Voltage data processing method and device for zero point detection and direct current brushless motor

Abstract

The invention relates to the field of voltage data processing, in particular to a voltage data processing method and device for zero point detection and a direct current brushless motor. The method comprises the following steps: respectively monitoring and acquiring voltage values of U, V and W phases; if the voltage value of one preset period is accumulated in each phase, generating a first change diagram, and calculating a first deviation value according to the generated first change diagram; translating a curve graph in the first change graph to obtain a second change graph, and calculating a second deviation value according to the second change graph; obtaining a preset number of first change diagrams corresponding to the preset periods of which accumulation is completed, and calculating a third deviation value according to the obtained first change diagrams; obtaining a fourth deviation value according to the first deviation value, the second deviation value and the third deviation value; and in the next preset period of the preset period T, correcting the latest acquired voltage values of the three phases according to the fourth deviation value to obtain corrected voltage values of the three phases. According to the invention, the problem of insufficient accuracy of voltage data is solved.

Description

Technical Field

[0001] The present invention relates to the field of voltage data processing, and particularly to a voltage data processing method, device and brushless DC motor for zero point detection. Background Art

[0002] In the field of sensorless control of brushless DC motors (BLDC), zero point detection is an essential technology. The principle is that by precisely capturing the moment when the voltage signal on the motor stator changes from high level to low level, the motor controller can accurately determine the position of the motor rotor, thereby achieving precise control of the motor movement.

[0003] For zero point detection, voltage data needs to be collected for detection. Currently, the adopted method is to perform high-frequency voltage sampling on the three phases of the brushless DC motor through a hardware circuit to obtain the voltage data of the three phases, and then perform software debouncing on the obtained voltage data of the three phases to obtain stable voltage data of the three phases.

[0004] Doing so, since the hardware circuit will interfere with the voltage data during detection or transmission, the voltage data sampled by the hardware circuit itself may have certain errors. The purpose of software debouncing is to remove abnormal data caused by glitches and cannot correct the errors of the voltage data itself. Therefore, there is a problem of insufficient accuracy of the voltage data. Summary of the Invention

[0005] Based on this, it is necessary to provide a voltage data processing method, device and brushless DC motor for zero point detection in view of the above problems.

[0006] The embodiment of the present invention is implemented as follows. A voltage data processing method for zero point detection, the voltage data processing method for zero point detection includes: S101, respectively monitor and obtain the voltage values of three phases U, V, and W; S102, determine whether each phase has accumulated the voltage values of a preset period. If so, generate a first change graph according to the voltage values within the latest completed preset period T; S103, determine the zero crossing points of each phase in the first change graph, and obtain a first deviation value according to the voltage values corresponding to the zero crossing points; S104, translate the curve graph in the first change graph to obtain a second change graph, and obtain a second deviation value according to the voltage values corresponding to each angle of the second change graph; S105, obtain the first change graphs corresponding to a preset number of completed preset periods, and obtain a third deviation value according to the voltage values corresponding to each angle in the obtained first change graphs; S106. Obtain a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; S107. In the next preset period of the preset period T, correct the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases, so as to improve the accuracy of the obtained voltage values; S108. For each completed cumulative preset period, execute S102 - S107 to update the fourth deviation value, thereby correcting the voltage values obtained in the next preset period of the preset period T.

[0007] In one embodiment, the present invention provides a voltage data processing device for zero - point detection, and the voltage data processing device for zero - point detection includes: A monitored voltage module, configured to respectively monitor and obtain the voltage values of three phases U, V, and W; An image generation module, configured to determine whether the voltage values of each phase have been accumulated for a preset period. If so, generate a first change graph according to the voltage values within the latest completed cumulative preset period T; A first deviation module, configured to determine the zero - crossing points of each phase in the first change graph, and obtain the first deviation value according to the voltage values corresponding to the zero - crossing points; A second deviation module, configured to translate the curve graph in the first change graph to obtain a second change graph, and obtain the second deviation value according to the voltage values corresponding to each angle of the second change graph; A third deviation module, configured to obtain the first change graphs corresponding to a preset number of completed cumulative preset periods, and obtain the third deviation value according to the voltage values corresponding to each angle in the obtained first change graphs; A fourth deviation module, configured to obtain a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; A corrected voltage module, configured to, in the next preset period of the preset period T, correct the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases, so as to improve the accuracy of the obtained voltage values.

[0008] In one embodiment, the present invention provides a direct - current brushless motor, and the direct - current brushless motor includes a motor device and a control module for controlling the motor device; The motor device is configured to implement a rotation function to realize the function of the direct - current brushless motor; The control module is configured to execute the steps of the above - mentioned voltage data processing method for zero - point detection.

