球殻内金属球の位置計測による全加速度方向の検出

抄録

This paper proposes a measurement principle for determining the central position of a metallic ball in a 3-D space so that the position is beneficial to sense all directions of resultant acceleration of motion and gravity. The ball is housed and free to roll in a spherical shell. The distance of the ball from the front position of a proximity sensor of high-frequency oscillation type is collected always by an electric driver. We show the sensor outputs obtained by changing attributes of the ball in its material, configuration, and size. Three ellipsoids of revolution generated individually by three sensors in orthogonal arrangement make it clear to explain formulations to determine the central ball position. Our sensor head has an acrylic shell of inner radius 25mm and a steel ball of radius 24mm. Experimental results showed that the formulation is valid and the measurement error is dependent on shell's exactness in interior dimension.