Modeling of two-plate capacitive position sensing systems for high precision planar three DOF measurement

Leon Clark, Bijan Shirinzadeh

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7 Citations (Scopus)


This paper investigates the issues associated with the use of two-plate capacitive sensors for the measurement of coupled linear and angular motions, particularly those of three planar degrees of freedom (DOF) micro/nano positioners. Commonly, such sensors are employed for the measurement of linear motions, and angular motion could introduce non-linearities in the capacitance response. An analytic model of a general three sensor system is developed, together with its linearization, which transform the position and orientation (pose) of the end effector of a planar positioner to the capacitance of each sensor. The sensitivities of pose estimations to capacitance non-linearity and parameter variation are analyzed, which further leads to the identification of optimized sensor positioning strategies. The response of a single sensor to tilt is investigated, and experimentation is performed to determine the magnitude of non-linear effects, and its subsequent impact on the three DOF position estimation.

Original languageEnglish
Pages (from-to)383-392
Number of pages10
JournalPrecision Engineering
Publication statusPublished - 1 Oct 2016


  • Capacitive sensors
  • Coupled 3DOF motion
  • Micro-nano positioning
  • Non-linearity
  • Sensor location

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