Motor phase loss detection methods, servo drivers, media and servo systems

Abstract

This application provides a method for detecting phase loss in a motor, a servo driver, a medium, and a servo system. The method includes: before the motor enters the operating mode, acquiring the current electrical angle of the motor based on a phase loss detection command, and determining a detection electrical angle based on the current electrical angle. The detection electrical angle is an angle parameter used for coordinate transformation in a field-oriented control loop, which is a current loop used to control the motor. The field-oriented control loop is controlled according to a preset quadrature-axis current to acquire the three-phase current of the motor. A quadrature-axis feedback current is determined based on the three-phase current and the detection electrical angle. The quadrature-axis feedback current is the feedback current of the three-phase current in the quadrature-axis direction. The phase loss detection result of the motor is determined based on the preset quadrature-axis current and the quadrature-axis feedback current. This application solves the problem that existing servo motor phase loss detection methods struggle to pre-identify phase loss faults before operation, leading to robot malfunctions.

Description

Technical Field

[0001] This application relates to the field of motor fault detection technology, and more specifically, to a method for detecting a phase loss in a motor, a servo driver, a computer-readable storage medium, and a servo system. Background Technology

[0002] With the continuous improvement of industrial automation, industrial robots are widely used in manufacturing scenarios. As a crucial actuator of industrial robots, the operating status of servo motors directly affects the stability and safety of robot motion control. During the operation of a servo motor, if any one or more phases of the motor's three-phase windings become loose, disconnected, or have broken lines with the servo driver, it can easily lead to a phase loss fault in the motor.

[0003] A phase loss fault in a servo motor can prevent it from outputting torque as expected, thus affecting the normal motion control of the robot's joints. Especially during the robot's startup or enable phase, if a phase loss fault exists in the servo motor before it enters normal operation and this fault is not identified in time, it may lead to the robot failing to start properly, or even causing abnormal arm movements, uncontrolled drooping, or collisions. Therefore, detecting phase loss faults before the servo motor is put into operation is crucial for ensuring the safe operation of the robot system.

[0004] Existing servo motor phase loss detection methods typically rely on the current or operating status of the motor during operation, meaning that a phase loss fault can only be identified after the motor has already started running. This type of detection method struggles to pre-identify phase loss faults before the servo motor enters normal operating mode, resulting in a lack of effective fault diagnosis mechanisms before robot startup. When a phase loss fault actually exists in the motor, the robot may fail to operate normally because the servo motor cannot output power correctly.

[0005] Therefore, there is an urgent need for a solution that can detect phase loss faults in advance before the servo motor is put into operation, so as to reduce the impact of motor phase loss on the normal operation of the robot. Summary of the Invention

[0006] The main objective of this application is to provide a method for detecting phase loss in a motor, a servo driver, a computer-readable storage medium, and a servo system, so as to at least solve the problem that existing servo motor phase loss detection methods cannot pre-identify phase loss faults before operation, resulting in the robot being unable to operate normally.

[0007] To achieve the above objectives, according to one aspect of this application, a method for detecting a phase loss in a motor is provided, comprising: before the motor enters an operating mode, acquiring the current electrical angle of the motor based on a phase loss detection command, and determining a detection electrical angle based on the current electrical angle, wherein the detection electrical angle is an angle parameter used for coordinate transformation in a field-oriented control loop, and the field-oriented control loop is a current loop used to control the motor; controlling the field-oriented control loop according to a preset quadrature-axis current to acquire the three-phase current of the motor; determining a quadrature-axis feedback current based on the three-phase current and the detection electrical angle, wherein the quadrature-axis feedback current is a feedback current of the three-phase current in the quadrature-axis direction; and determining a phase loss detection result of the motor based on the preset quadrature-axis current and the quadrature-axis feedback current.

[0008] Optionally, the phase loss detection result of the motor is determined based on the preset quadrature-axis current and the quadrature-axis feedback current, including: determining that the motor has a phase loss fault when the current difference is greater than or equal to a preset difference, wherein the current difference is the absolute value of a first difference, and the first difference is the difference between the preset quadrature-axis current and the quadrature-axis feedback current; and determining that the motor has not experienced the phase loss fault when the current difference is less than the preset difference.

[0009] Optionally, before determining that the motor has a phase loss fault when the current difference is greater than or equal to a preset difference, the phase loss detection method further includes: determining the preset difference as the product of the preset quadrature axis current and the first preset constant.

[0010] Optionally, obtaining the current electrical angle of the motor and determining the detection electrical angle based on the current electrical angle includes: obtaining the current electrical angle of the motor; and determining the difference between the current electrical angle and a preset electrical angle as the detection electrical angle.

[0011] Optionally, determining the quadrature-axis feedback current based on the three-phase current and the detected electrical angle includes: determining a first stationary-axis current and a second stationary-axis current based on the three-phase current, wherein the first stationary-axis current is the current component of the three-phase current on the first coordinate axis of the two-phase stationary coordinate system, and the second stationary-axis current is the current component of the three-phase current on the second coordinate axis of the two-phase stationary coordinate system; and determining the quadrature-axis feedback current based on the detected electrical angle, the first stationary-axis current, and the second stationary-axis current.

[0012] Optionally, the three-phase current includes a first-phase current, a second-phase current, and a third-phase current. Determining the first stationary axis current and the second stationary axis current based on the three-phase current includes: determining a second product as the product of the second-phase current and a second preset constant; determining a third product as the product of the third-phase current and the second preset constant; determining a third difference as the difference between the first-phase current and the second product; determining a fourth difference as the difference between the third difference and the third product; determining the first stationary axis current as the product of the fourth difference and the third preset constant, wherein the third preset constant is greater than the second preset constant; determining a fourth product as the product of the second-phase current and the fourth preset constant, wherein the fourth preset constant is greater than the third preset constant; determining a fifth product as the product of the third-phase current and the fourth preset constant; determining a fifth difference as the difference between the fourth product and the fifth product; and determining the second stationary axis current as the product of the fifth difference and the third preset constant.

[0013] Optionally, after determining the phase loss detection result of the motor based on the preset quadrature axis current and the quadrature axis feedback current, the phase loss detection method further includes: generating an alarm message to indicate that the motor has a phase loss fault if it is determined that the motor has a phase loss fault; and controlling the motor to enter the operating mode if it is determined that the motor has not a phase loss fault.

