Motor rotor position detection circuit and system

Abstract

The present invention relates to the field of signal measurement technology, and specifically to a detection circuit and system for the position of a motor rotor, comprising: at least one potentiometer, connected one-to-one with a motor to be measured; a collection unit, comprising at least one group of signal terminals corresponding to the potentiometer, the signal terminals comprising a current output terminal and a first voltage collection terminal; the current output terminal is connected to the corresponding tap of the potentiometer, and the first voltage collection terminal is connected to the corresponding tap of the potentiometer; a first selection switch is respectively connected to the two ends of each of the potentiometers, and is used to switch the connection between the two ends of the potentiometer and the signal ground. The current output terminal in the collection unit provides current to the tap of the potentiometer, thereby enhancing the anti-interference ability of the signal in a strong interference section, thereby reducing interference noise without affecting the collection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of signal measurement, and in particular to a detection circuit and system for a motor rotor position. Background Art

[0002] Generally speaking, there are two main uses for motor rotor position detection: one is that the system as a whole needs motor rotor position information to achieve accurate position loop control, such as servo, CNC machine tools or robots; the other is the need for motor control itself, such as brushless DC motors, which must detect the rotor position in order to commutate the stator current so that the rotor can rotate continuously in one direction and achieve optimal efficiency. Of course, it can also be used to calculate the actual / physical speed of the motor. The accuracy and reliability of rotor position detection are crucial for the system's position loop or motor control.

[0003] In the prior art, the motor rotor position is generally detected based on the potentiometer resistance, such as Figure 1 As shown, the power supply is added to both ends of the potentiometer resistor, that is, V + and V - The two ends of the potentiometer resistor are connected respectively, and the acquisition circuit reads the tap voltage V of the potentiometer p Determine the position of the motor rotor. The disadvantage of this position acquisition method is that the output signal V p The output impedance is large. In order to improve the acquisition accuracy, the input impedance of the acquisition circuit must be increased as much as possible.

[0004] Generally speaking, for the convenience of production, the motor drive power line and V + 、V - 、V p However, the motor drive power line is a strong interference source, which requires V + 、V - 、V p Sufficient current must flow through the line to eliminate the interference noise caused by the power line, and in order to make V p If there is enough current flowing through the line, the input impedance of the acquisition circuit must be reduced, but this sacrifices the position acquisition accuracy. Therefore, in actual application, only a balance point can be chosen between position acquisition accuracy and position acquisition noise, and it is difficult to take both into account. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a detection circuit and system for a motor rotor position to solve the problem of balancing position acquisition accuracy and position acquisition noise.

[0006] According to a first aspect, an embodiment of the present invention provides a detection circuit for a motor rotor position, comprising:

[0007] At least one potentiometer connected to the motor to be tested in a one-to-one correspondence;

[0008] A collection unit, comprising at least one group of signal terminals corresponding to the potentiometer, wherein the signal terminals include a current output terminal and a first voltage collection terminal; wherein the current output terminal is connected to the corresponding tap of the potentiometer, and the first voltage collection terminal is connected to the corresponding tap of the potentiometer;

[0009] The first selection switch is connected to the two ends of each of the potentiometers, and is used to switch the connection between the two ends of the potentiometer and the signal ground, so as to detect the position of the corresponding motor rotor to be tested based on the voltage collected by the first voltage collection end.

[0010] The detection circuit for the motor rotor position provided in the embodiment of the present invention provides current to the tap of the potentiometer through the current output terminal in the acquisition unit, thereby enhancing the anti-interference ability of the signal in the strong interference section. Even if the motor power line and the various signal lines of the acquisition unit are bundled together, since sufficient current always flows through the various signal lines of the acquisition unit, the interference noise caused by the motor power line can be offset, thereby reducing the interference noise without affecting the acquisition accuracy, thereby achieving a balance between the acquisition accuracy and the interference noise.

[0011] In combination with the first aspect, in a first implementation of the first aspect, the acquisition unit includes:

[0012] A current source circuit having the current output terminal;

[0013] The collection circuit comprises the first voltage collection terminal.

[0014] The motor rotor position detection circuit provided in the embodiment of the present invention can improve the reliability of the detection circuit by independently arranging the current source circuit and the acquisition circuit instead of integrating them together.

[0015] In combination with the first implementation of the first aspect, in the second implementation of the first aspect, the current source circuit includes:

[0016] At least one current source chip, corresponding one-to-one to the potentiometer;

[0017] At least one group of configuration resistors, each group of configuration resistors is connected to the output end of the current source chip, and is used to configure the output current of the current source chip.

