[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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An identification method for time-varying transfer function models is proposed by using wavelet-based periodograms of input/output data. The instantaneous periodograms are estimated by directly making wavelet transforms of input/output data. The time-varying frequency transfer function is identified from the ratio of input/output periodograms. It is shown that the proposed wavelet-based method is effective even when the output is contaminated with noise due to the band-pass filtering characteristics in the analyzing wavelet. In addition, it is demonstrated through simulation results that this method is more advantageous for its control application than the Blackman-Tukey based method that has already been proposed.

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A control law of an electronic throttle servo system is proposed consisting of a DC motor, a throttle valve and a return spring. The control law fulfills the demand for high robustness in nonlinear opening of the throttle that depends on negative pressure, characteristics of gears and elastic effects. Since these nonlinear system parameters are treated as unknown variables, a disturbance and sliding-mode observer is to be incorporated. The observer gain and system parameters are identified by using the genetic algorithm. A robust sliding-mode positioning control law is applied to the identified nonlinear throttle system. It is described through simulation results using MATLAB that better control performance is achieved by our robust sliding-mode approaches.

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This paper presents a role of network in the field of instrumentation and control. A really high performance network can speak with not only high level devices but also low level devices.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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The oval gear type flow meter was taken up as a candidate of a working standard, and it was examined whether this had an enough performance as a working standard. As a result, when the Reynolds number larger than 1000, reproducibility of flow rate became ±0.17%. Therefore, oval gear meter uncertainly is 0.43% (coverage factor k=2). But it was able to make correction curve for flow rate and can correction. Finally therefore, uncertainty becomes 0.26% (coverage factor k=2).

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In this paper, the experiment result of two kinds of flowmeter made to obtain a fundamental knowledge for designing the ultrasonic flowmeter for hydrogen gas will be presented. Characteristics of calibration factors and pressure loss of the ultrasonic flowmeters were investigated using sonic Venturi nozzles. As a result, it was confirmed that the uncertainty of one of the flowmeters is less than ±1% for the flow rate range from 30 to 360L/min at the pressure condition of 50kPa, and the pressure loss is below 3kPa.

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[in Japanese]

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Wet gas meters are increasingly growing in importance in connection with the development of traceability systems based on the new Testing and Calibration Act. The measuring accuracy of the gas meters must be represented by the “uncertainty”. But there is a little misunderstanding about the “uncertainty”. This may be caused by only a small amount of reliable technical references available regarding the relationship between the volume error of wet gas meters and their structural and principial features. This paper describes the basic operation characteristics of wet gas meters and provides an analysis of the liquid level and volume error to encourage a correct evaluation of the “uncertainty” of the gas meters.

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This paper reveals the characteristic of the pneumatic jumping by a cylinder which can lead to the energy-saved jumping. First, the basic equations to derive the jumping height are shown. Second, the desired shape and the weight-ratio with respect to the cylinder are pointed out. And third, the jumping height control by the valve control is mentioned.

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[in Japanese]

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[in Japanese]

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This paper proposes a new type of the pneumatic system whose name is “Closed System”. This system is composed of one pomp and one cylinder. The key issue here is how to recycle exhaust air and how to reduce the power rates consumption of this system. In order to answer those issue, I construct the two system and verify the effect of those system.

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Recently, in order to prepare for an aged society, various welfare systems are studied. This study purposes to develop the Tendon-Driven 2-Link Manipulator as the care lift for assisting the rising and sitting of elderly person. The Tendon-Driven 2-Link Manipulator consists of 2 links, 6 pulleys made of acrylic and 4 tendons made of wire, and make use of the Pneumatic Cylinder as an actuator. The Tendon-Driven 2-Link Manipulator is driven by tension force of tendons generated by thrust of the Pneumatic Cylinder. This paper gives the structure, the Tendon-Driven mechanism, the dynamic analysis and the experimental static characteristics of the Tendon-Driven 2-Link Manipulator.

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[in Japanese]

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[in Japanese]

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The air consumption of pneumatic servo system with the process of driving is unclear. To clarify the energy consumption (fatigue tester, the control of bodywork etc), the air consumption needs to be clarified. This research shows that the air consumption is separated in the consumption of displacement and that of acceleration. Also it shows a drive condition where the system can be driven by only the air consumption of displacement.

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In this paper, we propose and simulate the acceleration estimate method in pneumatic servo systems. Acceleration feedback is important in pneumatic servo systems. Although finite-differences-method and derivative-filter-method are ordinarily used, the former cannot detect acceleration in low-acceleration-region and the latter causes a time-delay. In our proposed estimation method, finite-differences-method is used in high-acceleration-region and interval of encoder pulse and flow order is used in low-acceleration-region. The proposed method gives better feedback simulation results than ordinary one especially in low-acceleration-region.

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In order to realize a power assisting suit for assisting a nurse caring a patient in her arm, a new actuator using Bellows have been developed. The power assisting suit consists of shoulders, arms waist and legs made of aluminum, and is fitted on the nurse body. The power assisting suit was originated with the concept of a master and slave system in one body. This paper gives the characteristics of Bellows pressure, compliance, and circuit clear for the purpose of developing how to control an actuator.

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[in Japanese]

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This paper proposes the DiThCo cylinder, and presents the principle of the displacement, thrust and compliance control. DiThCo cylinder is an actuator, which consists of hydraulic cylinder, spool, sleeve, mechanical feedback mechanism, stepping motor and displacement sensor. We can simply realize the highly precise displacement control and the high output thrust control by adjusting the input of stepping motor.

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This study analyzes the behavior of the control valve-positioner system that has large grand friction and examines its control scheme for performance improvement. The authors have confirmed that introducing the PI-D control with a gap in the integrator of position controller and the minor feedback control of the diaphragm pressure is the effective way for the stability and dynamic response of the system. In order to improve the behavior to the small change of the set point, this paper proposes the hysteresis compensation of control valve considering the flow condition and confirms its effectiveness.

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