Inductance type encoder for measuring axial runout and measuring method

Abstract

The invention discloses an inductance type encoder for measuring axial runout and a measuring method, and relates to the technical field of encoder tests.The inductance type encoder comprises a stator and a rotor, a capacitor and an inductor are arranged in the rotor, the inductor is connected with the two ends of the capacitor, a sin coil, a cos coil and an excitation coil are arranged in the stator, and the excitation coil is connected with the inductor. The sin coil and the cos coil are arranged on the inner wall of the circumference of the stator, and the excitation coil is arranged at the end part, far away from the rotor, of the stator; an MCU (Microprogrammed Control Unit) is arranged in the stator and is used for measuring a signal reflected by the rotor; according to the invention, the axial runout of the inductor encoder is measured through real-time signal intensity, so that the inductor encoder which can only measure the axial angle originally can also measure the axial runout at the same time. Hardware cost does not need to be increased, and design of a user is facilitated. The axial run-out information can be used for equipment operation state monitoring and fault diagnosis, and the equipment intelligence is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of encoder testing, and in particular to an inductive encoder for measuring axial runout and a measuring method. Background Art

[0002] Inductive encoders use the principle of electromagnetic induction to measure the position information of moving parts through the interaction between magnetic induction coils and code discs. The measurement of inductive encoders is based on the relationship between magnetic induction intensity and position, so they have high accuracy and reliability. Inductive encoders use PCB technology to achieve dense coil windings. This unique electromagnetic induction non-contact measurement technology makes inductive encoders have the advantages of small thickness, light weight, low power consumption, high accuracy, etc. It can achieve highly accurate and reliable measurements under harsh conditions; it is widely used in defense, industry and science and technology fields.

[0003] Inductive encoders are mainly used to measure axial angles. However, in the military and aerospace technology environment, tracking, observation and aiming equipment require not only the measurement of axial angles but also the measurement of axial runout. Therefore, the inductive encoder is required to have the function of axial runout measurement.

[0004] However, the existing technology can only realize the measurement of the axial angle of the inductive encoder, but cannot realize the measurement of the axial runout of the inductive encoder. At present, to realize the axial runout, an additional axial sensor needs to be installed, which increases the cost and occupies limited space. Summary of the invention

[0005] The purpose of the present invention is to provide an inductive encoder and a measuring method for measuring axial runout, so as to solve the technical problem that the prior art cannot realize the measurement of axial runout of the inductive encoder.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] An inductive encoder for measuring axial runout comprises a stator and a rotor, wherein a capacitor and an inductor are arranged in the rotor, wherein the inductor is connected to two ends of the capacitor, wherein a sin coil, a cos coil and an excitation coil are arranged in the stator, wherein the sin coil and the cos coil are arranged on the inner wall of the stator circumference, and the excitation coil is arranged at the end of the stator away from the rotor; wherein an MCU is arranged in the stator, wherein the MCU is used to measure a signal reflected back from the rotor.

[0008] As a further solution of the present invention: a method for measuring axial runout, the measuring method uses the above-mentioned inductive encoder, and the specific method is:

[0009] Step 1: Install the inductive encoder to be tested on a standard turntable so that the initial spacing between the rotor and the stator of the inductive encoder is accurately set and in a calibrated state;

[0010] Step 2: Use MCU to collect the initial signal reflected by the rotor and record the initial signal strength;

[0011] Step 3: gradually increase the distance between the rotor and the stator to simulate the change of axial runout;

[0012] Step 4: At each new spacing, measure the signal strength of a point at a certain angle within the entire circle, record the signal strength values ​​of all measurement points at each spacing, and calculate the signal strength of the inductive encoder at the spacing;

[0013] Step 5: Analyze the change trend of signal strength values ​​at different spacings, and establish a relationship model between signal strength values ​​and axial spacing;

[0014] Step 6: Calculate the actual axial runout by comparing the signal strength differences at different spacings.

[0015] As a further solution of the present invention: the spacing between the rotor and the stator ranges from ±0.05 mm, and the spacing increases by 0.01 mm each time.

[0016] As a further solution of the present invention: a point is measured every 0.36° within the full circle, and a total of 1000 points are measured within the full circle.

[0017] As a further solution of the present invention: the signal strength of the inductive encoder at the spacing is calculated according to the mean formula Where y is the signal strength of the inductive encoder under test at the current rotor-stator distance, y i It is the signal strength at different angles under the current distance between the rotor and stator of the inductive encoder under test.

