Comb-teeth Cylindrical Capacitive Sensor Based on Mutual Capacitance Measuring Principle

Abstract

The invention discloses a comb tooth type cylindrical capacitive sensor on the basis of a mutual capacitance measurement principle. The comb tooth type cylindrical capacitive sensor sequentially and structurally consists of a sensor housing, an insulating medium layer and four groups of mutual capacitance measurement units adopting the same structure from outside to inside; the four groups of mutual capacitance measurement units are distributed at equal intervals along the inner circumference of the insulating medium layer; each group of mutual capacitance measurement unit is formed by first and second comb tooth type capacitance plates; the sensor is used for measuring a radial motion error of a high-precision axis rotor and is used as a stator to be coaxially arranged outside the measured rotor; and in the measuring process, radial jump generated by the rotor can cause change of a total capacitance of the corresponding capacitance measurement unit and a radial jump displacement value of the measured rotor can be obtained by measuring the capacitance and carrying out reasonable arithmetical operation. According to the invention, the mutual capacitance measurement principle is adopted; the rotor is only used as a measured object without being included in the structural configuration of the sensor, so that the configuration form of the sensor is simplified and the comb tooth type cylindrical capacitive sensor is more suitable for dynamic real-time measurement of the motion error of the rotor; and meanwhile, the comb tooth type cylindrical capacitive sensor has no special requirement for a material for forming the measured rotor.

Description

technical field [0001] The invention relates to a measuring device for a high-precision shafting rotor, in particular to a comb-tooth cylindrical capacitance sensor based on the principle of mutual capacitance measurement. Background technique [0002] In the process of continuous pursuit of high efficiency, high precision, high quality and extreme functions of modern electromechanical equipment, a series of complex electromechanical systems with complex structures, extreme working conditions, information integration, and precision and stability have emerged. For the detection and control of electromechanical systems, sensors will become an important part of information acquisition. [0003] High-precision shafting is used as a key component of ultra-precision equipment such as precision machining centers, high-end CNC machine tools, hard disk drives, micro-nano mechanical gyroscopes, large-scale axial flow compressors, or large-scale complex electromechanical equipment. Ac...

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Problems solved by technology

The method of laser interference has the problems of requiring a large enough installation space, high requirements for the use environment, and high cost, and is more sensitive to the roughness of the measured surface; the eddy current sensor is difficult to obtain higher resolution due to the low signal-to-noise ratio At present, although the commonly used capacitive sensors have high measurement resolution and precision, they all belong to one-dimensional measuring devices and can only be used for single-degree-of-freedom displacement detection; Measurement of eccentric motion; Korean scholar AhnHyeong-Joon proposed a columnar capacitive displacement sensor that can detect rotor radial two-degree-of-freedom motion errors, and analyzed the nonlinearity generated during the measurement process

In the measurement methods of the above scholars, the target rotor is configured as another electrode of the capacitive sensor, which is not conducive to the integration and miniaturization of the sensor.

Zhang Weiping of Shanghai Jiao Tong University used a concentric disc mutual capacitance sensor to detect the rotor position and orientation of the electrostatic levitation rotor micro-gyroscope, but it was limited to the detection of small angular displacement

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