Unipolar one-dimensional and two-dimensional capacitive deflection angle sensors

Abstract

The invention discloses unipolar one-dimensional and two-dimensional capacitive deflection angle sensors. The one-dimensional capacitive deflection angle sensor comprises a sensor probe and a signal conditioning circuit, the sensor probe comprises a probe housing and an inductive polar plate, the inductive polar plate comprises a substrate and two sets of sensing arrays, the signal conditioning circuit comprises two carrier modulation circuits integrated on a modulation circuit board and a differential amplifier and two demodulation circuits integrated on a demodulation circuit board, the modulation circuit board is mounted in the probe housing, both the carrier modulation circuits are connected to the two sets of sensing arrays through coaxial cables, the demodulation circuit board is mounted outside the probe housing, both the demodulation circuits are connected to both the carrier modulation circuits, the differential amplifier is connected to both the demodulation circuits, the difference between modulation voltages output after carrier modulation and the deviation angle of the measured object have a linear relation, and the structure of the two-dimensional capacitive deflection angle sensor is similar to the structure of the one-dimensional capacitive deflection angle sensor. The unipolar one-dimensional and two-dimensional capacitive deflection angle sensors can reduce the space occupation and improve the capacity of resisting disturbance.

Description

technical field [0001] The invention belongs to the field of sensor measurement, in particular to a unipolar one-dimensional and two-dimensional capacitive yaw angle sensor. Background technique [0002] Capacitive micro-displacement sensors have the characteristics of non-contact measurement, simple structure, high precision, good dynamic characteristics, wide frequency band, etc., and have been widely used in industrial production and scientific research. At present, there are two types of capacitive micro-displacement sensors with high measurement sensitivity: one is bipolar capacitors, the two plates of this capacitor need their own specific wires, and the measurement of capacitance comes from these two non-grounded electrodes. The other type is unipolar capacitor, one plate of this capacitor is grounded, the ground plate does not need a specific wire, and the measurement of capacitance comes from the other plate that is not grounded. [0003] In the fields of active op...

AI Technical Summary

Problems solved by technology

[0003] In the fields of active optical systems, precision manufacturing, and micro-nano operations, some components need to be deflected in the X direction and / or in the Y direction. In order to measure the size of the deflection angle, the current method is: use two identical The unipolar capacitive micro-displacement sensor is symmetrically composed of a one-dimensional capacitive yaw angle sensor, and four identical unipolar capacitive micro-displacement sensors are used to form a two-dimensional capacitive yaw angle sensor symmetrically; the capacitive yaw angle sensor formed in this way The pendulum angle sensor has a complex structure and requires a relatively large installation space, and it requires high accuracy in the installation position of the unipolar capacitive micro-displacement sensor

[0004] In addition, the existing unipolar capacitive micro-displacement sensor includes a sensor probe and a signal conditioning circuit. The sensor probe includes a probe housing and an induction plate installed at one end of the probe housing. The signal conditioning circuit includes a carrier modulation circuit and a demodulation circuit. , the carrier modulation circuit and the demodulation circuit are integrated on the signal conditioning circuit board, the signal conditioning circuit board is installed outside the probe shell, and the carrier modulation circuit is connected to the induction plate, because the distance between the carrier modulation circuit and the induction plate is relatively long , the signal output by the sensing plate is easily interfered, which affects the measurement accuracy; in order to reduce interference, capacitance matching is required, which makes the signal conditioning circuit complex, and the capacitive micro-displacement sensor after capacitance matching cannot arbitrarily change the connection cable Length, use is not flexible enough, and the cost is also high

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