[0009] A voltage data processing method for zero - point detection provided by an embodiment of the present invention monitors and obtains the voltage values of three phases U, V, and W respectively; determines whether the voltage values of each phase have been accumulated for a preset period. If so, a first change graph is generated according to the voltage values within the latest completed preset period T; the zero - crossing points of each phase are determined in the first change graph, and a first deviation value is obtained according to the voltage values corresponding to the zero - crossing points; the curve graph in the first change graph is translated to obtain a second change graph, and a second deviation value is obtained according to the voltage values corresponding to each angle of the second change graph; a preset number of first change graphs corresponding to the completed preset periods are obtained, and a third deviation value is obtained according to the voltage values corresponding to each angle in the obtained first change graphs; a fourth deviation value is obtained according to the first deviation value, the second deviation value, and the third deviation value; in the next preset period of the preset period T, the latest obtained voltage values of the three phases are corrected according to the fourth deviation value to obtain the corrected voltage values of the three phases, so as to improve the accuracy of the obtained voltage values; for each completed preset period, the above steps are repeated to update the fourth deviation value, thereby correcting the voltage values obtained in the next preset period of the preset period T. By doing so, a first deviation value representing the deviation degree of the total voltage is obtained according to the voltage values of the latest completed preset period T, a second deviation value representing the voltage deviation degree of the phase voltage is obtained, and a third deviation value representing the voltage deviation degree at the same moment within a preset period is obtained according to a preset number of first change graphs corresponding to the completed preset periods, so as to calculate a fourth deviation value representing the correction value. The latest obtained voltage values of the three phases are corrected according to the fourth deviation value, thus correcting the error of the voltage data itself, eliminating the error of the voltage data sampled by the hardware circuit, and solving the problem of insufficient accuracy of the voltage data. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a flowchart of a voltage data processing method for zero - point detection in an embodiment; Figure 2 is the first change graph in an ideal state; Figure 3 is the second change graph in an ideal state; Figure 4 is a structural block diagram of a voltage data processing device for zero - point detection in an embodiment; Figure 5 is an internal structural block diagram of a control module in an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0011] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0012] It is understood that the terms "first", "second", etc. used in the present invention may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of the present invention, the first xx script may be referred to as the second xx script, and similarly, the second xx script may be referred to as the first xx script.

[0013] As Figure 1 shown, in one embodiment, a method for processing voltage data for zero-crossing detection is proposed, which may specifically include the following steps: S101, respectively monitor and obtain the voltage values of three phases U, V, and W; S102, determine whether the voltage values of each phase have been accumulated for a preset period. If so, generate a first variation diagram according to the voltage values within the latest completed preset period T; S103, determine the zero-crossing points of each phase in the first variation diagram, and obtain a first deviation value according to the voltage values corresponding to the zero-crossing points; S104, translate the curve in the first variation diagram to obtain a second variation diagram, and obtain a second deviation value according to the voltage values corresponding to each angle in the second variation diagram; S105, obtain the first variation diagrams corresponding to a preset number of completed preset periods, and obtain a third deviation value according to the voltage values corresponding to each angle in the obtained first variation diagrams; S106, obtain a fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value; S107, in the next preset period of the preset period T, correct the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases so as to improve the accuracy of the obtained voltage values; S108, for each completed preset period, execute S102 - S107 to update the fourth deviation value so as to correct the voltage values obtained in the next preset period of the preset period T.

[0014] In this embodiment, the DC brushless motor has three phases U, V, and W, and a corresponding voltage detection circuit is provided for each phase to monitor and obtain the voltage values of the three phases U, V, and W. Here, the voltage value refers to the back electromotive force. The voltage detection circuit detects the phase voltages of the three phases, and then extracts the back electromotive force from the phase voltages; the extraction method is, for example, to obtain the back electromotive force through the virtual neutral point voltage.

[0015] In this embodiment, the cycle duration of the preset period for each phase is the same, but the starting points of the preset periods for each phase are different. Here, the starting point refers to the starting angle.

[0016] In this embodiment, the preset period T specifically refers to the latest completed cumulative preset period, and the completed cumulative preset periods before the preset period T cannot be represented by the preset period T.

[0017] In this embodiment, the first variation diagram is essentially a curve diagram in which the voltage value changes with the angle. The voltage value here refers to the back electromotive force, and the angle here refers to the electrical angle of the rotor of the DC brushless motor. The electrical angle of the rotor ranges from 0 to 360°. The initial position of the rotor is set to 0. The electrical angle is equal to the mechanical angle multiplied by the number of pole pairs of the DC brushless motor, and the mechanical angle is the physical angle of actual rotation of the motor rotor, which intuitively reflects the spatial position of the rotor.

[0018] In this embodiment, the horizontal axis of the first variation diagram is the angle, and the vertical axis is the voltage. The zero-crossing point here is the point where the voltage value is 0.

[0019] In this embodiment, translating the curve diagram in the first variation diagram only involves translation in the horizontal direction, that is, in the direction of the horizontal axis.

[0020] In this embodiment, the preset quantity can be set to any value between 10 and 100. If the number of completed cumulative preset periods is less than the preset quantity at this time, the number of completed cumulative preset periods can also be temporarily used to replace the preset quantity until the number of completed cumulative preset periods is greater than or equal to the preset quantity.

[0021] In this embodiment, during the cumulative process of the first preset period, there is no third deviation value at this time, and the third deviation value can be regarded as 0 at this time. It is even possible not to correct the voltage values within the previous several preset periods, for example, the previous 10.

