A disk-type capacitive sensor for five-dimensional motion measurements

This paper presents a disk-type capacitive sensor for the simultaneous measurement of five-dimensional motions of a target. The sensor detects both air gap and mutual area changes for these five-dimensional motions. In addition, the sensor is manufactured with a printed circuit board (PCB), which reduces manufacturing costs. The sensor is optimally designed through both an error analysis of possible mechanical errors and a finite element analysis of the parasitic capacitances. Furthermore, the sensor can correct measurement errors due to the initial misalignment between the sensor and the target. A prototype PCB sensor, electronics and a test rig were built, and the effectiveness of the developed sensor was proved through experiments.