[0014] According to another aspect of this application, a servo driver is provided, comprising: a response unit, configured to acquire the current electrical angle of the motor based on a phase loss detection command before the motor enters an operating mode, and determine a detection electrical angle based on the current electrical angle, wherein the detection electrical angle is an angle parameter for coordinate transformation in a field-oriented control loop, and the field-oriented control loop is a current loop for controlling the motor; a control unit, configured to control the field-oriented control loop based on a preset quadrature-axis current to acquire the three-phase current of the motor; a first determining unit, configured to determine a quadrature-axis feedback current based on the three-phase current and the detection electrical angle, wherein the quadrature-axis feedback current is a feedback current of the three-phase current in the quadrature-axis direction; and a second determining unit, configured to determine the phase loss detection result of the motor based on the preset quadrature-axis current and the quadrature-axis feedback current.

[0015] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the methods described.

[0016] According to another aspect of this application, a servo system is provided, the servo system including a servo driver and a motor, the servo driver being connected to the motor, the servo driver being used to perform the steps of any of the motor phase loss detection methods described above.

[0017] By applying the technical solution of this application, before the motor enters the operating mode, a detection electrical angle is determined based on the current electrical angle, and this detection electrical angle is used in the coordinate transformation of the field-oriented control loop. This allows the motor to establish the current control reference required for phase loss detection in a non-operating state. Based on this, the field-oriented control loop is controlled by a preset quadrature-axis current, and the three-phase current is obtained to determine the quadrature-axis feedback current. If the three-phase connection of the motor is normal, the quadrature-axis feedback current can match the preset quadrature-axis current; if the motor has a phase loss, the three-phase current cannot be established normally, resulting in a significant deviation between the quadrature-axis feedback current and the preset quadrature-axis current. Therefore, this application can determine whether the motor has a phase loss based on the preset quadrature-axis current and the quadrature-axis feedback current, thereby identifying phase loss faults before the motor enters the operating mode, preventing the robot from starting operation in a phase loss state, and improving the reliability of fault detection before robot operation. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 A schematic flowchart of a phase loss detection method for an electric motor according to an embodiment of this application is shown.

[0020] Figure 2 A schematic diagram of a typical FOC control loop structure provided according to an embodiment of this application is shown;

[0021] Figure 3 A schematic flowchart of another method for detecting a phase loss in a motor according to an embodiment of this application is shown;

[0022] Figure 4 An FOC control logic diagram according to an embodiment of this application is shown;

[0023] Figure 5 A schematic diagram of the structure of a servo driver provided according to an embodiment of this application is shown. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] As described in the background section, existing servo motor phase loss detection methods struggle to identify phase loss faults before operation, causing robots to malfunction. To address these technical problems, embodiments of this application provide a motor phase loss detection method, a servo driver, a computer-readable storage medium, and a servo system.

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] Figure 1 This is a flowchart of a phase loss detection method for a motor according to an embodiment of this application. Figure 1 As shown, the method includes the following steps:

[0030] Step S101: Before the motor enters the operating mode, the current electrical angle of the motor is obtained based on the phase loss detection command, and the detection electrical angle is determined according to the current electrical angle. The detection electrical angle is the angle parameter used for coordinate transformation in the field orientation control loop. The field orientation control loop is the current loop used to control the motor.

[0031] Specifically, the current electrical angle represents the current electrical angle position of the motor rotor, which can be obtained through the motor's encoder. Before the motor enters the operating mode, the controller responds to the phase loss detection command, reads the rotor position information sampled by the encoder, and determines the current electrical angle of the motor based on this rotor position information.

[0032] Step S102: Control the above-mentioned magnetic field orientation control loop according to the preset cross-axis current to obtain the three-phase current of the above-mentioned motor;

[0033] Specifically, the aforementioned preset quadrature-axis current is equivalent to the target quadrature-axis current given during the phase loss detection process, used to enable the field-oriented control loop to perform current control according to this preset quadrature-axis current. During this control process, the motor's three-phase circuit will generate corresponding three-phase currents, so the controller acquires the motor's three-phase currents to subsequently determine whether the motor has a phase loss based on the actual current conditions.

[0034] Step S103: Determine the quadrature axis feedback current based on the three-phase current and the detected electrical angle. The quadrature axis feedback current is the feedback current of the three-phase current in the quadrature axis direction.

[0035] Step S104: Determine the phase loss detection result of the motor based on the preset quadrature shaft current and the quadrature shaft feedback current.

[0036] Specifically, the preset quadrature-axis current is the desired quadrature-axis current generated by the motor during phase loss detection, while the quadrature-axis feedback current reflects the actual quadrature-axis feedback obtained from the three-phase currents of the motor. If the three-phase connection of the motor is normal, there should be a corresponding relationship between the quadrature-axis feedback current and the preset quadrature-axis current; if the motor has a phase loss, the three-phase current cannot be established normally, and the quadrature-axis feedback current will deviate from the preset quadrature-axis current. Therefore, by comparing the relationship between the two, it can be determined whether the motor has experienced a phase loss fault.

[0037] Through the above embodiments, by determining the detection electrical angle based on the current electrical angle before the motor enters the operating mode, and using this detection electrical angle to participate in the coordinate transformation of the field-oriented control loop, the motor can establish the current control reference required for phase loss detection in a state where it is not in formal operation. Based on this, the field-oriented control loop is controlled by a preset quadrature-axis current, and the three-phase current is obtained to determine the quadrature-axis feedback current. If the three-phase connection of the motor is normal, the quadrature-axis feedback current can match the preset quadrature-axis current; if the motor has a phase loss, the three-phase current cannot be established normally, resulting in a significant deviation between the quadrature-axis feedback current and the preset quadrature-axis current. Therefore, this application can determine whether the motor has a phase loss based on the preset quadrature-axis current and the quadrature-axis feedback current, thereby identifying phase loss faults in advance before the motor enters the operating mode, preventing the robot from starting operation in a phase loss state, and improving the reliability of fault detection before robot operation.

[0038] In one optional embodiment, determining the phase loss detection result of the motor based on the preset quadrature-axis current and the quadrature-axis feedback current includes: determining that the motor has a phase loss fault when the current difference is greater than or equal to a preset difference, wherein the current difference is the absolute value of a first difference, and the first difference is the difference between the preset quadrature-axis current and the quadrature-axis feedback current; and determining that the motor has not experienced the phase loss fault when the current difference is less than the preset difference.

[0039] In the above embodiments, by subtracting the preset quadrature-axis current from the quadrature-axis feedback current and taking the absolute value of the difference as the current difference value, the influence of the current deviation direction on the judgment result can be eliminated, allowing the current difference value to directly reflect the degree of deviation between the preset quadrature-axis current and the quadrature-axis feedback current. Through this method, phase loss judgment can be transformed into a deviation comparison between the preset quadrature-axis current and the quadrature-axis feedback current, simplifying the judgment process.

