Motor calibration circuit, motor calibration method, and motor drive apparatus

Abstract

The application is suitable for the technical field of motor calibration, and provides a motor calibration circuit, a motor calibration method and a motor driving device. The motor calibration circuit comprises a control module, an adjusting module and a first comparison module. The control module is used for outputting a preset control signal to a motor, and the preset control signal is used for controlling a rotor of the motor to reach a preset position. The first comparison module is used for outputting a first comparison signal according to a phase line signal on a to-be-detected phase line of the motor and a calibration signal output by the adjusting module. The control module is used for controlling the adjusting module to adjust the calibration signal according to the first comparison signal. When the first comparison signal flips, the control module is further used for controlling the adjusting module to stop adjusting the calibration signal. Thus, the calibration of the motor imbalance is completed. When the calibration signal is used for back electromotive force detection of the motor in the later period, the detection error caused by the imbalance characteristics of the motor itself can be reduced, and the precision of the back electromotive force detection is improved.

Description

Technical Field

[0001] This application belongs to the field of motor calibration technology, and in particular relates to a motor calibration circuit, a motor calibration method, and a motor drive device. Background Technology

[0002] In existing technologies, Hall effect sensors are generally used to determine the rotor's position relative to the stator, which not only complicates the motor structure but also increases costs. To address these issues with Hall effect sensors, many detection methods have emerged. Among them, determining the rotor's position through back electromotive force (EMF) detection is a common and relatively cost-effective approach. However, in practical applications, the inherent imbalance of the motor itself can lead to inaccurate back EMF detection. Summary of the Invention

[0003] This application provides a motor calibration circuit, a motor calibration method, and a motor drive device, which can solve the problem of inaccurate detection when performing back EMF detection on a motor.

[0004] In a first aspect, embodiments of this application provide a motor calibration circuit, including a control module, an adjustment module, and a first comparison module; the control module is electrically connected to the adjustment module and the first comparison module respectively, the adjustment module and the first comparison module are electrically connected, and both the first comparison module and the control module are used to be electrically connected to a motor;

[0005] The control module is used to output a preset control signal to the motor; the preset control signal is used to control the rotor of the motor to reach a preset position;

[0006] The first comparison module is used to output a first comparison signal based on the phase line signal on the phase line to be tested of the motor and the calibration signal output by the adjustment module;

[0007] The control module is used to control the adjustment module to adjust the calibration signal according to the first comparison signal;

[0008] When the first comparison signal flips, the control module is also used to control the adjustment module to stop adjusting the calibration signal.

[0009] In one possible implementation of the first aspect, the control module includes a controller and a driver, the controller being electrically connected to the driver, the adjustment module and the first comparison module respectively, and the driver being used to be electrically connected to the motor;

[0010] The driver is used to output the preset control signal to the motor according to the control command output by the controller;

[0011] The controller is used to control the adjustment module to adjust the calibration signal according to the first comparison signal;

[0012] When the first comparison signal flips, the controller is also used to control the adjustment module to stop adjusting the calibration signal.

[0013] In one possible implementation of the first aspect, the adjustment module includes a first adjustable resistor unit and a first resistor unit, wherein the first adjustable resistor unit is electrically connected to the control module, the first resistor unit and the first comparison module respectively;

[0014] The first adjustable resistor unit is used to adjust the resistance value according to the control command output by the control module.

[0015] In one possible implementation of the first aspect, the adjustment module further includes a second adjustable resistor unit, which is electrically connected to the control module, the first resistor unit, and the first comparison module, respectively.

[0016] Alternatively, the second adjustable resistor unit is electrically connected to the control module, the first adjustable resistor unit, and the first comparison module, respectively;

[0017] The second adjustable resistor unit is used to adjust the resistance value according to the control command output by the control module.

[0018] In one possible implementation of the first aspect, the motor calibration circuit further includes a second comparison module, which is electrically connected to the control module;

[0019] The second comparison module is used to output a second comparison signal based on the phase line signal on the phase line to be tested of the motor and the reference voltage signal;

[0020] The control module is used to determine the timing for activating the back EMF detection based on the second comparison signal.

[0021] Secondly, embodiments of this application provide a motor calibration method, applied to the motor calibration circuit described in any one of the first aspects, the motor calibration method comprising:

[0022] Send a preset control signal to the motor so that the rotor of the motor reaches a preset position;

[0023] The system receives a first comparison signal sent by the first comparison module; the first comparison signal is a signal generated by the first comparison module based on the phase line signal on the phase line to be detected of the motor and the calibration signal output by the adjustment module.

[0024] An adjustment command is sent to the adjustment module based on the first comparison signal; the adjustment command is used to instruct the adjustment module to adjust the calibration signal.

[0025] When the first comparison signal flips, a stop command is sent to the adjustment module; the stop command is used to instruct the adjustment module to stop adjusting the calibration signal.

[0026] In one possible implementation of the second aspect, sending a preset control signal to the motor to cause the motor rotor to reach a preset position includes:

[0027] A floating signal is sent to the phase line to be tested of the motor.

[0028] In one possible implementation of the second aspect, sending a preset control signal to the motor to cause the motor rotor to reach a preset position further includes:

[0029] Determine whether the output signal of the motor is a DC signal;

[0030] When the output signal of the motor is a DC signal, a floating signal is sent to the phase line to be tested of the motor; when the output signal of the motor is a non-DC signal, a preset level signal is sent to the working phase line of the motor to make the output signal of the motor a DC signal.

