3차원 변위 측정을 위한 원판형 정전 용량 센서

A cost-effective disk-type capacitive sensor is developed for three dimensional displacement measurement. The capacitance between a sensor disk and a grounded rotor depends on both their air gap and their mutual area overlap, which contains three dimensional position information of the target. The developed sensor has wide measurement range since it detects capacitance variation due to area change, and the sensor is made with a printed circuit board. First, effects of mechanical errors: irregular air gap, target roundness and sensor installation errors on the measuring process of the proposed sensor are analyzed, and a design criterion of the sensor is determined based on the error analysis. In addition, a compensation method for the sensor installation error is proposed. Finally, a test rig is built and the effectiveness of the proposed sensor is proven through experiments.