A three-degree-of-freedom linear displacement detection method

Abstract

The present invention relates to a three-degree of freedom linear displacement detection method. The technical scheme of the present invention is that: four rectangular sensing electrodes are arranged on an insulating substrate; an emission electrode of which the length-width ratio is same as that of the sensing electrodes and the area is less than that of the sensing electrodes is arranged on another one insulating substrate; the sensing electrode insulating substrate is fixed on a reference substance, and the length-width directions of the sensing electrodes are kept to be consistent with the two degree of freedom displacement directions of the to-be-detected three degree of freedom displacements; the emission electrode insulating substrate is fixed to a motion object, and the length-width direction of the emission electrode is kept to be parallel with the length-width directions of the sensing electrodes, and the gaps between the emission electrode insulating substrate and the sensing electrode insulating substrate are kept to be uniform; a sine AC signal source of which the amplitude and the frequency are fixed is connected with the emission electrode, the four sensing electrodes are connected with four signal processing circuits respectively to extract the amplitudes of the respective output signals, and the displacements of a target object along the length and width directions of the sensing electrodes can be detected by determining the relative relationship of the output values of the four signal processing circuits.

Description

technical field [0001] The invention belongs to the category of electrical methods, in particular to a three-degree-of-freedom linear displacement detection method. Background technique [0002] Precision displacement detection is the key basic technology to realize industrial automation, and it is widely used in numerical control machining equipment, industrial robots, precision analysis instruments and other fields. According to the type of movement, displacement detection can be divided into linear displacement detection and rotation angle detection. According to the degree of freedom of motion, displacement detection can be divided into single-degree-of-freedom and multi-degree-of-freedom detection. Among them, the three-degree-of-freedom linear displacement detection based on the Cartesian coordinate system is the most widely used, such as for multi-axis machining centers and three-coordinate measuring machines. , 3D printing equipment, etc. For this reason, the curre...

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Problems solved by technology

Affected by the assembly deviation of the orthogonal combination, this method not only easily introduces measurement errors, but also often causes problems such as excessive size after combination and complicated signal cable connections.

[0003] In order to realize the integrated detection of multi-free linear displacement, the German Heidenhain company designed and manufactured a planar grating device, but because of its high price, it is generally only used for the positioning control of ultra-precision machine tools or the precision calibration of precision machinery; the publication number is CN103308045A A Chinese patent application proposes a method for detecting three-dimensional spatial positions using microsensors, but the accuracy is limited; the Chinese patent with the publication number CN102221323A proposes a multi-degree-of-freedom variable capacitance position detection method of a planar rectangular electrode array and a multi-directional sensing electrode group, but the accuracy is limited. The coupling relationship between different measurement directions is complicated; the Chinese patent with the publication number CN104697424A proposes a planar position detection method of a planar four-quadrant emitting electrode and a single sensing electrode, but a mixed frequency signal is required to excite the emitting electrode, and the detection accuracy is extremely limited. The influence of plate gap variation is large

At present, in the field of multi-degree-of-freedom linear displacement detection, there is still a lack of high-precision, low-cost, simple-structure and easy-to-implement detection methods and measurement devices

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