CN111595233A - Non-magnetic sensor - Google Patents

Abstract

The invention relates to the technical field of meter measurement, in particular to a nonmagnetic sensor, wherein a PCB coil is arranged right above a metal sheet, the metal sheet is fixedly arranged on a rotating shaft and rotates along with the rotating shaft, the PCB coil comprises an exciting coil and a plurality of induction coils, the exciting coil and the induction coils are inductively coupled, the induction coils are positioned in the exciting coil, one ends of the induction coils are mutually connected at the same point, the other ends of the induction coils are connected to a signal amplifying unit, the signal amplifying unit is connected with a measuring device, the amplified signal measured by the measuring device is the influence value of the metal sheet rotating along with the rotating shaft on the induction coils, the difference S of the influence value is the distance L between the quantized metal sheet and the PCB coil, the direction and the angle of the metal sheet rotation can be measured, the distance between the metal sheet and the sensor can be quantized, the measuring speed is high, and the algorithm can be used, the distance is detected during design and production, and allowance is reserved for dealing with later environmental change, so that the stability of long-term operation is ensured.

Description

A non-magnetic sensor

technical field

The invention relates to the technical field of meter measurement, in particular to a non-magnetic sensor.

Background technique

At present, in the measurement of water and gas meters, the flow of liquid or gas drives the rotation of mechanical components. A low-power and long-distance sensor is required to accurately convert the rotational motion into an electrical signal and quantify the distance from the metal sheet to the sensor.

Existing technical solution: the patent number is ZL200680007522.8, the invention patent of the inductive angular position sensor, the method of outputting the symmetrical coil pair to the comparator cannot quantify the distance from the metal sheet to the PCB coil, the measurement distance is not far enough, and the measurement speed is not enough Fast, no algorithm can be used to correct when disturbed.

Because the distance from the metal sheet to the PCB coil cannot be quantified, it may be in a critical position when it leaves the factory, and the detection distance will be exceeded due to environmental changes in the future, so the stability of long-term operation cannot be guaranteed.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a non-magnetic sensor for detecting the distance and rotation of the metal sheet.

The technical solution adopted by the present invention to solve the technical problem is: a non-magnetic sensor, comprising a metal sheet, a PCB coil and a measuring device, the PCB coil is arranged directly above the metal sheet, the metal sheet is fixedly arranged on the rotating shaft, and Rotating with the rotating shaft, the PCB coil includes an excitation coil and a number of induction coils. The excitation coil and the induction coil are inductively coupled. The induction coil is located in the excitation coil. One end of the induction coil is connected to each other at the same point, and the other end is connected to the signal amplifying unit. , the signal amplifying unit is connected with the measuring device, the amplified signal measured by the measuring device is the influence value of the metal sheet rotating with the rotating shaft on the induction coil, so as to know whether the metal sheet is directly under an induction coil, through the cooperation of several induction coils, it can be The rotation direction and angle of the metal sheet are obtained, and the difference S of the influence values is the distance L between the quantized metal sheet and the PCB coil.

Further, the distance L is the difference S between the maximum value a of the metal sheet not under the induction coil measured by the measuring device and the minimum value b of the metal sheet under the induction coil, and the distance L is detected during design and production. There is a margin to deal with environmental changes in the later period to ensure the stability of long-term operation.

Further, in order to reduce the power consumption of the system, improve the detection rotation speed and the system measurement accuracy, the measurement device is an ADC measurement device, which is used to measure the voltage signal after each induction coil passes through the signal amplifying unit.

Further, in order to identify the accuracy of the rotation direction and angle of the metal sheet, the number of induction coils is 3 or more.

Further, the metal sheet is a partially metallized disc.

The beneficial effects of the present invention are: the present invention can not only measure the direction and angle of rotation of the metal sheet, but also quantify the distance from the metal sheet to the sensor, with low power consumption, fast measurement speed, and algorithm can be used to correct when it is disturbed. The distance from the metal sheet to the PCB coil can be quantified, and the distance is detected during design and production, and a margin is left to deal with the later environmental changes to ensure the stability of long-term operation.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the structural representation of the present invention;

Fig. 2 is the structural representation of the PCB coil of the present invention;

Fig. 3 is the detection principle diagram of the present invention;

FIG. 4 is a graph showing the influence of the rotating metal sheet of the present invention on the AD value of the induction coil.

In the figure: 1. Metal sheet, 2. PCB coil, 21. Excitation coil, 22. Induction coil, 3. Signal amplification unit, 4. Measuring device.

Detailed ways

The present invention will now be described in further detail with reference to the accompanying drawings and preferred embodiments. These drawings are all simplified schematic diagrams, and only illustrate the basic structure of the present invention in a schematic manner, so they only show the structures related to the present invention.

