Power module and position correction method

Abstract

The present application discloses a power module and a position correction method, wherein the power module includes an encoder and a processing unit, and the encoder is provided with a code disc and a reading head. The code disc is located on one side of the reading head and is spaced apart from the reading head. The code disc is mounted on a rotating member, and the code disc is used to rotate relative to the reading head as the rotating member rotates. The reading head includes at least one detection component, each detection component includes three detection elements, and the three detection elements are evenly spaced and distributed from each other, and are all used to detect the rotational position information of the code disc. The processing unit performs weighted filtering calculation on the rotational position information of the three code discs detected by the same detection component, thereby eliminating the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc in the rotational position information, and obtains the rotational position information of the corrected code disc. In this way, the power module of the present application can still maintain a high detection accuracy during long-term operation and in harsh and complex environments.

Description

Technical Field

[0001] The present application relates to the technical field of position detection, and in particular to a power module and a position correction method. Background Art

[0002] As an important component of mechanical equipment, encoders use photoelectric, electromagnetic, capacitive or inductive induction principles to convert the position change of mechanical equipment into corresponding electrical signals. Among the current encoders, photoelectric encoders have the advantages of small speed fluctuation and high precision, and are a popular choice for mechanical equipment. However, high-precision photoelectric encoders are expensive, and their position detection results are easily affected by the environment, making them unsuitable for use in harsh and complex environments. When machinery needs to operate in harsh and complex environments, magnetic encoders, inductive encoders or capacitive encoders that are resistant to harsh environments would be a better choice.

[0003] However, the accuracy of magnetic encoders, inductive encoders and capacitive encoders is subject to errors caused by the production quality of parts or installation misalignment. Moreover, after the mechanical equipment has been running for a long time, the deviation of parts due to factors such as wear, looseness, and deformation will further expand the error, causing the accuracy value of the encoder to further decrease. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the first purpose of the present application is to provide a power module, which can eliminate the detection errors caused by long-term operation and complex environment, and has the advantages of being resistant to harsh environment and maintaining high detection accuracy.

[0005] The second objective of the present application is to provide a position correction method that can obtain high-precision position detection results.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] A power module, comprising:

[0008] An encoder, the encoder comprising a code disc and a reading head, the code disc being located at one side of the reading head and spaced apart from the reading head, the code disc being mounted on a rotating member, the code disc being used to rotate relative to the reading head as the rotating member rotates; the reading head comprising at least one detection assembly, each of the detection assemblies comprising three detection elements, the three detection elements being evenly spaced apart from each other and all being used to detect rotational position information of the code disc;

[0009] Wherein, if the code disc is offset in the radial direction and / or axial direction of the rotating member relative to the reading head, for the same detection component, the rotational position information of the code disc detected by the three detection elements includes the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc;

[0010] A processing unit, wherein the processing unit is used to perform weighted filtering calculation on the rotational position information of the code disc detected by the three detection elements of the same detection component, thereby eliminating the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc, and obtaining the corrected rotational position information of the code disc.

[0011] Preferably, if the code disc is offset in the radial direction of the rotating member relative to the reading head, for the same detection assembly, the rotational position information of the code disc detected by two of the detection elements respectively includes the radial displacement deviation of the code disc generated in a first offset direction relative to the reading head, and the rotational position information of the code disc detected by another of the detection elements includes the radial displacement deviation of the code disc generated in a second offset direction relative to the reading head;

[0012] If the code disk is offset in the axial direction of the rotating part relative to the reading head, for the same detection component, the rotational position information of the code disk detected by two of the detection elements respectively includes the axial displacement deviation of the code disk generated in the third offset direction relative to the reading head, and the rotational position information of the code disk detected by the other detection element includes the axial displacement deviation of the code disk generated in the fourth offset direction relative to the reading head.

[0013] Preferably, the processing unit is used to perform weighted average calculation on the rotational position information of the calibrated code disk corresponding to all the detection components, and then perform error compensation on the weighted average calculation result, so as to obtain the actual rotational position information of the rotating part.

