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This paper focuses on the development of practical observers for semi-active suspensions. Many sensors are necessary to measure all the states used for a control system. Therefore, the estimation of states is valid for developing simple and low cost semi-active suspension systems. The nonlinearity, which is included in the absorber of semiactive suspensions, is a difficult problem in estimating accurate states using a usual linear observer theory such as the Kalman filter theory. To solve this problem, this paper presents a new practical observer which has two improvements. The first point is that the observer model includes a data map which reveals the nonlinear characteristic of the absorber. The second is that the observer feedback gain is scheduled. We design the feedback gain L0 for a linear quarter car model whose damping ratio is minimum, and L1, for that whose damping ratio is maximum. The feedback gain is determined using linear interpolation of L0 and L1 according to the control signal of the absorber valve. Applying this observer for actual systems, however, the problem that this observer needs more quantity of computation than the usual linear observer must be considered. Therefore, we reveal a method which reduces the quantity of the computation. To confirm the validity of this practical observer, simulations and experiments are carried out. These results show that the observer developed in this paper can estimate the suspension stroke velocity accurately using the vertical acceleration sensor on the unsprung mass.

A new experimental apparatus to visualize and measure the flow in the stator of a torque converter was proposed. A one-sided coaxial shaft constructed with an input shaft and an output shaft provides an open space inside the stator shaft for measurement. Through the window on the stator shaft, the flow in the stator can be directly observed. By visualizing the flow with an oil-film method and tuft method, separated regions near the blade surface and flow patterns in the blade passage were observed. Furthermore, using a laser doppler velocimeter, velocity vectors and turbulence intensities were measured in the inlet, outlet and the separated flow in the blade passage of the stator.

目的 レーザドップラ速度計 (LDV) を糸速測定に適用した場合の出力信号特性を明らかにする.とともに, よこ入れ試験機を用いて, よこ入れ過程の糸速変化の全般的な状況, 噴射終了段階の糸速変動状況, 並びにノズルの噴射条件とこれらの状況との関連性について調べる.成果 ドップラ信号の特性は糸の表面状態に依存し, 紡績糸の場合毛羽がシードの役割を果たすため, フィラメント糸に比べSN比が良好である.又, トラッカ出力 (速度信号) には10kHzに及ぶ不規則なノイズが重畳しており, 糸速波形の観測を行うに際しては高周波数域のノイズをローパスフィルタにより除去する必要がある.よこ糸にポリエステル・綿混紡糸45s (P/C45s) を用いた場合, このノイズは約2m/s (rms) 程度で, 2kHzのローパスフィルタを用いるとそのレベルは半減することが明らかとなった.エアプール方式において, グリッパ開放開始時及び自由噴射終了時には, 張力波の伝播に起因する特徴的な糸速変動が生じている.又, 飛走中の糸のゆるみ量及び自由噴射終了時の張力ピーク値の低減には, 供給速度をよこ入れ前中期で高め, かっ自由噴射後期で減らすように設定することが有効である.このような供給速度はメインノズルの圧力をよこ入れ前期で高めることにより実現できるが, 紡績糸 (特に単糸) の場合には解撚による糸切れの問題もあり注意を要する.

The characteristics of jets injected from sub-nozzles into air guides of an air jet loom were investigated experimentally. Special-reed system which is composed of special reeds with channel-shaped passage and subnozzles each with a small hole was used. It is shown that the flow pattern in steady jetting from single subnozzle is classified into 3 regions, and that the velocity after collision with the interior wall of the air guide decreases more repidly than that of free jet. Furthermore, the measured velocity profiles, turbulence intensities and static pressure in case of steady and pulsed jetting from plural sub-nozzles are presented.