[0018] The motor rotor position detection circuit provided in the embodiment of the present invention can save the multi-way switch required when using one current source chip by corresponding each motor to be tested to a current source chip, thereby improving circuit reliability.

[0019] In combination with the first implementation of the first aspect, in a third implementation of the first aspect, the current source circuit includes:

[0020] Current source chip;

[0021] a second selection switch connected to the output end of the current source chip; wherein the second selection switch has a current output end corresponding to the tap of the potentiometer one by one, and is used to switch the connection between the current output end and the tap of the potentiometer;

[0022] A configuration resistor is connected to the current output terminal and is used to configure an output current of the current output terminal.

[0023] The motor rotor position detection circuit provided in the embodiment of the present invention provides current to a potentiometer corresponding to at least one motor to be tested through a current source chip, and combines a second selection switch to perform time-sharing control of current output, thereby simplifying the circuit structure.

[0024] In combination with the first implementation of the first aspect, in a fourth implementation of the first aspect, the acquisition circuit includes:

[0025] An operational amplifier, whose input terminal is connected to the first voltage collection terminal; and whose output terminals are respectively connected to the input terminals of the analog-to-digital converter;

[0026] The analog-to-digital converter is used to convert the analog voltage signal output by the operational amplifier into a digital voltage signal, so as to detect the position of the rotor of the motor to be tested based on the digital voltage signal corresponding to the first voltage acquisition terminal.

[0027] The motor rotor position detection circuit provided in the embodiment of the present invention provides current to the tap of the potentiometer to offset the interference noise caused by the motor power line, so that the interference environment of the collected analog voltage signal does not exist before entering the operational amplifier. At this time, the high input impedance characteristic of the operational amplifier is used to input the signal to the analog-to-digital converter very realistically, thereby further improving the detection accuracy while ensuring low noise.

[0028] In combination with the first aspect, in a fifth implementation of the first aspect, the first selection switch includes:

[0029] A two-way selection switch corresponding to the potentiometer one by one; wherein the common end of the two-way selection switch is connected to the signal ground; the first selection end of the two-way selection switch is connected to one end of the potentiometer; and the second selection end of the two-way selection switch is connected to the other end of the potentiometer.

[0030] In combination with the first aspect, in a sixth implementation of the first aspect, the first selection switch is a multi-way switch; wherein the multi-way switch is used to connect the two ends of each of the potentiometers to the signal ground in a time-sharing manner.

[0031] In combination with the first aspect, or any one of the first to sixth embodiments of the first aspect, in the seventh embodiment of the first aspect, the acquisition unit also includes a second voltage acquisition terminal and a third voltage acquisition terminal, the second voltage acquisition terminal is connected to one end of the potentiometer, and the third voltage acquisition terminal is connected to the other end of the potentiometer, so as to detect the position of the rotor of the motor to be tested based on the voltages collected by the first voltage acquisition terminal, the second voltage acquisition terminal and the third voltage acquisition terminal.

[0032] The motor rotor position detection circuit provided in the embodiment of the present invention utilizes the second voltage acquisition terminal and the third voltage acquisition terminal to respectively acquire the voltage across the potentiometer. When detecting the motor rotor position to be measured, the voltage is utilized to eliminate the error caused by the internal resistance of the first selection switch, thereby improving the detection accuracy.

[0033] In combination with the first aspect, in a seventh implementation of the first aspect, further comprising:

[0034] The processor is connected to the acquisition unit and is used to calculate the corresponding position of the rotor of the motor to be tested based on the voltage collected by the acquisition unit.

[0035] According to a second aspect, an embodiment of the present invention further provides a motor rotor position detection system, comprising:

[0036] at least one motor to be tested;

[0037] The motor rotor position detection circuit described in the first aspect of the present invention, or any one of the embodiments of the first aspect; wherein the potentiometer is connected one-to-one with the motor to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of a detection circuit for a motor rotor position in the prior art is shown;

[0040] Figure 2 is a schematic diagram of a detection circuit for a motor rotor position according to an embodiment of the present invention;

[0041] Figure 3 is a connection structure diagram between a potentiometer and a first selection switch according to an embodiment of the present invention;

[0042] Figure 4 is a schematic diagram of the structure of a collection unit according to an embodiment of the present invention;

[0043] Figure 5 is a schematic diagram of a detection circuit for a motor rotor position according to an embodiment of the present invention;

[0044] Figure 6 is a schematic diagram of a detection circuit for a motor rotor position according to an embodiment of the present invention;

[0045] Figure 7 Schematic diagram of a motor rotor position detection circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0047] The motor rotor position detection circuit provided in the embodiment of the present invention can be applied to any device or system that requires motor rotor position measurement, for example, it can be applied to industries such as aerospace, weapons, unmanned vehicles, and robots, and is mainly used in situations where the signal line is relatively close to the interference source.