[0022] In this embodiment, for example, the latest completed cumulative preset period T is period 1, and the next preset period after the preset period T is period 2. At this time, the fourth deviation value generated by period 1 only corrects the voltage value in period 2. When period 2 is completed cumulatively, period 2 will become the latest completed cumulative preset period T. At this time, step S108 is performed, and period 2 generates a new fourth deviation value, and the new fourth deviation value only corrects the voltage value of the next preset period after period 2 (that is, period 3).

[0023] In this embodiment, the corrected voltage value will not affect the monitored and acquired voltage value. The entire process is to correct the acquired voltage value and then send the corrected voltage value to the control module so that the control module can commutate the current more accurately. The fourth deviation value based on which the acquired voltage value is corrected is obtained according to the acquired voltage value for each completed cumulative preset period, and has nothing to do with the corrected voltage value.

[0024] A voltage data processing method for zero - point detection provided by an embodiment of the present invention monitors and obtains the voltage values of three phases U, V, and W respectively; determines whether each phase has accumulated voltage values for a preset period. If so, a first change graph is generated based on the voltage values within the latest completed preset period T; the zero - crossing points of each phase are determined in the first change graph, and a first deviation value is obtained according to the voltage values corresponding to the zero - crossing points; the curve graph in the first change graph is translated to obtain a second change graph, and a second deviation value is obtained according to the voltage values corresponding to each angle of the second change graph; a first change graph corresponding to a preset number of completed preset periods is obtained, and a third deviation value is obtained according to the voltage values corresponding to each angle in the obtained first change graph; a fourth deviation value is obtained according to the first deviation value, the second deviation value, and the third deviation value; in the next preset period of the preset period T, the latest obtained voltage values of the three phases are corrected according to the fourth deviation value to obtain the corrected voltage values of the three phases, so as to improve the accuracy of the obtained voltage values; for each completed preset period, the above steps are repeated to update the fourth deviation value, thereby correcting the voltage values obtained in the next preset period of the preset period T. By doing so, a first deviation value representing the deviation degree of the total voltage is obtained based on the voltage values of the latest completed preset period T, a second deviation value representing the voltage deviation degree of the phase voltage is obtained, and a third deviation value representing the voltage deviation degree at the same moment within a preset period is obtained according to the first change graphs corresponding to a preset number of completed preset periods. Then, a fourth deviation value representing the correction value is calculated, and the latest obtained voltage values of the three phases are corrected according to the fourth deviation value. In this way, the error of the voltage data itself is corrected, the error of the voltage data sampled by the hardware circuit is eliminated, and the problem of insufficient accuracy of the voltage data is solved.

[0025] In one embodiment, the determination of whether each phase has accumulated voltage values for a preset period includes: S201. For each phase, determine whether the voltage value of this phase is 0. If so, record the angle corresponding to this voltage value as the first target angle; S202. Determine whether the voltage value corresponding to the next angle of the first target angle is greater than 0. If so, mark the first target angle as the starting point of a preset period. If not, execute S201; S203. After determining the starting point of this preset period, determine whether the voltage value of this phase is 0. If so, record the angle corresponding to this voltage value as the second target angle; S204. Determine whether the voltage value corresponding to the next angle of the second target angle is greater than 0. If so, mark the second target angle as the end point of this preset period, and mark the second target angle as the starting point of the next preset period; S205, determine whether both the start point and the end point of a preset period are marked. If so, the voltage value of this phase has accumulated for a preset period.

[0026] In this embodiment, for an ideal first variation diagram, as Figure 2 shown, taking phase U as an example, the voltage value first changes from 0 to a positive value. When the rotor rotates to an angle of 180°, the voltage value returns from the positive value to 0 and changes to a negative value. When the rotational angle reaches 360° (i.e., 0), the voltage value changes from the negative value to 0, completing a preset period. For phase V, the start point of the preset period of this phase is 120° (i.e., the rotor angle is 120°), and the end point is 480°. For phase W, the start point of the preset period of this phase is 240° (i.e., the rotor angle is 240°), and the end point is 600°. It can be considered that phase V is delayed by 120° compared to phase U, and phase W is delayed by 120° compared to phase V. The initial position of the rotor in the first variation diagram here is set to the position of the rotor when phase U starts to be energized, and at this time, the position of the rotor is set to 0. It should be noted that the first variation diagram has not been generated during the judgment process. Only the voltage values of the three phases are obtained, and it is judged whether to generate the first variation diagram based on the voltage values of the three phases.

[0027] In this embodiment, Figure 2 、 Figure 3 in is 180°.

[0028] In this embodiment, the end point of a preset period is also the start point of the next preset period of this preset period.