[0031] In one possible implementation of the second aspect, the motor calibration method further includes:

[0032] Receive a second comparison signal; the second comparison signal is a signal generated by the second comparison module based on the phase line signal on the phase line to be detected of the motor and the reference voltage signal;

[0033] The timing for activating the back EMF detection is determined based on the second comparison signal.

[0034] In one possible implementation of the second aspect, the motor calibration method further includes:

[0035] Obtain multiple back electromotive forces of the motor;

[0036] The multiple back electromotive forces and the corresponding rotor positions of the motor are associated and stored.

[0037] Thirdly, embodiments of this application provide a motor drive device, including the motor calibration circuit described in any one of the first aspects.

[0038] The beneficial effects of the embodiments in this application compared with the prior art are:

[0039] The motor calibration circuit provided in this application includes a control module, an adjustment module, and a first comparison module. The control module outputs a preset control signal to the motor, which controls the motor rotor to reach a preset position, bringing the rotor to a stationary state. When the motor rotor is stationary, the first comparison module outputs a first comparison signal based on the phase line signal on the phase line to be tested and the calibration signal output by the adjustment module. The control module then controls the adjustment module to adjust the calibration signal based on the first comparison signal. Since the motor rotor is stationary, the phase line signal on the phase line to be tested remains unchanged. Adjusting the calibration signal changes the first comparison signal output by the first comparison module. By continuously controlling the adjustment module to adjust the calibration signal, the first comparison signal will flip. When the control module detects the flipping of the first comparison signal, it can control the adjustment module to stop adjusting the calibration signal. At this point, the calibration signal is very close to the phase line signal on the phase line to be tested. This completes the calibration of the motor imbalance. Later, when using the calibration signal to detect the back EMF of the motor, the detection error caused by the inherent imbalance characteristics of the motor can be reduced, improving the accuracy of the back EMF detection. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic block diagram of a motor calibration circuit provided in one embodiment of this application;

[0042] Figure 2 This is a circuit connection diagram of a motor calibration circuit provided in an embodiment of this application;

[0043] Figure 3 This is a circuit connection diagram of an adjustment module provided in an embodiment of this application;

[0044] Figure 4 This is a circuit connection diagram of the adjustment module provided in another embodiment of this application;

[0045] Figure 5 This is a circuit connection diagram of the adjustment module provided in another embodiment of this application;

[0046] Figure 6 This is a waveform diagram of the first input terminal of the second comparison module provided in an embodiment of this application;

[0047] Figure 7This is a schematic flowchart of a motor calibration method provided in an embodiment of this application. Detailed Implementation

[0048] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0049] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0050] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0051] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0052] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0053] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0054] In existing technologies, Hall effect sensors are generally used to determine the rotor's position relative to the stator, which not only complicates the motor structure but also increases costs. To address these issues with Hall effect sensors, many detection methods have emerged. Among them, determining the rotor's position through back electromotive force (EMF) detection is a common and relatively cost-effective approach. However, in practical applications, the inherent imbalance of the motor itself can lead to inaccurate back EMF detection.

[0055] Based on the above problems, the motor calibration circuit provided in this application includes a control module, an adjustment module, and a first comparison module. The control module outputs a preset control signal to the motor, which controls the motor rotor to reach a preset position, making the motor rotor stationary. When the motor rotor is stationary, the first comparison module outputs a first comparison signal based on the phase line signal on the phase line to be tested and the calibration signal output by the adjustment module. The control module controls the adjustment module to adjust the calibration signal based on the first comparison signal. Since the motor rotor is stationary, the phase line signal on the phase line to be tested remains unchanged. The first comparison signal output by the first comparison module is changed by adjusting the calibration signal. By continuously controlling the adjustment module to adjust the calibration signal, the first comparison signal will flip. When the control module detects that the first comparison signal has flipped, the control module can control the adjustment module to stop adjusting the calibration signal. At this time, the calibration signal is very close to the phase line signal on the phase line to be tested. Thus, the motor imbalance calibration is completed. When the calibration signal is used to detect the back EMF of the motor later, the detection error caused by the inherent imbalance characteristics of the motor can be reduced, and the accuracy of the back EMF detection can be improved.

[0056] To illustrate the technical solution described in this application, specific embodiments are provided below.

[0057] Figure 1 A schematic block diagram of a motor calibration circuit 10 according to an embodiment of this application is shown. See also... Figure 1 As shown, the motor calibration circuit 10 includes a control module 101, an adjustment module 102, and a first comparison module 103. The control module 101 is electrically connected to both the adjustment module 102 and the first comparison module 103. The adjustment module 102 and the first comparison module 103 are also electrically connected. Both the first comparison module 103 and the control module 101 are used to electrically connect to the motor 20.

[0058] Specifically, the control module 101 outputs a preset control signal to the motor 20. This preset control signal controls the motor rotor to reach a preset position, bringing the motor 20 to a stationary state. When the motor 20 rotor is stationary, the first comparison module 103 outputs a first comparison signal based on the phase line signal on the phase line to be detected of the motor 20 and the calibration signal output by the adjustment module 102. The control module 101 then controls the adjustment module 102 to adjust the calibration signal based on the first comparison signal. Since the motor 20 rotor is stationary, the phase line signal on the phase line to be detected of the motor 20 remains unchanged. The first comparison signal output by the first comparison module 103 is changed by adjusting the calibration signal. By continuously controlling the adjustment module 102 to adjust the calibration signal, the first comparison signal will flip. When the control module 101 detects that the first comparison signal has flipped, the control module 101 can control the adjustment module 102 to stop adjusting the calibration signal. At this time, the calibration signal is very close to the phase line signal on the phase line to be detected of the motor 20. Thus, the unbalance of motor 20 is calibrated. When the calibration signal is used to detect the back electromotive force of motor 20 in the later stage, the detection error caused by the unbalance characteristics of motor 20 itself can be reduced, and the accuracy of back electromotive force detection can be improved.