[0048] The inventive concept of the motor rotor position detection circuit described in the present invention is: by providing current to the tap of the potentiometer, using a first selection switch to connect the two ends of the potentiometer to the signal ground in a time-sharing manner, and detecting the voltage of the potentiometer tap in a time-sharing manner, the position of the motor rotor can be obtained by using the ratio of the voltages measured in a time-sharing manner.

[0049] Among them, the detection circuit of the motor rotor position can detect the position of one motor rotor, and can also detect the positions of multiple motor rotors. The specific circuit can be constructed according to actual needs.

[0050] In the following embodiments, the detection of the rotor positions of 1, 2 and 4 motors is taken as examples for detailed description.

[0051] Figure 2 The circuit structure for detecting the rotor position of a motor is shown in FIG. Figure 2As shown, the detection circuit of the motor rotor position comprises: a potentiometer 10, a collection unit 20 and a first selection switch. In this embodiment, the first selection switch is a two-way selection switch 31.

[0052] The acquisition unit 20 includes a current output terminal 23 and a first voltage acquisition terminal 26. The potentiometer 10 has a first terminal 11, a second terminal 12, and a tap 13. The current output terminal 23 is connected to the tap 13 of the potentiometer, and the first voltage acquisition terminal 26 is connected to the tap 13 of the potentiometer 10, for acquiring the voltage of the tap 13 of the potentiometer 10. The common terminal 31c of the two-way selection switch 31 is connected to the signal ground, the first selection terminal 31a is connected to the first terminal 11 of the potentiometer 10, and the second selection terminal 31b is connected to the second terminal 12 of the potentiometer 10.

[0053] The current output terminal 23 is used to provide a current i to the tap 13 of the potentiometer 10 . The current i flows into the potentiometer 10 from the tap 13 of the potentiometer 10 , and then flows back to the acquisition unit 20 from the first terminal 11 and the second terminal 12 of the potentiometer 10 .

[0054] The detection circuit for the motor rotor position provided in this embodiment provides current to the tap 13 of the potentiometer 10 through the current output terminal 23 in the acquisition unit 20, thereby enhancing the anti-interference ability of the signal in the strong interference section. Even if the motor power line is bundled with the various signal lines of the acquisition unit 20, since sufficient current always flows through the various signal lines of the acquisition unit 20, the interference noise caused by the motor power line can be offset, thereby reducing the interference noise without affecting the acquisition accuracy, thereby achieving a balance between the acquisition accuracy and the interference noise.

[0055] Specifically, Figure 3 As shown, when the first selection terminal 31a of the dual-way selection switch 31 is connected to the common terminal 31c, the current flowing out of the first terminal 11 of the potentiometer 10 flows into the signal ground, that is, the potential V of the tap 13 of the potentiometer 10 collected by the collection unit 20 at this time x1 When the second selection terminal 31b of the dual-way selection switch 31 is connected to the common terminal 31c, the current flowing out of the second terminal 12 of the potentiometer 10 flows into the signal ground, that is, at this time, the acquisition unit 20 acquires the potential V of the tap 13 of the potentiometer 10 x2 .

[0056] The two-way selection switch 31 is used to make the return current of the potentiometer 10 flow out from both ends of the potentiometer 10 in a time-sharing manner, and the voltage collection value V of the potentiometer 10 is collected. x1 and V x2 , calculate V x1 With V x2 The ratio of can reflect the position of the motor rotor without paying attention to the resistance value of the potentiometer 10 itself.

[0057] The acquisition unit 20 may be an integrated chip that can output current (i.e., has a current output terminal) and collect voltage (i.e., has a first voltage collection terminal). The acquisition unit 20 may also be Figure 4 As shown, it includes a current source circuit 25 and a collection circuit 24. The current source circuit 25 has a current output terminal 23, and the collection circuit 24 has a first voltage collection terminal 26. By independently setting the current source circuit 25 and the collection circuit 24 instead of integrating them together, the reliability of the detection circuit can be improved.

