Operation method for avoiding zero alignment abnormity of closed-loop stepping motor encoder
By using closed-loop control and encoder feedback determination methods in the zero position alignment process of the incremental encoder closed-loop stepper motor, the problem of zero position identification abnormality caused by blockage is solved, the operating performance and stability of the motor is improved, and fast and accurate fault positioning is achieved.
Patent Information
- Application Number
- CN202510101384.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-04-11
AI Technical Summary
The zero-position alignment method of existing incremental encoder closed-loop stepper motor cannot be accurately identified and processed when the rotor is blocked, resulting in abnormal zero-position identification, affecting the operating performance and stability of the motor.
In the zero alignment process of the incremental encoder closed-loop stepper motor, a closed-loop control method is used, combined with the encoder feedback value, to determine whether the rotor is blocked, and in the case of blockage, the open-loop control motor runs a specific angle in the opposite direction to ensure the accuracy of zero alignment.
It effectively avoids zero position identification abnormalities caused by blockage, ensures normal zero position alignment, improves the operating performance and stability of the motor, and achieves faster and more accurate fault positioning and handling.
Smart Images
Figure CN119813846A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of stepper motor driving, and in particular to an operating method for avoiding abnormal zero position alignment of a closed-loop stepper motor encoder. Background Art
[0002] Zero alignment of the incremental encoder closed-loop stepper motor refers to determining a specific reference position of the motor rotor in electrical angle, and defining this position as the zero point (0 position) of electrical angle. In this process, specific control methods and means are required to put the motor rotor in an accurately identifiable and stable position state, so that in the subsequent motor operation process, the actual position and rotation angle of the rotor can be accurately calculated based on this zero position, thereby achieving precise control. Zero alignment of the incremental encoder closed-loop stepper motor can accurately control the motor position and movement, ensure the motor's operating performance and stability, and facilitate system fault diagnosis and maintenance.
[0003] The zero-position alignment of existing incremental encoder closed-loop stepper motors is mainly achieved by controlling the current of the stator winding. The stator generates magnetic force to attract the rotor to a corresponding electrical angle position. After a period of time, the motor rotor is assumed to be stable, and the current encoder position is determined as the zero point of the rotor electrical angle in the closed-loop control. This operation method can only be applied during the encoder zero-position alignment process. The rotor cannot be blocked due to the influence of the external mechanical limit position. In the case of a blockage, the rotor electrical angle zero point obtained according to this open-loop operation method is abnormal. If the erroneous zero electrical angle is used for closed-loop control, the motor torque will be abnormal at best, and the motor will run out of control at worst. Since it is impossible to guarantee whether a blockage will occur during zero-position alignment, this operation method has certain application limitations. Summary of the invention
[0004] (1) Technical issues to be solved
[0005] In view of the deficiencies in the prior art, the present invention adopts an encoder to participate in zero-position alignment, and the operation mode is transformed from an open-loop to a closed-loop, which can monitor the state of the motor rotor in real time, and no longer simply rely on the open-loop method that assumes the rotor is stable, making the operation more accurate and reliable; it can effectively deal with the stalling caused by the randomness of the motor rotor position, and can accurately identify and handle the stalling by running in the initial direction and the reverse direction and combining the encoder feedback judgment, avoiding the zero-position identification abnormality caused by the stalling, ensuring the normal zero-position alignment, and solving the pain point of the stalling problem; when there is an abnormality in the encoder or the line, during the encoder zero-position alignment process, the detailed operating status data and the encoder feedback data can be used to report the fault, so as to locate the fault point faster and more accurately, and facilitate the rapid resolution of the problem on site.
[0006] (2) Technical solution
[0007] To achieve the above object, the present invention provides the following technical solution: an operation method for avoiding abnormal zero alignment of a closed-loop stepping motor encoder, comprising the following steps:
[0008] S1: During the process of zero position alignment of the incremental encoder closed-loop stepper motor, the open-loop control motor rotor rotates in an initial direction by a specific angle;
[0009] S2: Combined with the encoder feedback value, determine whether the rotor is currently blocked;
[0010] S3: In case of stall, the open loop controls the motor to run in the opposite direction for a specific angle;
[0011] S4: Combined with the encoder feedback value again, determine whether the rotor is currently blocked.