[0014] Furthermore, the encoder device further comprises a storage unit, wherein the storage unit stores the accuracy error compensation values ​​of all detection elements;

[0015] The storage unit is connected to the processing unit, and the processing unit is used to superimpose the precision error compensation value and the weighted average calculation result, so as to obtain the actual rotation position information of the rotating part.

[0016] A position correction method is applied to the above power module, and the position correction method comprises the following steps:

[0017] Respectively detecting the rotational position information of the code disk by means of three detection elements in each of the detection components;

[0018] When the code disc is offset in the radial direction and / or axial direction of the rotating member relative to the reading head, for the same detection assembly, the rotational position information of the code disc detected by the three detection elements all includes the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc;

[0019] The rotational position information of the code disc detected by the three detection elements of the same detection component is subjected to weighted filtering calculation, thereby eliminating the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc, and obtaining the corrected rotational position information of the code disc.

[0020] Preferably, when the code disk is offset in the radial direction of the rotating member relative to the reading head, for the same detection assembly, the rotational position information of the code disk detected by two of the detection elements respectively includes the radial displacement deviation of the code disk generated in a first offset direction relative to the reading head, and the rotational position information of the code disk detected by another of the detection elements includes the radial displacement deviation of the code disk generated in a second offset direction relative to the reading head;

[0021] When the code disk is offset in the axial direction of the rotating part relative to the reading head, for the same detection component, the rotational position information of the code disk detected by two of the detection elements respectively includes the axial displacement deviation of the code disk generated in the third offset direction relative to the reading head, and the rotational position information of the code disk detected by the other detection element includes the axial displacement deviation of the code disk generated in the fourth offset direction relative to the reading head.

[0022] Preferably, the method further comprises:

[0023] After obtaining the rotational position information of the calibrated code disk corresponding to each of the detection components, performing weighted average calculation on the rotational position information of all the calibrated code disks to obtain a weighted average calculation result;

[0024] The weighted average calculation result is error compensated to obtain the actual rotation position information of the rotating member.

[0025] Preferably, the error compensation for the weighted average calculation result comprises the following steps:

[0026] Finding a corresponding precision error compensation value according to the weighted average calculation result;

[0027] The weighted average calculation result and the precision error compensation value are superimposed to obtain the actual rotation position information of the rotating part.

[0028] Preferably, the method further comprises:

[0029] Determining whether the detection element is abnormal according to the rotation position information of the code disk detected by the detection element;

[0030] When at least one of the detection elements in any one of the detection components is abnormal, the rotation position information of the code disk detected by the abnormal detection element is discarded.

[0031] Compared with the prior art, this application has the following advantages:

[0032] 1. The present application evenly distributes the three detection elements of the same detection component at equal intervals. Based on this position distribution relationship, when the rotation position information P1 of the three code disks in the same group is weighted filtered and calculated, the displacement deviations in the three P1s can be offset during the calculation process, thereby preventing the displacement deviations from affecting the accuracy of position detection, thereby keeping the position detection accuracy unchanged. Moreover, the present application sets multiple detection elements to reduce the differences between P1s and obtain more stable and reliable rotation position information.

[0033] 2. The present application can gradually improve the accuracy of position detection through a multi-layer mechanism. First, the rotational position information P1 of the code disk is detected by multiple detection elements, and the P1 of the same group is filtered, weighted summed and averaged, so as to obtain a result P2 that has eliminated abnormal values ​​and eliminated deviations caused by long-term operation and complex environment, and the accuracy is better than the accuracy of using only one detection element. Secondly, the P2 obtained by multiple groups of detection elements is weighted averaged to obtain a result P3 with better accuracy than using only one detection component. Subsequently, P3 is compensated for accuracy errors to eliminate errors caused by production processes, installation processes, etc., and further improve the accuracy of position detection.