[0018] As a further solution of the present invention: the specific method of establishing the relationship model between the signal strength value and the axial spacing is:

[0019] Experiments were conducted on a standard turntable using an inductive encoder, with different spacings between the rotor and stator adjusted, and the signal strength data at each spacing recorded;

[0020] Clean the collected data to remove outliers or erroneous data; organize the cleaned data into a table or data set showing the correspondence between signal intensity and axial spacing;

[0021] According to the characteristics of the corresponding relationship table or data set, a corresponding mathematical model is selected to describe the relationship between the signal intensity and the axial spacing;

[0022] Statistical software or data analysis tools are used to fit the data of signal intensity and axial spacing to obtain parameter values ​​of the mathematical model and complete the establishment of the relationship model.

[0023] As a further solution of the present invention: during the process of establishing the relational model, the model is verified using a reserved known verification data set to check the prediction accuracy of the model on unknown data.

[0024] The beneficial effects of the present invention are as follows: by measuring the axial runout of the inductor encoder through real-time signal strength, the inductor encoder, which can only measure the axial angle, can also measure the axial runout at the same time. There is no need to increase the hardware cost, which is convenient for the user's design. The axial runout information can be used for equipment operation status monitoring and fault diagnosis, which greatly improves the intelligence of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] Figure 1 It is a schematic diagram of the structure of the inductive encoder of the present invention;

[0027] Figure 2 It is a flow chart of the measuring method of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1 As shown, an embodiment of the first aspect of the present invention provides an inductive encoder for measuring axial runout, including a stator and a rotor, wherein a capacitor and an inductor are arranged in the rotor, wherein the inductor is connected to both ends of the capacitor, wherein a sin coil, a cos coil and an excitation coil are arranged in the stator, wherein the sin coil and the cos coil are arranged on the inner wall of the stator circumference, and the excitation coil is arranged at the end of the stator away from the rotor; wherein an MCU is arranged in the stator, and wherein the MCU is used to measure the signal reflected back from the rotor.

[0030] When the inductive encoder is correctly installed, the MCU inside the stator measures the signal reflected from the rotor, and the axial runout of the inductive encoder can be calculated based on the signal strength.

[0031] The present invention measures the corresponding signal strength according to the different spacings between the rotor and the stator of the inductive encoder, and the measurement accuracy can reach 0.01mm.

[0032] See also Figure 2 As shown, the second aspect of the present invention provides a method for measuring axial runout, wherein the measuring method uses the above-mentioned inductive encoder, and the specific method is as follows:

[0033] Step 1: Install the inductive encoder to be tested on a standard turntable so that the initial spacing between the rotor and the stator of the inductive encoder is accurately set and in a calibrated state;

[0034] Step 2: Use MCU to collect the initial signal reflected by the rotor and record the initial signal strength;

[0035] Step 3: gradually increase the distance between the rotor and the stator to simulate the change of axial runout;

[0036] Step 4: At each new spacing, measure the signal strength of a point at a certain angle within the entire circle, record the signal strength values ​​of all measurement points at each spacing, and calculate the signal strength of the inductive encoder at the spacing;

[0037] Step 5: Analyze the change trend of signal strength values ​​at different spacings, and establish a relationship model between signal strength values ​​and axial spacing;

[0038] Step 6: Calculate the actual axial runout by comparing the signal strength differences at different spacings.

[0039] The range of the spacing between the rotor and the stator is ±0.05 mm, and the spacing increases by 0.01 mm each time.

[0040] One point is measured every 0.36° in the whole circle, and a total of 1000 points are measured in the whole circle.

[0041] The signal strength of the inductive encoder at the spacing is calculated according to the mean formula Where y is the signal strength at the current rotor-stator distance of the inductive encoder under test, n is the number of points measured, and y is i It is the signal strength at different angles under the current distance between the rotor and stator of the inductive encoder under test.

[0042] The specific method of establishing the relationship model between the signal strength value and the axial spacing is:

[0043] Experiments were conducted on a standard turntable using an inductive encoder, with different spacings between the rotor and stator adjusted, and the signal strength data at each spacing recorded;

[0044] Clean the collected data to remove outliers or erroneous data; organize the cleaned data into a table or data set showing the correspondence between signal intensity and axial spacing;

[0045] According to the characteristics of the corresponding relationship table or data set, a corresponding mathematical model is selected to describe the relationship between the signal intensity and the axial spacing;

[0046] Statistical software or data analysis tools are used to fit the data of signal intensity and axial spacing to obtain parameter values ​​of the mathematical model and complete the establishment of the relationship model.

