Noncontact displacement sensor based on capacitive grating

Abstract

The invention discloses a noncontact displacement sensor based on a capacitive grating. The fixed electrode plate of a conventional capacitive grating displacement sensor is used as a static grating unit, and the movable electrode plate of the conventional capacitive grating displacement sensor is used as a movable grating unit. The static grating unit and the movable grating unit are integrated into a reading head, and such structure is equivalent to that the reading head and the static grating unit form a capacitive grating displacement sensor. A controller simultaneously obtains the capacitive grating displacement measured data and the high-precision displacement measured data. The data of the capacitive grating is used as a basis and the displacement data of the high-precision displacement sensor is added so as to improve measurement accuracy. Thus, the noncontact displacement sensor can achieve high-speed high-precision performance of the high-precision displacement sensor, and the absolute value output number and the fast response function of the capacitive grating displacement sensor, realizes the switching of absolute value and non-absolute value output. Further, the noncontact displacement sensor is based on capacitance change, displacement or magnetic induction, is insensitive to dust and strong light in the measurement environment, and has high reliability.

Description

technical field [0001] The invention relates to the field of high-precision displacement sensors, in particular to a non-contact displacement sensor based on a capacitor. Background technique [0002] High-precision high-speed grating scales are mainly used in linear motors and CNC machine tools. The current grating scale equipment market has been dominated by foreign brands, such as Heidenhain in Germany and Renishaw in the UK. Some of them cost as much as 10,000 yuan per meter. It costs thousands of yuan per meter to choose a magnetic scale with low precision, which causes great difficulties in equipment procurement and maintenance. However, the domestic high-precision high-speed grating scale and magnetic scale technology are not mature enough to provide low-cost and high-precision Higher displacement sensor equipment; at the same time, the data collected by the grating scale and magnetic scale are not absolute values, and the results need to be converted to numerical val...

AI Technical Summary

Problems solved by technology

[0002] High-precision high-speed grating scales are mainly used in linear motors and CNC machine tools. The current grating scale equipment market has been dominated by foreign brands, such as Heidenhain in Germany and Renishaw in the UK. Some of them cost as much as 10,000 yuan per meter. It costs thousands of yuan per meter to choose a magnetic scale with low precision, which causes great difficulties in equipment procurement and maintenance. However, the domestic high-precision high-speed grating scale and magnetic scale technology are not mature enough to provide low-cost and high-precision Higher displacement sensor equipment; at the same time, the data collected by the grating scale and magnetic scale are not absolute values, and the results need to be converted to numerical values, which brings trouble to the measurement; this patent is aimed at the current high market price of grating scales and magnetic scales. To solve the problems of low equipment reliability and non-absolute measurement results, design a new displacement sensor

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