Naoki Kamiya

Development and Evaluation of a Multi-Functional Steering Wheel Switch

In this paper we propose a new multi-functional steering wheel switch for HVAC and audio systems. This new switch has five buttons on the front side of the spoke area and one button with vibration on the backside of it. Drivers can operate either HVAC or audio functions with the front switches, and HVAC or audio mode can be alternatively selected by pressing the back switch. Since different vibration modes are assigned for the HVAC and audio mode, drivers can also easily recognize which function can be operated. By changing the assignment of the mode in this way, the switch can operate more than 10 functions with 6 buttons allocated on the spoke area. Several kinds of evaluations were performed in order to develop this multi-functional switch. At first, to optimize the positions of the buttons, the behaviors of thumbs and fingers were measured. Also the physical workload of the thumb motion and middle fingers postures was evaluated when subjects operated the switches. Secondly, tactile sensibility of humans was investigated, and sensory evaluations concerned with vibration sensitivity were performed to decide the specification of the vibration. Thirdly, functions for operating the HVAC and audio systems with this switch were selected by considering driving situations. Finally, the switch that was developed based on the results of these evaluations was re-evaluated by using a driving simulator to verify the operability of the switch. As a result of this evaluation, it was shown that the new switch with the functions for both the HVAC and audio systems performs well compared to the conventional switches.

Proposal and Verification of a Method for Maintaining Arousal by Inducing Intrinsic Motivation: Aiming at Application to Driving of Automobiles

With the advance of automation in recent years, the interaction between systems and users has become less intense and more monotonous. Thus, there is some concern that the arousal level of users is liable to decrease while interacting with a system. The decrease in the arousal levels of users causes drowsiness in their bodies and deterioration of their performance, potentially leading to serious accidents. Thus, it is necessary to establish a method for maintaining arousal level. At present, external-stimulation methods such as sounds or vibrations are popular; on the other hand, some psychophysiological studies have suggested a relationship between motivation and arousal, but there has been little research on how to apply these studies, as well as only a few examples of practical application. Therefore, in this research, we propose and verify a method for maintaining arousal by inducing intrinsic motivations. This arousal maintenance was found to work well during manual operations, but to be less effective by influence of stress during automatic operations. In addition, the varieties of presentation of feedbacks and the arousal level during operations were found to be influenced the effectiveness.

Physiological Responses Related to Visual Impressions of a Product: Evaluating Automobile Interior Design

In many products, the visual impressions of the product are extremely important components—sight accounts for 83 % of the five senses (An education apparatus editing committee in An industrial education apparatus system manual. JUS Press 1972). However, manufacturers still depend on the aspect of the effectiveness, efficiency, and usability for the design evaluation of products; yet, consumer emotion is hard to measure because the mental side of users such as visual impressions cannot be observed directly and the index to measure them has not been established. The function, performance, and usability can be measured by the behavioral index of users (e.g., operation time and error rate) (Nagashima and Kubo in The sensitivity and information for the new manufacturing. Morikita Shuppan Co., Ltd, 2007). In this study, we experimentally searched for indices to objectively detect the impression of appearance with car images as targets. We observed that MPFC activation is related to high “familiarity” and low “mechanical” features.

A method to evaluate consumer desire for continued product usage: Incorporation of the method in the automobile design process

Consumers expect mature products such as cars to provide value in addition to conventional features such as safety and usability. Hence, introducing methods to evaluate consumer perceptions of the worth of new features during the design process benefits manufacturers. Consequently, increasing attention has been recently focused on user experience (UX). This project examined three aspects of UX, namely, the “desire to try using” during an encounter, the “goodness of using,” and the “desire to continue to use” after the initial usage. Then, a method for introducing these aspects into the product design process was developed. Thus, the factors that influence user desire to continue the product usage were obtained. The relation between the user requirements and the design elements was examined, and a method that quantitatively evaluates user desires based on the design elements during the design process was proposed.

An Evaluation of Physical Load in Switch Operation with Thumb

1.は じめ に 自動車用ステア リングには,カ ーナビやエァ コ ン,オ ー トクルーズ等のス イッチが配置 され ている.こ れ らのスイッチは,自 動車運転 中の 操作 が想定されるため,ス テア リング把持状態 での親指操作 が容易 なス イッチ配置が求 め ら れ る,本 研究では,操 作性 のよいスイ ヅチ配置 の導出 を 目的に親指動作 負担度 の評価 と関節 角度の計測 を行った.実 験では,ス テア リング 把持状態で のプ ヅシュスイ ッチの操作 を想定 し,親 指先端 を任 意の位置 に移動させたときの 動作負担度 を一対比較法で評価 する とともに, スイヅチ押込み時の手関節 ・親指関節の角度 を 計測 した.そ の結果,小 さい負担での動作 には 掌側内外転方向が有利であること,手 関節の動 作が負担の要因であることを確認 した. 2.負 担 度 評価 及 び関節 角度 計測 実験 ステ ア リング把持時 において負担が 少ない 親指動作の調査のための動作 負担度の評価,負 担要因の調査のための手関節 ・親指関節角度 の 計測 を行った. 本実験 システムを図1に 示す.シ ステ ムはス テア リング,シ ー ト,仮 想物体 を表現 するため の力覚呈示装置等で構成され る.ス テア リング には外半径200mm,断 面直径20mmの 円形 リング を使用 し,鉛 直方向から23° 前傾 させて固定 し た.ま た,ス テア リング中心 を原 点 と し,図 2(i)に 示すような直交座標系を定義 した. 親指動作負担度 の評価では,標 準的な成人男 子がステ ア リングを把持 しなが ら親指で到達 可能 な範 囲か ら選定 した(140,0,0)に 設置 した 基準点 と,同 一平面上にある8点 の 目標点 を親 指 で往復動作 させた ときの動作 負担度 を評価 した.こ こで,基 準点 と目標点は力覚呈示装 置 によ り設けた直径20mmの 円筒状の仮想物体 で ある.被 験者(成 人男子4名)は 乗用車の運転姿 勢 をとり,基 準点 にあるプッシュスイ ヅチの操 作 を想定 してステア リングを握 り,任 意の目標 点への親指動作の負担度を7点 法の尺度で評価 した.得 られた評点か らシェッフェの一対比較 図1 実験 システム