球殻弾性層内金属球の位置計測に基づく三次元運動体の合成加速度検出

抄録

This paper describes measurement of resultant acceleration of motion and gravity in 3D space based on sensing a metallic ball position on elastic layer located at inside of a spherical shell. Construction of different types of elastic layers by silicon rubber is introduced and their displacements against pressure are calculated by using the Hertz' law. Since the resultant acceleration makes the ball roll toward the direction to find a balanced position in the shell, center position of the metallic ball is the target to be pursued. The elastic layer is concentric to the shell and liable to distort so that three proximity sensors of high-frequency oscillation type can detect ball sink against pressure. We show measurement principle of extracting the acceleration by using characteristics of the sink versus pressure. Experimental results are shown and compared among various rubbers to have the most appropriate design of the sensor. These data are important for making specifications of the spherical acceleration sensor. We got practical data such that amount error less than -0.032∼+0.097[m/s²]; angular error less than 7.4[deg]; insensible range less than ±4.9[deg] with almost no vibration.