[0034] 3. The power module of the present application can greatly improve the position detection accuracy of the encoder without adding hardware equipment, and solves the problem of reduced detection accuracy caused by wear of the rotating parts due to long-term use, deformation displacement of the installation position, vibration or looseness. Therefore, the power module of the present application has the advantages of low cost, high precision, high stability and resistance to harsh environments.

[0035] 4. The power module of the present application can select a magnetic encoder, a capacitive encoder or an inductive encoder for position detection according to actual conditions, and the number of detection components can also be set according to actual needs. Therefore, the power module of the present application is more flexible and has a wider range of uses. For example, it can be applied to mechanical equipment such as robots, CNC machine tools, automobiles and elevators. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0037] Figure 1 A schematic diagram of a power module provided in an embodiment of the present application.

[0038] Figure 2 for Figure 1 Schematic diagram of the detection components and code disc in the reading head.

[0039] Figure 3 for Figure 1 Schematic diagram of the distribution of one detection component in the reading head.

[0040] Figure 4 for Figure 1 Schematic diagram of the layout of the two detection components in the readhead.

[0041] Figure 5 Schematic diagram of the radial displacement deviation of the code disk.

[0042] Figure 6 Schematic diagram of the axial displacement deviation of the code disk.

[0043] Figure 7 It is the time curve diagram of the accuracy error compensation value.

[0044] Figure 8 A flow chart of a position correction method provided in an embodiment of the present application.

[0045] Fig. 9 for Figure 8 Schematic diagram of the process of obtaining the actual rotation position information of the rotating part in the method.

[0046] Main component symbols

[0047] Power module 100

[0048] Power take-off unit 10

[0049] Body 11

[0050] Rotating member 12

[0051] Encoder 20

[0052] Reading head 21

[0053] Detection component 212

[0054] Detection elements A, B, C, D, E, F

[0055] Code disc 22

[0056] Code 221

[0057] Processing unit 30

[0058] Storage unit 40

[0059] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0060] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0061] The terms "first", "second", "third" and "fourth" in the specification of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the term "comprising" and any variation thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or modules is not limited to the listed steps or modules, but optionally also includes steps or modules that are not listed, or optionally also includes other steps or modules inherent to these processes, methods, products or devices.

[0062] Please refer to Figure 1 The embodiment of the present application provides a power module 100. The power module 100 includes a power output unit 10, an encoder 20 and a processing unit 30.

[0063] like Figure 1As shown, the power output unit 10 includes a body 11 and a rotating member 12. The body 11 is connected to the rotating member 12, and can be connected to other mechanical mechanisms through the rotating member 12. The body 11 is used to generate driving force, and can drive the rotating member 12 to rotate, so as to output driving force to the connected mechanical mechanism through the rotating member 12. For example, in some embodiments, the power output unit 10 uses a motor, and the rotating member 12 is a rotating shaft, and the rotating shaft is connected to the rotor of the motor.

[0064] Please refer again Figure 1 The encoder 20 includes a reading head 21 and a code disc 22. The code disc 22 is a circular ring structure and can be installed on the rotating member 12. Figure 2 The reading head 21 is fixed on the machine body 11 and is located on one side of the code disc 22. The code disc 22 and the reading head 21 are spaced apart.

[0065] In the embodiments of the present application, for the convenience of description, Figure 2 The extending direction of the rotating member 12, that is, the axial direction is set to be a vertical direction, and the reading head 21 is set to be located above the top surface of the code disk 22.

[0066] The reading head 21 includes at least one detection component 212. Figure 2 and Figure 3 Each detection component 212 includes three detection elements, and the three detection elements are evenly spaced from each other. That is, the positions of the three detection elements are not collinear, and the three detection elements can be located in the same equilateral triangle (refer to Figure 5 ) or the same circle (refer to Figure 6 ), and the distance between every two detection elements is equal. Therefore, it can be understood that Figure 3 As shown in the figure, when the reading head 21 is located above the code disk 22, in the top view, the center point O of the equilateral triangle formed by the lines connecting the three detection elements overlaps with the center point of the code disk 22. Moreover, when the positions of the three detection elements are connected to the center point O, the angle formed by every two connecting lines is 120 degrees.