[0040] Specifically, when the current difference is less than the preset difference, it indicates that during the current phase loss detection process, the quadrature-axis feedback current obtained based on the three-phase current can remain within the allowable deviation range from the preset quadrature-axis current. This means that the motor's three-phase circuit can establish current normally, and therefore it can be determined that the motor has not experienced a phase loss fault. When the current difference is greater than or equal to the preset difference, it indicates that the deviation between the quadrature-axis feedback current and the preset quadrature-axis current exceeds the allowable range. This means that there may be a phase loss or current failure in the motor's three-phase circuit, and therefore it can be determined that the motor has experienced a phase loss fault.

[0041] In another alternative, before determining that the motor has a phase loss fault when the current difference is greater than or equal to a preset difference, the phase loss detection method further includes: determining the product of the preset quadrature axis current and the first preset constant as the preset difference.

[0042] In some embodiments, a first preset constant is used to represent the ratio of the allowable current deviation to a preset quadrature-axis current. The first preset constant can be determined based on the motor's current sampling accuracy, the current following error of the field-oriented control loop, the current fluctuation range during the detection process, and the required sensitivity for phase loss detection. Specifically, phase loss detection can be performed under normal three-phase connection conditions of the motor to obtain the normal deviation range between the preset quadrature-axis current and the quadrature-axis feedback current. The first preset constant is then determined based on this normal deviation range, ensuring that the preset difference determined by the first preset constant is greater than the normal deviation range. This avoids misjudging a phase loss fault due to normal current fluctuations.

[0043] For example, the first preset constant can be between 0.01 and 0.02. That is, the preset difference can be between 0.01 and 0.02 times the preset quadrature-axis current. By using this proportional coefficient, the preset difference can be made to change synchronously with the magnitude of the preset quadrature-axis current, thereby matching the phase loss judgment threshold with the magnitude of the detection current and improving the reliability of the phase loss detection results.

[0044] In the above embodiments, since the preset quadrature-axis current used for different motors or under different detection conditions may be different, if a fixed value is used for the preset difference, it may be too sensitive when the preset quadrature-axis current is large, easily misjudging normal current fluctuations as phase loss; when the preset quadrature-axis current is small, it may be too lenient, making phase loss faults difficult to identify. The above method allows for a reasonable range to be reserved for current control errors and sampling fluctuations, avoiding an excessively large judgment threshold that would reduce the sensitivity of phase loss detection. Therefore, this scheme can match the phase loss judgment threshold with the current given level during detection, improving the consistency and reliability of phase loss judgment under different detection current conditions, and reducing the risk of misjudgment or missed judgment due to unreasonable fixed threshold settings.

[0045] In some exemplary embodiments, obtaining the current electrical angle of the motor and determining the detection electrical angle based on the current electrical angle includes: obtaining the current electrical angle of the motor; and determining the difference between the current electrical angle and a preset electrical angle as the detection electrical angle.

[0046] In the above embodiments, by acquiring the current electrical angle of the motor and determining the difference between the current electrical angle and the preset electrical angle as the detection electrical angle, the detection electrical angle can be determined based on the current electrical angle position of the motor. Since the detection electrical angle is used for coordinate transformation in the field-oriented control loop, the above method can provide clear angle parameters for subsequent coordinate transformations. Simultaneously, the detection electrical angle is obtained by subtracting the preset electrical angle from the current electrical angle. Therefore, the coordinate transformation angle used for phase loss detection can be adjusted according to the preset electrical angle, so that a preset angle difference is formed between the coordinate transformation angle during phase loss detection and the current electrical angle of the motor. This provides an angle basis for subsequently determining the quadrature-axis feedback current based on the three-phase current and the detection electrical angle.

[0047] In some embodiments, the preset electrical angle can be pre-set according to the coordinate transformation angle offset required by the magnetic field orientation control loop during phase loss detection. Specifically, the preset electrical angle is used to make the detection electrical angle form a predetermined angle difference with the current electrical angle, so that the subsequent coordinate transformation can be performed according to the angle parameters required for phase loss detection.

[0048] In one specific implementation, the preset electrical angle can be 90 degrees. That is, after obtaining the current electrical angle of the motor, 90 degrees is subtracted from the current electrical angle to obtain the detected electrical angle. Thus, the detected electrical angle lags behind the current electrical angle by 90 degrees, and this detected electrical angle is used as the angle parameter for coordinate transformation in the field-oriented control loop.

[0049] In other exemplary embodiments, determining the quadrature-axis feedback current based on the three-phase current and the detected electrical angle includes: determining a first stationary axis current and a second stationary axis current based on the three-phase current, wherein the first stationary axis current is the current component of the three-phase current on the first coordinate axis of the two-phase stationary coordinate system, and the second stationary axis current is the current component of the three-phase current on the second coordinate axis of the two-phase stationary coordinate system; and determining the quadrature-axis feedback current based on the detected electrical angle, the first stationary axis current, and the second stationary axis current.

[0050] In the above embodiments, the first stationary axis current and the second stationary axis current are first determined based on the three-phase currents, thereby converting the three-phase currents of the motor into a current representation in a two-phase stationary coordinate system. Further, the quadrature axis feedback current is determined based on the detected electrical angle, the first stationary axis current, and the second stationary axis current, ensuring that the quadrature axis feedback current is related not only to the actual three-phase currents collected by the motor but also to the detected electrical angle used in the phase loss detection process. This allows for the acquisition of the feedback current of the three-phase current in the quadrature axis direction, providing a basis for subsequent comparison of the quadrature axis feedback current with the preset quadrature axis current.

[0051] In some embodiments, the three-phase current includes a first-phase current, a second-phase current, and a third-phase current. Determining the first stationary axis current and the second stationary axis current based on the three-phase current includes: determining a second product as the product of the second-phase current and a second preset constant; determining a third product as the product of the third-phase current and the second preset constant; determining a third difference as the difference between the first-phase current and the second product; determining a fourth difference as the difference between the third difference and the third product; determining the first stationary axis current as the product of the fourth difference and the third preset constant, wherein the third preset constant is greater than the second preset constant; determining a fourth product as the product of the second-phase current and the fourth preset constant, wherein the fourth preset constant is greater than the third preset constant; determining a fifth product as the product of the third-phase current and the fourth preset constant; determining a fifth difference as the difference between the fourth product and the fifth product; and determining the second stationary axis current as the product of the fifth difference and the third preset constant.

