Experimental Study on Vibration Control of Structural Systems Subjected with Random Excitations by Observers

This paper presents the experimental study of vibration control for the five stories building model subjected to several excitations. The structural model is controlled by the active mass damper that is driven by the DC survomotor. On the control, the state feedback is employed, and state variables are estimated by the minimal order observers. The controller is realized by the DSP(digital signal processor). The experimental tests are performed for the structural model excited by the sinusoidal, impact and earthquake accelerations. The results shown that vibration control by the DSP is more effective than by the personal computer

High Accurate Dynamical Structural Characteristic Estimation with AR Model for Ambient Vibration

To recognize the level of structural deterioration, high accurate structural identification is indispensable. It is considered that frequency of vibration would be decreased when structure deteriorated with rust or clack. This paper subscribes high accurate structural identification algorithm, which can compute the vibration characteristic by ambient vibrations nf the structure. This method is based on AR model

Structural Vibration Control using Observers

In this study, optimal control techniques using observers are applied to vibration control of a five story building model subjected to random excitation. The minimal order observer and the full order observer are adapted to estimate state variables of the controlled model. The optimal closed-loop control scheme using the observer is employed to the system. As numerical examples, we confirm efficiency of vibration control using the minimal order observer for the five-degree-of-freedom system modeled as the building model

15-6-9 : スピンドル式事紡ぎの制御構造と技能の取得

繊維のリサイクルが叫ばれて久しいが,廃布より反毛して得られた繊維から糸を紡績する事が望まれている.さらに,特殊な原料より特殊機能糸を少量生産する要求がある.これらの原料は紡績性が悪く,一般の紡績機では不可能である.しかし,これらの要求に対応可能な紡績の1つにスピンドル(紡ぎ車)式手紡ぎがある.これらは紡績性の悪い原料に対しても多品種少量生産あるいは任意の混紡が可能である.同時に生産性が低い,熟練を要する点が挙げられる.本研究ではスピンドル式手紡ぎに焦点を絞り,手紡ぎ方法における技能の取得を中心として計測を行い,近い将来これの自動化を行う事を目的とする.Article文部科学省2 1世紀COEプログラム「先進ファイバー工学研究教育拠点」研究成果報告書12:168-169(2006)research repor

磁気粘弾性エラストマを用いた可変剛性型動吸振器の開発

The dynamic vibration absorber is well known as a kind of passive-type vibration control device, where the mass and the stiffness elements basically comprise 1-dof system. Despite the reliability and the simplicity in constitution, the absorber does not work effectively for unexpected disturbances. The use of the absorber with fixed property is usually limited to a harmonically excited case, where the damper is only effective for pre-determined narrow frequency range. The damper design following well-known optimal tuning theory can extend the effective range, whereas the damping performance remains at a certain amount and yet the vibration caused by transient disturbances cannot be reduced sufficiently. A frequency-tunable dynamic absorber incorporating element with variable stiffness property can be a measure for placing adaptability to the structure against non-stationary disturbances, but the realization of such variability would be mechanistically complex and the problem of response time may become an issue. The Magneto-rheological elastomer (MRE) is known as a class of smart materials whose elastic property can be varied by the applied external magnetic field. In this paper, the MRE is adopted as the stiffness element in the dynamic absorber whose natural frequency is tunable by the external magnetic field. Both numerical and experimental investigations show that the vibration of 1-dof structure can be fully reduced by the proposed dynamic absorber with variable stiffness functionality

急速な再発、転移をきたした顎下腺原発粘表皮癌の1例

70歳女。左側顎下部に無痛性の腫脹が出現し、改善しないため受診した。画像所見と穿刺細胞診の結果から、顎下腺良性腫瘍(多形腺腫)と診断し、全身麻酔下に腫瘍切除術を行った。病理組織検査結果は中悪性型粘表皮癌であった。術後1ヵ月、術前の穿刺部位ではない顎下部の皮膚に潰瘍の形成を認め、悪性度が増した高悪性型粘表皮癌と診断した。全身麻酔下に顎下部皮膚を含む広範囲な腫瘍切除術、左側下顎骨区域切除術および頸部郭清術を施行した。しかし、術後2ヵ月に切除部と連続性のない左側上顎第1大臼歯周囲歯肉に疼痛を伴う潰瘍形成を認め、組織生検で低分化型扁平上皮癌に類似した高悪性型粘表皮癌と診断した。タキサン系抗癌剤を併用して放射線照射を施行した。著効と判断した。しかし、広範囲な腫瘍の再発を生じ、頸部の再発と胸部への多発転移を認めた。他院にて免疫療法(癌樹状細胞療法)を行うため転院した