[0058] Optionally, the current source circuit 25 may be a current source dedicated chip, a current output type DAC, a circuit built with discrete devices, a circuit built with an operational amplifier, etc. The specific structure of the current source circuit 25 is not limited in any way. In the following embodiments, the current source circuit 25 is described in detail by taking the current source chip and the configuration circuit as an example.

[0059] The current source circuit 25 includes a current source chip is and a configuration resistor R, and the configuration resistor R is used to configure the output current of the current source chip is, that is, the size of the configuration resistor R can be specifically set according to the current actually required to be output by the current output terminal 23. It should be noted that, Figure 4 Only one configuration resistor R is output, but the protection scope of the present invention is not limited to this. The configuration resistor can be a plurality of resistors in parallel, series or mixed connection, etc. There is no restriction on the specific connection structure and resistance value of the configuration resistor R. It is only necessary to ensure that the configuration circuit R can configure the output current of the current source chip is.

[0060] As an optional implementation of this embodiment, the acquisition circuit 24 includes an operational amplifier and an analog-to-digital converter. The input end of the operational amplifier is respectively connected to the first voltage acquisition end 26, and the output end is respectively connected to the input end of the analog-to-digital converter. That is, the operational amplifier is used to condition and amplify the voltage signal collected by the first voltage acquisition end 26 to obtain an analog voltage signal, and output the analog voltage signal to the analog-to-digital converter.

[0061] The analog-to-digital converter is used to convert the analog voltage signal output by the operational amplifier into a digital voltage signal, so as to facilitate the subsequent detection of the position of the rotor of the motor to be tested based on the digital voltage signal corresponding to the first voltage acquisition terminal 26.

[0062] By supplying current to the tap 13 of the potentiometer 10 to offset the interference noise caused by the motor power line, the interference environment does not exist before the collected analog voltage signal enters the operational amplifier. At this time, the high input impedance characteristic of the operational amplifier is used to input the signal very realistically to the analog-to-digital converter, so that the detection accuracy can be further improved while ensuring low noise.

[0063] As an optional implementation of this embodiment, Figure 5 As shown, the acquisition unit also includes a second voltage acquisition terminal 21 and a third voltage acquisition terminal 23. The second voltage acquisition terminal 21 is connected to the first terminal 11 of the potentiometer 10, and is used to measure the potential of the first terminal 11 of the potentiometer 10. The third voltage acquisition terminal 22 is connected to the second terminal 12 of the potentiometer 10, and is used to measure the potential of the second terminal 12 of the potentiometer 10. When the position of the motor rotor is detected, the voltage of the first voltage acquisition terminal 26 is sampled in a time-sharing manner. That is, at the first moment t1, the first selection terminal 31a of the dual-way selection switch 31 is connected to the signal ground, and the potential collected by the second voltage acquisition terminal 21 is V xt2 , the potential collected by the first voltage collection terminal 26 is V xt11 At the first moment t2, the second selection terminal 31b of the dual-way selection switch 31 is connected to the signal ground, and the potential collected by the third voltage collection terminal 22 is V xt3 , the potential collected by the first voltage collection terminal 26 is V xt12 That is, (V xt11 -V xt2 ) / (V xt12 -V xt3 ) to calculate the position of the motor rotor.

[0064] The voltages of the first terminal 11 and the second terminal 12 of the potentiometer 10 are respectively collected by the second voltage collection terminal 21 and the third voltage collection terminal 22. When detecting the rotor position of the motor to be measured, the error caused by the internal resistance of the first selection switch can be eliminated by using the voltages, thereby improving the detection accuracy.

[0065] Furthermore, the detection circuit may also include a processor for calculating the position of the motor rotor based on the collected voltages of each voltage collection terminal. For example, when the first voltage collection terminal is used to collect the voltage V of the tap of the potentiometer 10 in a time-sharing manner, x1 With V x2 When the processor uses V x1 With V x2 The ratio reflects the position of the motor rotor; when three voltage collection terminals are used to collect the output voltages of the two ends and the tap of the potentiometer 10, the processor uses (V xt11 -V xt2 ) / (V xt12 -Vxt3 ) to calculate the position of the motor rotor. xt11 、V xt2 、V xt12 and V xt3 For the meaning of Figure 5 The relevant description of the illustrated embodiment will not be repeated here.