[0029] In one embodiment, generating the first variation diagram according to the voltage values within the preset period T that has been newly completed and accumulated includes: Taking the angle as the horizontal axis, and taking the voltage values of the three phases U, V, and W as the vertical axes respectively, generate three sub-coordinate systems, arrange them in the same column and share the horizontal axis, and establish a multi- Figure 2 dimensional coordinate system; For each phase, mark the voltage value of this phase within the preset period T that has been newly completed and accumulated and its corresponding angle on the corresponding sub-coordinate system of this phase in the multi- Figure 2 dimensional coordinate system to obtain a number of coordinate points; Connect two adjacent coordinate points to obtain the curve graph of this phase on the multi- Figure 2 dimensional coordinate system; Record the curve graphs of the three phases on the multi- Figure 2 dimensional coordinate system as the first variation diagram.

[0030] In this embodiment, the established multi- Figure 2 dimensional coordinate system is as Figure 2 、 Figure 3As shown, a common horizontal axis is shared. A sub - coordinate system is a two - dimensional coordinate system composed of a vertical axis and the shared horizontal axis.

[0031] In this embodiment, as Figure 2 shown, the horizontal axis can be set to cycle with an angle period from 0 to 360°. However, actually for the second 0 (360°), at this time the rotor is at the initial angle of the second circle. Even though it is the same as the initial angle of the first circle, in terms of the time axis, the moments corresponding to these two initial angles are different. Of course, the horizontal axis can also be set to cycle with an angle period from 0 to 720°, as Figure 2 、 Figure 3 the adopted method. Because for the W - phase, the starting point of the preset period of this phase is 240° (i.e., the rotor angle is 120°), and the end point is 600°. Within the angle period from 0 to 720°, the voltage value of this phase starts to be counted within the latest completed cumulative preset period T from 240°. The voltage value before 240° belongs to the previous completed cumulative preset period (i.e., the previous preset period of the preset period T). In this case, for the U - phase, the voltage value after 360° belongs to the next preset period (i.e., the next preset period of the preset period T). This embodiment preferably selects the method of setting the horizontal axis with an angle period from 0 to 720°.

[0032] In this embodiment, the first change diagram contains 3 curve graphs, that is, the curve graphs of three phases.

[0033] In one embodiment, determining the zero - crossing point of each phase in the first change diagram and obtaining the first deviation value according to the voltage value corresponding to the zero - crossing point includes: For each phase, record the angle corresponding to the voltage value of 0 of this phase as the zero - crossing point; For each zero - crossing point, obtain the voltage value corresponding to this zero - crossing point in each phase in the first change diagram; From get the voltage offset of this zero - crossing point; From get the first deviation value; where, U U is the voltage value corresponding to this zero - crossing point in the U - phase, U V is the voltage value corresponding to this zero - crossing point in the V - phase, U W is the voltage value corresponding to this zero - crossing point in the W - phase, n is the total number of zero - crossing points of three phases, i is the serial number of the zero - crossing points of three phases, and a i is the voltage offset of the i - th zero - crossing point.

[0034] In this embodiment, each phase has 3 zero - crossing points, so there are 9 zero - crossing points in the first change diagram, that is, n is 9.

[0035] In this embodiment, for each phase, the third zero-crossing point of this phase is also the first zero-crossing point in the first variation graph generated in the next preset period.

[0036] In this embodiment, when a zero-crossing point appears, in an ideal state, the sum of the voltage values of the three phases at this time is 0. Therefore, the voltage offset of the zero-crossing point is the absolute value of the difference between the sum of the voltage values of the three phases and 0.

[0037] In this embodiment, the first deviation value is the average value of the voltage offsets of all zero-crossing points, and the first deviation value represents the deviation degree of the total voltage.

[0038] In one embodiment, the step of translating the curve graph in the first variation graph to obtain a second variation graph and obtaining a second deviation value according to the voltage value corresponding to each angle of the second variation graph includes: For each phase, the angle corresponding to the voltage value of 0 of this phase is recorded as the zero-crossing point; Determine the first zero-crossing point among the zero-crossing points of the three phases according to the time sequence; Determine the phase corresponding to the first zero-crossing point as the reference phase; Move the curve graphs of the other two phases along the horizontal axis so that the starting points of their curve graphs are the same as the starting point of the reference phase; Record the curve graphs of the three phases in the multi-dimensional coordinate system as the second variation graph; Figure 2 For each angle, obtain the voltage value corresponding to this angle in each phase in the second variation graph; From obtain the voltage offset of this angle; From obtain the second deviation value; wherein, u is the voltage value corresponding to this angle in the U phase, u U is the voltage value corresponding to this angle in the V phase, u V is the voltage value corresponding to this angle in the W phase, U0 is the reference voltage value corresponding to this angle in the reference phase, m is the total number of angles, j is the serial number of the angle, and b W is the voltage offset of the j-th angle. j In this embodiment, generally speaking, since the initial position of the rotor is set to the position of the rotor when the U phase starts to be energized, the first zero-crossing point is the starting point of the preset period corresponding to the U phase. At this time, the reference phase is the U phase.

[0039] In this embodiment, the ideal second variation graph is as

[0040] shown. Figure 3 as shown.