[0012] Furthermore, after the initial direction of operation is determined to be stalled, the open-loop controlled motor rotor is rotated in the reverse direction for at least one electrical angle cycle, and the encoder feedback value is again compared with the stall detection value to determine whether the rotor is stalled when running in the reverse direction. If the encoder feedback value is greater than the stall detection value when running in the reverse direction, it is determined that no stall has occurred, and the encoder zero position alignment is deemed normal.
[0013] Furthermore, if a stall occurs when running in the initial direction and a stall still occurs when running in the reverse direction, the encoder feedback value when the stall occurs when running in the initial direction is further analyzed. If the value is less than the stall detection value, it is determined that the motor may be stalled at the 0 electrical angle position within the current running distance.
[0014] Furthermore, after determining that there may be a stall at the 0 electrical angle position, the motor rotor is controlled to run in the reverse direction for a specific angle, and the encoder feedback value is continuously monitored during the reverse direction operation. If the value is greater than the stall detection value, it is determined that there is a stable 0 electrical angle position during the reverse direction operation.
[0015] Furthermore, after determining that there is a stable 0 electrical angle position during the reverse direction operation, the motor rotor is controlled to move a specific angle in the initial direction, and the position where the motor rotor finally stops is identified as the motor rotor electrical angle 0 position, completing the zero position alignment operation.
[0016] Furthermore, during the entire operation process, the operating parameters of the motor are monitored in real time, including but not limited to current and temperature. If the operating parameters exceed the preset normal range, the operation is suspended and corresponding adjustments are made to ensure that the motor is in normal operating state to ensure the accuracy of the zero alignment operation.
[0017] Furthermore, during the rotation of the motor rotor, the number of electrical angle cycles is reasonably set according to the actual characteristics and application scenarios of the motor. Different numbers of electrical angle cycles can be used in different stages to adapt to different zero alignment requirements.
[0018] Furthermore, if the motor is determined to be stalled multiple times during operation and a stable 0 electrical angle position cannot be determined, fault error processing is immediately performed. The error information includes detailed information such as motor operating status data and encoder feedback data, so as to quickly and accurately locate the fault point and take effective solutions.
[0019] Furthermore, when the motor rotor is locked in the initial position, ensure that the magnitude and stability of the locking force meet the motor design requirements to avoid the initial position of the motor rotor being offset or unstable due to abnormal locking force, thereby affecting the accuracy of subsequent zero-position alignment operations.
[0020] Furthermore, during the operation, the encoder and related lines are detected in real time. If an encoder signal abnormality or a line fault is detected, the operation is suspended and repaired. After the repair is completed, the zero-position alignment operation is continued from the step before the fault occurred to ensure the continuity and accuracy of the operation.
[0021] (3) Beneficial effects
[0022] Compared with the prior art, the present invention provides an operating method to avoid abnormal zero-position alignment of a closed-loop stepper motor encoder, and has the following beneficial effects: the present invention adopts an encoder to participate in zero-position alignment, and the operating mode is changed from open-loop to closed-loop, and the motor rotor state can be monitored in real time, and the open-loop mode no longer relies solely on the assumption that the rotor is stable, making the operation more accurate and reliable; it can effectively deal with the stalling caused by the randomness of the motor rotor position, and can accurately identify and handle the stalling by running in the initial direction and the reverse direction and combining the encoder feedback judgment, avoiding zero-position identification abnormalities caused by stalling, ensuring normal zero-position alignment, and solving the pain points of the stalling problem; when there is an abnormality in the encoder or the line, during the encoder zero-position alignment process, a fault report can be performed through detailed operating status data and encoder feedback data, so as to locate the fault point faster and more accurately, and facilitate on-site rapid problem solving. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 is a flow chart of the method of the present invention;
[0024] Figure 2 It is the principle diagram of the method of the present invention;
[0025] Figure 3 A schematic diagram of a module according to a specific embodiment of the present invention;
[0026] Figure 4Schematic diagram of a motor rotor of an incremental closed-loop stepping motor before zero alignment according to a first embodiment of the present invention;
[0027] Figure 5 Schematic diagram of the motor rotor of the incremental closed-loop stepping motor before zero alignment in Embodiment 2 of the present invention;
[0028] Figure 6 Schematic diagram of the motor rotor of the incremental closed-loop stepping motor before zero alignment according to Embodiment 3 of the present invention;
[0029] Figure 7 Schematic diagram of a motor rotor of an incremental closed-loop stepping motor before zero alignment according to a fourth embodiment of the present invention;
[0030] Figure 8 Schematic diagram of the motor rotor of the incremental closed-loop stepping motor before zero-position alignment according to Embodiment 5 of the present invention.
