A full-angle infinite rotation single potentiometer and angle calibration method

Abstract

The present invention relates to the field of 360° angle sensors, and provides a full-angle infinitely rotatable single potentiometer and an angle calibration method. The purpose of the present invention is to provide a full-angle infinitely rotatable single potentiometer, which has no measurement dead angle and can perform 360° circular measurement. The main scheme includes a shell, an electrode holder, and a top cover. The electrode holder is installed in the shell and fixed by the top cover. An upper carbon film ring is arranged on the top surface of the electrode holder, and a lower carbon film ring is arranged on the bottom surface of the electrode holder. The upper carbon film ring is provided with an upper carbon film ring opening, and the lower carbon film ring is provided with a lower carbon film ring opening. The horizontal projections of the upper carbon film ring opening and the lower carbon film ring opening do not overlap. A rotating shaft is arranged at the center of the electrode holder, and an electrode sheet is arranged on the rotating shaft. The electrode sheet includes an upper electrode sheet electrically contacting the upper carbon film ring and a lower electrode sheet electrically contacting the lower carbon film ring.

Description

Technical Field

[0001] The invention relates to the field of 360-degree angle sensors and provides a full-angle infinitely rotatable single potentiometer and an angle calibration method. Background Art

[0002] Angle potentiometers usually have three terminals and are designed according to the principle of linear change of resistance at different angles. Potentiometers usually consist of a carbon film resistor coil and a movable electrode brush. When the electrode brush moves along the resistor body, a resistance value or voltage that is related to the displacement is obtained at the output end, and existing angle potentiometers cannot achieve 360° continuous measurement.

[0003] The prior art is a multi-turn precision potentiometer CN 204360863 U. The method and device in the literature have complex structures and require three-dimensional space, that is, three-dimensional coordinates for quantitative calculation. The article only has a qualitative introduction and no quantitative algorithm. In particular, during use, the potentiometer shaft moves up and down as it rotates, which has high requirements for the connection of the object to be measured, increases space, and also increases volume, limiting the scope of application.

[0004] Prior art A wind turbine impeller azimuth angle measuring device and method CN 112855468A, the device and method in the article also need a displacement sensor to measure the angle. The algorithm given in the article requires s in calculation, which is difficult to implement with a single chip microcomputer.

[0005] The prior art wide-range potentiometer CN 103489554 A has a complex structure, and requires three-dimensional space, that is, three-dimensional coordinates for quantitative calculation. The article only provides a qualitative introduction, but no quantitative algorithm. In particular, during use, the potentiometer shaft moves up and down as it rotates, which requires a high connection to the object being measured. The space increases, and the volume also increases, limiting the scope of application.

[0006] The prior art 360-degree rotating potentiometer CN 204189544 U requires two potentiometers and does not provide a specific algorithm. Summary of the invention

[0007] The object of the present invention is to provide a full-angle infinitely rotatable single potentiometer, which has no measurement dead angle and can perform 360° circular measurement.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A full-angle infinitely rotatable single potentiometer comprises a shell, an electrode seat and a top cover, wherein the electrode seat is installed in the shell and fixed by the top cover, an upper carbon film ring is arranged on the top surface of the electrode seat, and a lower carbon film ring is arranged on the bottom surface of the electrode seat, the upper carbon film ring is provided with an upper carbon film ring opening, and the lower carbon film ring is provided with a lower carbon film ring opening, and the horizontal projections of the upper carbon film ring opening and the lower carbon film ring opening do not overlap, a rotating shaft is arranged at the center of the electrode seat, and an electrode sheet is arranged on the rotating shaft, and the electrode sheet comprises an upper electrode sheet electrically contacting the upper carbon film ring and a lower electrode sheet electrically contacting the lower carbon film ring.

[0010] In the above technical solution, one end of the opening of the upper carbon film ring is the upper carbon film ring electrode lead-out end, the upper carbon film ring electrode lead-out end is led out through the electrode, and the other end is the upper carbon film ring jumper end;

[0011] One end of the opening of the lower carbon film ring is the lower carbon film ring electrode lead-out end, the lower carbon film ring electrode lead-out end is led out through the electrode, and the other end is the lower carbon film ring jumper end;

[0012] The upper carbon film ring jumper end is electrically connected with the lower carbon film ring jumper end through a jumper wire.