[0041] In this embodiment, for example, for phase V, the starting angle of the rotor is 120°. When it rotates 10°, the voltage value of phase V should ideally be the same as the voltage value of phase U corresponding to 10°. The same applies to phase W. Therefore, in the second variation graph, the voltage values of the three phases corresponding to the same angle are the same ideally and equal to U0; otherwise, there is a voltage offset. U0 can be obtained from the curve graph showing the variation of the voltage value of the reference phase (phase U) with the angle under ideal conditions. Figure 2 The curve graph represented is the curve graph under ideal conditions.

[0042] In this embodiment, the second deviation value is the average of the voltage offsets at all angles, and the second deviation value represents the deviation degree of the single-phase voltage.

[0043] In one embodiment, obtaining the third deviation value according to the voltage values corresponding to each angle in the obtained first variation graph includes: For each phase, determine the voltage values corresponding to each angle of this phase in the obtained first variation graph; For each angle of this phase, from obtain the voltage deviation degree of this angle of this phase; From obtain the voltage offset of this phase; From obtain the third deviation value; where N is the number of the obtained first variation graphs, k is the serial number of the first variation graph, x k is the voltage value corresponding to this angle of this phase in the k-th first variation graph, M is the total number of angles, J is the serial number of the angle, c J is the voltage deviation degree of the J-th angle of this phase, C U is the voltage offset of phase U, C V is the voltage offset of phase V, C W is the voltage offset of phase W.

[0044] In this embodiment, the standard deviation method is used to calculate the voltage deviation degree of this angle of this phase instead of using the average value of the differences between the voltage values corresponding to this angle of this phase in all the first variation graphs and the reference voltage value corresponding to this angle of this phase, because there is a large amount of reference data, and the voltage fluctuation situation can be clearly known. Moreover, the reference voltage value corresponding to this angle of this phase is a value that can only be obtained under ideal conditions, and it may not be achievable all the time in the actual circuit, so there is a state value. The voltage values corresponding to this angle of this phase in all the first variation graphs fluctuate around this state value. Therefore, it is more appropriate to use the standard deviation method.

[0045] In this embodiment, the single-phase voltage offset represents the degree of voltage deviation at the same moment of a single phase within a preset period. The third deviation value is the average value of the voltage offsets of the three phases.

[0046] In one embodiment, obtaining the fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value includes: From Obtain the fourth deviation value; wherein, K1 is the first coefficient, K2 is the second coefficient, K3 is the third coefficient, the sum of K1, K2, and K3 is 1, d1 is the first deviation value, d2 is the second deviation value, and d3 is the third deviation value.

[0047] In this embodiment, the sum of K1, K2, and K3 is 1, and K1, K2, and K3 can be set to 1 / 3.

[0048] In one embodiment, correcting the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases to improve the accuracy of the obtained voltage values includes: For each latest obtained voltage value of each phase, determine the time difference t between the acquisition time of the latest obtained voltage value of this phase and the end time of the latest completed cumulative preset period T of this phase; From Obtain the real-time angle; Obtain the reference voltage value corresponding to the real-time angle on this phase; Calculate the voltage difference U1 between the latest obtained voltage value of this phase and the reference voltage value corresponding to the real-time angle on this phase; Judge whether the voltage difference U1 is greater than 0. If so, from Obtain the corrected voltage value of the latest obtained voltage value of this phase. If not, from Obtain the corrected voltage value of the latest obtained voltage value of this phase; wherein, P is the number of pole pairs of the DC brushless motor, v is the rotational speed of the DC brushless motor, U2 is the latest obtained voltage value of this phase, and d4 is the fourth deviation value.

[0049] In this embodiment, It can also be written as , and the two are only different in units. is the formula for calculating the mechanical angle of the rotor, is to constrain the calculated mechanical angle within a single circle (i.e., 360°), and after multiplying by the number of pole pairs P, the rotating electrical angle, that is, the real-time angle, is obtained. The time difference t between the acquisition time of the latest obtained voltage value of this phase and the end time of the latest completed cumulative preset period T of this phase is less than the preset period, so directly using It's also okay.

[0050] In this embodiment, the real-time angle is the rotation angle of the rotor relative to the initialization position (0). For phase V, although the starting angle of the rotor is 120°, when the real-time angle is 120°, the corresponding reference voltage value of phase V at this time is 0. The same is true for phase W.

[0051] In this embodiment, the reference voltage value corresponding to the real-time angle on this phase can be obtained from the curve graph of the voltage value of this phase changing with the angle in the ideal state.

[0052] In this embodiment, v is the rotational speed of the DC brushless motor, and the rated speed can be adopted, with the unit of revolutions per minute (RPM).

[0053] As Figure 4 shown, in one embodiment, a voltage data processing device for zero-point detection is provided, which may specifically include: A monitoring voltage module for respectively monitoring and obtaining the voltage values of the three phases U, V, and W; An image generation module for determining whether each phase has accumulated the voltage values for a preset period. If so, a first variation graph is generated according to the voltage values within the latest completed preset period T; A first deviation module for determining the zero-crossing points of each phase in the first variation graph and obtaining a first deviation value according to the voltage values corresponding to the zero-crossing points; A second deviation module for translating the curve graph in the first variation graph to obtain a second variation graph and obtaining a second deviation value according to the voltage values corresponding to each angle in the second variation graph; A third deviation module for obtaining the first variation graphs corresponding to a preset number of completed preset periods and obtaining a third deviation value according to the voltage values corresponding to each angle in the obtained first variation graphs; A fourth deviation module for obtaining a fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value; A corrected voltage module for correcting the latest obtained voltage values of the three phases according to the fourth deviation value in the next preset period of the preset period T to obtain the corrected voltage values of the three phases so as to improve the accuracy of the obtained voltage values.