[0031] In the figure, 1, motor; 2, left hard limit; 3, mechanical load; 4, right hard limit. DETAILED DESCRIPTION
[0032] In order to better understand the purpose, structure and function of the present invention, and to solve the limitations of the prior art, the present invention adopts an encoder to participate in zero-position alignment, and the operation mode is changed from open-loop to closed-loop, which can monitor the state of the motor rotor in real time, and no longer rely solely on the open-loop mode that assumes the rotor is stable, so that the operation is more accurate and reliable; effectively deal with the stalling caused by the randomness of the motor rotor position, by running in the initial direction and the reverse direction and combining the encoder feedback judgment, it can accurately identify and handle the stalling, avoid the zero-position identification abnormality caused by the stalling, ensure the normal zero-position alignment, and solve the pain point of the stalling problem; when there is an abnormality in the encoder or the circuit, in the process of the encoder zero-position alignment, through detailed operating status data and encoder feedback data, fault reporting can be performed, and faster and more accurate positioning of the fault point can be achieved, which is convenient for quick problem solving on site. A method of operation of the present invention to avoid the abnormal zero-position alignment of the closed-loop stepper motor encoder is further described in detail.
[0033] refer to Figure 1-2 The present invention provides an operation method for avoiding abnormal zero alignment of a closed-loop stepping motor encoder, comprising the following steps:
[0034] S1: During the process of zero position alignment of the incremental encoder closed-loop stepper motor, the open-loop control motor rotor rotates in an initial direction by a specific angle;
[0035] S2: Combined with the encoder feedback value, determine whether the rotor is currently blocked;
[0036] S3: In case of stall, the open loop controls the motor to run in the opposite direction for a specific angle;
[0037] S4: Combined with the encoder feedback value again, determine whether the rotor is currently blocked.
[0038] Specifically, after the initial direction operation is determined to be stalled, the motor rotor is open-loop controlled to rotate in the reverse direction for at least one electrical angle cycle, and the encoder feedback value is compared with the stall detection value again to determine whether the rotor is stalled when running in the reverse direction. If the encoder feedback value is greater than the stall detection value when running in the reverse direction, it is determined that no stall has occurred. At this time, it is determined that the encoder zero position alignment is normal. If stall occurs when running in the initial direction and stall still occurs when running in the reverse direction, the encoder feedback value is further analyzed when stall occurs when running in the initial direction. If the value is less than the stall detection value, it is determined that the motor may be stalled at the 0 electrical angle position within the current running distance.
[0039] Furthermore, after determining that there may be a stall at the 0 electrical angle position, the motor rotor is controlled to run in the reverse direction for a specific angle, and the encoder feedback value is continuously monitored during the reverse direction operation. If the value is greater than the stall detection value, it is determined that there is a stable 0 electrical angle position during the reverse direction operation. After determining that there is a stable 0 electrical angle position during the reverse direction operation, the motor rotor is controlled to move in the initial direction for a specific angle, and the position where the motor rotor finally stops is determined as the motor rotor electrical angle 0 position, completing the zero alignment operation.
[0040] Furthermore, during the entire operation process, the operating parameters of the motor are monitored in real time, including but not limited to current and temperature. If the operating parameters exceed the preset normal range, the operation is suspended and corresponding adjustments are made to ensure that the motor is in normal operation to ensure the accuracy of the zero alignment operation. During the rotation of the motor rotor, the number of electrical angle cycles is reasonably set according to the actual characteristics and application scenarios of the motor. Different numbers of electrical angle cycles can be used at different stages to meet different zero alignment requirements.
