Capacitance measuring sensor device in absolute position

Abstract

The invention discloses a capacitance measuring sensor device in an absolute position, which comprises a capacitive grating sensor, a measurement signal processor, a data processor and a display, wherein the capacitive grating sensor comprises a one-grade or multi-grade calibration sensor and a measurement sensor and a memory electronic element is used for memorizing a phase value and a phase difference of the calibration sensor and the measurement sensor so as to determine a counting zero of the measurement; the calibration sensor has absolute measurement function in an effective working range and the pitch score of the measurement sensor is larger than or equal to the pitch score of the calibration sensor. As for measurement in an absolute circumferential position, the capacitive grating sensor is a round capacitive grating sensor comprising a one-grade or multi-grade calibration sensor and the measurement sensor; as for measurement in an absolute angle (arc) position, the capacitive grating sensor comprises a one-grade round grating calibration sensor and a flexible hinge grating measurement sensor; as for measurement in an absolute linear position, the capacitive grating sensor comprises a one-grade or multi-grade calibration sensor and a linear measurement sensor.

Description

(1) Technical field: [0001] The invention belongs to a measuring device, in particular to a capacitance measuring sensor device for absolutely measuring a position. (two) background technology: [0002] The digital display measuring device of the traditional digital caliper is a capacitive sensor, which is composed of a moving grid and a fixed grid. The fixed grid and the moving grid of the digital caliper are respectively fixed on the ruler body and the ruler frame. The sensor composed of the movable grid and the fixed grid is an incremental measurement sensor. As the ruler frame moves on the ruler body, the movable grid and the fixed grid relatively sense the moving distance and display it through the LCD screen. The sensor has absolute measurement characteristics within a pitch, and the measurement range of a general measuring tool is often greater than 1 pitch of the capacitive grid, so its measurement and spatial position are not one-to-one absolute measurement, but onl...

AI Technical Summary

Problems solved by technology

[0004] 1. The problem lies in the statement in claim 1 that "the circular capacitive grid contains a coarse sensor and a subdivision sensor, and the pitch of the subdivision sensor is greater than the two resolutions of the coarse sensor", and there is no definition of the coarse sensor. Pitch value, when the pitch number of the coarse sensor is greater than one, the above device will lose the absolute measurement function when working at 360°

[0005] 2. The problem is also that the "coarse and subdivision sensors have a common initial zero point" proposed in claim 1 is difficult to realize in sensor production, especially when the subdivision sensor pitches are large, it will be more difficult to manufacture and more It is difficult to ensure the consistency of product technical indicators during mass production, and it is difficult to mass produce products

What's more, the current dedicated IC (microprocessor) for incremental capacitive displacement sensors, because its receiving pole signal adopts the asymmetry of differential operational amplifiers, even if "coarse and fine-grained sensors have a common initial zero point", the physical positions are aligned, and the obtained The output phase data will not be zero, so it cannot be realized by taking this as the absolute zero point

This means that the coarse sensor cannot perform position calibration on the pitch series of the fine sensor

[0006] 3. The problem also lies in the claim 5 that "there is only one measurement signal processing circuit between the measurement signal processing part of the capacitance grid IC and the circular capacitance grid sensor. To the signal processing part of the capacitive IC switch circuit", because the receiving signal of the capacitive circuit is a micro-voltage signal, the ordinary switching circuit will introduce a strong interference signal, which will cause the above-mentioned device to fail to work normally. If a high-quality switch is used circuit, the price is high, and the production cost of the device is correspondingly increased, failing to achieve the purpose of cost reduction

[0007] In summary, the invention patent of "absolute circular capacitance sensor measuring device for absolute position measurement" is basically impossible to implement

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