[0059] It should be noted that when motor 20 is a three-phase motor, the preset control signal includes three signals, which are respectively applied to the three phase lines of motor 20 to control the rotor of the three-phase motor 20 to reach the preset position. For example, the first control signal in the preset control signal is a high-level signal applied to the first phase line of motor 20, the second control signal is a low-level signal applied to the second phase line of motor 20, and the third control signal is a floating signal applied to the third phase line of motor 20 (the third phase line of motor 20 is in a floating state; it is neither a high-level signal nor a low-level signal). After the preset control signal is applied to the three phase lines of motor 20, the rotor of motor 20 rotates to the preset position and brakes at the preset position. The third phase line is the phase line to be detected, and the phase line signal on the third phase line is the phase line signal on the phase line to be detected.

[0060] For example, if motor 20 is a three-phase motor, the three-phase motor 20 includes phase A, phase B, and phase C. If a high-level signal in the preset control signal is applied to phase B, a low-level signal in the preset control signal is applied to phase C, and a floating signal in the preset control signal is applied to phase A, then the rotor of motor 20 rotates to a preset position and brakes at the preset position. Phase C is the phase line to be detected, and the phase line signal on phase C is the phase line signal on the phase line to be detected. The first comparison module 103 outputs a first comparison signal based on the phase line signal of phase A and the calibration signal output by the adjustment module 102.

[0061] For example, designers can set the loading time of the preset control signals loaded on phase A, phase B and phase C according to the actual situation. For instance, the loading time of the preset control signals loaded on phase A, phase B and phase C can be selected as 10ms.

[0062] It is important to note that during the calibration signal adjustment process, to ensure the effectiveness and accuracy of the calibration, it is generally necessary to ensure that the adjustment direction of the calibration signal remains consistent. That is, the calibration signal should be continuously adjusted in the same direction. If the adjustment direction of the calibration signal is inconsistent, it may lead to errors in the calibration results and affect the normal operation of the system. Therefore, it is essential to ensure that the adjustment direction of the calibration signal remains consistent during the adjustment process.

[0063] It should be noted that if the calibration signal output by the adjustment module 102 is greater than the phase line signal on the phase line to be detected of the motor 20, and the first comparison signal output by the first comparison module is low, the control module 101 controls the adjustment module 102 to adjust the calibration signal, making the calibration signal gradually smaller. When the calibration signal changes from being greater than the phase line signal to being less than the phase line signal, the first comparison signal output by the first comparison module changes from low to high, and the first comparison signal flips. If the calibration signal output by the adjustment module 102 is less than the phase line signal on the phase line to be detected of the motor 20, and the first comparison signal output by the first comparison module is high, the control module 101 controls the adjustment module 102 to adjust the calibration signal, making the calibration signal gradually larger. When the calibration signal changes from being less than the phase line signal to being greater than the phase line signal, the first comparison signal output by the first comparison module changes from high to low, and the first comparison signal flips. Both of these processes indicate that the first comparison signal has flipped. After the control module 101 detects that the first comparison signal has flipped, it controls the adjustment module 102 to stop adjusting the calibration signal.

[0064] In one embodiment of this application, such as Figure 2 As shown, the control module 101 includes a controller MCU and a driver DRV. The controller MCU is electrically connected to the driver DRV, the adjustment module 102 and the first comparison module 103 respectively. The driver DRV is used to be electrically connected to the motor 20.

[0065] Specifically, the driver DRV outputs a preset control signal to the motor 20 according to the control command output by the controller MCU. The preset control signal is used to control the rotor of the motor 20 to reach a preset position. At this time, the rotor of the motor 20 is stationary. When the rotor of the motor 20 is stationary, the first comparison module 103 outputs a first comparison signal based on the phase line signal on the phase line to be detected of the motor 20 and the calibration signal output by the adjustment module 102. The controller MCU controls the adjustment module 102 to adjust the calibration signal based on the first comparison signal. Since the rotor of the motor 20 is stationary, the phase line signal on the phase line to be detected of the motor 20 remains unchanged. The first comparison signal output by the first comparison module 103 can be changed by adjusting the calibration signal. During the continuous adjustment of the calibration signal, the first comparison signal will flip. When the controller MCU detects the flipping of the first comparison signal, the controller MCU can control the adjustment module 102 to stop adjusting the calibration signal. Thus, the unbalance calibration of the motor 20 is completed. When performing back EMF detection on the motor 20, the detection error caused by the inherent unbalance characteristics of the motor 20 can be reduced, and the accuracy of back EMF detection can be improved.

[0066] It should be noted that, as Figure 2 As shown, the controller MCU outputs three control signals to the driver DRV: PWMA, PWMB, and PWMC. These three control signals control the driver DRV to output preset control signals to the motor 20 (OUTA is floating, OUTB is high, and OUTC is low), thereby causing the rotor of the motor 20 to reach a preset position and bring it to a standstill. The driver DRV is also used to output drive signals to the motor 20 according to the control signals output by the controller MCU, thereby driving the motor 20 to rotate.