[0054] In this embodiment, each module of the voltage data processing device for zero-point detection is modularized in the method part of the present invention. For the specific explanations of each module, please refer to the corresponding content in the method part of the present invention, and the embodiments of the present invention will not be elaborated here.

[0055] In one embodiment, a DC brushless motor is provided, which may specifically include: a motor module and a control module for controlling the motor module; The motor module is used to implement a rotation function to realize the function of a brushless DC motor; The control module is used to execute the steps of the above voltage data processing method for zero point detection.

[0056] In this embodiment, the motor module includes a stator, a rotor, a position sensor, an electronic commutator, etc.

[0057] In this embodiment, the brushless DC motor further includes a mechanical support module and a heat dissipation module.

[0058] A brushless DC motor provided by an embodiment of the present invention monitors and obtains the voltage values of three phases U, V, and W respectively; determines whether each phase has accumulated the voltage values of a preset period, and if so, generates a first change graph according to the voltage values within the latest completed preset period T; determines the zero crossing points of each phase in the first change graph, and obtains a first deviation value according to the voltage values corresponding to the zero crossing points; translates the curve graph in the first change graph to obtain a second change graph, and obtains a second deviation value according to the voltage values corresponding to each angle of the second change graph; obtains the first change graphs corresponding to a preset number of completed preset periods, and obtains a third deviation value according to the voltage values corresponding to each angle in the obtained first change graphs; obtains a fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value; in the next preset period of the preset period T, corrects the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases to improve the accuracy of the obtained voltage values; for each completed preset period, repeats the above steps to update the fourth deviation value so as to correct the voltage values obtained in the next preset period of the preset period T. By doing so, a first deviation value representing the deviation degree of the total voltage and a second deviation value representing the deviation degree of the phase voltage are obtained according to the voltage values of the latest completed preset period T, and a third deviation value representing the deviation degree of the voltage at the same moment within a preset period is obtained according to the first change graphs corresponding to a preset number of completed preset periods, so as to calculate a fourth deviation value representing the correction value, and correct the latest obtained voltage values of the three phases according to the fourth deviation value, thereby correcting the error of the voltage data itself, eliminating the error of the voltage data sampled by the hardware circuit, and solving the problem of insufficient accuracy of the voltage data.

[0059] Figure 5 Shows the internal structure diagram of the control module in one embodiment. As Figure 5As shown in the figure, the control module includes a processor, a memory, and a network interface connected through a system bus. Among them, the memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the control module stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor can implement a voltage data processing method for zero point detection provided by an embodiment of the present invention. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor can execute a voltage data processing method for zero point detection provided by an embodiment of the present invention.

[0060] Those skilled in the art can understand that Figure 5 the structure shown in the figure is only a block diagram of some structures related to the solution of the present invention, and does not constitute a limitation on the control module to which the solution of the present invention is applied. The specific control module may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0061] In one embodiment, a voltage data processing device for zero point detection provided by an embodiment of the present invention can be implemented in the form of a computer program, and the computer program can run on a control module as shown in Figure 5 the figure. Each program module constituting the voltage data processing device for zero point detection can be stored in the memory of the control module. For example, Figure 4 the monitoring voltage module, the image generation module, the first deviation module, the second deviation module, the third deviation module, the fourth deviation module, and the correction voltage module shown in the figure. The computer program composed of each program module enables the processor to execute the steps in a voltage data processing method for zero point detection in various embodiments of the present invention described in this specification.

[0062] For example, Figure 5 the control module shown in the figure can execute step S101 through the monitoring voltage module in a voltage data processing device for zero point detection as shown in Figure 4 the figure; the control module can execute step S102 through the image generation module; the control module can execute step S103 through the first deviation module; the control module can execute step S104 through the second deviation module; the control module can execute step S105 through the third deviation module; the control module can execute step S106 through the fourth deviation module; the control module can execute step S107 through the correction voltage module.

[0063] In one embodiment, a control module is proposed. The control module includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented: S101, respectively monitor and obtain the voltage values of the three phases U, V, and W; S102, Determine whether the voltage values of each phase have been accumulated for a preset period. If so, generate a first variation graph based on the voltage values within the latest completed preset period T; S103, Determine the zero-crossing points of each phase in the first variation graph, and obtain a first deviation value based on the voltage values corresponding to the zero-crossing points; S104, Translate the curve graph in the first variation graph to obtain a second variation graph, and obtain a second deviation value based on the voltage values corresponding to each angle of the second variation graph; S105, Obtain the first variation graphs corresponding to a preset number of completed preset periods, and obtain a third deviation value based on the voltage values corresponding to each angle in the obtained first variation graphs; S106, Obtain a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; S107, In the next preset period of the preset period T, correct the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases, so as to improve the accuracy of the obtained voltage values; S108, For each completed preset period, execute S102 - S107 to update the fourth deviation value, thereby correcting the voltage values obtained in the next preset period of the preset period T.