[0041] If the motor is determined to be stalled multiple times during operation and a stable 0 electrical angle position cannot be determined, the fault error processing will be performed immediately. The error information includes detailed information such as motor operation status data and encoder feedback data, so as to quickly and accurately locate the fault point and take effective solutions;
[0042] When the motor rotor is locked in the initial position, ensure that the magnitude and stability of the locking force meet the motor design requirements to avoid the motor rotor initial position deviation or instability caused by abnormal locking force, which may affect the accuracy of subsequent zero alignment operations;
[0043] During the operation, the encoder and related lines are checked in real time. If an encoder signal abnormality or line fault is detected, the operation is suspended and repaired. After the repair is completed, the zero-position alignment operation is continued from the steps before the fault occurred to ensure the continuity and accuracy of the operation.
[0044] Attached Figure 3 This is a schematic diagram of a conventional motor and screw module;
[0045] Embodiment 1: As shown in the attached Figure 3 and attached Figure 4 , is a schematic diagram of a motor rotor of an incremental closed-loop stepper motor before zero-position alignment. When zero-position alignment is performed, the motor rotor will be locked to the (3!) position and remain stable. Then, according to the implementation steps of the present invention, the motor will be controlled to move rightward by 2 electrical angle cycles. Since the right hardware limit is not touched during the rightward movement, no stalling will occur. Finally, the rotor will be stable at the (3!!!) position. The present invention will determine whether a stall occurs based on the feedback of the incremental encoder during the movement from (3!) to (3!!!). In this example, the encoder feedback exceeds the stall detection value, so no stall occurs. The motor is controlled to move leftward by 1 electrical angle cycle back to the 0 electrical angle position and wait for stability. It is determined that the (3!!) position at this time is the electrical angle 0 position.
[0046] Embodiment 2: As shown in the attached Figure 3 and attached Figure 5 In the embodiment, before the zero-position alignment is performed, the rotor is located at position (3). When the zero-position alignment operation is performed, the motor rotor will be locked at position (3!) and remain stable. Then, according to the implementation steps of the present invention, the motor is controlled to move rightward by 2 electrical angle cycles. In the example diagram, the right limit position (4) will be encountered during the rightward movement, causing a stall. However, the encoder feedback still exceeds the stall setting threshold, that is, there is a situation in which the motor will not be stalled at 0 electrical angle during the operation. Therefore, the motor is controlled to run leftward by 1 electrical angle cycle, and the motor rotor will be stable at position (3!!). At this time, the position (3!!) is determined to be the electrical angle 0 position.
[0047] Embodiment 3: As shown in the attached Figure 3 and attached Figure 6In the embodiment, before the zero alignment is performed, the rotor is located at position (3). When the zero alignment operation is performed, the motor rotor will be locked at position (3!) and remain stable. Then, according to the implementation steps of the present invention, the motor is controlled to move rightward by 2 electrical angle cycles. In the example diagram, the rightward movement process will encounter the right limit position (4) and cause a stall, and finally remain stable at position (4). At this time, the encoder feedback value is less than the stall setting threshold, and it is determined that the motor may be stalled at the 0 electrical angle position within the current running distance. Therefore, the motor is controlled to run to the left for 2 electrical angle cycles. At this time, the motor rotor will move to position (3!!). The encoder feedback during the movement is detected. The encoder feedback exceeds the stall setting threshold. Therefore, there is a stable 0 electrical angle position during the leftward movement. Therefore, the motor is controlled to move rightward by one electrical angle cycle to (3!), and the position at this time is determined to be the motor rotor electrical angle 0 position.
[0048] Embodiment 4: As shown in the attached Figure 3 and attached Figure 7 In the embodiment, before the zero alignment is performed, the rotor is located at position (3). When the zero alignment operation is performed, the motor rotor will be locked to the right mechanical limit position (4) to cause a stall. Then, according to the implementation steps of the present invention, the motor is controlled to move to the right by 2 electrical angle cycles. In the example diagram, the motor will remain at position (4). At this time, the encoder feedback value is less than the stall setting threshold, and it is determined that the motor is stalled. At this time, the motor is controlled to move to the left by 2 electrical angle cycles, and the motor rotor will move to position (3!!) and remain stable. At this time, the encoder feedback value is greater than the stall setting threshold, and it is determined that the motor has a stable 0 electrical angle position during the leftward movement. Therefore, the motor is controlled to move to the right by one electrical angle cycle, and the motor will move to position (3!). The current position is determined to be the motor rotor electrical angle 0 position.