[0067] The controller MCU can be an ARM-based processor, a RISC-V-based processor, or other types of processors, or it can be a digital circuit with a custom-defined algorithm.

[0068] In one embodiment of this application, such as Figure 2 As shown, the adjustment module 102 includes a first adjustable resistor unit 1021 and a first resistor unit 1022. The first adjustable resistor unit 1021 is electrically connected to the control module 101, the first resistor unit 1022 and the first comparison module 103, respectively.

[0069] Specifically, the first adjustable resistor unit 1021 is used to adjust the calibration signal according to the control command output by the control module 101, and the first resistor unit 1022 is used for voltage division. For example... Figure 2As shown, the first terminal of the first adjustable resistor unit 1021 is electrically connected to the DC power supply VCC, the second terminal of the first adjustable resistor unit 1021 is electrically connected to the first terminal of the first resistor unit 1022 and the first comparison module 103, the control terminal of the first adjustable resistor unit 1021 is electrically connected to the controller MCU, and the second terminal of the first resistor unit 1022 is grounded.

[0070] When the first comparison signal output by the first comparison module 103 is a high-level signal, it indicates that the phase line signal on the phase line to be detected of the motor 20 is greater than the calibration signal output by the adjustment module 102. At this time, the controller MCU controls the resistance value of the first adjustable resistor unit 1021 to continuously decrease until the first comparison signal flips, that is, the first comparison signal changes from a high-level signal to a low-level signal, indicating that the phase line signal on the phase line to be detected of the motor 20 is less than the calibration signal output by the adjustment module 102. The controller MCU can then control the first adjustable resistor unit 1021 to stop adjusting the calibration signal. When the first comparison signal output by the first comparison module 103 is a low-level signal, it indicates that the phase line signal on the phase line to be detected of the motor 20 is less than the calibration signal output by the adjustment module 102. At this time, the controller MCU controls the resistance value of the first adjustable resistor unit 1021 to continue to increase until the first comparison signal flips, that is, the first comparison signal changes from a low level signal to a high level signal, indicating that the phase line signal on the phase line to be detected of the motor 20 is greater than the calibration signal output by the adjustment module 102. The controller MCU can then control the first adjustable resistor unit 1021 to stop adjusting the calibration signal.

[0071] It should be noted that the first adjustable resistor unit 1021 and the first resistor unit 1022 can also be Figure 3 The connection relationship shown is as follows: the first end of the first resistor unit 1022 is electrically connected to the DC power supply VCC; the second end of the first resistor unit 1022 is electrically connected to the first end of the first adjustable resistor unit 1021 and the first comparison module 103 respectively; the control end of the first adjustable resistor unit 1021 is electrically connected to the controller MCU; and the second end of the first adjustable resistor unit 1021 is grounded.

[0072] When the first comparison signal output by the first comparison module 103 is a high-level signal, it indicates that the phase line signal on the phase line to be detected of the motor 20 is greater than the calibration signal output by the adjustment module 102. At this time, the controller MCU controls the resistance value of the first adjustable resistor unit 1021 to continuously increase until the first comparison signal flips, that is, the first comparison signal changes from a high-level signal to a low-level signal, indicating that the phase line signal on the phase line to be detected of the motor 20 is less than the calibration signal output by the adjustment module 102. The controller MCU can then control the first adjustable resistor unit 1021 to stop adjusting the calibration signal. When the first comparison signal output by the first comparison module 103 is a low-level signal, it indicates that the phase line signal on the phase line to be detected of the motor 20 is less than the calibration signal output by the adjustment module 102. At this time, the controller MCU controls the resistance value of the first adjustable resistor unit 1021 to continue to decrease until the first comparison signal flips, that is, the first comparison signal changes from a low-level signal to a high-level signal, indicating that the phase line signal on the phase line to be detected of the motor 20 is greater than the calibration signal output by the adjustment module 102. The controller MCU can then control the first adjustable resistor unit 1021 to stop adjusting the calibration signal.

[0073] For example, the first adjustable resistor unit 1021 includes at least one first adjustable resistor Radj1, all of which are connected in series; the first resistor unit 1022 includes at least one first resistor R1, all of which are connected in series. This application's... Figure 2 and Figure 3 The circuit connection diagram shown only illustrates a first adjustable resistor unit 1021 including one first adjustable resistor Radj1 and a first resistor unit 1022 including one first resistor R1, and does not represent all embodiments. The circuit connection diagram of the first adjustable resistor unit 1021 including multiple first adjustable resistors Radj1 and the first resistor unit 1022 including multiple first resistors R1 can be adapted according to... Figure 2 or Figure 3 The circuit connection diagram is obtained, and the basic working principle is similar, so it will not be elaborated on here.

[0074] For example, the controller can adjust the resistance value of the first adjustable resistor Radj1 by changing the values ​​of DA0 to DAN. Here, DA0 to DAN are binary numbers, and the resistance value of the first adjustable resistor Radj1 can be adjusted using any encoding method (e.g., two's complement, Gray code, or temperature code). The adjustment method can be to decrease or increase the numbers DA0 to DAN each time, for example, by adding or subtracting 1. It is understood that when calibrating the motor, the smaller the number adjusted each time, the higher the accuracy of the motor calibration.

[0075] In one embodiment of this application, such as Figure 4As shown, the adjustment module 102 also includes a second adjustable resistor unit 1023, which is electrically connected to the control module 101 and the first resistor unit 1022 respectively.

