Shaking machine vibrates various test structures with different mass according to their test purposes, while its control characteristics are under the potent influence of the mass of such structures. The feedback gains for the control system must be adjusted to compensate for this influences. This report describes an automatic feedback gain control system for shaking machine.
From the viewpoint of reliable reproduction of the reference input signal such as earthquake records or random waves which have various frequency components, it is most desirable that the control system for shaking machine should have a dead time characteristic. The velocity and the acceleration feedback gains are determined so that the control system can be approximated most closely to such characteristic. And an automatic feedback gain control algorithm is derived using model reference adaptive control. This method is verified experimentally by means of a shaking machine with a 1.0×10³ kg table.

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Component characteristics are degraded when particulate contaminants are entrained in hydraulic oil. The NFPA (National Fluid Power Association) recommended standard for contaminant sensitivity, which assesses the degradation of pump characteristics by the decrease in pump flow rate, is at present the only test method to measure the component contaminant sensitivity.
This study examines whether the degradation of pumps by the particulate contamination can be accurately assessed by the standard.
To conduct the contaminant sensitivity test, the correct test facility and test dust must be prepared. The first report treats experiences and technical problems relating to the manufacture of a test facility compatible with the NFPA standard.
The most important characteristic of the contaminant sensitivity test facility is the dispersion uniformity of the injected dust. The description in the NFPA standard relating to the test facility gives the basic requirements; however, some technical expertise is required to satisfy the requirements.

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