A driving control system for a stepping motor

Abstract

The present invention discloses a drive control system for a stepper motor. This system uses the stepper motor's angle difference to determine the degree of step loss and stall. It then adaptively adjusts an angle reference value based on the angle difference and speed difference. A sine module and a cosine module generate current reference values ​​for the A-phase winding and the B-phase winding, respectively, to control the stepper motor's drive. This drive control system can prevent step loss and stall during sudden load changes or variable speed operation, enhance the stepper motor's rapid adjustment capabilities, and improve the stepper motor's control accuracy and reliability.

Description

Technical Field

[0001] The present invention relates to the field of stepping motors, and in particular to a driving control system of a stepping motor. Background Art

[0002] A stepper motor is a converter that converts electrical pulse signals into corresponding angular displacement or linear displacement. It is an important component in automation control systems. It has the characteristics of simple control, fast start and stop, low price and easy maintenance. Therefore, it is widely used in mechatronic control systems.

[0003] Currently, stepper motors are commonly controlled using pulse-based control. The motor's accuracy and speed are completely determined by the input pulses, and the angle the stepper motor rotates through depends on the number of control pulses received. In theory, the angular speed and step length of a stepper motor depend solely on the input pulse frequency and number of pulses. However, in practice, the motor's operating conditions are affected by its torque. When the stepper motor's load suddenly changes or its speed changes, it cannot provide the torque required to complete a single step angle. This can cause the stepper motor to lose steps and stall, reducing the control system's accuracy.

[0004] Therefore, it is urgent to further optimize the configuration of the drive control system of the stepper motor to avoid loss of steps and stalling during sudden load changes or variable speed operation, and to improve the control accuracy and reliability of the stepper motor. Summary of the Invention

[0005] In view of the above problems, the present invention is proposed to provide a drive control system for a stepper motor, which uses the angle difference of the stepper motor to judge the degree of step loss and stall, and adaptively adjusts the angle reference value θ according to the angle difference and the speed difference. ref , A phase winding current reference value i aref , B phase winding current reference value i bref , avoid loss of step and stall during sudden load change or variable speed operation, enhance the rapid adjustment capability of the stepper motor, and improve the control accuracy and reliability of the stepper motor.

[0006] In one embodiment of the present invention, a drive control system for a stepper motor is provided, comprising:

[0007] Angle reference value generation module, based on the angle feedback value θ of the stepper motor el Generate angle reference value θ ref ;

[0008] Speed ​​reference value generation module, based on the angle reference value θ ref Generate speed reference value ω ref ;

[0009] The first differential module, based on the angle feedback value θel Generate speed feedback value ω el ;

[0010] Speed ​​subtractor, based on the speed reference ω ref and speed feedback value ω el , calculate and generate the speed error value;

[0011] PI adjustment module, which performs PI adjustment on the speed error value to generate the current reference value amplitude;

[0012] Sine module, speed reference value ω ref Perform integration and sine operations to generate a sine signal;

[0013] Cosine module, speed reference value ω ref Perform integration and cosine operations to generate a cosine signal;

[0014] The first multiplier performs multiplication operation on the current reference value amplitude and the cosine signal to obtain the A phase winding current reference value i aref ;

[0015] The second multiplier multiplies the current reference value amplitude and the sinusoidal signal to obtain the B-phase winding current reference value i bref ;

[0016] Current loop regulation module, based on the A phase winding current reference value i aref , B phase winding current reference value i bref , A phase winding current feedback value i a and B-phase winding current feedback value i b , generating A-phase winding control voltage and B-phase winding control voltage;

[0017] A PWM modulation module generates a PWM signal for the A-phase winding and a PWM signal for the B-phase winding based on the control voltage of the A-phase winding and the control voltage of the B-phase winding;

[0018] The dual H-bridge module controls the current of the A-phase winding and the B-phase winding in the stepper motor based on the A-phase winding PWM signal and the B-phase winding PWM signal to achieve step control.

[0019] The angle reference value generating module includes:

[0020] Angle difference acquisition module, the preset angle setting value θ com and the angle feedback value θ of the stepper motor el After making the difference, obtain the real-time angle difference Δθ of the stepper motor;

[0021] Angle difference range judgment module, which obtains the real-time angle difference Δθ and the range threshold θ thComparing and determining whether the angle difference Δθ is within a predetermined range;

[0022] An angle difference polarity judgment module compares the real-time angle difference Δθ with zero to determine the polarity of the angle difference Δθ;

[0023] Angle reference value setting module, based on the angle difference range and angle difference polarity, sets the angle reference value θ ref .