[0076] Specifically, the second adjustable resistor unit 1023 is used to adjust the resistance value according to the control commands output by the control module 101. For example... Figure 4 As shown, the first terminal of the first adjustable resistor unit 1021 is electrically connected to the DC power supply VCC. The second terminal of the first adjustable resistor unit 1021 is electrically connected to the first terminal of the first resistor unit 1022 and the first comparison module 103, respectively. The control terminal of the first adjustable resistor unit 1021 is electrically connected to the controller MCU. The second terminal of the first resistor unit 1022 is electrically connected to the first terminal of the second adjustable resistor unit 1023. The second terminal of the second adjustable resistor unit 1023 is grounded. The control terminal of the second adjustable resistor unit 1023 is electrically connected to the controller MCU.

[0077] When the first comparison signal output by the first comparison module 103 is a high-level signal, it indicates that the phase line signal on the phase line to be detected of the motor 20 is greater than the calibration signal output by the adjustment module 102. At this time, the controller MCU controls the resistance value of the second adjustable resistor unit 1023 to continuously increase until the first comparison signal flips, that is, the first comparison signal changes from a high-level signal to a low-level signal, indicating that the phase line signal on the phase line to be detected of the motor 20 is less than the calibration signal output by the adjustment module 102. The controller MCU can then control the second adjustable resistor unit 1023 to stop adjusting the calibration signal. When the first comparison signal output by the first comparison module 103 is a low-level signal, it indicates that the phase line signal on the phase line to be detected of the motor 20 is less than the calibration signal output by the adjustment module 102. At this time, the controller MCU controls the resistance value of the second adjustable resistor unit 1023 to continuously decrease until the first comparison signal flips, that is, the first comparison signal changes from a low-level signal to a high-level signal, indicating that the phase line signal on the phase line to be detected of the motor 20 is greater than the calibration signal output by the adjustment module 102. The controller MCU can then control the second adjustable resistor unit 1023 to stop adjusting the calibration signal.

[0078] It should be noted that when the first comparison signal output by the first comparison module 103 is a high-level signal, it indicates that the phase line signal on the phase line to be detected of the motor 20 is greater than the calibration signal output by the adjustment module 102. At this time, the controller MCU can simultaneously control the resistance value of the second adjustable resistor unit 1023 to continuously increase and the resistance value of the first adjustable resistor unit 1021 to continuously decrease, thereby improving the efficiency of adjusting the calibration signal. When the first comparison signal output by the first comparison module 103 is a low-level signal, it indicates that the phase line signal on the phase line to be detected of the motor 20 is less than the calibration signal output by the adjustment module 102. At this time, the controller MCU can simultaneously control the resistance value of the second adjustable resistor unit 1023 to continuously decrease and the resistance value of the first adjustable resistor unit 1021 to continuously increase, thereby improving the efficiency of adjusting the calibration signal.

[0079] It should be noted that the second adjustable resistor unit 1023 can also be Figure 5 The connection relationships shown are as follows: the first end of the first resistor unit 1022 is electrically connected to the DC power supply VCC; the second end of the first resistor unit 1022 is electrically connected to the first end of the first adjustable resistor unit 1021; the control end of the first adjustable resistor unit 1021 is electrically connected to the controller MCU; the second end of the first adjustable resistor unit 1021 is electrically connected to the first end of the second adjustable resistor unit 1023 and the first comparison module 103, respectively; the second end of the second adjustable resistor unit 1023 is grounded; and the control end of the second adjustable resistor unit 1023 is electrically connected to the controller MCU.

[0080] For example, the second adjustable resistor unit 1023 includes at least one second adjustable resistor Radj2, and all second adjustable resistors Radj2 are connected in series. This application's Figure 4 This illustration only shows the case where the second adjustable resistor unit 1023 includes one second adjustable resistor Radj2, and does not represent all embodiments. A circuit connection diagram showing the second adjustable resistor unit 1023 including multiple second adjustable resistors Radj2 can be provided based on... Figure 4 The circuit connection diagram is obtained, and the basic working principle is similar, so it will not be elaborated on here.

[0081] For example, the controller can adjust the resistance value of the second adjustable resistor Radj2 by changing the values ​​of DB0 to DBN. Here, DB0 to DBN are binary numbers, and any encoding method (e.g., two's complement, Gray code, or temperature code) can be used to adjust the resistance value of the second adjustable resistor Radj2. The adjustment method can be to decrease or increase the numbers DB0 to DBN each time, for example, by adding or subtracting 1.

[0082] In one embodiment of this application, such as Figure 5As shown, the adjustment module 102 also includes a second resistor unit 1024. The first end of the second resistor unit 1024 is electrically connected to the first resistor unit 1022 and the first comparison module 103, respectively. The second end of the second resistor unit 1024 is electrically connected to the first end of the second adjustable resistor unit 1023.

[0083] For example, the connection relationship between the second resistor unit 1024 and the second adjustable resistor unit 1023 is not limited to... Figure 5 The circuit connection diagram shown is not exhaustive. Other connection relationships are also possible, such as: the first terminal of the second resistor unit 1024 is electrically connected to the second adjustable resistor unit 1023, and the second terminal of the second resistor unit 1024 is grounded. Furthermore, the connection relationship between the first resistor unit 1022 and the first adjustable resistor unit 1021 is not fixed and will not be elaborated upon here.

