We developed high precision altitude measurement technology for a watch. The technology uses barometer and GPS together in which barometer calibrated with GPS altitude. We optimized the intake part of the air to improve the accuracy of the barometer. Moreover, we developed an automatic correction method of barometer using the temperature formula based on the statistical data and the altitude data acquired by a GPS receiver. With combining these methods, we realized high precision altitude measurement on a watch.
Édouard Phillips, a theoretician of 19th century, advocated the conditions of inner and outer end of Archimedes spiral, which is referred to as Conditions of Phillips. However, Phillips developed the expression for conditions using approximation, actual effect has not been adequately evaluated. We conduct holomorphic computation and it is realized that conditions of Phillips improve significantly not only isochronism of horizontal position but also that of vertical position.
Inch worm mechanism using piezoelectric actuators is one of the driving mechanisms for precision positioning devices or stages, because high precision and long stroke motion can be achieved simultaneously, and the motion is smooth without backlash. However, one of the problems of conventional inch worm mechanisms is that it cannot hold large load on the guide rail. A new inch worm mechanism proposed in this study utilized linear ball guide and four micro X-Z positioning units with eight piezoelectric elements to solve this problem. Motion characteristics of the proposed mechanism were evaluated by various driving voltage wave patterns.