[0067] It is understood that when the reading head 21 is provided with more than two detection components 212, the present application does not limit the distance between two detection elements belonging to different detection components 212. Figure 4 As shown, the reading head 21 is provided with two detection components 212, wherein the detection elements A, B, and C form a group, and the detection elements D, E, and F form another group, and the detection element D can be located at any position between the detection elements A and B.

[0068] In the embodiment of the present application, considering that the power module 100 needs to be used in a relatively harsh and complex environment such as high vibration, the encoder 20 needs to have a certain ability to withstand harsh environments, such as being insensitive to vibration. Therefore, in some embodiments, the encoder 20 may adopt any one of a magnetic encoder, a capacitive encoder, and an inductive encoder. Among them, when the encoder 20 is a magnetic encoder, the detection element is a magnetic sensor, such as a Hall sensor or a magnetoresistive sensor. When the encoder 20 is an inductive encoder, the detection element is an inductive sensor. When the encoder 20 is a capacitive encoder, the detection element is a capacitive sensor.

[0069] In the embodiment of the present application, the encoder 20 is an absolute encoder 20. Figure 2 As shown, the code disc 22 is provided with a code track 221 on one side thereof close to the reading head 21. It is to be understood that the present application does not limit the number of the code tracks 221. When the code disc 22 rotates relative to the reading head 21, each detection element of the reading head 21 can detect the sensing signal generated by the position of the code track 221 after rotation, and convert the sensing signal into a corresponding digital signal, which is the rotation position information P1 of the code disc 22.

[0070] Among them, it can be understood that the size of the rotational position information P1 detected by the detection element is related to the positional relationship between the detection element and the code disk 22. Taking the magnetic encoder as an example, since the code track 221 of the code disk 22 in the magnetic encoder is composed of multiple pairs of different magnetic poles, there is an uneven magnetic field on the code disk 22. Therefore, when the code disk 22 is offset and the positional relationship between the detection element and the code disk 22 changes, the magnetic signal detected by each detection element also changes accordingly. Based on this, the rotational position information P1 of the code disk 22 detected by each detection element also correspondingly includes the displacement deviation caused by the offset of the code disk 22.

[0071] For example, if the code disc 22 is offset in the radial direction of the rotating member 12 relative to the reading head 21, P1 detected by the three detection elements of the same detection assembly 212 all include the corresponding code disc radial displacement deviation. Moreover, for the same detection assembly 212, two of the detection elements generate the corresponding code disc radial displacement deviation in the first offset direction, and the other detection element generates the corresponding code disc radial displacement deviation in the second offset direction.

[0072] Take the magnetic encoder as an example. Please refer to Figure 5 , when the position of the reading head 21 remains unchanged and the code disk 22 is offset to the left by a distance L, it is equivalent to that the position of the code disk 22 remains unchanged and the detection component 212 of the reading head 21 is offset to the right by a distance L relative to the code disk 22. Among them, the offset positions of the detection elements A, B, and C are the positions of the points A', B', and C'.

[0073] It can be understood that the rightward shift of the detection elements A, B, C by a distance L will change the distance between the detection elements A, B, C and the center point O. Since the distance between the detection elements A, B, C and the center point O changes, the phase of the magnetic field sensed by the detection elements A, B, C will also change accordingly, thereby causing a deviation in P1. Therefore, the radial displacement deviation of the code disk corresponding to each detection element is the change in the distance between the detection element and the center point O caused by the rightward shift.

