著者

米岡 裕矢 宮田 なつき 前田 雄介

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.18-00055, (Released:2018-06-08)

参考文献数

16

被引用文献数

1

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In this study, we measured and analyzed the degree of posture discomfort with respect to the coordinated range of motion (ROM) of the thumb. For ergonomic assessment of a product CAD model using a digital hand model, such joint properties are necessary to be clarified when estimating possible natural postures to use the product. We concentrated on the thumb, which plays an important part to form various grasps by opposition. To model range of motion considering coordination among joint variables, each subject's hand during a given set of exercises was captured by an optical mocap system. A posture of the carpometacarpal (CM) joint of the thumb was expressed with spherical coordinates to integrate different subjects' ROM easily. The result was shown some characteristics of the thumb such as coordination among joint variables or collision between thumb and other parts of the hand. The posture discomfort data was collected through the experiments for four adults with healthy hand. To control variety of the postures, each subject was asked to reproduce about 45 displayed postures and to answer whether the subject felt discomfort or not in terms of keeping that posture for 10 seconds. The discomfort experiment results were combined into a discomfort possibility map with respect to joint postures. This map can assist product design, for example considering interface layout.

著者

遠藤 維 金井 理 宮田 なつき 河内 まき子 持丸 正明

出版者

公益社団法人 精密工学会

雑誌

精密工学会誌 (ISSN:09120289)

巻号頁・発行日

vol.75, no.4, pp.548-553, 2009-04-05 (Released:2011-02-07)

参考文献数

9

被引用文献数

2 3

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The purpose of this research is to develop a virtual ergonomic assessment system that evaluates grasp stability and ease of grasping of products such as digital cameras without real subjects and physical mockups by integrating 3D digital hand models with the 3D CAD models of the products. In this paper, we propose “ease of grasping” as a new index for the assessment. This index is calculated from the “EOG-map”, in which example grasp postures of real subjects are plotted as principal component scores in low dimensional space. We also propose an optimization-based correction method for an inappropriate finger posture by using the EOG-map.

著者

小林 巧 家永 直人 杉浦 裕太 斎藤 英雄 宮田 なつき 多田 充徳

出版者

公益社団法人 精密工学会

雑誌

精密工学会誌 (ISSN:09120289)

巻号頁・発行日

vol.84, no.12, pp.996-1002, 2018-12-05 (Released:2018-12-05)

参考文献数

15

被引用文献数

2

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This paper presents a method to measure foot shape from a 3D point cloud as input captured from multiple directions using a smartphone depth camera. Such a 3D point cloud could potentially include noise or omit parts of the foot due to occlusion. To deal with this occlusion problem, we propose to use a dataset of 3D foot shapes collected by a precise 3D shape scanner of foot shapes. According to the dataset of 3D foot shapes, we can generate a deformable model by performing a principal component analysis (PCA) on the dataset. Then we minimize the error of the shape represented by the deformable model and the 3D point cloud acquired by the smartphone camera, to recover a complete 3D shape of the entire foot with high accuracy. We test this method by comparing the 3D shape produced by our proposed method to the 3D shape precisely measured by the 3D scanner. Our proposed method can scan the foot shape with an error of about 1.13mm.

著者

栗原 恒弥 宮田 なつき

出版者

一般社団法人 画像電子学会

雑誌

画像電子学会誌 (ISSN:02859831)

巻号頁・発行日

vol.33, no.4B, pp.539-546, 2004 (Released:2006-05-18)

参考文献数

14

被引用文献数

1

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本論文では,医用画像 (CT) を用いて変形可能な手のCGモデルを生成する方法を提案する.複雑に変形する手の形状を表現するためには,正確なリンク構造の推定と,姿勢に依存した皮膚の変形を実現する必要がある.このため,提案手法では,医用画像を用いて複数の姿勢における,骨格形状,皮膚形状を同時に取得し,これらを用いて変形可能な手のモデルを生成する.提案手法は,以下の3つのステップからなる.第一に,複数姿勢における手の骨格形状から,骨格のリンク構造(各関節の回転中心,回転角度)を推定する.次に,各姿勢における皮膚表面形状を同一構造のポリゴンメッシュに変換する.具体的には,ある姿勢の皮膚表面形状(以下基準形状と呼ぶ)を変形,フィッティングすることで,別の姿勢の形状を表現する.このために,まず基準形状を,求められた関節中心および関節角度を用いて変形する.さらに,変形された形状を計測データに対話的にフィッティングすることで,同一構造のポリゴンメッシュを得る.最後に,求められたリンク構造と皮膚形状をpose space deformationによって補間して,皮膚形状の変形を表現する.CT画像を用いた実験を行い,約50,000頂点から構成される複雑な手の形状変形を実現した.