[0084] For example, the second resistor unit 1024 includes at least one second resistor R2, and all the second resistors R2 are connected in series. This application's Figure 5 This illustration only shows the case where the second resistor unit 1024 includes one second resistor R2, and does not represent all embodiments. A circuit connection diagram showing the second resistor unit 1024 including multiple second resistors R2 can be provided based on... Figure 5 The circuit connection diagram is obtained, and the basic working principle is similar, so it will not be elaborated on here.

[0085] In one embodiment of this application, such as Figure 2 As shown, the first comparison module 103 includes a first comparator U1. The positive input terminal of the first comparator U1 is electrically connected to the motor 20, the negative input terminal of the first comparator U1 is electrically connected to the adjustment module 102, and the output terminal of the first comparator U1 is electrically connected to the controller MCU.

[0086] Specifically, the first comparator U1 outputs a first comparison signal based on the phase line signal on the phase line to be tested of the motor 20 and the calibration signal output by the adjustment module 102. When the phase line signal on the phase line to be tested of the motor 20 is greater than the calibration signal output by the adjustment module 102, the first comparison signal output by the first comparator U1 is a high-level signal. When the phase line signal on the phase line to be tested of the motor 20 is less than or equal to the calibration signal output by the adjustment module 102, the first comparison signal output by the first comparator U1 is a low-level signal.

[0087] It should be noted that the first comparison module 103 may also include a first comparator U1 and a first inverter ( Figure 2(Not shown in the diagram). Since the connection relationship between the positive and negative input terminals of the first comparator U1 is not limited, if the negative input terminal of the first comparator U1 is electrically connected to the motor 20 and the positive input terminal of the first comparator U1 is electrically connected to the adjustment module 102, then the output terminal of the first comparator U1 is electrically connected to the input terminal of the first inverter, and the output terminal of the first inverter is electrically connected to the controller MCU, which can also achieve the calibration of the motor 20.

[0088] In one embodiment of this application, such as Figure 2 As shown, the motor calibration circuit 10 also includes a second comparison module 104, which is electrically connected to the controller MCU.

[0089] Specifically, the second comparison module 104 outputs a second comparison signal based on the phase line signal on the phase line to be detected of the motor 20 and the reference voltage signal. The controller MCU determines the timing for back EMF detection based on the second comparison signal. When the rotor of the motor 20 rotates normally, the phase line signal on the phase line to be detected of the motor 20 is the same as the reference voltage signal. At this time, the second comparison signal outputs a low-level signal, and the controller MCU does not perform back EMF detection based on the low-level signal. When a reverse current occurs during the rotation of the rotor of the motor 20, the phase line signal on the phase line to be detected of the motor 20 is greater than the reference voltage signal. The second comparison signal outputs a high-level signal, and the controller MCU performs back EMF detection based on the high-level signal.

[0090] For example, if the motor 20 is driven by a PWM signal, when the rotor of the motor 20 rotates normally, the signal waveform at the first input terminal of the second comparison module 104 is as follows: Figure 6 As shown in a), when a reverse current occurs in the rotor of motor 20 during rotation, the signal waveform at the first input terminal of the second comparison module 104 is as follows. Figure 6 As shown in b) of the diagram.

[0091] For example, see Figure 2 As shown, when reverse current occurs in the rotor of motor 20 during rotation, the current flows from motor 20 through OUTA, through the body diode of the switching transistor in driver DRV, and into the DC power supply VCC. At this time, the voltage of OUTA will be 0.7V higher than the DC power supply VCC voltage.

[0092] In one embodiment of this application, such as Figure 2 As shown, the second comparison module 104 includes a second comparator U2. The positive input terminal of the second comparator U2 is electrically connected to the motor 20, the negative input terminal of the second comparator U2 is electrically connected to the DC power supply VCC, and the output terminal of the second comparator U2 is electrically connected to the controller MCU.

[0093] Specifically, the second comparator U2 is used to output a second comparison signal based on the phase line signal on the phase line to be detected of the motor 20 and the reference voltage signal. When the phase line signal on the phase line to be detected of the motor 20 is greater than the reference voltage signal, the second comparison signal output by the second comparator U2 is a high-level signal. When the phase line signal on the phase line to be detected of the motor 20 is less than or equal to the reference voltage signal, the second comparison signal output by the second comparator U2 is a low-level signal.

[0094] It should be noted that the second comparison module 104 may also include a second comparator U2 and a second inverter. Figure 2 (Not shown in the diagram). Since the connection relationship between the positive and negative input terminals of the second comparator U2 is not limited, if the negative input terminal of the second comparator U2 is electrically connected to the motor 20, and the positive input terminal of the second comparator U2 is electrically connected to the DC power supply VCC, then the output terminal of the second comparator U2 is electrically connected to the input terminal of the second inverter, and the output terminal of the second inverter is electrically connected to the controller MCU. This also allows for the determination of the back EMF detection timing.

[0095] In one embodiment of this application, such as Figure 2 As shown, the motor calibration circuit 10 also includes an oscillator OSC, which is electrically connected to the control module 101.

[0096] Specifically, the oscillator (OSC) generates a clock signal CK and provides it to the controller (MCU). The controller MCU reads the output signal of the second comparison module 104 according to the clock signal CK. When driving the motor 20, the controller MCU needs a stable clock signal to synchronize various operations and actions. The oscillator (OSC) can generate a stable and accurate signal, such as a sine wave, square wave, or pulse, which can be used to provide a clock signal to the controller MCU. Furthermore, the oscillator (OSC) has adjustable frequency capabilities, thus enabling it to generate clock signals of different frequencies according to the controller MCU's requirements. After receiving this clock signal, the controller MCU can perform control operations according to the timing sequence, improving the reliability of the motor calibration circuit 10.