[0013] In the above technical solution, the misalignment angle between the jumper end of the lower carbon film ring and the jumper end of the upper carbon film ring is θ, where θ is the electrical angle phase difference.

[0014] In the above technical solution, the rotation angle α of the potentiometer is:

[0015]

[0016] Among them, v c is the voltage at the electrode sheet, I is the constant current source current, R1 and R2 are the resistances of the lower carbon film ring and the upper carbon film ring respectively, γ is the mechanical angle corresponding to the opening of the upper carbon film ring and the opening of the lower carbon film ring, and θ is the misalignment angle between the jumper end of the lower carbon film ring and the jumper end of the upper carbon film ring, that is, the electrical angle phase difference.

[0017] In the above technical solution, the radius, material, area, etc. of the upper carbon film ring and the lower carbon film ring are exactly the same.

[0018] In the above technical solution, the shell includes a cylindrical cavity structure, including a lower cylindrical cavity and an upper cylindrical cavity, the cavity radius of the lower cylindrical cavity is smaller than the cavity radius of the upper cylindrical cavity, an annular step is formed between the lower cylindrical cavity and the upper cylindrical cavity, and the electrode seat is arranged on the annular step.

[0019] In the above technical solution, the top cover includes a top surface and a cylindrical cavity, and the outer surface of the cylindrical cavity is inserted into the cylindrical cavity and has an interference fit with the upper cylindrical cavity.

[0020] The present invention provides a high-precision angle calibration method for a 360-degree potentiometer, comprising the following steps:

[0021] Step 1: The CPU central processing unit starts the ADC to convert data once every millisecond, obtains the instantaneous voltage data of the potentiometer center tap for n consecutive milliseconds, and stores it as v0, v1, ...v n-1 , determine whether the adjacent voltage values ​​of these n values ​​exceed m millivolts. If so, remove the value and replace it with an interpolation value, that is, replace the value with the average of the values ​​before and after the value. If the last value v n , more than 15 mV, use 2V n-2 -v n-3 Instead of v n , remove the two largest and two smallest values, and calculate the arithmetic mean of the remaining values. The mean is the instantaneous voltage value b0 in n milliseconds. If 0≤b0≤v S , otherwise store α0;

[0022] Step 2: Repeat step 1 at interval nΔt to obtain α1, and store α0 and α1;

[0023] Step 3: Calculate Angular Velocity Store ω0;

[0024] Step 4: Repeat steps 1, 2, and 3 at intervals of n milliseconds. After the loop, obtain and store the angles α0, α1, α2, and the angular velocities ω0, ω1.

[0025] Step 5: Calculate the angular acceleration, Store λ0;

[0026] Because the present invention adopts the above technical solution, it has the following beneficial effects:

[0027] The invention adopts an upper electrode sheet and a lower electrode sheet, which are respectively slidably connected with an upper carbon film ring and a lower carbon film ring, and can rotate infinitely without any measurement dead angle.

[0028] The method provided by the present invention can perform data quality control. Since the circuit is disturbed by lightning, lightning and strong magnetic fields, these disturbances, although short-lived, will inevitably cause product quality to decline. We use a high-precision angle calibration method after data quality control to deal with it. Solve the interference of lightning, lightning and strong magnetic fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the present invention;

[0030] Figure 2 It is an exploded view of the structure of the present invention;

[0031] Figure 3 This is a schematic diagram after the outer shell and top cover are partially cut away;

[0032] Figure 4 is a side sectional view;

[0033] Figure 5 This is a perspective view of the motor base;

[0034] Figure 6 is the relationship diagram between voltage and angle;

[0035] Figure 7 is the equivalent circuit diagram;

[0036] Figure 8 It is the relationship diagram between the equivalent circuit diagram and the voltage and angle diagram.