[0074] Understandably, due to Figure 5 Point A' in the figure is on the line where segment OA is, while point B' is not on the line where segment OB is, and point C' is not on the line where segment OC is. Therefore, when calculating the displacement deviation in the radial direction, it is necessary to project point B' onto the line where segment OB is, and project point C' onto the line where segment OC is. Therefore, after calculation, Figure 5 The distance between the detection element A and the center point O in the image increases by L, while the distance between the detection elements B and C and the center point O decreases by L / 2. Therefore, the radial displacement deviation of the code disk corresponding to the detection element A is +L, and the radial displacement deviation of the code disk corresponding to the detection elements B and C is -L / 2. The direction of the straight line where the line segment OA is located is the second offset direction, and the direction of the straight line where the line segments OB and OC are located is the first offset direction.

[0075] Similarly, if the code disc 22 is offset in the axial direction of the rotating member 12 relative to the reading head 21, the P1 detected by the three detection elements of the same detection assembly 212 also includes the corresponding code disc axial displacement deviation. In addition, for the same detection assembly 212, two of the detection elements generate the corresponding code disc axial displacement deviation in the third offset direction, and the other detection element generates the corresponding code disc axial displacement deviation in the fourth offset direction.

[0076] Take the magnetic encoder as an example. Please refer to Figure 6 When the position of the reading head 21 remains unchanged and the code disk 22 deflects in the vertical direction, it is equivalent to that the position of the code disk 22 remains unchanged, and the detection component 212 of the reading head 21 is offset in the vertical direction relative to the code disk 22 with the center point O as the rotation point. Among them, the positions of the detection elements A, B, and C after the offset are the positions of the points A", B", and C".

[0077] It can be understood that the detection elements A, B, and C are offset in the vertical direction with the center point O as the rotation point, which will cause a height difference between the detection elements A, B, and C and the center point O. Since the height difference between the detection elements A, B, and C and the center point O changes, the intensity of the magnetic field detected by the detection elements A, B, and C will also change accordingly, thereby causing a deviation in P1. Therefore, the axial displacement deviation of the code disk corresponding to each detection element is the height difference between the detection element and the center point O caused by the offset in the vertical direction.

[0078] Therefore, after calculation, Figure 6 The detection element A in the code disk 22 moves up by R·sinθ, that is, the detection element A is higher than the center point O, and the height difference is R·sinθ. The detection elements B and C both move down by R / 2·sinθ, that is, the detection elements B and C are lower than the center point O, and the height difference is R / 2·sinθ. Among them, R is the distance between the detection element and the center of the code disk 22, and θ is the deflection angle of the code disk 22 in the axial direction. Therefore, if the upward direction is taken as the positive direction, the axial displacement deviation of the code disk corresponding to the detection element A is +R·sinθ, and the axial displacement deviation of the code disk corresponding to the detection elements B and C is -R / 2·sinθ. The upward direction is the fourth offset direction, and the downward direction is the third offset direction.

[0079] In the embodiment of the present application, the processing unit 30 may be a central processing unit 30 (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The processing unit 30 may be connected to each detection component 212 in the encoder 20 using various interfaces and lines, so as to obtain the rotation position information P1 of the code disk 22 detected by each detection component 212.

[0080] The processing unit 30 is further configured to perform weighted filtering calculation on the three P1 detected by each detection component 212, that is, to perform weighted summation on the three P1, and then perform average calculation on the result of the weighted summation.

[0081] It can be understood that, since the processing unit 30 performs weighted summation on the three P1s, when P1 includes the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc, the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc are also weighted summed accordingly. Since the numerical directions of the three radial displacement deviations of the code disc and / or the axial displacement deviations of the code disc of the same detection component are opposite, the weighted summation can make the radial displacement deviations of the code disc and / or the axial displacement deviations of the code disc in the three P1s offset each other, and the processing unit 30 can thereby obtain the rotational position information P2 of the corrected code disc 22.