[0097] like Figure 7 As shown, this application also discloses a motor calibration method applied to the above-mentioned motor calibration circuit. The motor calibration method includes steps S101 to S104.

[0098] Step S101: Send a preset control signal to the motor so that the motor rotor reaches the preset position.

[0099] Specifically, after receiving a preset control signal, the motor rotor can reach a preset position, thus bringing the rotor to a standstill. When the rotor is stationary, calibrating the motor significantly reduces measurement errors caused by motor movement and interference from environmental factors, improving calibration accuracy and ultimately increasing the motor's operating efficiency.

[0100] Step S101 includes steps S1011 and S1012.

[0101] Step S1011: Send a floating signal to the phase line to be tested of the motor.

[0102] Step S1012: Determine whether the motor's output signal is a DC signal.

[0103] Specifically, when the motor's output signal is a DC signal, a floating signal is sent to the motor's phase line to be tested; when the motor's output signal is a non-DC signal, a preset level signal is sent to the motor's working phase line to make the motor's output signal a DC signal.

[0104] It should be noted that if the motor is a single-phase motor, sending a floating signal to the phase line to be tested can keep the motor rotor stationary, thus achieving a braking effect.

[0105] If the motor is a three-phase motor, it can be determined whether the motor's output signal is a DC signal. If the motor's output signal is not a DC signal, the motor's operating phase lines are the first and second phase lines. A first-level signal is applied to the first phase line, a second-level signal is applied to the second phase line, and a floating signal is applied to the phase line to be detected. When the preset control signal is applied to the three phase lines of the motor, the motor rotor rotates to the preset position and brakes at the preset position.

[0106] It should be noted that the first level signal can be a high level signal and the second level signal can be a low level signal. In this case, the signal of the drive motor is a DC signal, which can achieve the braking effect.

[0107] Prior to step S101, the motor calibration method further includes:

[0108] Perform power-on initialization.

[0109] Specifically, the controller performs power-on initialization the instant the motor calibration circuit is powered on. Initialization includes the preparation of analog and digital signals, such as the completion of internal power supply voltage startup in the chip, oscillator startup, power-on reset of the digital circuit, and reading the necessary parameters from the multiple-programmable-times-store (MTP) memory. This initialization process helps the controller identify the type of motor connected, thereby enabling precise motor control.

[0110] Step S102: Receive the first comparison signal sent by the first comparison module; the first comparison signal is a signal generated by the first comparison module based on the phase line signal on the phase line to be detected of the motor and the calibration signal output by the adjustment module.

[0111] Specifically, when the motor rotor is determined to be stationary, the phase signal on the phase line to be tested remains unchanged. The calibration signal output by the adjustment module can be adjusted, thereby changing the first comparison signal generated by the first comparison module. After receiving the first comparison signal, the control module calibrates the motor according to the first comparison signal.

[0112] Step S103: Send an adjustment command to the adjustment module based on the first comparison signal; the adjustment command is used to instruct the adjustment module to adjust the calibration signal.

[0113] Specifically, upon receiving the first comparison signal, an adjustment command is sent to the adjustment module based on the first comparison signal, causing the adjustment module to adjust the calibration signal, thereby calibrating the motor. When the first comparison signal output by the first comparison module is a high-level signal, it indicates that the phase line signal on the phase line to be tested of the motor is greater than the calibration signal output by the adjustment module. At this time, a first adjustment command is sent to the adjustment module based on the high-level signal, causing the adjustment module to adjust the calibration signal, thereby calibrating the motor. When the first comparison signal output by the first comparison module is a low-level signal, it indicates that the phase line signal on the phase line to be tested of the motor is less than the calibration signal output by the adjustment module. At this time, a second adjustment command is sent to the adjustment module based on the low-level signal, causing the adjustment module to adjust the calibration signal, thereby calibrating the motor.

[0114] Step S104: When the first comparison signal flips, a stop command is sent to the adjustment module; the stop command is used to instruct the adjustment module to stop adjusting the calibration signal.

[0115] Specifically, during the continuous adjustment of the calibration signal, the first comparison signal will flip. When the control module detects this flip, it can control the adjustment module to stop adjusting the calibration signal. This completes the calibration of the motor imbalance.

[0116] The motor calibration method includes steps S105 to S106.

[0117] Step S105: Receive the second comparison signal; the second comparison signal is a signal generated by the second comparison module based on the phase line signal on the phase line to be detected of the motor and the reference voltage signal.

[0118] Specifically, upon receiving the second comparison signal, the timing for back EMF detection of the motor is determined based on this signal. When the second comparison signal output by the second comparison module is a low-level signal, it indicates that the phase line signal on the phase line to be detected in the motor is equal to the reference voltage signal. In this case, back EMF detection is not performed based on the low-level signal. When the second comparison signal output by the second comparison module is a high-level signal, it indicates that the phase line signal on the phase line to be detected in the motor is greater than the calibration signal output by the adjustment module. In this case, back EMF detection is performed based on the high-level signal.

[0119] Step S106: Determine the timing for starting the back EMF detection based on the second comparison signal.

[0120] Specifically, when the motor rotor rotates normally, the phase line signal on the phase line to be detected is the same as the reference voltage signal. At this time, the second comparison signal outputs a low-level signal, and the controller does not perform back EMF detection based on the low-level signal. When a reverse current occurs during the rotation of the motor rotor, the phase line signal on the phase line to be detected is greater than the reference voltage signal. The second comparison signal outputs a high-level signal, and the controller performs back EMF detection based on the high-level signal.

