Multielectrode Differential Capacitive Sensors—Model Simulation With Design Application

In this paper, we first derive an analytical formulation for capacitance prediction of multi-conductor and multi-dielectric system. A simulation model based on this formulation is then developed. By introducing the effective capacitance, we also propose a new methodology to measure the capacitance for multi-conductor system. Results from simulated model are compared with measurement data. It shows that our model can make reasonable predictions of capacitive sensors in the environment of multi-conductor/dielectrics. This simulated model is subsequently used to evaluate the input/output linearity of the radial displacement capacitance sensor that our newly proposed. It shows that the linearity coefficient between the input torsion angle and output differential capacitance of this new device is within 0.3% of perfect straight.