X-Y-Theta displacement direct decoupling measuring device and method based on plane capacitor

Abstract

The invention discloses a X-Y-Theta displacement direct decoupling measuring device and a method based on plane capacitors. The X-Y-Theta displacement direct decoupling measuring device consists of a moving polar plate and a fixed polar plate, wherein four groups of capacitor-electrode banks which are arranged in a quadrate shape are arranged on the fixed polar plate; four groups of sensing capacitor-electrode banks (eight in total) which are in one-to-one correspondence with the capacitor-electrode banks arranged on the fixed polar plate are arranged on the moving polar plate, and the initial positions of the two capacitor-electrode banks in one group in the corresponding measuring direction have a position difference of one quarter of period, making output signals have a phase difference of 90 degrees; in the process of measurement, when the moving polar plate generates plane displacement relatively to the fixed polar plate, the eight sensing capacitor-electrode banks generate eight capacitance output signals, X-axis and Y-axis plane displacement output signals can be directly decoupled through product-to-sum calculation under small-angle displacement so as to obtain a small angle displacement signal theta. The method can directly decouple to output X-axis and Y-axis displacement signals and the small-angle displacement signal theta, and has a high measuring speed.

Description

technical field [0001] The invention relates to a device and method for direct decoupling measurement of X-Y-θ displacement based on planar capacitance. Background technique [0002] Precision displacement measurement technology is closely related to the development level of VLSI (IC) manufacturing and packaging, micro-electromechanical system (MEMS) assembly and integration, ultra-precision processing, nano-material manufacturing, optical instruments, cell manipulation, bioengineering, etc. high-tech. The primary task of precision displacement measurement technology is to break through the bottleneck of large-stroke measurement while maintaining high-precision measurement. [0003] At present, the most widely used precision displacement measurement methods include: optical measurement method, inductance measurement method (Linear Variable Differential Transformer, LVDT, linear variable differential transformer), resistance measurement method and capacitance measurement met...

AI Technical Summary

Problems solved by technology

For the installation deviation, although it can be reduced as much as possible through calibration, it cannot be completely eliminated, and the guarantee measures in the process are difficult and the cost is high

The angular deviation caused by motion error is a dynamic disturbance, although it can be improved by real-time feedback correction, it will cause the system to become too complex and difficult to implement

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