[0066] Figure 6 The circuit structure for detecting the rotor position of two motors is shown. Figure 6 As shown, one motor to be tested corresponds to one potentiometer 10, and the acquisition unit 20 has two groups of signal terminals, namely signal terminal A1 and signal terminal A2. Among them, signal terminal A1 corresponds to motor to be tested 1, and signal terminal A2 corresponds to motor to be tested 2. Each group of signal terminals includes a current output terminal 23 and a first voltage acquisition terminal 26.

[0067] In this embodiment, the first selection switch is a two-way selection switch 31 , and the two-way selection switch 31 corresponds to the potentiometer 10 one by one.

[0068] Of course, the first selection switch can also adopt a multi-way switch, which is used to connect the two ends of each potentiometer to the signal ground in a time-sharing manner, that is, the multi-way switch has a common end connected to the signal ground, and there are 4 selection ends, the selection end 1 is connected to the first end of the potentiometer 10 corresponding to the motor 1 to be tested, the selection end 2 is connected to the second end of the potentiometer 10 corresponding to the motor 1 to be tested, the selection end 3 is connected to the first end of the potentiometer 10 corresponding to the motor 2 to be tested, and the selection end 4 is connected to the second end of the potentiometer 10 corresponding to the motor 2 to be tested.

[0069] Correspondingly, the current source circuit may include only one current source chip, and a second selection switch is used to connect the output end of the current source chip, wherein the second selection switch has a current output end corresponding to the tap of the potentiometer, and is used to switch the connection between the current output end and the tap of the potentiometer. By providing current to the potentiometer corresponding to at least one motor to be tested through one current source chip, and combining the second selection switch to perform time-sharing control of current output, the circuit structure can be simplified.

[0070] Optionally, two current source chips may be included, each current source chip corresponding to a potentiometer. By corresponding each motor to be tested to a current source chip, the multi-way switch required when using a current source chip can be omitted, thereby improving circuit reliability.

[0071] Figure 7The circuit structure for detecting the rotor position of four motors is shown. The current source chip uses the integrated current source chip LT3092 of Liner Company, and its output is configured to 1mA output current through the configuration resistor. This current is supplied to the potentiometer taps corresponding to the four motors in a time-sharing manner through the second selection switch DG1048. Figure 7 The four potentiometers are represented by Rund1-Rund4, which correspond to the motors 1 to 4 to be tested. The output voltages of the four potentiometer taps and the two output terminals are V1 (corresponding to Vt11 and Vt12 at different times), V11, V12; V2 (corresponding to Vt21 and Vt22 at different times), V9, V10; V3 (corresponding to Vt31 and Vt32 at different times), V7, V8; V4 (corresponding to Vt41 and Vt42 at different times), V5, V6. Both ends of the potentiometer corresponding to each motor are connected to the ground in time-sharing through another first selection switch DG1048, and then V1-V12 are followed and processed respectively and then collected by ADC. The follower uses TI's operational amplifier LMV612. Among them, the voltage output of V1-V12 after operational amplification and ADC collection is Vin1-Vin12. Specifically, Vin1 corresponds to Vint11 and Vint12 at different times, Vin2 corresponds to Vint21 and Vint22 at different times, Vin3 corresponds to Vint31 and Vint32 at different times, and Vin4 corresponds to Vint41 and Vint42 at different times.

[0072] The position of the motor 1 to be tested can be accurately calculated according to (Vint11-Vin12) / (Vint12-Vin11);

[0073] The position of the motor 2 to be tested can be accurately calculated according to (Vint21-Vin9) / (Vint22-Vin10);

[0074] The position of the motor 3 to be tested can be accurately calculated according to (Vint31-Vin7) / (Vint32-Vin8);

[0075] The position of the motor 4 to be tested can be accurately calculated according to (Vint41-Vin5) / (Vint42-Vin6).

[0076] As an optional implementation of this embodiment, four current source chips can be set so that each potentiometer corresponds to one current source chip, that is, four LT3092 chips are used to output the taps of the potentiometers corresponding to the four motors, thereby eliminating the second selection switch DG1408 (U8) for current source branching. Further optionally, the first selection switch U9 can also be replaced with an analog switch with four common terminals, thereby reducing the number of switch switching times and simplifying the control logic.

[0077] The embodiment of the present invention further provides a motor rotor position detection system, the detection system comprising at least one motor to be detected, and Figure 2-Figure 7 The detection circuit of the motor rotor position in the embodiment shown. Wherein, the potentiometer in the detection circuit of the motor rotor position is connected to the motor to be tested in a one-to-one correspondence.