[0047] During the process of establishing the relational model, the model is validated using a reserved known validation data set to check the prediction accuracy of the model on unknown data.

[0048] Working principle of the present invention: The present invention installs the inductive encoder to be tested on the standard turntable, adjusts the distance between the rotor and the stator to be tested, and tests the current signal strength. Then the distance between the rotor and the stator of the inductive encoder is increased by 0.01mm, and the signal strength of the inductive encoder to be tested is read, recorded as yi. A point is measured every 0.36° within the range of the whole circle, for a total of 1000 points, and the mean value formula is used to calculate the signal strength of the inductive encoder. Calculate the signal strength of the rotor and stator at each pitch, y i It is the signal strength at each angle under the current rotor-stator spacing of the inductive encoder under test. The test range of the rotor-stator spacing of the inductive encoder is: standard spacing ±0.05mm, increasing by 0.01mm each time, and then testing the signal strength of the inductive encoder at this spacing according to the above method, you can get the relationship between the spacing between the rotor and stator of the inductive encoder and the signal strength, and you can output the curve and data through the computer display. The above test data can adjust the number of test points per circle, as well as the spacing value between the rotor and stator of the inductive encoder, and then complete the measurement of the axial runout of the inductive encoder.

[0049] When the inductive encoder is correctly installed on the equipment, the distance between the inductive encoder rotor and stator can be monitored in real time. When there are some faults in the equipment, it will cause abnormal vibration between the inductive encoder rotor and stator, which can be detected by the encoder.

[0050] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. An inductive encoder for measuring axial runout, characterized in that: It includes a stator and a rotor, wherein a capacitor and an inductor are arranged in the rotor, wherein the inductor is connected to both ends of the capacitor, wherein a sin coil, a cos coil and an excitation coil are arranged in the stator, wherein the sin coil and the cos coil are arranged on the inner wall of the stator circumference, and the excitation coil is arranged at the end of the stator away from the rotor; wherein an MCU is arranged in the stator, wherein the MCU is used to measure the signal reflected back from the rotor.

2. A method for measuring axial runout, characterized in that: The measuring method uses the inductive encoder as claimed in claim 1, and the specific method is: Step 1: Install the inductive encoder to be tested on a standard turntable so that the initial spacing between the rotor and the stator of the inductive encoder is accurately set and in a calibrated state; Step 2: Use MCU to collect the initial signal reflected by the rotor and record the initial signal strength; Step 3: gradually increase the distance between the rotor and the stator to simulate the change of axial runout; Step 4: At each new spacing, measure the signal strength of a point at a certain angle within the entire circle, record the signal strength values ​​of all measurement points at each spacing, and calculate the signal strength of the inductive encoder at the spacing; Step 5: Analyze the change trend of signal strength values ​​at different spacings, and establish a relationship model between signal strength values ​​and axial spacing; Step 6: Calculate the actual axial runout by comparing the signal strength differences at different spacings.

3. A method for measuring axial runout according to claim 2, characterized in that: The range of the spacing between the rotor and the stator is ±0.05 mm, and the spacing increases by 0.01 mm each time.

4. A method for measuring axial runout according to claim 2, characterized in that: One point is measured every 0.36° in the whole circle, and a total of 1000 points are measured in the whole circle.

5. A method for measuring axial runout according to claim 4, characterized in that: The signal strength of the inductive encoder at the spacing is calculated according to the mean formula Where y is the signal strength of the inductive encoder under test at the current rotor-stator distance, y i It is the signal strength at different angles under the current distance between the rotor and stator of the inductive encoder under test.

6. A method for measuring axial runout according to claim 2, characterized in that: The specific method of establishing the relationship model between the signal strength value and the axial spacing is: Experiments were conducted on a standard turntable using an inductive encoder, with different spacings between the rotor and stator adjusted, and the signal strength data at each spacing recorded; Clean the collected data to remove outliers or erroneous data; organize the cleaned data into a table or data set showing the correspondence between signal intensity and axial spacing; According to the characteristics of the corresponding relationship table or data set, a corresponding mathematical model is selected to describe the relationship between the signal intensity and the axial spacing; Statistical software or data analysis tools are used to fit the data of signal intensity and axial spacing to obtain parameter values ​​of the mathematical model and complete the establishment of the relationship model.

7. A method for measuring axial runout according to claim 6, characterized in that: During the process of establishing the relational model, the model is validated using a reserved known validation data set to check the prediction accuracy of the model on unknown data.

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