[0082] It can be understood that before performing weighted summation on P1, the processing unit 30 can also compare the three P1s detected by the same detection component 212. When one of the P1s obviously exceeds the rotation angle that can be achieved at the current speed of the rotating part 12, or the difference between one of the P1s and the other two P1s is greater than the normal range, it means that the P1 is abnormal data, and the detection element corresponding to the P1 is abnormal. Therefore, when the power module 100 is equipped with multiple groups of detection components 212, the rotation position information of the entire group of code disks 22 where the abnormal P1 is located is directly eliminated to avoid the influence of abnormal data on P2, and ensure that the detection component 212 provides accurate rotation position information. When the power module 100 is only equipped with one group of detection components 212, the abnormal P1 is directly eliminated. In this way, it can be ensured that the detection component 212 can still provide a normal position detection function.

[0083] In the embodiment of the present application, after the processing unit 30 calculates the rotational position information P2 of the calibrated code disk 22 corresponding to each detection component 212, the processing unit 30 is also used to perform a weighted average calculation on all P2s, that is, to perform weighted summation and averaging on all P2s to obtain a weighted average calculation result P3, and then perform error compensation on the weighted average calculation result P3, so as to obtain the actual rotational position information P4 of the rotating part 12.

[0084] It can be understood that when the power module 100 is provided with only one set of detection components 212 , after obtaining P2 , error compensation is directly performed on P2 , thereby obtaining the actual rotation position information P4 of the rotating member 12 .

[0085] It is understandable that in the embodiment of the present application, the power module 100 also includes a storage unit 40. The storage unit 40 stores the precision error compensation value △P. It is understandable that △P can be obtained in advance through tooling testing. Specifically, before the power module 100 is officially used, the photoelectric encoder is first installed on the rotating part 12 through a coupling. During the process of the code disk 22 rotating a full circle, the photoelectric encoder is used to detect the high-precision rotation position information P0 of the rotating part 12. Thereafter, the difference between P2 and P0 can be calculated, and the difference is △P. After obtaining △P, the photoelectric encoder can be removed from the power module 100. It is understandable that the storage unit 40 can, for example, adopt an electrically erasable memory (such as Flash, EEPROM, etc.), which can ensure that △P will not be lost even after power failure.

[0086] It is understood that ΔP can be stored in at least one form of a data set, a chart, and a function, and the present application does not impose any limitation on this. For example, Figure 7 As shown, ΔP is stored in the storage unit 40 in the form of a curve graph, wherein the horizontal axis is the rotation angle and the vertical axis is the precision error. Figure 7 It can be seen that for each rotation angle, Figure 7 Find the corresponding size of △P in.

[0087] The storage unit 40 is connected to the processing unit 30 , and the processing unit 30 can be used to obtain the precision error compensation value ΔP from the storage unit 40 , and superimpose the precision error compensation value ΔP and the weighted average calculation result P3 , so as to obtain the actual rotation position information P4 of the rotating member 12 .

[0088] And, from Figure 7 It can be learned that Figure 7 The curve corresponding to P4 in the figure is closer to 0 than the curve corresponding to P3. Therefore, it can be concluded that after P3 is superimposed with △P, the precision error can be reduced and made closer to 0.

[0089] In the embodiment of the present application, the processing unit 30 is also connected to the body 11 in the power output unit 10. In this way, the processing unit 30 can accurately control the working state of the body 11 according to the calculated actual rotation position information P4 of the rotating member 12, so as to control the body 11 to accurately provide the actual required driving force.

[0090] Please refer to Figure 8 The embodiment of the present application also provides a position correction method. The position correction method can be applied to the above-mentioned power module 100. The specific structure of the power module 100 can be found in the above content, and will not be repeated here.

[0091] like Figure 8 As shown, the position correction method specifically includes the following steps:

[0092] The rotational position information P1 of the code disk 22 is detected respectively by three detection elements in the same detection component 212 .

[0093] The rotational position information of the code disc 22 detected by the three detection elements of the same detection component 212 is subjected to weighted filtering calculation, thereby eliminating the code disc radial displacement deviation and / or the code disc axial displacement deviation in P1 and obtaining the corrected rotational position information P2 of the code disc 22.

[0094] Before the weighted filtering calculation, the position correction method may further include the following steps:

[0095] Based on the rotation position information P1 of the code disk 22 detected by the detection element, it is determined whether the detection element is abnormal.

