No abstract

In experimentally investigating the effect of servo valve dynamics on control of a pneumatic servo table with an air bearing, we propose control using a PDD2 and a feedforward controller, then test step and trajectory tracking response with natural servo valve frequencies. We confirmed that pneumatic servo performance is affected by servo valve dynamics. We found that tracking error fell below +- 0.5 mm when the servo valve has a natural frequency of 300 Hz.

Absfrml-We developed a pneumatic high precise position controllable servo valve for a pneumatic precise positioning system.To improve the performance o f a pneumatic, improvement of the servo valve characteristic is essential because the system performance is dominated by it. This valve is not affected by friction force because an air bearing is mounted on sliding surfaces of the valve. Furthermore, this valve bas P high-resolution position sensor to accurately control of the spool position. We analyzed characteristics of this valve to design the optimum digital controller. Then, the digital controller was designed. Furthermore, the characteristic experiment of this valve was done to confirm the effectiveness of the controller.

A metal microslit has been used as an interaction circuit between a CO2 laser beam and nonrelativistic free electrons. Evanescent waves which are induced on the slit by illumination of the laser light modulate the energy of electrons passing close to the surface of the slit. The electron-energy change of more than ±5 eV for the 80 keV electron beam has been observed using the 7 kW laser beam at the wavelength of 10.6 μm.

Assisting the elderly to or from a toilet for excretion is a heavy burden, and staff at nursing homes and families at home have problems such as backache and tiredness. There are several previous studies on standing up from a chair, bed, or toilet seat but almost no studies on the series of actions required for excretion (i.e., from a bed to a transfer apparatus and from the transfer apparatus to the toilet seat). The difference in the physical burden (muscular strength) for helpers when using the Norisukesan II, a transfer-type wheelchair developed in collaboration with the authors, and an ordinary wheelchair when transferring a patient to or from a toilet for excretion was studied by biometrics with surface electromyogram (EMG) patterns. We chose a total of 11 healthy adult examinees, 10 males and one female, with an average age of 47.7±9.7. Muscle activity was measured at eight positions: right and left biceps brachii muscles, right and left quadriceps femoris muscles, upper right and left trapezius muscles, and right and left waist muscles. The results showed that if the transfer-type wheelchair was used, the muscle activity of the helpers’ biceps brachii muscles decreased by 70%, that of the quadriceps femoris muscles decreased by 60%, that of the trapezius muscles decreased by 70%, and that of the waist muscles decreased by 40%, when compared to using the ordinary wheelchair. It was therefore quantitatively clarified that assisting patients with the transfer-type wheelchair could reduce the assisting burden significantly, as the helpers did not have to tightly hold or turn the patients.