[0052] In the above embodiments, the three-phase currents are weighted using a second, third, and fourth preset constant, and the first and second stationary axis currents are calculated by combining the difference. This clarifies the conversion method from three-phase currents to two-phase stationary coordinate system currents. Consequently, an intermediate current quantity can be obtained for subsequent determination of the quadrature axis feedback current, providing a clear data source and calculation basis for the quadrature axis feedback current calculation process, thereby improving the certainty of the phase loss detection results.

[0053] For example, the three-phase currents mentioned above include a first-phase current, a second-phase current, and a third-phase current, denoted as Ia, Ib, and Ic. After acquiring the three-phase currents, the controller can determine the first stationary axis current and the second stationary axis current in the two-phase stationary coordinate system based on the first-phase current, the second-phase current, and the third-phase current.

[0054] Specifically, the second preset constant can be 1 / 2, the third preset constant can be 2 / 3, and the fourth preset constant can be... / 2. First, determine the product of the second-phase current Ib and 1 / 2, and then determine the product of the third-phase current Ic and 1 / 2; then, subtract the above two products from the first-phase current Ia in sequence to obtain the fourth difference; then multiply this fourth difference by 2 / 3 to obtain the first stationary axis current. That is to say, the first stationary axis current Iα can be expressed as: Iα = 2 / 3 × (Ia - 1 / 2Ib - 1 / 2Ic); further, the controller determines the product of the second-phase current Ib and 1 / 2Ic. The product of / 2, and determine the third phase current Ic with The product of 2 / 2; then, the difference between the two products is the fifth difference; then, the fifth difference is multiplied by 2 / 3 to obtain the second stationary axis current. That is, the second stationary axis current Iβ can be expressed as: Iβ = 2 / 3 × ( / 2Ib- / 2Ic).

[0055] Using the above method, the first-phase current, second-phase current, and third-phase current can be converted into the first stationary axis current and the second stationary axis current in a two-phase stationary coordinate system. Then, the quadrature-axis feedback current can be determined based on the detected electrical angle, the first stationary axis current, and the second stationary axis current.

[0056] Specifically, the process of determining the quadrature-axis feedback current based on the detected electrical angle, the first stationary axis current, and the second stationary axis current includes: after obtaining the first and second stationary axis currents, converting them into current components in a two-phase rotating coordinate system based on the detected electrical angle to determine the quadrature-axis feedback current. Specifically, the detected electrical angle is denoted as θd, the first stationary axis current as Iα, and the second stationary axis current as Iβ. The controller can determine the quadrature-axis feedback current Iq according to the following relationship: Iq = -Iαsinθd + Iβcosθd, where Iq is the quadrature-axis feedback current. In some embodiments, the direct-axis feedback current Id = Iαcosθd + Iβsinθd, thus the controller can convert the first and second stationary axis currents in the two-phase stationary coordinate system into direct-axis and quadrature-axis feedback currents in the two-phase rotating coordinate system. The quadrature-axis feedback current is used for subsequent comparison with a preset quadrature-axis current to determine the motor's phase loss detection result.

[0057] In some exemplary embodiments, after determining the phase loss detection result of the motor based on the preset cross-axis current and the cross-axis feedback current, the phase loss detection method further includes: generating an alarm message to indicate that the motor has a phase loss fault when it is determined that the motor has a phase loss fault; and controlling the motor to enter the operating mode when it is determined that the motor has not a phase loss fault.

[0058] In the above embodiments, when a phase loss fault is detected in the motor, an alarm message is generated to promptly alert the user or maintenance personnel to the presence of the fault. This allows them to inspect the motor wiring, drive circuit, or related components before the motor enters the operating mode, preventing the motor from continuing to start and run in a phase loss state. If no phase loss fault is detected, controlling the motor to enter the operating mode ensures that the motor enters normal operation only after passing the phase loss detection. Therefore, the phase loss detection result can be combined with subsequent motor operation control, preventing the motor from entering the operating mode before the fault is resolved, while ensuring that subsequent motor startup and operation are not affected when the detection is normal. Through this method, fault indication and operation control can be completed before the motor enters the operating mode, improving the utilization of phase loss detection results before motor startup and reducing the risk of abnormal motor operation due to phase loss faults.

[0059] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the motor phase loss detection method of this application will be described in detail below with reference to specific embodiments.

[0060] In some embodiments, the phase loss detection method provided in this application can be applied to an FOC (Field-Oriented Control) loop. The FOC control loop can be used for closed-loop current control of a servo motor. For example... Figure 2 As shown, a typical FOC control loop may include a speed regulator, a current regulator, a dq-αβ coordinate transformation module, an SVPWM (Space Vector Pulse Width Modulation) module, an inverter drive module, a motor, an abc-αβ coordinate transformation module, and an αβ-dq coordinate transformation module. The inverter drive module may include power switching devices such as IGBTs. During normal operation, the FOC control loop can form a dual closed-loop control structure of a speed loop and a current loop. The speed loop generates the desired q-axis current based on the deviation between the desired speed and the speed feedback; the current loop performs closed-loop current control based on the desired q-axis current, the desired d-axis current, and the corresponding current feedback. Specifically, the difference between the desired q-axis current and the q-axis current feedback is used to generate a q-axis voltage command via the current regulator; the difference between the desired d-axis current and the d-axis current feedback is used to generate a d-axis voltage command via the current regulator. The aforementioned q-axis voltage command and d-axis voltage command are transformed into voltage control quantities in the αβ coordinate system via dq-αβ coordinate transformation, and then used by the SVPWM module to generate the switching control signal for the inverter drive module. The inverter drive module outputs three-phase current according to the aforementioned switch control signal to drive the motor. During motor operation, the three-phase currents Ia, Ib, and Ic of the motor can be acquired, and an abc-αβ coordinate transformation is performed on the three-phase currents Ia, Ib, and Ic to obtain the current components in the αβ coordinate system. Then, combined with the electrical angle θ obtained from the motor sensor sampling, an αβ-dq coordinate transformation is performed on the current components in the αβ coordinate system to obtain the q-axis current feedback and d-axis current feedback. The aforementioned q-axis current feedback and d-axis current feedback are used as feedback quantities in the current loop, and compared with the corresponding desired current to complete the current closed-loop control. The electrical angle θ can be obtained by sampling from the encoder or other position detection components at the motor end, and used as the angle parameters for the αβ-dq coordinate transformation and the dq-αβ coordinate transformation. Through the above process, the FOC control loop can convert the three-phase current control of the motor into current control in the d-axis and q-axis directions, thereby realizing vector control of the servo motor. It should be noted that the q-axis in this application is the quadrature axis in field-oriented control.