A non-magnetic sensor as shown in Figures 1 to 4 includes a metal sheet 1, a PCB coil 2 and a measuring device 4. The metal sheet 1 is a partially metallized disk, and the PCB coil 2 is located directly above the metal sheet 1. The sheet 1 is fixedly arranged on the rotating shaft and rotates with the rotating shaft,

The PCB coil 2 shown in FIG. 2 includes an excitation coil 21 and a plurality of induction coils 22, the excitation coil 21 and the induction coil 22 are inductively coupled, the induction coil 22 is located in the excitation coil 21, and the number of induction coils 22 is 3 or more, One end of the induction coil 22 is connected to each other at the same point, and the other end is connected to the signal amplifying unit 3. The signal amplifying unit 3 is connected to the measuring device 4. The amplified signal measured by the measuring device 4 is the effect of the metal sheet 1 on the induction coil 22 when the rotating shaft rotates. The influence value, the difference value S of the influence value is the distance L between the quantized metal sheet 1 and the PCB coil 2 .

The distance L is the difference between the maximum value of the metal sheet 1 not under the induction coil 22 measured by the measuring device 4 and the minimum value of the metal sheet 1 under the induction coil 22 .

The measuring device is an ADC measuring device, which is used to measure the voltage signal of each induction coil 22 after passing through the signal amplifying unit 3 .

The specific excitation coil 21 and several induction coils 22 are illuminated on the PCB coil 6, and the metal sheet 1 is a partially metallized disk. During operation, the metal sheet 1 rotates with the rotating shaft and blocks the induction coil 22, as shown in FIG. 3 The excitation signal 5 shown is a pulse signal to the excitation coil 21, and the pulse signal radiates the electromagnetic signal through the excitation coil 21 at a certain period, and each induction coil 22 receives the induction signal. Magnetic flux, the induction signal has a size, the induction signal is transmitted to the signal amplifying unit 3, and after amplification, the ADC sampling and measuring device (measuring device 4) obtains the signal AD value, which can be seen from the signal AD value: 1. Know from the size of the induction signal Whether the metal sheet 1 is directly under an induction coil, through the cooperation of several induction coils 22, the measured AD value is compared with the preset position code table, and the relationship between the state changes can be known. direction and angle of rotation;

2: As shown in Figure 4, it can be seen that the difference S of the influence value of the metal sheet 1 on the induction coil 22 is the ADC maximum value a of the metal sheet 1 not under the induction coil 22 and the ADC of the metal sheet 1 under the induction coil 22 The difference between the minimum values b, the difference S is the distance L between the quantized metal sheet 1 and the PCB coil 2, the smaller the difference, the farther the distance L is.

In addition, the excitation signal 5 is generated multiple times for each measurement, and the influence of each pulse is accumulated by the signal amplification unit 3 to achieve the effect of amplifying weak signals, and at the same time, it can weaken the influence of a single pulse by external interference.

It can be seen from the above that not only the direction and angle of the metal sheet rotation can be measured, but also the distance from the metal sheet to the sensor can be quantified, with low power consumption and fast measurement speed. The distance of the PCB coil is detected during design and production, and a margin is reserved to deal with environmental changes in the later period to ensure the stability of long-term operation.

What is described in the above specification is only the specific embodiment of the present invention, and various examples do not limit the essential content of the present invention. Those of ordinary skill in the art can modify or modify the specific embodiment described above after reading the specification. variations without departing from the spirit and scope of the invention.

Claims (5)

1. A non-magnetic sensor, characterized by: comprises a metal sheet (1), a PCB coil (2) and a measuring device (4), wherein the PCB coil (2) is arranged right above the metal sheet (1), the metal sheet (1) is fixedly arranged on a rotating shaft and rotates along with the rotating shaft,

the PCB coil (2) comprises an exciting coil (21) and a plurality of induction coils (22), the exciting coil (21) and the induction coils (22) are in inductive coupling, the induction coils (22) are located in the exciting coil (21), one ends of the induction coils (22) are connected to the same point, the other ends of the induction coils are connected to a signal amplification unit (3), the signal amplification unit (3) is connected with a measuring device (4), an amplification signal measured by the measuring device (4) is an influence value of the sheet metal (1) on the induction coils (22) along with rotation of a rotating shaft, and a difference S of the influence value is a distance L between the quantized sheet metal (1) and the PCB coil (2).

2. A non-magnetic sensor as defined in claim 1, wherein: the distance L is the difference S between the maximum value a of the metal sheet (1) not under the induction coil (22) and the minimum value b of the metal sheet (1) under the induction coil (22) measured by the measuring device (4).

3. A non-magnetic sensor as defined in claim 1, wherein: the measuring device is an ADC measuring device and is used for measuring voltage signals of each induction coil (22) after passing through the signal amplifying unit (3).

4. A non-magnetic sensor as defined in claim 1, wherein: the number of the induction coils (22) is 3 or more.

5. A non-magnetic sensor as defined in claim 1, wherein: the metal sheet (1) is a partially metallized disk.

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