[0037] Reference numerals

[0038] 1-housing, 1-1-lower cylindrical cavity, 1-2-upper cylindrical cavity, electrode holder (7), 2-top cover, 2-1-top surface, 2-2-cylindrical cavity, 3-rotating shaft, 4-carbon film ring, 4-1-upper carbon film ring, 4-1-1-upper carbon film ring opening, 4-2-lower carbon film ring, 4-2-1-lower carbon film ring opening, 5-electrode sheet, 5-1-upper electrode sheet, 5-2-lower electrode sheet, 6-electrode, 7-electrode holder, 5-a-contact, A-upper carbon film ring jumper end, B-upper carbon film ring electrode lead end, C-lower carbon film ring electrode lead end, D-lower carbon film ring jumper end. DETAILED DESCRIPTION

[0039] The following is a detailed description of the embodiments of the present invention. Although the present invention will be described and illustrated in conjunction with some specific embodiments, it should be noted that the present invention is not limited to these embodiments. On the contrary, modifications or equivalent substitutions made to the present invention should all be included in the scope of the claims of the present invention.

[0040] In addition, in order to better illustrate the present invention, numerous specific details are given in the following specific embodiments. It will be understood by those skilled in the art that the present invention can also be implemented without these specific details.

[0041] In order to facilitate those skilled in the art to better understand the solutions and application scenarios of the present invention, the technologies related to the present invention are first described in detail:

[0042] The four ends of the two carbon film circles are A, B, C, and D respectively. The AD ends are connected by wires, and a constant current source is connected to the B end. The current flows to the A end through the first conductive film, and then flows to the C end through the second conductive film. The C end is grounded.

[0043] The present invention is provided with two independent upper carbon film rings and lower carbon film rings (or two independent inner carbon film rings and outer carbon film rings), the upper carbon film rings and the lower carbon film rings have the same radius, material, area, etc., the carbon film rings are connected end to end with wires, and the remaining two ends are used as two connection ends of the potentiometer; the electrode sheet is divided into upper and lower contact heads, which are respectively connected with the upper carbon film ring and the lower carbon film ring in sliding, and can be rotated infinitely, and the sliding sheet wire is led out as the center tap end of the potentiometer (i.e., the output end of the electrode sheet 5); the electrical angle of the upper and lower carbon film rings of the potentiometer is misaligned, and the phase difference is up to 180°, ensuring that at least one contact head of the upper and lower contact heads of the sliding contact sheet contacts the carbon film ring when it rotates to any position. The four ends of the two conductive films are A, B and C, D respectively, and the AD end is connected by wires. A constant current source is added to the potentiometer, and the constant current source flows in from the B end, and the current flows to the A end through the first conductive film, and then flows to the C end through the second conductive film, and the C end is grounded.

[0044] The calculation formula is as follows:

[0045]

[0046]

[0047] Among them, v c —potentiometer center tap voltage, that is, the voltage at the contact position of contact 5-a and carbon film ring, α—potentiometer rotation angle, I—constant current source current, R1, R2—respectively the resistance of the two carbon films, γ—the mechanical angle corresponding to the gap of the two carbon film rings, θ is the misalignment angle of the starting point of the two conductive films, that is, the electrical angle phase difference. There is a jump in voltage at α=2π-γ±0 and at α=2π-0 to α=0. This algorithm is more convenient to understand with the following figure. Solve to get α, then we have

[0048]

[0049] like Figure 6 , there are two jump points at 2π-γ and 2π. For the two jump points: a full-angle potentiometer and a designed and debugged circuit have been selected. I, γ, R1, R2, and θ are all known numbers and can be measured by relevant methods. Let v S =IR1, Then there is

[0050]

[0051] Instantaneous angular velocity formula

[0052] ω—Instantaneous angular velocity, which can be calculated by software processing. Basic method: α is obtained through the previous calculation, and an α is calculated every 0.01 seconds. The α within the unit time (the unit time is 1 second, so there are 100 α values) constitutes an array. The angle difference between the two adjacent time points before and after a certain moment is Δα. Δt = 0.02 seconds, then ω can be calculated.

[0053] Instantaneous angular velocity formula

[0054] λ—Instantaneous angular acceleration, which can be calculated by software processing. Basic method: Obtain ω through the previous calculation, calculate one ω every 0.01 seconds, and the ω within the unit time (the unit time is 1 second, so there are 100 ω values) constitute an array, and the angle difference between the two adjacent time points before and after a certain moment is Δω, Δt = 0.02 seconds, then λ can be calculated.