[0049] Embodiment 5: As attached Figure 3 and attached Figure 8 In the embodiment, before the zero alignment is performed, the rotor is located at the (3) position. When the zero alignment operation is performed, the motor rotor will be locked at the (3!) position. Then, according to the implementation steps of the present invention, the motor is controlled to move to the right by 2 electrical angle cycles. In the example diagram, the motor will eventually remain at the (3!) position. At this time, the encoder feedback value is less than the stall setting threshold, and it is determined that the motor is stalled. At this time, the motor is controlled to move to the left by 2 electrical angle cycles, and the motor rotor will move to the (3!!!) position and remain stable. At this time, the encoder feedback value is greater than the stall setting threshold, and it is determined that the motor has a stable 0 electrical angle position during the leftward movement. Therefore, the motor is controlled to move to the right by one electrical angle cycle, and the motor rotor will move to the (3!!) position. The position at this time is determined to be the motor rotor electrical angle 0 position.
[0050] In the above process, if the motor is still determined to be blocked during the leftward movement, a fault error reporting process will be performed to more accurately locate the fault point and quickly handle the fault.
[0051] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.
Claims
1. An operating method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder, characterized in that: The following steps are involved: S1: During the process of zero position alignment of the incremental encoder closed-loop stepper motor, the open-loop control motor rotor rotates in an initial direction by a specific angle; S2: Combined with the encoder feedback value, determine whether the rotor is currently blocked; S3: In case of stall, the open loop controls the motor to run in the opposite direction for a specific angle; S4: Combined with the encoder feedback value again, determine whether the rotor is currently blocked.
2. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 1, characterized in that: After it is determined that a stall occurs during operation in the initial direction, the motor rotor is open-loop controlled to rotate in the reverse direction for at least one electrical angle cycle, and the encoder feedback value is compared with the stall detection value to determine whether the rotor is stalled when running in the reverse direction. If the encoder feedback value is greater than the stall detection value when running in the reverse direction, it is determined that no stall occurs, and the encoder zero position alignment is deemed normal.
3. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 2, characterized in that: If a stall occurs when running in the initial direction and a stall still occurs when running in the reverse direction, the encoder feedback value when the stall occurs when running in the initial direction is further analyzed. If the value is less than the stall detection value, it is determined that the motor may be stalled at the 0 electrical angle position within the current running distance.
4. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 3, characterized in that: After determining that there may be a stall at the 0 electrical angle position, the motor rotor is controlled to run in the reverse direction for a specific angle, and the encoder feedback value is continuously monitored during the reverse direction operation. If the value is greater than the stall detection value, it is determined that there is a stable 0 electrical angle position during the reverse direction operation.
5. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 4, characterized in that: After determining that there is a stable 0 electrical angle position during the reverse direction operation, the motor rotor is controlled to move a specific angle in the initial direction, and the position where the motor rotor finally stops is identified as the motor rotor electrical angle 0 position, thereby completing the zero position alignment operation.
6. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 5, characterized in that: During the entire operation process, the operating parameters of the motor are monitored in real time, including but not limited to current and temperature. If the operating parameters exceed the preset normal range, the operation is suspended and corresponding adjustments are made to ensure that the motor is in normal operating state to ensure the accuracy of the zero alignment operation.
7. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 6, characterized in that: During the rotation of the motor rotor, the number of electrical angle cycles is reasonably set according to the actual characteristics and application scenarios of the motor. Different numbers of electrical angle cycles can be used in different stages to meet different zero alignment requirements.
8. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 7, characterized in that: If the motor is determined to be stalled multiple times during operation and a stable 0 electrical angle position cannot be determined, fault error processing is immediately performed, and the error information includes detailed information such as motor operating status data and encoder feedback data, so as to quickly and accurately locate the fault point and take effective solutions.
9. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 8, characterized in that: When the motor rotor is locked in the initial position, the magnitude and stability of the locking force are ensured to meet the motor design requirements to avoid the initial position of the motor rotor being offset or unstable due to abnormal locking force, thereby affecting the accuracy of subsequent zero alignment operations.
10. The method for avoiding abnormal zero alignment of a closed-loop stepper motor encoder according to claim 9, characterized in that: During the operation, the encoder and related lines are detected in real time. If an encoder signal abnormality or a line fault is detected, the operation is suspended and repaired. After the repair is completed, the zero-position alignment operation is continued from the steps before the fault occurs to ensure the continuity and accuracy of the operation.