[0096] Among them, when there is a P1 that obviously exceeds the rotation angle that can be achieved by the rotating part 12 at the current speed, or the difference between one P1 and the other two P1 in the same group is greater than the normal range, then the P1 is judged as abnormal data and the detection element corresponding to the P1 is abnormal.

[0097] When at least one detection element in any detection component 212 is abnormal, P1 detected by the abnormal detection element is discarded to avoid the influence of the abnormal P1 on P2 and ensure the accuracy of P2.

[0098] When there are multiple detection components 212, the rotation position information of the entire set of code disks 22 where the abnormal P1 is located is directly discarded.

[0099] When there is only one detection component 212, the abnormal P1 is directly discarded.

[0100] It can be understood that when determining that the detection element is abnormal, the following may also be included:

[0101] For abnormal detection elements, corresponding alarms are generated to provide alarm prompts.

[0102] Please refer to Fig. 9 If there are multiple detection components, after obtaining P2 corresponding to the detection component 212, the position correction method may further include the following steps:

[0103] In the first step, weighted average calculation is performed on the rotation position information P2 of all calibrated code disks 22 to obtain a weighted average calculation result P3.

[0104] In the second step, error compensation is performed on the weighted average calculation result P3 to obtain the actual rotation position information P4 of the rotating member 12.

[0105] It can be understood that if there is only one detection component, the first step above can be omitted, and error compensation can be performed directly on P2 to obtain P4.

[0106] The error compensation process includes the following steps:

[0107] Find the corresponding precision error compensation value △P according to the weighted average calculation result P3.

[0108] The weighted average calculation result P3 and the precision error compensation value ΔP are superimposed to obtain the actual rotation position information P4 of the rotating member 12.

[0109] It can be understood that the position correction method may further include a preparation step:

[0110] During the complete rotation of the code disc 22 , the photoelectric encoder detects the high-precision rotation position information P0 of the rotating member 12 .

[0111] At the same time, P1 is detected by the detection component 212, and P2 is calculated.

[0112] Then, the difference between P2 and P0 is calculated and stored as ΔP.

[0113] In summary, the present application evenly distributes the three detection elements of the same detection component 212 at equal intervals. Based on this position distribution relationship, even if the code disk 22 is offset and causes the detection element to generate a displacement deviation, the numerical direction of the displacement deviation generated by the two detection elements in the same group can be opposite to the numerical direction of the displacement deviation generated by another detection element in the same group. Based on this, when the present application performs weighted filtering calculation on the P1 detected by the three detection elements in the same group, the displacement deviations in the three P1s can be offset during the calculation process, thereby preventing the displacement deviation from affecting the accuracy of position detection. Moreover, the weighted filtering calculation of multiple P1s can also make the results more stable and reliable, and make the detection accuracy better than the detection accuracy using only one detection element.

[0114] Therefore, the power module 100 and the position correction method of the present application can eliminate the detection errors caused by long-term operation and complex environment, so that the position detection accuracy remains unchanged. In addition, the present application further compensates the accuracy error of the rotation position information, thereby overcoming the errors caused by the production process, installation process, etc., and further improving the accuracy of position detection.

[0115] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power module, characterized in that: include: An encoder, the encoder comprising a code disc and a reading head, the code disc being located at one side of the reading head and spaced apart from the reading head, the code disc being mounted on a rotating member, the code disc being used to rotate relative to the reading head as the rotating member rotates; the reading head comprising at least one detection assembly, each of the detection assemblies comprising three detection elements, the three detection elements being spaced apart from each other and located on the same equilateral triangle or the same circumference, and the distance between every two of the detection elements being equal, and the three detection elements being used to detect the rotational position information of the code disc; Wherein, if the code disc is offset in the radial direction and / or axial direction of the rotating member relative to the reading head, for the same detection component, the rotational position information of the code disc detected by the three detection elements includes the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc; A processing unit, wherein the processing unit is used to perform weighted sum and average calculation on the rotational position information of the code disc detected by the three detection elements of the same detection component, thereby eliminating the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc, and obtaining the corrected rotational position information of the code disc.