[0064] In one embodiment, a computer-readable storage medium is provided. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, the processor executes the following steps: S101, Monitor and obtain the voltage values of the three phases U, V, and W respectively; S102, Determine whether the voltage values of each phase have been accumulated for a preset period. If so, generate a first variation graph based on the voltage values within the latest completed preset period T; S103, Determine the zero-crossing points of each phase in the first variation graph, and obtain a first deviation value based on the voltage values corresponding to the zero-crossing points; S104, Translate the curve graph in the first variation graph to obtain a second variation graph, and obtain a second deviation value based on the voltage values corresponding to each angle of the second variation graph; S105, Obtain the first variation graphs corresponding to a preset number of completed preset periods, and obtain a third deviation value based on the voltage values corresponding to each angle in the obtained first variation graphs; S106, Obtain a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; S107, In the next preset period of the preset period T, correct the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases, so as to improve the accuracy of the obtained voltage values; S108. For each preset period for which accumulation is completed, execute S102 - S107 to update the fourth deviation value, thereby correcting the voltage value obtained in the next preset period of the preset period T.

[0065] It should be understood that although the steps in the flowcharts of the embodiments of the present invention are shown in sequence according to the indications of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, there is no strict order limit for the execution of these steps, and these steps can be executed in other orders. Moreover, at least some of the steps in each embodiment may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps. Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided by the present invention can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0066] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, 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, it should be considered to be within the scope described in this specification.

[0067] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention.

Claims

1. A voltage data processing method for zero point detection, characterized in that, The voltage data processing method for zero - point detection includes: S101, respectively monitor and obtain the voltage values of three phases U, V, and W; S102, determine whether the voltage values of each phase have been accumulated for a preset period. If so, generate a first change graph according to the voltage values within the latest completed preset period T; S103, determine the zero - crossing points of each phase in the first change graph, and obtain a first deviation value according to the voltage values corresponding to the zero - crossing points; S104, translate the curve graph in the first change graph to obtain a second change graph, and obtain a second deviation value according to the voltage values corresponding to each angle of the second change graph; S105, obtain the first change graphs corresponding to a preset number of completed preset periods, and obtain a third deviation value according to the voltage values corresponding to each angle in the obtained first change graphs; S106, obtain a fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value; S107, in the next preset period of the preset period T, correct the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases so as to improve the accuracy of the obtained voltage values; S108, for each completed preset period, execute S102 - S107 to update the fourth deviation value, thereby correcting the voltage values obtained in the next preset period of the preset period T.

2. The voltage data processing method for zero point detection according to claim 1, wherein, The determination of whether the voltage values of each phase have been accumulated for a preset period includes: S201, for each phase, determine whether the voltage value of this phase is 0. If so, record the angle corresponding to this voltage value as the first target angle; S202, determine whether the voltage value corresponding to the next angle of the first target angle is greater than 0. If so, mark the first target angle as the starting point of a preset period. If not, execute S201; S203, after determining the starting point of this preset period, determine whether the voltage value of this phase is 0. If so, record the angle corresponding to this voltage value as the second target angle; S204, determine whether the voltage value corresponding to the next angle of the second target angle is greater than 0. If so, mark the second target angle as the end point of this preset period, and mark the second target angle as the starting point of the next preset period; S205, determine whether both the starting point and the end point of a preset period have been marked. If so, the voltage values of this phase have been accumulated for a preset period.

3. The voltage data processing method for zero point detection according to claim 1, wherein The generation of the first change graph according to the voltage values within the latest completed preset period T includes: Taking the angle as the horizontal axis, and taking the voltage values of three phases U, V, and W as the vertical axes respectively, generate three sub - coordinate systems, arrange them in the same column and share the horizontal axis, and establish a multi - sub - graph two - dimensional coordinate system; For each phase, mark the voltage values and their corresponding angles of this phase within the latest completed preset period T on the corresponding sub - coordinate system of this phase to obtain a number of coordinate points; Connect two adjacent coordinate points to obtain the curve graph of this phase on the multi - sub - graph two - dimensional coordinate system; Record the curve graphs of the three phases on the multi - sub - graph two - dimensional coordinate system as the first change graph.

4. The voltage data processing method for zero point detection according to claim 1, wherein, The determination of the zero - crossing points of each phase in the first change graph and the obtaining of the first deviation value according to the voltage values corresponding to the zero - crossing points include: For each phase, record the angle corresponding to the voltage value of 0 in this phase as the zero crossing point; For each zero crossing point, obtain the voltage value corresponding to this zero crossing point in each phase in the first variation graph; From the voltage offset of the zero crossing point is obtained; Obtained from the first deviation value is obtained; Among them, U U is the voltage value corresponding to this zero crossing point in U, U V is the voltage value corresponding to this zero crossing point in V, U W is the voltage value corresponding to this zero crossing point in W, n is the total number of zero crossing points of the three phases, i is the serial number of the zero crossing points of the three phases, a i is the voltage offset of the i-th zero crossing point.