[0055] Example 1

[0056] A full-angle infinitely rotatable single potentiometer comprises a shell, an electrode seat and a top cover, wherein the electrode seat is installed in the shell and fixed by the top cover, an upper carbon film ring is arranged on the top surface of the electrode seat, and a lower carbon film ring is arranged on the bottom surface of the electrode seat, the upper carbon film ring is provided with an upper carbon film ring opening, and the lower carbon film ring is provided with a lower carbon film ring opening, and the horizontal projections of the upper carbon film ring opening and the lower carbon film ring opening do not overlap, a rotating shaft is arranged at the center of the electrode seat, and an electrode sheet is arranged on the rotating shaft, and the electrode sheet comprises an upper electrode sheet electrically contacting the upper carbon film ring and a lower electrode sheet electrically contacting the lower carbon film ring.

[0057] In the above technical solution, one end of the opening of the upper carbon film ring is the upper carbon film ring electrode lead-out end, the upper carbon film ring electrode lead-out end is led out through the electrode, and the other end is the upper carbon film ring jumper end;

[0058] One end of the opening of the lower carbon film ring is the lower carbon film ring electrode lead-out end, the lower carbon film ring electrode lead-out end is led out through the electrode, and the other end is the lower carbon film ring jumper end;

[0059] The upper carbon film ring jumper end is electrically connected with the lower carbon film ring jumper end through a jumper wire.

[0060] In the above technical solution, the misalignment angle between the jumper end of the lower carbon film ring and the jumper end of the upper carbon film ring is θ, where θ is the electrical angle phase difference.

[0061] In the above technical solution, the rotation angle α of the potentiometer is:

[0062]

[0063] Among them, v cis the voltage at the electrode sheet, I is the constant current source current, R1 and R2 are the resistances of the lower carbon film ring and the upper carbon film ring respectively, γ is the mechanical angle corresponding to the opening of the upper carbon film ring and the opening of the lower carbon film ring, and θ is the misalignment angle between the jumper end of the lower carbon film ring and the jumper end of the upper carbon film ring, that is, the electrical angle phase difference.

[0064] In the above technical solution, the radius, material, area, etc. of the upper carbon film ring and the lower carbon film ring are exactly the same.

[0065] In the above technical solution, the shell includes a cylindrical cavity structure, including a lower cylindrical cavity and an upper cylindrical cavity, the cavity radius of the lower cylindrical cavity is smaller than the cavity radius of the upper cylindrical cavity, an annular step is formed between the lower cylindrical cavity and the upper cylindrical cavity, and the electrode seat is arranged on the annular step.

[0066] In the above technical solution, the top cover includes a top surface and a cylindrical cavity, and the outer surface of the cylindrical cavity is inserted into the cylindrical cavity and has an interference fit with the upper cylindrical cavity.

[0067] Example 2

[0068] After the potentiometer rotates by an angle α, the angular velocity and angular acceleration can be calculated based on the unit time.

[0069] Instantaneous angular velocity formula

[0070] ω—Instantaneous angular velocity, which can be calculated through software processing. Basic method: α is obtained through the previous calculation, and an α is calculated every 0.01 seconds. The α within the unit time (the unit time is 1 second, so there are 100 α values) constitutes an array. The angle difference between the two adjacent time points before and after a certain moment is Δα. Δt = 0.02 seconds, then ω can be calculated;

[0071] Instantaneous angular velocity formula

[0072] λ—Instantaneous angular acceleration, which can be calculated by software processing. Basic method: Obtain ω through the previous calculation, calculate one ω every 0.01 seconds, and the ω within the unit time (the unit time is 1 second, so there are 100 ω values) constitute an array, and the angle difference between the two adjacent time points before and after a certain moment is Δω, Δt = 0.02 seconds, then λ can be calculated.