[0024] Furthermore, the angle difference range judgment module determines that the angle difference Δθ is within a predetermined range; when Δθ < -θ th Or Δθ>θ th When , the angle difference range judgment module determines that the angle difference Δθ is outside the predetermined range.

[0025] Furthermore, when 0≤Δθ, the angle difference polarity judgment module determines that the angle difference Δθ is a non-negative value; when Δθ<0, the angle difference polarity judgment module determines that the angle difference Δθ is a negative value.

[0026] Furthermore, when the angle difference Δθ is within a predetermined range, the angle reference value θ ref =θ com .

[0027] Furthermore, when the angle difference Δθ is outside the predetermined range and is negative, the angle reference value θ ref =θ com -θ1-θ2; when the angle difference Δθ is outside the predetermined range and the angle difference Δθ is positive, the angle reference value θ ref =θ com +θ1+θ2; wherein θ1 is the first angle adjustment value, and θ2 is the second angle adjustment value.

[0028] Furthermore, the angle difference Δθ is proportionally adjusted to obtain a first angle adjustment value θ1.

[0029] Furthermore, the preset angle setting values ​​θ are respectively com , angle feedback value θ el Differentiate to get the speed setting value ω com , speed feedback value ω el , obtain the real-time speed difference Δω of the stepper motor; perform proportional-integral adjustment on the speed difference Δω to obtain the second angle adjustment value θ2.

[0030] Furthermore, the speed reference value generating module generates the speed reference value ω using differential calculation. ref .

[0031] The beneficial technical effects of the present invention are:

[0032] (1) The present invention provides a stepper motor drive control system, which uses an angle reference value θ ref Real-time adjustment of the A-phase winding current reference value i aref , B phase winding current reference value i bref , which enhances the rapid adjustment capability of the stepper motor when it loses steps and stalls, and improves the control accuracy and reliability of the stepper motor.

[0033] (2) The present invention uses the angle difference of the stepping motor to judge the degree of step loss and stall, and adaptively adjusts the angle reference value θ according to the angle difference and the speed difference. ref , avoiding loss of steps and stalling during sudden load changes or variable speed operation, further enhancing the rapid adjustment capability of the stepper motor and improving the control accuracy and reliability of the stepper motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is the specific principle block diagram of the stepper motor drive control system;

[0036] Figure 2 Detailed schematic diagram of the angle reference value generation module. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0038] The present invention provides a drive control system for a stepper motor, which uses the angle difference of the stepper motor to judge the degree of step loss and stall, and adaptively adjusts the angle reference value θ according to the angle difference and the speed difference. ref , A phase winding current reference value i aref , B phase winding current reference value i bref , avoid loss of step and stall during sudden load change or variable speed operation, enhance the rapid adjustment capability of the stepper motor, and improve the control accuracy and reliability of the stepper motor.

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Figure 1 This is the specific principle block diagram of the stepper motor drive control system. Figure 1 As shown, the drive control system includes:

[0041] Angle reference value generation module, based on the angle feedback value θ of the stepper motor el Generate angle reference value θ ref ;

[0042] Speed ​​reference value generation module, based on the angle reference value θ of the stepper motor ref Generate speed reference value ω ref ; Among them, the speed reference value generation module gives priority to differential calculation;

[0043] The first differential module, based on the angle feedback value θ el Generate speed feedback value ω el ;

[0044] Speed ​​subtractor, based on the speed reference ω ref and speed feedback value ω el , calculate and generate the speed error value;

[0045] PI adjustment module, which performs PI adjustment on the speed error value to generate the current reference value amplitude;

[0046] Sine module, speed reference value ω ref Perform integration and sine operations to generate a sine signal;

[0047] Cosine module, speed reference value ω ref Perform integration and cosine operations to generate a cosine signal;

[0048] The first multiplier performs multiplication operation on the current reference value amplitude and the cosine signal to obtain the A phase winding current reference value i aref ;

