬県桐生市天神町 1-5-1) *3 正員，東京都市大学(〒158-8557 東京都世田谷区玉堤 1-28-1) *4 正員，慶應義塾大学(〒223-8522 神奈川県横浜市港北区日吉 3-14-1) *5 正員，電力中央研究所(〒270-1194 千葉県我孫子市我孫子 1646) *6 正員，山形大学(〒992-8510 山形県米沢市城南 4-3-16) *7 正員，フェロー，東京工業大学(〒152-8550 東京都目黒区大岡山 2-12-1
Japan Journal of Industrial and Applied Mathematics, 2011
Customers preferences are difficult to predict automatically because they are subjective and rela... more Customers preferences are difficult to predict automatically because they are subjective and relative to human likeness patterns which are different from each people. This paper proposes the combination of Interactive Genetic Algorithm (IGA) with Artificial Neural Networks to model the fitness function and find the optimally colored image according to user's preference. As the search space for the IGA is very large, proposed system reduces it creating genotypes with colors restrictions developed with a new graph coloring technique. Two functions are proposed for coding color restrictions. The system presented in this study takes the case of the color design of a building for illustration purposes. Experimental results show that 80% reduction in the number of users evaluations is achieved with proposed combination and speedup in IGA evolution is achieved when color restrictions are coded by proposed mutation and crossover operators.
The journal of the INCE of Japan, Oct 1, 2001
Dynamics & Design Conference, 2012
Nihon kikai gakkai ronbunshu, 2015
Honeycomb panel is widely applied into various structures such as lightweight and high stiffness ... more Honeycomb panel is widely applied into various structures such as lightweight and high stiffness panel. The glued honeycomb panel may catch fire. That's why some new high stiffness technologies have been developed. As a result of that, Truss Core Panel (TCP) has recently been developed. TCP has equivalent bending stiffness as honeycomb panel, and stronger in shear and more fire resistant than honeycomb panel. However, it is difficult in general to form TCPs compared to honeycomb panel. Therefore, multi-stage press forming process was investigated, but it cannot manufacture its structure with high aspect ratio for the limit of press forming process. The main aim of our research is to develop a new manufacturing process for Assembled Truss Core Panel (ATCP) by using bending method, suggesting the possibility to make much wider range of structures than before. In this paper, firstly we show the results of the trial product to confirm the ability of manufacturing ATCP. Then we evaluate the bending stiffness of the trial product of ATCP by measurements and FEM analysis. Finally, we conclude ATCP can be manufactured with high aspect ratio and the bending stiffness of ATCP can be estimated at the design-planning stage by FEM analysis. Some tasks on the development of ATCP will be presented by us in the near future.
Transactions of the Japan Society of Mechanical Engineers. A, 2008
Dynamics & Design Conference, 2016
Two pairing origami structures have been attracting attention as a three-dimensional version of t... more Two pairing origami structures have been attracting attention as a three-dimensional version of the Miura-Ori. Here, as a typical example, we treat Nojima polyhedron (NP) and Tachi-Miura polyhedron (TMP) to check the validity as an energy-absorbing material. Effectiveness as an energy absorber of reversed spiral cylindrical origami structure (RSC); the amount of energy absorption is 1.7 times the current hollow hat-shaped cross-section structure, no excessive initial peak load by a flat characteristics of relation between load and displacement, to extend the crash time by inverting. Although its effectiveness was shown, it is not always easy to use practically by relying on expensive hydroforming. On the other hand, NP, there is less initial peak load, shows a gentle characteristics of relation between load and displacement, that variation lasts up to 90 per cent of its own length, and the manufacturing costs inexpensive, so it is shown that there is a possibility as an energy absorbing structure.
Effect of source position on the sound fields inside acoustically structurally coupled enclosed spaces
日本機械学会機械力学・計測制御部門講演会論文集, 1999
Transactions of the JSME (in Japanese), 2021
In order to develop a new crash energy absorb structure, in this paper, we propose a new reverse ... more In order to develop a new crash energy absorb structure, in this paper, we propose a new reverse torsion type origami structure (RTO) and a partial heating torsion method. The RTO can adjust the distribution of crash buckling wrinkles by arranging polygonal lines along the side surface, and can have the property of stably continuing accordion-type crushing deformation during the crushing process. In the newly proposed partial heating torsion method, the square pipe material is divided into multiple stages along the axial direction, and a formed RTO can be obtained by repeating partial heating and simple torsion forming for each stage. In addition, by applying the method of heating only to the torsional deformed part, it is possible to process with a small processing load, and it is possible to realize the simplification of the jig for fixing the square tube material. This study examines the problems of forming RTO by the partial heating and torsion method and the forming shape quality. We will also examine whether the obtained RTO has sufficient crash energy absorption performance.
Mathematical Elucidation of the Traditional Japanese Fan Focusing on Its Structure
Volume 8B: 45th Mechanisms and Robotics Conference (MR), 2021
The Japanese traditional fan, which is a form of origami originating in Japan with a folding cult... more The Japanese traditional fan, which is a form of origami originating in Japan with a folding culture, has a variety of three-dimensional expression that differs from two-dimensional expression. The image painted on the fan deforms when the fan is folded. In this study, we create a digital fan model for clarifying the deformation on the fan face according to parameters such as length of the bamboo bones. We then validate the digital model with an actual fan. Furthermore, we obtain the original plan view from images of the folded fan as a reverse problem. Because folding fans are made of paper and bamboo and held in the hand, old traditional folding fans are more or less damaged; for example, many culturally valuable folding fans have lost their bones and have damaged edges, have been stretched flat, and have been framed like paintings. Reproducing the original fan without information of the original form is difficult. In the present study, we provide a digital fan model for examining...
Transactions of the JSME (in Japanese), 2020
If the octet truss core, which is a space filling structure of half regular octahedrons and regul... more If the octet truss core, which is a space filling structure of half regular octahedrons and regular tetrahedrons, has excellent sound insulation characteristics, the possibility of using the octet truss core is sufficiently widened. From this fact, we have studied to obtain sound insulation characteristics of the flat plate and the plate with single core using acoustic tube by the finite element method (FEM) with high accuracy. The calculation of sound insulation performance by FEM was limited to the qualitative study so far. For example, the correction is required due to the difference from the theoretical value, and the magnitudes of the correction values differ depending on the test pieces. In this study, we considered the incident wave and compared the sound insulation calculation result by the FEM calculation using the non-reflective boundary at the rear end of the sound receiving room with the theoretical calculation. As a result, both calculation values were almost the same. Therefore, it can be said that when the magnitudes of the incident wave and the reflective wave are almost equal, a quantitative study is possible. Taking advantage of this fact, in this paper the sound insulation characteristics of the plate with single core are compared with that of flat plate, and the effects of the sound insulation characteristics by the aspect ratio of the core are examined.
The Proceedings of Design & Systems Conference, 2005
Uploads
Papers by Ichiro Hagiwara