5. The voltage data processing method for zero point detection according to claim 1, characterized in that, The translation of the curve graph in the first variation graph to obtain the second variation graph, and obtaining the second deviation value according to the voltage value corresponding to each angle in the second variation graph includes: For each phase, record the angle corresponding to the voltage value of 0 in this phase as the zero crossing point; Determine the first zero crossing point among the zero crossing points of the three phases according to the time sequence; Determine the phase corresponding to the first zero crossing point as the reference phase; Move the curve graphs of the remaining two phases along the horizontal axis so that the starting points of their curve graphs are the same as the starting point of the reference phase; Record the curve graphs of the three phases on the multi-subplot two-dimensional coordinate system as the second variation graph; For each angle, obtain the voltage value corresponding to this angle in each phase in the second variation graph; From obtain the voltage offset of this angle; Obtained from Obtain a second deviation value; where, u U is the voltage value corresponding to this angle in U, u V is the voltage value corresponding to this angle in V, u W is the voltage value corresponding to this angle in W, U0 is the reference voltage value corresponding to this angle in the reference phase, m is the total number of angles, j is the serial number of the angle, b j is the voltage offset of the j-th angle.

6. The voltage data processing method for zero point detection according to claim 1, wherein The obtaining the third deviation value according to the voltage value corresponding to each angle in the obtained first variation graph includes: For each phase, determine the voltage value corresponding to each angle in this phase in the obtained first variation graph; For each angle of the phase, from the degree of voltage deviation at that angle of the phase is obtained; From obtain the voltage offset of this phase; Obtained from to obtain a third deviation value; Among them, N is the number of the obtained first change diagrams, k is the serial number of the first change diagram, and x k is the voltage value corresponding to the angle of this phase in the k-th first change diagram, M is the total number of angles, J is the serial number of the angle, and c J is the voltage deviation degree of the J-th angle of this phase, C U is the voltage offset of phase U, C V is the voltage offset of phase V, C W is the voltage offset of phase W.

7. The voltage data processing method for zero point detection according to claim 1, characterized in that The obtaining the fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value includes: From obtain the fourth deviation value; Wherein, K1 is the first coefficient, K2 is the second coefficient, K3 is the third coefficient, the sum of K1, K2, and K3 is 1, d1 is the first deviation value, d2 is the second deviation value, and d3 is the third deviation value.

8. The voltage data processing method for zero point detection according to claim 1, characterized in that The correcting the latest obtained voltage values of the three phases according to the fourth deviation value to obtain the corrected voltage values of the three phases to improve the accuracy of the obtained voltage values includes: For each latest obtained voltage value of each phase, determine the time difference t between the acquisition time of this latest obtained voltage value of this phase and the end time of the latest completed cumulative preset period T of this phase; From obtain the real-time angle; Obtain the reference voltage value corresponding to the real-time angle in this phase; Calculate the voltage difference U1 between this latest obtained voltage value of this phase and the reference voltage value corresponding to the real-time angle in this phase; Determine whether the voltage difference U1 is greater than 0. If so, then by obtain the corrected voltage value of the latest obtained voltage value of this phase. If not, then by obtain the corrected voltage value of the latest obtained voltage value of this phase; Wherein, P is the number of pole pairs of the DC brushless motor, v is the rotational speed of the DC brushless motor, U2 is this latest obtained voltage value of this phase, and d4 is the fourth deviation value.

9. A voltage data processing device for zero point detection, characterized in that, The zero crossing detection voltage data processing device includes: A monitoring voltage module for respectively monitoring and obtaining the voltage values of the U, V, and W phases; An image generation module for determining whether each phase has accumulated the voltage values of a preset period. If so, generate a first variation graph according to the voltage values within the latest completed cumulative preset period T; A first deviation module for determining the zero crossing points of each phase in the first variation graph and obtaining the first deviation value according to the voltage values corresponding to the zero crossing points; A second deviation module for translating the curve graph in the first variation graph to obtain the second variation graph and obtaining the second deviation value according to the voltage value corresponding to each angle in the second variation graph; A third deviation module for obtaining the first variation graphs corresponding to a preset number of completed cumulative preset periods and obtaining the third deviation value according to the voltage value corresponding to each angle in the obtained first variation graph; A fourth deviation module for obtaining the fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value; A correction voltage module is used to correct the latest obtained voltage values of three phases according to a fourth deviation value in the next preset period of a preset period T to obtain the corrected voltage values of the three phases, so as to improve the accuracy of the obtained voltage values.

10. A brushless DC motor, characterized in that, The DC brushless motor includes a motor device and a control module for controlling the motor device; The motor device is used to realize the rotation function to realize the function of the DC brushless motor; The control module is used to execute the steps of the voltage data processing method for zero point detection described in any one of claims 1 to 8.

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