[0061] This embodiment relates to a specific method for detecting phase loss in a motor, such as... Figure 3 As shown, it includes the following steps:

[0062] Step S1: With the phase loss detection function enabled, inject the desired q-axis current into the magnetic field orientation control loop and redetermine the electrical angle used for coordinate transformation.

[0063] The q-axis mentioned above is the intersection axis in field-oriented control. For example... Figure 4 As shown, Figure 4 This paper illustrates an FOC (Field-Oriented Control) control logic diagram for injecting q-axis current and a custom electrical angle θ, according to an embodiment of this application. When the phase loss detection function is enabled, the program controls the FOC current loop to enter the phase loss detection logic. At this time, the desired q-axis current is no longer output by the speed regulator, but is set by the program. In one specific embodiment, the magnitude of the desired q-axis current can be set to the rated current on the motor nameplate. This allows the current loop to generate a current response for detecting phase loss while avoiding excessive injected current that could affect motor safety. Simultaneously, the program reads the current electrical angle θ sampled by the servo motor encoder. The electrical angle θ sampled by the encoder is delayed by 90 degrees to obtain the adjusted electrical angle θ-90°, which is then used as the input angle for subsequent coordinate transformations. During the phase loss detection process, this adjusted electrical angle remains unchanged. That is, the phase loss detection is not controlled according to the real-time changing electrical angle during normal motor rotation, but rather a fixed detection electrical angle is determined at the start of detection, allowing the motor to perform phase loss detection while remaining stationary.

[0064] Step S2: During the injection of the desired q-axis current, the three-phase current is collected and q-axis current feedback is generated;

[0065] Specifically, after injecting the desired q-axis current into the current loop, the driver outputs the corresponding three-phase current according to the control logic of the FOC current loop. At this time, the program collects the three-phase currents Ia, Ib, and Ic of the motor. After collecting the three-phase current, the three-phase currents Ia, Ib, and Ic are first transformed into abc-αβ coordinates to obtain the α-axis current and β-axis current. That is, the actual three-phase current collected by the motor is converted into current in a two-phase stationary coordinate system. Then, using the adjusted electrical angle θ-90° obtained in step S1, the α-axis current and β-axis current are transformed into αβ-dq coordinates to obtain the d-axis current feedback and q-axis current feedback. Among them, this scheme mainly uses the q-axis current feedback for phase loss judgment. The q-axis current feedback can be understood as: the feedback current obtained in the q-axis direction after the actual three-phase current of the motor is transformed into coordinates. This q-axis current feedback is used to reflect the actual current feedback of the motor after the current desired q-axis current is injected. The transformation matrices of αβ-dq coordinate change and dq-αβ coordinate change are shown in formulas (1) and (2), respectively:

[0066] (1)

[0067] (2)

[0068] Step S3: Compare the expected q-axis current with the q-axis current feedback, and determine whether there is a phase loss based on the deviation between the two.

[0069] Specifically, the difference between the expected q-axis current and the q-axis current feedback is calculated, and the absolute value of this difference is taken. Then, this absolute value is compared with a preset threshold. In one specific implementation, the preset threshold can be set to 0.01 times the magnitude of the expected q-axis current. If the absolute value of the difference between the expected q-axis current and the q-axis current feedback is less than the preset threshold, it is considered that the q-axis current feedback can follow the expected q-axis current, indicating that the three-phase current of the motor can be established normally. At this time, it is determined that the servo motor has not experienced a phase loss fault, the phase loss detection is passed, and the motor can enter normal servo operation mode. If the absolute value of the difference between the expected q-axis current and the q-axis current feedback is greater than the preset threshold, it indicates that the actual feedback current deviates significantly from the set expected q-axis current, and the three-phase current of the motor has failed to be established as expected. At this time, it is determined that the servo motor has experienced a phase loss fault.

[0070] Through the above steps, phase loss detection can be completed without the motor actually rotating. In other words, this solution determines whether the motor has a phase loss fault by injecting the desired q-axis current, fixing the adjusted electrical angle, and detecting the q-axis current feedback before the servo motor is officially running, thereby preventing the motor from entering normal operation mode in a phase loss state.

[0071] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0072] This application also provides a servo driver. It should be noted that the servo driver in this application embodiment can be used to execute the motor phase loss detection method provided in this application embodiment. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0073] The following describes the servo driver provided in the embodiments of this application.

[0074] Figure 5 This is a schematic diagram of a servo driver according to an embodiment of this application. Figure 5 As shown, the servo driver includes:

[0075] The response unit 10 is used to obtain the current electrical angle of the motor based on the phase loss detection command before the motor enters the operating mode, and to determine the detection electrical angle based on the current electrical angle. The detection electrical angle is an angle parameter used for coordinate transformation in the field orientation control loop. The field orientation control loop is a current loop used to control the motor.

[0076] The first control unit 20 is used to control the above-mentioned field orientation control loop according to the preset cross-axis current in order to obtain the three-phase current of the above-mentioned motor;

[0077] The first determining unit 30 is used to determine the quadrature axis feedback current based on the three-phase current and the detected electrical angle, wherein the quadrature axis feedback current is the feedback current of the three-phase current in the quadrature axis direction.

[0078] The second determining unit 40 is used to determine the phase loss detection result of the motor based on the preset cross-axis current and the cross-axis feedback current.

[0079] In the aforementioned servo driver, the response unit can acquire the current electrical angle before the motor enters the operating mode and determine the detection electrical angle based on the current electrical angle, enabling phase loss detection to establish an angular basis for coordinate transformation before the motor officially starts running. The control unit controls the field-oriented control loop based on the preset quadrature-axis current and acquires the three-phase current of the motor, allowing the motor to generate current feedback data for phase loss judgment before entering the operating mode. The first determining unit determines the quadrature-axis feedback current based on the three-phase current and the detection electrical angle, enabling the three-phase current to be converted into feedback current in the quadrature-axis direction. The second determining unit then determines the phase loss detection result of the motor based on the preset quadrature-axis current and the quadrature-axis feedback current. Thus, this servo driver can complete phase loss detection before the motor enters the operating mode, without waiting for the motor to start to determine whether there is a phase loss. It can identify the motor phase loss fault in advance, reducing the risk of the motor entering the operating mode with a fault, thereby improving the reliability of the servo system's pre-start detection.