[0049] The second multiplier multiplies the current reference value amplitude and the sinusoidal signal to obtain the B-phase winding current reference value i bref ;

[0050] Current loop regulation module, based on the A phase winding current reference value i aref , B phase winding current reference value i bref , A phase winding current feedback value i a and B-phase winding current feedback value i b , generating A-phase winding control voltage and B-phase winding control voltage;

[0051] A PWM modulation module generates a PWM signal for the A-phase winding and a PWM signal for the B-phase winding based on the control voltage of the A-phase winding and the control voltage of the B-phase winding;

[0052] The dual H-bridge module controls the current of the A-phase winding and the B-phase winding in the stepper motor based on the A-phase winding PWM signal and the B-phase winding PWM signal to achieve step control.

[0053] The present invention uses the angle reference value θ ref Real-time adjustment of the A-phase winding current reference value i aref , B phase winding current reference value i bref , which enhances the rapid adjustment capability of the stepper motor when it loses steps and stalls, and improves the control accuracy and reliability of the stepper motor.

[0054] Further, Figure 2 This is the specific schematic diagram of the angle reference value generation module. Figure 2 As shown, the angle reference value generating module includes:

[0055] Angle difference acquisition module, the preset angle setting value θ com and the angle feedback value θ of the stepper motor el After making the difference, the real-time angle difference Δθ of the stepper motor is obtained. Where Δθ=θ com -θ el .

[0056] Angle difference range judgment module, which obtains the real-time angle difference Δθ and the range threshold θ th The comparison is performed to determine whether the angle difference Δθ is within a predetermined range.

[0057] Specifically, when -θ th ≤Δθ≤θ th When Δθ<-θ th Or Δθ>θ th When , the angle difference range judgment module determines that the angle difference Δθ is outside the predetermined range.

[0058] In the present invention, when the stepper motor loses step or stalls, the angle feedback value θ of the stepper motor is el Will deviate from the preset angle comparison value θ com , and then the angle difference Δθ gradually increases and deviates from the predetermined range.

[0059] The angle difference polarity judgment module compares the real-time angle difference Δθ with zero to determine the polarity of the angle difference Δθ.

[0060] Specifically, when 0≤Δθ, the angle difference polarity judgment module determines that the angle difference Δθ is a non-negative value; when Δθ<0, the angle difference polarity judgment module determines that the angle difference Δθ is a negative value.

[0061] Angle reference value setting module, based on the angle difference range and angle difference polarity, sets the angle reference value θ ref .

[0062] Specifically, when the angle difference Δθ is within a predetermined range, the angle reference value θ ref =θ com When the angle difference Δθ is outside the predetermined range and the angle difference Δθ is negative, the angle reference value θ ref =θ com -θ1-θ2; when the angle difference Δθ is outside the predetermined range and the angle difference Δθ is positive, the angle reference value θ ref =θ com +θ1+θ2; wherein θ1 is the first angle adjustment value, and θ2 is the second angle adjustment value.

[0063] Furthermore, the specific method for obtaining the first angle adjustment value θ1 is as follows:

[0064] Proportional adjustment is performed on the angle difference Δθ to obtain a first angle adjustment value θ1;

[0065] Furthermore, the specific method for obtaining the second angle adjustment value θ2 is as follows:

[0066] Set the preset angle value θ com , angle feedback value θ el Differentiate to get the speed setting value ω com , speed feedback value ω el , get the real-time speed difference Δω of the stepper motor, where Δω=ω com -ω el .

[0067] The speed difference Δω is adjusted proportionally and integrally to obtain a second angle adjustment value θ2.

[0068] In the present invention, when the stepper motor loses step, the stepper motor shows a step loss or step over, and the angle feedback value θ of the stepper motor is el Will deviate from the preset angle comparison value θ com Therefore, the angle difference Δθ is used to judge the degree of stepping out of step of the stepper motor. When the stepper motor loses step seriously, it is judged whether the stepper motor loses step or skips step, and the angle reference value θ is increased or decreased accordingly. ref When the stepper motor is stalled, the angle feedback value θ of the stepper motor is el It will still deviate from the preset angle comparison value θ comTherefore, the angle difference Δθ can also be used to judge the degree of stepper motor stall. When the stepper motor stall is serious, the angle reference value θ is increased accordingly. ref At the same time, the present invention also introduces angle difference adjustment and speed difference adjustment. When the stepping motor loses step, the first angle adjustment value θ1 plays a major role in adjustment; when the stepping motor is blocked, the second angle adjustment value θ2 plays a major role in adjustment, enhancing the angle reference value θ ref Rapid adjustment capability.