[0121] The motor calibration method also includes steps S107 to S108.

[0122] Step S107: Obtain multiple back electromotive forces of the motor.

[0123] Specifically, when the back EMF detection time is reached, the back EMF is detected to obtain multiple back EMFs of the motor, and these multiple back EMFs are stored.

[0124] Step S108: Associate and store multiple back electromotive forces and the corresponding rotor positions of the motors.

[0125] Specifically, the controller detects the back electromotive force (EMF) based on the second comparison signal. Each back EMF corresponds to a rotor position information. Each back EMF and its corresponding rotor position information are recorded in a table, and these are linked to form a back EMF-rotor position relationship. This relationship is then stored in memory so that the controller can determine the rotor's position information based on it. Simultaneously, the controller can also calibrate the motor using the back EMF-rotor position relationship.

[0126] This application also discloses a motor calibration system, including the aforementioned motor calibration method, wherein the motor calibration system performs closed-loop control based on the zero-crossing point of the back electromotive force.

[0127] This application also discloses a motor drive device, including the aforementioned motor calibration circuit, wherein the control module in the motor calibration circuit is used to execute the aforementioned motor calibration method.

[0128] Since the processing and functions implemented by the motor drive device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned motor calibration circuit and motor calibration method, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0129] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A motor calibration circuit, characterized in that, It includes a control module, an adjustment module, and a first comparison module; the control module is electrically connected to both the adjustment module and the first comparison module, the adjustment module is electrically connected to the first comparison module, and both the first comparison module and the control module are used to be electrically connected to a motor; The control module is used to output a preset control signal to the motor; the preset control signal is used to control the rotor of the motor to reach a preset position, so that the rotor of the motor is stationary. The first comparison module is used to output a first comparison signal based on the phase line signal on the phase line to be tested of the motor and the calibration signal output by the adjustment module; The control module is used to control the adjustment module to adjust the calibration signal according to the first comparison signal; When the first comparison signal flips, the control module is also used to control the adjustment module to stop adjusting the calibration signal; The motor calibration circuit further includes a second comparison module, which is electrically connected to the control module. The second comparison module is used to output a second comparison signal based on the phase line signal on the phase line to be tested of the motor and the reference voltage signal; The control module is used to determine the timing for activating the back EMF detection based on the second comparison signal.

2. The motor calibration circuit according to claim 1, characterized in that, The control module includes a controller and a driver. The controller is electrically connected to the driver, the adjustment module and the first comparison module respectively. The driver is used to be electrically connected to the motor. The driver is used to output the preset control signal to the motor according to the control command output by the controller; The controller is used to control the adjustment module to adjust the calibration signal according to the first comparison signal; When the first comparison signal flips, the controller is also used to control the adjustment module to stop adjusting the calibration signal.

3. The motor calibration circuit according to claim 1, characterized in that, The adjustment module includes a first adjustable resistor unit and a first resistor unit, wherein the first adjustable resistor unit is electrically connected to the control module, the first resistor unit and the first comparison module respectively; The first adjustable resistor unit is used to adjust the resistance value according to the control command output by the control module.

4. The motor calibration circuit according to claim 3, characterized in that, The adjustment module further includes a second adjustable resistor unit, which is electrically connected to the control module and the first resistor unit respectively. The second adjustable resistor unit is used to adjust the resistance value according to the control command output by the control module.

5. A method for calibrating a motor, characterized in that, The motor calibration method, applied to the motor calibration circuit according to any one of claims 1-4, comprises: Send a preset control signal to the motor to make the rotor of the motor reach a preset position and make the rotor of the motor stationary. The system receives a first comparison signal sent by the first comparison module; the first comparison signal is a signal generated by the first comparison module based on the phase line signal on the phase line to be detected of the motor and the calibration signal output by the adjustment module. An adjustment command is sent to the adjustment module based on the first comparison signal; the adjustment command is used to instruct the adjustment module to adjust the calibration signal. When the first comparison signal flips, a stop command is sent to the adjustment module; the stop command is used to instruct the adjustment module to stop adjusting the calibration signal. The motor calibration method further includes: Receive a second comparison signal; the second comparison signal is a signal generated by the second comparison module based on the phase line signal on the phase line to be detected of the motor and the reference voltage signal; The timing for activating the back EMF detection is determined based on the second comparison signal.

6. The motor calibration method according to claim 5, characterized in that, Sending a preset control signal to the motor to cause the motor rotor to reach a preset position includes: A floating signal is sent to the phase line to be tested of the motor.

7. The motor calibration method according to claim 6, characterized in that, Sending a preset control signal to the motor to cause the motor rotor to reach a preset position further includes: Determine whether the output signal of the motor is a DC signal; When the output signal of the motor is a DC signal, the floating signal is sent to the phase line to be tested of the motor; when the output signal of the motor is a non-DC signal, a preset level signal is sent to the working phase line of the motor to make the output signal of the motor a DC signal.

8. The motor calibration method according to any one of claims 5-7, characterized in that, The motor calibration method further includes: Obtain multiple back electromotive forces of the motor; The multiple back electromotive forces and the corresponding rotor positions of the motor are associated and stored.

9. A motor drive device, characterized in that, Includes the motor calibration circuit as described in any one of claims 1-4.

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