[0078] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A detection circuit for a motor rotor position, characterized in that: include: At least one potentiometer connected to the motor to be tested in a one-to-one correspondence; A collection unit, comprising at least one group of signal terminals corresponding to the potentiometer, wherein the signal terminals include a current output terminal and a first voltage collection terminal; wherein the current output terminal is connected to the corresponding tap of the potentiometer, and the first voltage collection terminal is connected to the corresponding tap of the potentiometer, and sufficient current flows through each signal line of the collection unit at all times to offset the interference noise caused by the motor power line; A first selection switch, connected to two ends of each of the potentiometers, respectively, for switching the connection between the two ends of the potentiometer and the signal ground, so as to detect the position of the rotor of the motor to be tested corresponding to the voltage collected by the first voltage collection end; Among them, the first selection switch is a two-way selection switch, the common end of the two-way selection switch is grounded, the first selection end is connected to the first end of the potentiometer, and the second selection end is connected to the second end of the potentiometer. The two-way selection switch is used to make the return current of the potentiometer flow out from the two ends of the potentiometer in a time-sharing manner. By collecting two voltage collection values ​​of the potentiometer, the ratio of the two voltage collection values ​​is calculated to reflect the position of the motor rotor.

2. The detection circuit according to claim 1, characterized in that: The acquisition unit comprises: A current source circuit having the current output terminal; The collection circuit comprises the first voltage collection terminal.

3. The detection circuit according to claim 2, characterized in that: The current source circuit comprises: At least one current source chip, corresponding one-to-one to the potentiometer; At least one group of configuration resistors, each group of configuration resistors is connected to the output end of the current source chip, and is used to configure the output current of the current source chip.

4. The detection circuit according to claim 2, characterized in that: The current source circuit comprises: Current source chip; a second selection switch connected to the output end of the current source chip; wherein the second selection switch has a current output end corresponding to the tap of the potentiometer one by one, and is used to switch the connection between the current output end and the tap of the potentiometer; A configuration resistor is connected to the current output terminal and is used to configure an output current of the current output terminal.

5. The detection circuit according to claim 2, characterized in that: The acquisition circuit comprises: An operational amplifier, whose input terminal is connected to the first voltage collection terminal; and whose output terminals are respectively connected to the input terminals of the analog-to-digital converter; The analog-to-digital converter is used to convert the analog voltage signal output by the operational amplifier into a digital voltage signal, so as to detect the position of the rotor of the motor to be tested based on the digital voltage signal corresponding to the first voltage acquisition terminal.

6. The detection circuit according to claim 1, characterized in that: The first selection switch comprises: A two-way selection switch corresponding to the potentiometer one by one; wherein the common end of the two-way selection switch is connected to the signal ground; the first selection end of the two-way selection switch is connected to the first end of the potentiometer; and the second selection end of the two-way selection switch is connected to the second end of the potentiometer.

7. The detection circuit according to claim 1, characterized in that: The first selection switch is a multi-way switch; wherein the multi-way switch is used to connect the two ends of each of the potentiometers to the signal ground in a time-sharing manner.

8. The detection circuit according to any one of claims 1 to 7, characterized in that: The acquisition unit further includes a second voltage acquisition terminal and a third voltage acquisition terminal, wherein the second voltage acquisition terminal is connected to the first terminal of the potentiometer, and the third voltage acquisition terminal is connected to the second terminal of the potentiometer, so as to detect the position of the rotor of the motor to be tested based on the voltages collected by the first voltage acquisition terminal, the second voltage acquisition terminal and the third voltage acquisition terminal; Among them, using (V xt11 -V xt2 ) / (V xt12 -V xt3 ) to calculate the position of the motor rotor, where V xt11 is the potential collected by the first voltage collection terminal when the first selection terminal of the dual-way selection switch is connected to the signal ground, V xt2 The potential collected by the second voltage collection terminal when the first selection terminal of the dual-way selection switch is connected to the signal ground, V xt12 The potential collected by the first voltage collection terminal when the second selection terminal of the dual-way selection switch is connected to the signal ground, V xt3 It is the potential collected by the third voltage collection terminal when the second selection terminal of the dual-way selection switch is connected to the signal ground.

9. The detection circuit according to claim 1, characterized in that: Also includes: The processor is connected to the acquisition unit and is used to calculate the corresponding position of the rotor of the motor to be tested based on the voltage collected by the acquisition unit.

10. A motor rotor position detection system, characterized in that: include: at least one motor to be tested; The detection circuit for the motor rotor position according to any one of claims 1 to 9; wherein the potentiometer is connected one-to-one with the motor to be tested.

Images