Large buses and trucks often give rise to an accident at a turn to the left (right in U. S. A. and other countries). Three serious defects in the left outside mirror are illustrated. The defects can be corrected when an outside mirror is supplemented by two plane mirrors. A better mirror system can be composed if an adequate aspherical mirror is used as a substitute for the spherical mirror.

View full abstract

The purpose of this paper is to construct subjective equal sense countours in order grasp a general tendency of whole body sensation for low frequency vibrations below 1Hz under osillating surroundings on offshore floating structure. Namely, using an experimental simulator which satisfies oscillating conditions for the offshore floating structure and a magnitude estimate method by S. S. Stevens as a psychological dimensional scaling, the subjective equal sense countours are proposed for low frequency vertical sinusoidal vibrations from 0.03 to 0.2Hz for standing posture.
As the results, it became clear that Stevens' power function which indicated a relationship of stimulus and reaction existed also in the region of low frequency vibrations and whole body vibration sensation was regulated by velocity and acceleration in these frequencies.

View full abstract

The manual control system has been investigated having the trajectory display which shows the output history of some time interval. In comparison, the usual display showing the actual output and the prediction display showing the predicted value of output have been considered. Considerable decrease achieved in control error by using the trajectory display; the amouni of decrease is similar to that of the prediction display. In some systems, the prediction display shows a bad effect on control error; however, the trajectory display does not cause such a phenomenon. Control effort is almost the same as the case of the usual display. Considerable decrease in control error occured by using the prediction display.

View full abstract