[0080] As an optional solution, the second determining unit includes: a first determining module, used to determine that the motor has a phase loss fault when the current difference is greater than or equal to a preset difference, wherein the current difference is the absolute value of a first difference, and the first difference is the difference between the preset quadrature axis current and the quadrature axis feedback current; and a second determining module, used to determine that the motor has not experienced the phase loss fault when the current difference is less than the preset difference.

[0081] In an optional embodiment, the second determining unit further includes a third determining module, used to determine the product of the preset quadrature axis current and the first preset constant as the preset difference.

[0082] In another alternative embodiment, the response unit includes: an acquisition module for acquiring the current electrical angle of the motor; and a fourth determination module for determining the difference between the current electrical angle and a preset electrical angle as the detected electrical angle.

[0083] In some exemplary embodiments, the first determining unit includes: a fifth determining module, configured to determine a first stationary axis current and a second stationary axis current based on the three-phase currents, wherein the first stationary axis current is the current component of the three-phase current on the first coordinate axis of the two-phase stationary coordinate system, and the second stationary axis current is the current component of the three-phase current on the second coordinate axis of the two-phase stationary coordinate system; and a sixth determining module, configured to determine the cross-axis feedback current based on the detected electrical angle, the first stationary axis current, and the second stationary axis current.

[0084] In some other exemplary embodiments, the fifth determining module includes: a first determining submodule, configured to determine that the second product is the product of the second phase current and a second preset constant; a second determining submodule, configured to determine that the third product is the product of the third phase current and the second preset constant; a third determining submodule, configured to determine that the third difference is the difference between the first phase current and the second product; a fourth determining submodule, configured to determine that the fourth difference is the difference between the third difference and the third product; a fifth determining submodule, configured to determine that the first stationary axis current is the product of the fourth difference and the third preset constant, wherein the third preset constant is greater than the second preset constant; a sixth determining submodule, configured to determine that the fourth product is the product of the second phase current and the fourth preset constant, wherein the fourth preset constant is greater than the third preset constant; a seventh determining submodule, configured to determine that the fifth product is the product of the third phase current and the fourth preset constant; an eighth determining submodule, configured to determine that the fifth difference is the difference between the fourth product and the fifth product; and a ninth determining submodule, configured to determine that the second stationary axis current is the product of the fifth difference and the third preset constant.

[0085] In one alternative embodiment, the servo driver further includes: a generation unit, configured to generate alarm information to indicate the presence of a phase loss fault in the motor when it is determined that a phase loss fault has occurred in the motor; and a second control unit, configured to control the motor to enter the operating mode when it is determined that no phase loss fault has occurred in the motor.

[0086] The aforementioned Z device includes a processor and a memory. The aforementioned response unit, the aforementioned first control unit, the aforementioned first determining unit, and the aforementioned second determining unit are all stored as program units in the memory. The processor executes the aforementioned program units stored in the memory to implement the corresponding functions. All of the aforementioned modules are located in the same processor; or, the aforementioned modules are located in different processors in any combination.

[0087] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and adjusting kernel parameters can at least address the problem that existing servo motor phase loss detection systems struggle to pre-identify phase loss faults before operation, leading to robot malfunctions.

[0088] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0089] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the motor phase loss detection method.

[0090] Specifically, the methods for detecting phase loss in a motor include:

[0091] Step S101: Before the motor enters the operating mode, the current electrical angle of the motor is obtained based on the phase loss detection command, and the detection electrical angle is determined according to the current electrical angle. The detection electrical angle is the angle parameter used for coordinate transformation in the field orientation control loop. The field orientation control loop is the current loop used to control the motor.

[0092] Specifically, the current electrical angle represents the current electrical angle position of the motor rotor, which can be obtained through the motor's encoder. Before the motor enters the operating mode, the controller responds to the phase loss detection command, reads the rotor position information sampled by the encoder, and determines the current electrical angle of the motor based on this rotor position information.

[0093] Step S102: Control the above-mentioned magnetic field orientation control loop according to the preset cross-axis current to obtain the three-phase current of the above-mentioned motor;

[0094] Specifically, the aforementioned preset quadrature-axis current is equivalent to the target quadrature-axis current given during the phase loss detection process, used to enable the field-oriented control loop to perform current control according to this preset quadrature-axis current. During this control process, the motor's three-phase circuit will generate corresponding three-phase currents, so the controller acquires the motor's three-phase currents to subsequently determine whether the motor has a phase loss based on the actual current conditions.

[0095] Step S103: Determine the quadrature axis feedback current based on the three-phase current and the detected electrical angle. The quadrature axis feedback current is the feedback current of the three-phase current in the quadrature axis direction.

[0096] Step S104: Determine the phase loss detection result of the motor based on the preset quadrature shaft current and the quadrature shaft feedback current.

[0097] Specifically, the preset quadrature-axis current is the desired quadrature-axis current generated by the motor during phase loss detection, while the quadrature-axis feedback current reflects the actual quadrature-axis feedback obtained from the three-phase currents of the motor. If the three-phase connection of the motor is normal, there should be a corresponding relationship between the quadrature-axis feedback current and the preset quadrature-axis current; if the motor has a phase loss, the three-phase current cannot be established normally, and the quadrature-axis feedback current will deviate from the preset quadrature-axis current. Therefore, by comparing the relationship between the two, it can be determined whether the motor has experienced a phase loss fault.

[0098] Optionally, the phase loss detection result of the motor is determined based on the preset quadrature-axis current and the quadrature-axis feedback current, including: if the current difference is greater than or equal to the preset difference, the motor is determined to have a phase loss fault, wherein the current difference is the absolute value of the first difference, and the first difference is the difference between the preset quadrature-axis current and the quadrature-axis feedback current; if the current difference is less than the preset difference, the motor is determined not to have a phase loss fault.

[0099] Optionally, before determining that the motor has a phase loss fault when the current difference is greater than or equal to a preset difference, the phase loss detection method further includes: determining the product of the preset quadrature axis current and the first preset constant as the preset difference.

[0100] Optionally, obtaining the current electrical angle of the motor and determining the detection electrical angle based on the current electrical angle includes: obtaining the current electrical angle of the motor; and determining the difference between the current electrical angle and a preset electrical angle as the detection electrical angle.