[0069] Therefore, the present invention can avoid step loss and stalling during sudden load changes or variable speed operation, and improve the control accuracy and reliability of the stepper motor.

[0070] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.

[0071] The foregoing description shows and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein by the teachings above or by techniques or knowledge in the relevant art. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be protected by the appended claims.

Claims

1. A stepper motor drive control system, characterized in that: include: Angle reference value generation module, based on the angle feedback value θ of the stepper motor el Generate angle reference value θ ref ; Speed ​​reference value generation module, based on the angle reference value θ ref Generate speed reference value ω ref ; The first differential module, based on the angle feedback value θ el Generate speed feedback value ω el ; Speed ​​subtractor, based on the speed reference ω ref and speed feedback value ω el , calculate and generate the speed error value; PI adjustment module, which performs PI adjustment on the speed error value to generate the current reference value amplitude; Sine module, speed reference value ω ref Perform integration and sine operations to generate a sine signal; Cosine module, speed reference value ω ref Perform integration and cosine operations to generate a cosine signal; The first multiplier performs multiplication operation on the current reference value amplitude and the cosine signal to obtain the A phase winding current reference value i aref ; The second multiplier multiplies the current reference value amplitude and the sinusoidal signal to obtain the B-phase winding current reference value i bref ; Current loop regulation module, based on the A phase winding current reference value i aref , B phase winding current reference value i bref , A phase winding current feedback value i a and B-phase winding current feedback value i b , generating A-phase winding control voltage and B-phase winding control voltage; A PWM modulation module generates a PWM signal for the A-phase winding and a PWM signal for the B-phase winding based on the control voltage of the A-phase winding and the control voltage of the B-phase winding; The dual H-bridge module controls the current of the A-phase winding and the B-phase winding in the stepper motor based on the A-phase winding PWM signal and the B-phase winding PWM signal to achieve step control.

2. The driving control system according to claim 1, characterized in that: The angle reference value generating module includes: Angle difference acquisition module, the preset angle setting value θ com and the angle feedback value θ of the stepper motor el After making the difference, obtain the real-time angle difference Δθ of the stepper motor; Angle difference range judgment module, which obtains the real-time angle difference Δθ and the range threshold θ th Comparing and determining whether the angle difference Δθ is within a predetermined range; An angle difference polarity judgment module compares the real-time angle difference Δθ with zero to determine the polarity of the angle difference Δθ; Angle reference value setting module, set the angle reference value θ ref ; When the angle difference Δθ is within the predetermined range, the angle reference value θ ref =θ com ; When the angle difference Δθ is outside the predetermined range and is negative, the angle reference value θ ref =θ com -θ1-θ2; when the angle difference Δθ is outside the predetermined range and the angle difference Δθ is positive, the angle reference value θ ref =θ com +θ1+θ2; wherein θ1 is the first angle adjustment value, and θ2 is the second angle adjustment value.

3. The driving control system according to claim 2, characterized in that: When -θ th ≤Δθ≤θ th When Δθ<-θ th Or Δθ>θ th When , the angle difference range judgment module determines that the angle difference Δθ is outside the predetermined range.

4. The driving control system according to claim 3, characterized in that: When 0≤Δθ, the angle difference polarity judgment module determines that the angle difference Δθ is a non-negative value; when Δθ<0, the angle difference polarity judgment module determines that the angle difference Δθ is a negative value.

5. The driving control system according to claim 4, characterized in that: The angle difference Δθ is proportionally adjusted to obtain a first angle adjustment value θ1.

6. The driving control system according to claim 5, characterized in that: Set the preset angle value θ com , angle feedback value θ el Differentiate to get the speed setting value ω com , speed feedback value ω el , obtain the real-time speed difference Δω of the stepper motor; perform proportional-integral adjustment on the speed difference Δω to obtain the second angle adjustment value θ2.

7. The driving control system according to claim 1, characterized in that: The speed reference value generating module generates a speed reference value ω using differential calculation ref .

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