[0073] The present invention also provides a high-precision angle calibration method for a 360-degree potentiometer, comprising the following steps: Step 1: The CPU central processing unit starts the ADC to convert data once every millisecond, obtains 10 milliseconds, 10 consecutive milliseconds of instantaneous voltage data of the center tap of the potentiometer, and stores them as v0, v1, v2, v3, v4, v5, v6, v7, v8, and v9, and determines whether the adjacent voltage values ​​of these 10 values ​​exceed 15 millivolts. If so, remove the value and replace it with an interpolation value, that is, replace the value with the average of the values ​​before and after the value (for example, if v5 exceeds, replace it with Replace v5), if the last value v9 exceeds 15 mV, replace v9 with 2v8-v7, remove the largest and smallest two values, and calculate the arithmetic mean of the six values. The average value is the instantaneous voltage value of 10 milliseconds, which is set as b0. At this time, b0 replaces v c And put it into formula 3, judge if 0≤b0≤v S , otherwise Store α0.

[0074] Step 2: Repeat step 1 at an interval of 10 milliseconds to obtain α1, and store α0 and α1;

[0075] Step 3: Calculate Angular Velocity Store ω0;

[0076] Step 4: Repeat steps 1, 2 and 3 at intervals of 10 milliseconds. After the cycle, obtain and store the angles α0, α1, α2 and the angular velocities ω0, ω1.

[0077] Step 5: Calculate the angular acceleration, Store λ0;

[0078] Step 6: Loop through steps 1 to 5 to obtain 100 milliseconds of duration, 10 consecutive instantaneous angle values ​​α0, α1, α2, α3, α4, α5, α6, α7, α8, α9, each with a data interval of 10 milliseconds, 9 consecutive instantaneous angular velocity values ​​ω0, ω1, ω1, ω2, ω3, ω4, ω5, ω6, ω7, ω8, and 8 consecutive instantaneous angular acceleration values ​​λ0, λ1, λ1, λ2, λ3, λ4, λ5, λ6, λ7. All are stored, and α9, ω8, λ7 are identified as the angle, angular velocity, and angular acceleration at the current moment. The data are updated every 10 milliseconds. After N+2 updates, the data obtained is: the instantaneous angle value is α N+2 , α N+3 , α N+4 , α N+5 , α N+6 , α N+7 , α N+8 , α N+9 ,α N+10 , α N+11, the instantaneous value of angular velocity is ω N+1 ,ω N+2 ,ω N+3 ,ω N+4 ,ω N+5 ,ω N+6 ,ω N+7 ,ω N+8 ,ω N+9 ,ω N+10 , the angular acceleration is λ N , N+1 , N+2 , N+3 , N+4 , N+5 , N+6 , N+7 , N+8 , N+9 , α N+11 ,ω N+10 , N+9 They are identified as the current angle, angular velocity, and angular acceleration, respectively, and are output once every 10 milliseconds.

[0079] illustrate:

[0080] 1. According to different measurement objects, different requirements and different rotation speeds, it can be divided into four levels. The processing rate is determined by judging the position of the dial switch. It is specifically divided into (1) 10 millisecond level: the above is the processing flow of the 10 millisecond level (2) millisecond level: the CPU central processing unit starts the ADC to convert data once every 0.1 millisecond, and obtains 1 millisecond long, 10 times of 100 microseconds of voltage instantaneous data. The processing method is the same as before, and a set of angle, angular velocity and angular acceleration at the current moment is output every millisecond. (3) 100 millisecond level: the CPU central processing unit starts the ADC to convert data once every 10 milliseconds, and obtains 100 milliseconds of 10 times of 10 milliseconds of voltage instantaneous data. The processing method is the same as before, and a set of angle, angular velocity and angular acceleration at the current moment is output every 100 milliseconds. (4) 1000 millisecond level: the CPU central processing unit starts the ADC to convert data once every 100 milliseconds, and obtains 1000 milliseconds of 10 times of 100 milliseconds of voltage instantaneous data. The processing method is the same as before, and a set of angle, angular velocity and angular acceleration at the current moment is output every second.

[0081] 2. Three signal outputs: SPI, 4-20 mA, 0-3.3 V voltage output.