[0101] Optionally, determining the quadrature-axis feedback current based on the three-phase current and the detected electrical angle includes: determining a first stationary axis current and a second stationary axis current based on the three-phase current, wherein the first stationary axis current is the current component of the three-phase current on the first coordinate axis of the two-phase stationary coordinate system, and the second stationary axis current is the current component of the three-phase current on the second coordinate axis of the two-phase stationary coordinate system; and determining the quadrature-axis feedback current based on the detected electrical angle, the first stationary axis current, and the second stationary axis current.

[0102] Optionally, the three-phase currents include a first-phase current, a second-phase current, and a third-phase current. Determining the first stationary axis current and the second stationary axis current based on the three-phase currents includes: determining a second product as the product of the second-phase current and a second preset constant; determining a third product as the product of the third-phase current and the second preset constant; determining a third difference as the difference between the first-phase current and the second product; determining a fourth difference as the difference between the third difference and the third product; determining the first stationary axis current as the product of the fourth difference and the third preset constant, wherein the third preset constant is greater than the second preset constant; determining a fourth product as the product of the second-phase current and the fourth preset constant, wherein the fourth preset constant is greater than the third preset constant; determining a fifth product as the product of the third-phase current and the fourth preset constant; determining a fifth difference as the difference between the fourth product and the fifth product; and determining the second stationary axis current as the product of the fifth difference and the third preset constant.

[0103] Optionally, after determining the phase loss detection result of the motor based on the preset quadrature shaft current and the quadrature shaft feedback current, the phase loss detection method further includes: generating an alarm message to indicate that the motor has a phase loss fault when it is determined that the motor has a phase loss fault; and controlling the motor to enter the operating mode when it is determined that the motor has not a phase loss fault.

[0104] This invention provides a servo system, including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps: Step S101, before the motor enters the operating mode, the current electrical angle of the motor is obtained based on a phase loss detection instruction, and a detection electrical angle is determined based on the current electrical angle. The detection electrical angle is an angle parameter used for coordinate transformation in the field orientation control loop, and the field orientation control loop is a current loop used to control the motor.

[0105] Specifically, the current electrical angle represents the current electrical angle position of the motor rotor, which can be obtained through the motor's encoder. Before the motor enters the operating mode, the controller responds to the phase loss detection command, reads the rotor position information sampled by the encoder, and determines the current electrical angle of the motor based on this rotor position information.

[0106] Step S102: Control the above-mentioned magnetic field orientation control loop according to the preset cross-axis current to obtain the three-phase current of the above-mentioned motor;

[0107] Specifically, the aforementioned preset quadrature-axis current is equivalent to the target quadrature-axis current given during the phase loss detection process, used to enable the field-oriented control loop to perform current control according to this preset quadrature-axis current. During this control process, the motor's three-phase circuit will generate corresponding three-phase currents, so the controller acquires the motor's three-phase currents to subsequently determine whether the motor has a phase loss based on the actual current conditions.

[0108] Step S103: Determine the quadrature axis feedback current based on the three-phase current and the detected electrical angle. The quadrature axis feedback current is the feedback current of the three-phase current in the quadrature axis direction.

[0109] Step S104: Determine the phase loss detection result of the motor based on the preset quadrature shaft current and the quadrature shaft feedback current.

[0110] Specifically, the preset quadrature-axis current is the desired quadrature-axis current generated by the motor during phase loss detection, while the quadrature-axis feedback current reflects the actual quadrature-axis feedback obtained from the three-phase currents of the motor. If the three-phase connection of the motor is normal, there should be a corresponding relationship between the quadrature-axis feedback current and the preset quadrature-axis current; if the motor has a phase loss, the three-phase current cannot be established normally, and the quadrature-axis feedback current will deviate from the preset quadrature-axis current. Therefore, by comparing the relationship between the two, it can be determined whether the motor has experienced a phase loss fault.

[0111] Optionally, the phase loss detection result of the motor is determined based on the preset quadrature-axis current and the quadrature-axis feedback current, including: if the current difference is greater than or equal to the preset difference, the motor is determined to have a phase loss fault, wherein the current difference is the absolute value of the first difference, and the first difference is the difference between the preset quadrature-axis current and the quadrature-axis feedback current; if the current difference is less than the preset difference, the motor is determined not to have a phase loss fault.

[0112] Optionally, before determining that the motor has a phase loss fault when the current difference is greater than or equal to a preset difference, the phase loss detection method further includes: determining the product of the preset quadrature axis current and the first preset constant as the preset difference.

[0113] Optionally, obtaining the current electrical angle of the motor and determining the detection electrical angle based on the current electrical angle includes: obtaining the current electrical angle of the motor; and determining the difference between the current electrical angle and a preset electrical angle as the detection electrical angle.

[0114] Optionally, determining the quadrature-axis feedback current based on the three-phase current and the detected electrical angle includes: determining a first stationary axis current and a second stationary axis current based on the three-phase current, wherein the first stationary axis current is the current component of the three-phase current on the first coordinate axis of the two-phase stationary coordinate system, and the second stationary axis current is the current component of the three-phase current on the second coordinate axis of the two-phase stationary coordinate system; and determining the quadrature-axis feedback current based on the detected electrical angle, the first stationary axis current, and the second stationary axis current.

[0115] Optionally, the three-phase currents include a first-phase current, a second-phase current, and a third-phase current. Determining the first stationary axis current and the second stationary axis current based on the three-phase currents includes: determining a second product as the product of the second-phase current and a second preset constant; determining a third product as the product of the third-phase current and the second preset constant; determining a third difference as the difference between the first-phase current and the second product; determining a fourth difference as the difference between the third difference and the third product; determining the first stationary axis current as the product of the fourth difference and the third preset constant, wherein the third preset constant is greater than the second preset constant; determining a fourth product as the product of the second-phase current and the fourth preset constant, wherein the fourth preset constant is greater than the third preset constant; determining a fifth product as the product of the third-phase current and the fourth preset constant; determining a fifth difference as the difference between the fourth product and the fifth product; and determining the second stationary axis current as the product of the fifth difference and the third preset constant.

[0116] Optionally, after determining the phase loss detection result of the motor based on the preset quadrature shaft current and the quadrature shaft feedback current, the phase loss detection method further includes: generating an alarm message to indicate that the motor has a phase loss fault when it is determined that the motor has a phase loss fault; and controlling the motor to enter the operating mode when it is determined that the motor has not a phase loss fault.

[0117] The devices mentioned in this article can be servers, PCs, tablets, mobile phones, etc.