2. The power module according to claim 1, characterized in that: If the code disk is offset in the radial direction of the rotating member relative to the reading head, for the same detection assembly, the rotational position information of the code disk detected by two of the detection elements respectively includes the radial displacement deviation of the code disk generated in the first offset direction relative to the reading head, and the rotational position information of the code disk detected by the other detection element includes the radial displacement deviation of the code disk generated in the second offset direction relative to the reading head; If the code disk is offset in the axial direction of the rotating part relative to the reading head, for the same detection component, the rotational position information of the code disk detected by two of the detection elements respectively includes the axial displacement deviation of the code disk generated in the third offset direction relative to the reading head, and the rotational position information of the code disk detected by the other detection element includes the axial displacement deviation of the code disk generated in the fourth offset direction relative to the reading head.

3. The power module according to claim 1, characterized in that: The processing unit is used to perform weighted average calculation on the rotational position information of the calibrated code disc corresponding to all the detection components, and then perform error compensation on the weighted average calculation result, so as to obtain the actual rotational position information of the rotating member.

4. The power module according to claim 3, characterized in that: The encoder device further comprises a storage unit, wherein the storage unit stores the accuracy error compensation values ​​of all detection elements; The storage unit is connected to the processing unit, and the processing unit is used to superimpose the precision error compensation value and the weighted average calculation result, so as to obtain the actual rotation position information of the rotating part.

5. A position correction method, characterized in that: The position correction method is applied to the power module according to any one of claims 1 to 4, and the position correction method comprises the following steps: The rotational position information of the code disc is detected respectively by three detection elements in each detection component; When the code disc is offset in the radial direction and / or axial direction of the rotating member relative to the reading head, for the same detection assembly, the rotational position information of the code disc detected by the three detection elements all includes the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc; The rotational position information of the code disc detected by the three detection elements of the same detection component is subjected to weighted filtering calculation, thereby eliminating the radial displacement deviation of the code disc and / or the axial displacement deviation of the code disc, and obtaining the corrected rotational position information of the code disc.

6. The position correction method according to claim 5, characterized in that: When the code disk is offset in the radial direction of the rotating member relative to the reading head, for the same detection component, the rotational position information of the code disk detected by two of the detection elements respectively includes the radial displacement deviation of the code disk generated in the first offset direction relative to the reading head, and the rotational position information of the code disk detected by the other detection element includes the radial displacement deviation of the code disk generated in the second offset direction relative to the reading head; When the code disk is offset in the axial direction of the rotating part relative to the reading head, for the same detection component, the rotational position information of the code disk detected by two of the detection elements respectively includes the axial displacement deviation of the code disk generated in the third offset direction relative to the reading head, and the rotational position information of the code disk detected by the other detection element includes the axial displacement deviation of the code disk generated in the fourth offset direction relative to the reading head.

7. The position correction method according to claim 5, characterized in that: The method further comprises: After obtaining the rotational position information of the calibrated code disk corresponding to each of the detection components, performing weighted average calculation on the rotational position information of all the calibrated code disks to obtain a weighted average calculation result; The weighted average calculation result is error compensated to obtain the actual rotation position information of the rotating member.

8. The position correction method according to claim 7, characterized in that: Performing error compensation on the weighted average calculation result comprises the following steps: Finding a corresponding precision error compensation value according to the weighted average calculation result; The weighted average calculation result and the precision error compensation value are superimposed to obtain the actual rotation position information of the rotating part.

9. The position correction method according to claim 5, characterized in that: The method further comprises: Determining whether the detection element is abnormal according to the rotation position information of the code disk detected by the detection element; When at least one of the detection elements in any one of the detection components is abnormal, the rotation position information of the code disk detected by the abnormal detection element is discarded.

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