Claims

1. A method for calibrating the angle of a full-angle infinitely rotatable single potentiometer, the full-angle infinitely rotatable single potentiometer comprising a housing (1), an electrode holder (7), and a top cover (2), wherein the electrode holder (7) is installed in the housing (1) and fixed by the top cover (2), an upper carbon film ring (4-1) is arranged on the top surface of the electrode holder (7), and a lower carbon film ring (4-2) is arranged on the bottom surface of the electrode holder (7), the upper carbon film ring (4-1) is provided with an upper carbon film ring opening (4-1-1), and the lower carbon film ring (4-2) is provided with a lower carbon film ring opening (4-2-1), and the upper carbon film ring opening (4-1-1) and the lower carbon film ring opening (4-2-1) do not overlap in horizontal projection, a rotating shaft (3) is arranged at the center of the electrode holder (7), an electrode sheet (5) is arranged on the rotating shaft (3), and the electrode sheet (5) includes a plurality of electrodes. The invention comprises an upper electrode sheet (5-1) electrically contacting an upper carbon film ring (4-1) and a lower electrode sheet (5-2) electrically contacting a lower carbon film ring (4-2); one end of the upper carbon film ring opening (4-1-1) is an upper carbon film ring electrode lead-out terminal (B), the upper carbon film ring electrode lead-out terminal (B) is led out through a first electrode, and the other end is an upper carbon film ring jumper terminal (A); one end of the lower carbon film ring opening (4-2-1) is a lower carbon film ring electrode lead-out terminal (C), the lower carbon film ring electrode lead-out terminal (C) is led out through a second electrode, and the other end is a lower carbon film ring jumper terminal (D); the upper carbon film ring jumper terminal (A) and the lower carbon film ring jumper terminal (D) are electrically connected via a jumper, characterized in that: The following steps are involved: Step 1: The CPU central processing unit starts the ADC to convert data once every millisecond to obtain the duration n milliseconds, continuous n The millisecond instantaneous voltage data of the center tap of the potentiometer is stored as , , …, , judge this n Are there any adjacent voltage values ​​of a value that are greater than 15 millivolts? If so, remove the value and replace it with an interpolated value, that is, replace the value with the average of the values ​​before and after the value. If the last value , more than 15 mV, use - replace , remove the two largest and two smallest values, and find the arithmetic mean of the remaining values. The mean is n Millisecond voltage instantaneous value , judge as , , ,otherwise ,storage ; Step 2: Interval Time n Repeat step 1 to get ,storage , ; Step 3: Calculate Angular Velocity ,storage ; Step 4: Spacing n Repeat steps 1, 2, and 3 for 10 milliseconds, and get and store the angle after the loop. , , , angular velocity , ; Step 5: Calculate the angular acceleration, ,storage ; in, is the constant current source current, , They are the resistance of the lower carbon film ring and the upper carbon film ring, is the mechanical angle corresponding to the upper carbon film ring opening (4-1-1) and the lower carbon film ring opening (4-2-1), It is the misalignment angle between the lower carbon film ring jumper end (D) and the upper carbon film ring jumper end (A), that is, the electrical angle phase difference.

2. The angle calibration method of a full-angle infinite rotation single potentiometer according to claim 1 is characterized in that: The radius, material and area of ​​the upper carbon film ring (4-1) and the lower carbon film ring (4-2) are exactly the same.

3. The angle calibration method of a full-angle infinite rotation single potentiometer according to claim 1 is characterized in that: The housing (1) comprises a cylindrical cavity structure, which comprises a lower cylindrical cavity (1-1) and an upper cylindrical cavity (1-2), the cavity radius of the lower cylindrical cavity (1-1) being smaller than the cavity radius of the upper cylindrical cavity (1-2), an annular step being formed between the lower cylindrical cavity (1-1) and the upper cylindrical cavity (1-2), and the electrode seat (7) being arranged on the annular step.

4. The angle calibration method of a full-angle infinite rotation single potentiometer according to claim 3 is characterized in that: The top cover (2) comprises a top surface (2-1) and a cylindrical cavity (2-2); the outer surface of the cylindrical cavity (2-2) is inserted into the upper cylindrical cavity (1-2) and is interference-fitted with the upper cylindrical cavity (1-2).

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