[0118] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0119] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0120] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0121] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0122] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0123] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0124] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0125] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0126] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0127] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0128] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0129] 1) The motor phase loss detection method of this application determines the detection electrical angle based on the current electrical angle before the motor enters the operating mode, and uses this detection electrical angle to participate in the coordinate transformation of the field-oriented control loop, enabling the motor to establish the current control benchmark required for phase loss detection in a non-operating state. Based on this, the field-oriented control loop is controlled by a preset quadrature-axis current, and the three-phase current is obtained to determine the quadrature-axis feedback current. If the three-phase connection of the motor is normal, the quadrature-axis feedback current can match the preset quadrature-axis current; if the motor has a phase loss, the three-phase current cannot be established normally, resulting in a significant deviation between the quadrature-axis feedback current and the preset quadrature-axis current. Therefore, this application can determine whether the motor has a phase loss based on the preset quadrature-axis current and the quadrature-axis feedback current, thereby identifying phase loss faults before the motor enters the operating mode, preventing the robot from starting operation in a phase loss state, and improving the reliability of fault detection before robot operation.

[0130] 2) The servo driver of this application has a response unit that can acquire the current electrical angle before the motor enters the operating mode and determine the detection electrical angle based on the current electrical angle, so that the phase loss detection can establish an angular basis for coordinate transformation before the motor officially starts running. The control unit controls the field-oriented control loop according to the preset quadrature-axis current and acquires the three-phase current of the motor, so that the current feedback data for phase loss judgment can be formed before the motor enters the operating mode. The first determining unit determines the quadrature-axis feedback current based on the three-phase current and the detection electrical angle, so that the three-phase current can be converted into feedback current in the quadrature-axis direction. The second determining unit then determines the phase loss detection result of the motor according to the preset quadrature-axis current and the quadrature-axis feedback current. Therefore, the servo driver can complete the phase loss detection before the motor enters the operating mode, without waiting for the motor to start running to determine whether there is a phase loss. It can identify the motor phase loss fault in advance, reduce the risk of the motor entering the operating mode with a fault, and thus improve the reliability of the servo system's pre-start detection.

[0131] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of open-phase detection of an electric machine, characterized in that, include: Before the motor enters the operating mode, the current electrical angle of the motor is obtained based on the phase loss detection command, and the detection electrical angle is determined according to the current electrical angle. The detection electrical angle is an angle parameter used for coordinate transformation in the field orientation control loop, and the field orientation control loop is a current loop used to control the motor. The magnetic field orientation control loop is controlled according to a preset cross-axis current to obtain the three-phase current of the motor; The quadrature-axis feedback current is determined based on the three-phase current and the detected electrical angle, and the quadrature-axis feedback current is the feedback current of the three-phase current in the quadrature-axis direction; The phase loss detection result of the motor is determined based on the preset quadrature axis current and the quadrature axis feedback current.

2. The phase deficiency detection method according to claim 1, characterized by, The phase loss detection result of the motor is determined based on the preset quadrature-axis current and the quadrature-axis feedback current, including: If the current difference is greater than or equal to a preset difference, it is determined that the motor has a phase loss fault, wherein the current difference is the absolute value of a first difference, and the first difference is the difference between the preset quadrature axis current and the quadrature axis feedback current; If the current difference is less than the preset difference, it is determined that the motor has not experienced the phase loss fault.

3. The phase deficiency detection method according to claim 2, characterized by, Before determining that the motor has experienced a phase loss fault when the current difference is greater than or equal to a preset difference, the phase loss detection method further includes: The product of the preset quadrature current and the first preset constant is determined as the preset difference.

4. The phase deficiency detection method of claim 1, wherein The process includes obtaining the current electrical angle of the motor based on a phase loss detection command, and determining the detection electrical angle based on the current electrical angle, including: Obtain the current electrical angle of the motor; The difference between the current electrical angle and the preset electrical angle is determined as the detected electrical angle.

5. The phase failure detection method of claim 1, wherein Determining the quadrature-axis feedback current based on the three-phase current and the detected electrical angle includes: The first stationary axis current and the second stationary axis current are determined based on the three-phase current. The first stationary axis current is the current component of the three-phase current on the first coordinate axis of the two-phase stationary coordinate system, and the second stationary axis current is the current component of the three-phase current on the second axis of the two-phase stationary coordinate system. The cross-axis feedback current is determined based on the detected electrical angle, the first stationary axis current, and the second stationary axis current.

6. The phase loss detection method according to claim 5, characterized in that, The three-phase current includes a first-phase current, a second-phase current, and a third-phase current. Determining the first stationary axis current and the second stationary axis current based on the three-phase current includes: The second product is determined to be the product of the second phase current and the second preset constant; The third product is determined to be the product of the third phase current and the second preset constant; The third difference is determined to be the difference between the product of the first phase current and the second phase current; The fourth difference is determined to be the difference between the third difference and the third product; The first stationary axis current is determined to be the product of the fourth difference and the third preset constant, wherein the third preset constant is greater than the second preset constant; The fourth product is determined to be the product of the second phase current and the fourth preset constant, wherein the fourth preset constant is greater than the third preset constant; The fifth product is determined to be the product of the third phase current and the fourth preset constant; The fifth difference is determined to be the difference between the fourth product and the fifth product; The second stationary axis current is determined to be the product of the fifth difference and the third preset constant.

7. The phase loss detection method according to claim 1, characterized in that, After determining the phase loss detection result of the motor based on the preset quadrature-axis current and the quadrature-axis feedback current, the phase loss detection method further includes: If it is determined that the motor has a phase loss fault, an alarm message is generated to indicate that the motor has the phase loss fault; If it is determined that the motor has not experienced the phase loss fault, the motor is controlled to enter the operating mode.

8. A servo driver, characterized in that, include: The response unit is used to obtain the current electrical angle of the motor based on the phase loss detection command before the motor enters the operating mode, and to determine the detection electrical angle based on the current electrical angle. The detection electrical angle is an angle parameter used for coordinate transformation in the field-oriented control loop, and the field-oriented control loop is a current loop used to control the motor. The control unit is used to control the field orientation control loop according to the preset cross-axis current in order to obtain the three-phase current of the motor; The first determining unit is used to determine the quadrature-axis feedback current based on the three-phase current and the detected electrical angle, wherein the quadrature-axis feedback current is the feedback current of the three-phase current in the quadrature-axis direction; The second determining unit is used to determine the phase loss detection result of the motor based on the preset quadrature axis current and the quadrature axis feedback current.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 7.

10. A servo system, characterized in that, The servo system includes a servo driver and a motor, the servo driver being connected to the motor, and the servo driver being used to perform the steps of the motor phase loss detection method as described in any one of claims 1 to 7.

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